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Reasoned Document for RDSO/SPN/183/2011 version -2 of 40

Remarks on comments received on TPWS specification RDSO/SPN/183/2010 ver -1

SN Clause

No.

Clause Details Comments

from

Comment & Suggestion RDSO’s remarks

1. 5.1 Healthy condition of system: A steady lit green

light indicating that TPWS is in working condition

shall be available in the cab or on the driver’s

indication -cum -control panel. This TPWS healthy

indication light shall extinguish when any fault is

detected by TPWS and immediately “TPWS faulty”

red light shall be lit and audible alarm shall sound

to attract attention of driver (which shall stop on

acknowledgement by the driver). In such case,

Emergency brake shall be applied by the TPWS and

the train shall be able to move only after the TPWS

is isolated. However, the “TPWS faulty” red light

shall remain lit till such time fault persists.

Bombardier Bombardier (BT) onboard system has

built-in advanced self-diagnostic features

and as such BT proposes the use of its

existing functionality in determining the

health status of the system (as described

below).

During the Start of Mission phase the

onboard system will automatically

undergo start up healthy tests. All tests

are initiated automatically and if some

part of the system is found faulty, a faulty

message will be displayed on the driver’s

DMI. The onboard system will not be

ready for operation and must be

maintained.

On the other hand if all start up tests are

successful, this will also be indicated on

DMI and the Driver will be allowed to

start the operation.

During the train run, if some onboard

fault occurs this will also be immediately

indicated on the DMI and an alarm will be

given to the driver. The system will also

automatically apply brake, which can be

released when the train has fully stopped.

Further action depends on the type of

fault, however if the fault does not

recover, the driver has to switch OFF the

onboard then the DMI becomes dark as a

best indication to the driver that the

onboard system is not working.

BT believes introducing additional

The requirement of ‘TPWS Healthy’ &

‘TPWS Faulty’ indications is in addition

to the indications existing on DMI/

SDMI. These additional indications shall

be prominent & will immediately

attract the attention of the Driver.

Therefore, the requirement as

mentioned in the clause is considered

necessary.


components as e.g. lamps and switches

for healthy indication will require

additional maintenance in the future and

will in any case have some impact on

system MTBF and reliability. In this

regard, BT believes it is better to avoid

adding extra indication lamps and just

fulfil this requirement with the

functionality described above.

2. 5.8.1 TPWS shall continuously compare the current

speed of train with the permitted speed at all

locations in all those modes in which speed

monitoring is available except for release speed

monitoring. A warning must be given to the driver

to enable him to react and avoid intervention from

TPWS before the application of service brake. The

following actions shall be taken by TPWS depending

upon the difference in current train speed &

permitted speed:

------

------

------

The system shall have provision of configuring the

speed limits/ slabs as mentioned in column 2 of the

above table, by the purchaser. However, these

speed limits shall be in multiples of 5 KMPH or less.

Bombardier BT onboard system fully complies with

Subset – 26 v2.3.0 regarding these

parameters and furthermore actual

implementation in assigning these values

can be further discussed with the end

customer.

These requirements comply with ETCS

standards. Any deviation with this

specification shall be specifically

brought out. However, clause is

modified.

3. 5.14 Isolation of TPWS: System shall have provision so

that TPWS is bypassed in case of failure situation.

Isolation of the entire train borne equipment must

result in disconnection of the system from the

vehicle braking system. This shall be indicated to

the driver by means of a visual indication which

shall be available even if SDMI/DMI has failed. To

avoid accidental/ unwarranted use, the isolation

arrangement of the equipment must be protected

and sealed. Isolation of system must be recorded

by the system as well as recorded in a non-

resettable veeder counter.

Bombardier During isolation of the onboard system

(by mean of Isolation Switch) all

connection to the brake system will be

bypassed and additional EB SIFA valve will

be energized by the vehicle battery.

Isolation of the system is indicated to the

driver by means of a dark DMI.

However if this is not considered as

sufficient, an additional contact can be

The requirement is based on clause no.

4.1.6.3a of ETCS FRS ver.4 .50.

The clause details as “A clear indication

shall be given to the driver, that ETCS

has been isolated, even if the normal

ETCS DMI is defective.”

Indication of TPWS isolation is required

even in case of DMI/SDMI failure e.g.

blanking of DMI screen.


implemented into the isolation switch

and an alarm lamp can be then lit. This is

a matter for further discussion with the

customer as introducing any additional

components will require extra

maintenance and decrease reliability.

Isolation switch can be sealed to prevent

unauthorized isolations.

All isolation will be recorded by proposed

JRU and the stored data inside JRU can

not be erased nor manipulated by

unauthorized personnel.

Non-resettable counter is also

necessary so that even without

downloading the data from JRU,

number of EB application cases could

be known.

4. 6.7.2 Where required by the purchaser, an atleast 8

position switch to select the configuration of

different train characteristics predefined based on

maximum permissible speed, train load, brake

characteristics & any other relevant considerations.

Bombardier Such a mechanical switch is not required

by Bombardier onboard system. All fixed

train data parameters are entered during

the installation phase onboard, while

variable parameters can be entered by

the driver using keys on DMI (touch-

screen buttons) according to UNISIG

ERTMS standard.

Below is the list of the variable

parameters that can be entered by the

driver using the DMI during start-up:

Alternative 1.

ATP installed for “fixed train data entry”,

permits the driver to select the type of

train/train configuration from a menu at

the DMI that corresponds to the train he

is going to start-up.

The selected train type includes all

relevant train data needed for the ATP.

Driver chooses and approves the correct

selection.

Alternative 2.

ATP installed for “flexible train data

entry”, permits the driver to individually

select the value of the train data menu

Provision of 8-position switch has not

been considered necessary for

CENELEC DMI. However, the same

would be required for SDMI. (Clause

6.18 of ver-2)


presented at the DMI. Train data are as

an example, Train length, Maximum

Permitted Train Speed, Loading gauge,

Axle load, Traction, Airtight system, Brake

percentage etc.

After driver programmed those data he

approves the set-up.

Alternative 3.

DMI offers driver to select Alternative 1 or

2.

Not having the electromechanical switch

also allows a better system reliability.

5. 6.7.3 Green light indicating healthy condition of On

Board TPWS.

Bombardier See comments in 5.1 Required as indicated in remarks

against 5.1.

6. 6.7.4 Red light indicating Faulty condition of On Board

TPWS.

Bombardier See comments in 5.1 Required as indicated in remarks

against 5.1.

7. 6.7.5 Non-resettable type electromechanical counter for

recording the cases of emergency brake application

Bombardier In stead of a mechanical counter

Bombardier proposes the use of JRU to

register any type of emergency brake

application (authorized and non

authorized actions). JRU is also an

integrated standard part of any ERTMS

system and have excellent data storage

functionality. The stored data inside JRU

can not be erased nor manipulated by

unauthorized personnel. Thus any

additional components as mechanical

counters can be avoided ensuring better

system reliability.

Se also applicable comments in 5.14.

Non-resettable counter is also

necessary so that even without

downloading the data from JRU,

number of EB application cases could

be known.


Remarks on Draft TPWS specification RDSO/SPN/183/2010 ver -1

SN Clause No. Clause Details Comments

from


1. 4.20 The system shall be compatible & interoperable

with the existing TPWS on Indian Railways. The

supplier manufacturer shall also submit

certificate mentioning the systems working on

world railways with which their system is

interoperable. The certificate shall include

systems of those manufacturers also whose

TPWS are already working on IR.

ALSTOM Interoperability has to be distinguished between “product

level” and “system level”. Product level (i.e.) Eurobalise is

stable almost from the beginning. ……….

-------

-------

Regarding the interoperability between 2.2.2 and 2.3.0d

“subsystem”, the situation is as summarized in the table

below:

System

interoperability

Train 2.2.2

based on 2.2.2

Train 2.3.0d

Trackside based

on 2.2.2

OK Case by case

analysis

Trackside 2.3.0d Case by case

analysis

OK

It has to be understood which “version of 2.2.2” has been

implemented in the two Indian pilot lines (for both

trackside and trainbourne) (i.e which Change Requests

(CRs) in complement to SRS 2.2.2 have been implemented)

and if there are any plan to up-grade to 2.3.0d of existing

trackside and trains.

The supplier should study

the equipment installed in

the section and make the

system compatible with

the existing one.

The purchaser should

specify the existing

installed TPWS as per

cl.14.0(l).

2. 7.1 The MTBF of each sub-system of track side as well as

On board system shall be as under:

Sub-System Minimum MTBF

(Hrs.)

OBC with JRU 25,000

SDMI/DMI 20,000

BTM 25,000

Balise Antenna 1,00,000

Speed & Distance

Measuring Unit

25,000

TIU 15,000

LEU 60,000

Balise 1,00,000

ALSTOM MTBSF (Mean Time Between Service Failure) for complete

trainborne subsystem (including OBC, JRU, BTM, SDMU,

Eurobalise antenna, TIU, and DMI) more than 20000 hours.

Following is added in the

clause:

“However, manufacturer

shall have adequate

redundancy to achieve the

MTBSF of entire on board

system shall be more than

20000 hrs.”


3. 4.17 The TPWS track-side system shall interface with

the signalling system without affecting normal

working & safety of signalling system. It shall

take input regarding signal aspect through

potential free contacts of the Lamp Checking

Relays (ECRs).

ALSTOM We propose to reinsert (in the ver2) at the end of

paragraph 4.17 the sentence already present in the version

1 (dated 30 june 2010):

Manufacturer/ supplier shall give details of any other

interfacing arrangement offered.

This will allow the supplier to offer the cheapest solution

available. Moreover this will allow also studying freely the

best technical solution available.

Only one type of

arrangement is kept for

universal adoption in IR.

4. 4.13.2 On the locomotives provided with electronic/

microprocessor controlled brake system, the

brake commands of TPWS, through an

interface, shall be given to the existing brake

control system of locomotive and based on

these commands given by the TPWS, the

existing brake control system shall apply the

corresponding brakes.

Alstom The scope of interface design, in case of processor

controlled brake system has not been clearly laid out.

There are different types

of locomotives having

different types of brake

system. The information

regarding type of

locomotives and their

brake system shall be

supplied by the purchaser

as per cl.14.0.



manufacturer shall also submit certificate

mentioning the systems working on world

railways with which their system is



TPWS are working on IR.

Alstom 1) As far as we are aware we understand that TPWS system

are under provisional acceptance stage, so such existing

system can be subject to changes. We request you to

confirm our understanding, And we request you as well to

remove this requirement and replace by The system shall

be compatible & interoperable as per the Specification

xxxxxxx

2) Please can you clarify what you mean by certificate

working for IR as no system is in service for IR. Or could you

specify with manufacturer is having system in service for IR

1) The system shall be

compatible and

interoperable as per this

specification. The present

system installed with SRS

ver. 2.2.2.

2) Presently, Two sections

in IR are equipped with

M/s Ansaldo make TPWS.

The certificate shall also

include the manufacturer

of the TPWS system

installed on IR.


6. 5.3 Calculation of Speed: The speed of the train

shall be calculated accurately based on the data

from two separate dual (minimum) channel

speed sensors fitted over two independent

axles of the locomotive. There should be

provision for wheel slip & wheel skid correction

keeping existing automatic wheel slip

protection device if provided on the locomotive

functional. Manufacturer/supplier shall submit

the details of any other technology used for

speed sensing and for wheel slip/skid

correction. Calculation of speed shall be with an

accuracy of ±2% subject to maximum of ±2

kmph.

Alstom We would like to highlight that speed calculation is an

estimated and thsi is teh reason to have tolerance.

Therefore we request you to replace Calculation of speed

shall be with an accuracy of +-2% subject to maximum of +-

2kmph" with "Calculation of extimated speed shall be with

an accuracy of +-2% subject to maximum of +-2kmph".

It is already defined that

accuracy of calculated

speed is ±2% subject to

maximum of ±2kmph.

7. 5.8.1 TPWS shall continuously compare the current

speed of train with the permitted speed at all

locations in all those modes in which speed

monitoring is available except for release speed

monitoring. A warning must be given to the

driver to enable him to react and avoid

intervention from TPWS before the application

of service brake. The following actions shall be

taken by TPWS depending upon the difference

in current train speed & permitted speed:

Alstom These requirements are not compliant with ETCS standard.

Any change in versus Unisig will impact the globaly teh

system which could lead to serious impact and will

moreover affect the interoperability. We kindly request

you to specify instead of your existing requirements that it

shall be "According to Unisig Subset-026-3.

The clause modified

suitably. Any deviation

may be mentioned

specifically.


8. 5.14 Isolation of TPWS: System shall have provision

so that TPWS is bypassed in case of failure

situation. Isolation of the entire train borne

equipment must result in disconnection of the

system from the vehicle braking system. This

shall be indicated to the driver by means of a

visual indication which shall be available even if

SDMI/DMI has failed. To avoid accidental/

unwarranted use, the isolation arrangement of

the equipment must be protected and sealed.

Isolation of system must be recorded by the

system as well as recorded in a non-resettable

veeder counter.

Alstom Displaying of TPWS isolation in case of DMI/sDMI failure is

redundant since, failure of DMI/sDMI results in system

failure lits the RED lamp as required in cl 5.1

The requirement is based

on clause no. 4.1.6.3a of

ETCS FRS ver.4 .50.

The clause details as “A

clear indication shall be

given to the driver, that

ETCS has been isolated,

even if the normal ETCS

DMI is defective.”

Indication of TPWS

isolation is required even

in case of DMI/SDMI

failure e.g. blanking of DMI

screen.

9. 6.20 Design of trackside system shall be such that in

the event of simultaneous display of two

conflicting aspects caused by defective

components like signal lamp, information

corresponding to either the more restrictive of

the two aspects or the most restrictive aspect

of that signal shall be passed on to the OBC.

Likewise, in the case of blank signals, the

information corresponding to most restrictive

aspect of that signal shall be transmitted to

OBC.

Alstom If in case the most restrictive aspect is RED aspect, the said

situation (blank signals) requires to send trip order?

Yes

10. 6.21 LEU and Balise constituting track side system

shall be designed in such a way that for any

disconnection, low insulation or short circuit

fault in connecting cable, a visual indication

shall be given to the OBC and the information

corresponding to most restrictive aspect of that

signal shall be transmitted to OBC. These

failures shall be on safe side.

Alstom No visual information are transmitted from track site to

OBC.

We presume you mean to display alarm on DMI. Please

clarify.

Yes.

Alarm shall be provided to

OBC.

11. 7.1 The MTBF of each sub-system of track side as

well as On board system shall be as under:

Alstom Is there any MTBSF (Mean Time Between Service failure).

MTBSF (Mean Time

Between Service failure) is

not defined.


12. 9.4.2 Any other tests as considered necessary by the

purchaser.

Alstom We do need to know which additional test you may intend

to ask if require or at least the matter shall be discussed

with the supplier, therefore we propose you to either

cancel this sentence or replaced by

1) Any other tests as considered necessary by RDSO in

consultation with the supplier/manufacturer.

2) Any other tests as considered necessary by the

purchaser, if compliancy to the requirements has not been

already demonstrated in other way by the supplier"

Clause 9.4.2 deleted

13. 9.5 Routine tests: At least following tests shall

constitute routine tests:

a) Visual inspection as per clause 10.2;

b) Insulation Resistance test as per relevant

clause of RDSO/SPN/144;

c) Sub system/ Card level functional test as per

format approved by RDSO;

d) System level functional test as per format

approved by RDSO;

e) System diagnostics test.

f) Environmental Stress Screening (ESS) tests as

per RDSO specification no. RDSO/SPN/144.

g) Any other tests as considered necessary by

the purchaser.

Alstom We do need to know which additional test you may intend

to ask if require or at least the matter shall be discussed

with the supplier, therefore we propose you to either

cancel this sentence or replaced by

1) Any other tests as considered necessary by RDSO in

consultation with the supplier/manufacturer.

2) Any other tests as considered necessary by the

purchaser, if compliancy to the requirements has not been

already demonstrated in other way by the supplier"

Cl. 9.5 (g) was deleted in

draft ver-2.

14. General Approval, cross acceptance Alstom It is not clear to us how it shall be proceed, performed

(before contract, during contract); what is the time require,

is such approval requier before design stage ? Can you

please give moer information .

Initial approval and cross

acceptance approval is

defined in cl. 11.1 &11.3

respectively. Tests carried

out during initial type test

approval are defined in cl.

9.3. Other information as

asked does not form part

of the specification & may

be obtained separately.


RDSO’s remarks on comments received on Draft TPWS specification RDSO/SPN/183/2010 ver -2 (dt. 03-09-2010)


from


1. 4.1(ii)(b) Juridical Recorder Unit (JRU) for data logging for

diagnostics & investigation.

Hytronics � As per specification Juridical Recorder Unit (JRU) is for

(a)data logging & (b)diagnostics activities.

� We request RDSO to include detailed requirements

vis-à-vis Indian Railway Requirement/s i.e. parameters

required to be monitored, displayed and user

interface details for (a) Data logging & (b) Diagnostics.

The parameters to be

logged and diagnostics

are further covered in Cl.

5.16.

2. 4.1(ii)(j) System Isolating Unit (Both Electrical &

Mechanical)

Hytronics How do you exactly define “System Isolating Unit”? We

request RDSO to specify the requirements for this same

Meaning of isolation is

further covered in Cl.

5.14

3. 4.7 TPWS shall be capable of being correctly &

effectively interfaced to existing

Air/Vacuum/Dual/Electro-pneumatic brake

system of Diesel and Electric Locomotives as well

as other self propelled vehicles treated as train.

Hytronics � We request RDSO to include specifications of existing

Air/Vacuum/Dual/Electro-pneumatic brake system of

Diesel and Electric Locomotives as well as other self

propelled vehicles treated as train, vide different

annexures to the main specifications.

� This will facilitate the manufacturer of TPWS

equipment to develop the correct technology and

most efficient technology, suitable and complying

with the brake interface and characteristics, without

running from pillar to post to obtain the necessary

technical details, which may or may not be authentic

information.

� The most vital & important activity of TPWS

equipment is braking and brake interface. Hence it is

very much appropriate to include the Brake interface

and brake characteristics by RDSO, who is the

principal authority to approve, validate & accept the

TPWS equipment.

Type of brake interface

based on type of

locomotives is further

covered in Cl. 5.13 and Cl.

11.6.1. The type of

locomotive & existing

brake system will be

specified by the user as in

Cl. 14.0


4. 4.17 The TPWS track-side system shall interface with

the signalling system without affecting normal

working & safety of signalling system. It shall

take input regarding signal aspect through

potential free contacts of the Lamp Checking

Relays (ECRs).

Hytronics � We request RDSO to permit any other fail-safe &

reliable method for taking the “input data” of signal

aspect condition (other than potential free contact of

ECR) into TPWS system.

� The purpose of any specification is to comply with the

user requirements, in fail safe &reliable manner and

at the same time maintain SIL4 norm and it shall also

allow latest techniques/ technologies with cost

effective features to evolve. We request RDSO to

amend the clause suitably.

For standardization &

uniformity, only one

arrangement has been

specified.



supplier manufacturer shall also submit

certificate mentioning the systems working on

world railways with which their system is



TPWS are already working on IR.

Hytronics � We request RDSO to specify the modus operandi or

establish norms of responsibilities to prove

interoperability of equipment between different

suppliers of track side and on board systems.

� Without such a document of fixing responsibilities of

various equipment manufacturers, it will be herculean

task of achieve this norm.

� Alternately RDSO shall establish an interoperability

test lab with calibration facilities and specify the

responsibility of track side and on board equipments.

The interoperability test

with existing TPWS is

covered in Cl. 9.3.1 as a

part of initial type test.

For cross approval, the

interoperability test is

covered in Cl. 11.3.

6. 5.3 Calculation of Speed: The speed of the train

shall be calculated accurately based on the data

from two separate dual (minimum) channel

speed sensors fitted over two independent axles

of the locomotive. There should be provision for

wheel slip & wheel skid correction keeping

existing automatic wheel slip protection device if

provided on the locomotive functional.

Manufacturer/supplier shall submit the details of

any other technology used for speed sensing and

for wheel slip/skid correction. Calculation of

speed shall be with an accuracy of ±2% subject

to maximum of ±2 kmph.

Hytronics Could the “wheel slip & wheel skid correction” be

achieved by odometer subsystem instead of “existing

automatic wheel slip protection device if provided on the

locomotive functional”?

Yes, it should be done by

odometer subsystem of

TPWS.


7. 5.16 Data Logging & Diagnostics

5.16.1 System shall be provided with

diagnostic functions, which can be accessed

through PC/ laptop, and a standard interface

cable connected to the diagnostic interface of

train borne computer and track side equipment

to download or upload data. Memory capacity of

system shall be sufficient to keep log of

minimum last one-week train running data. The

memory shall keep log on First-In-First-Out basis.

5.16.2 Diagnostic/Analytical software will be

provided to analyse the events logged in Log File.

Diagnostic software shall perform following

minimum functions:

a) it shall be possible to download data of

logged events and selectively sort this data

regarding emergency brake application, service

brake application, speed overshoots of more

than 5 kmph than permitted speed, missing

balise, defective telegram, passing of manual

stop signal at ON, train trip etc. Every recorded

event shall be with date and time stamp and the

balise ID.

b) it shall be possible to download data of

failures of sub-systems .

c) it shall be possible to download and display

different Balise telegrams and parameters of

vehicle data.

d) The downloaded log shall be in standard file

format like text, html, excel etc

Hytronics � Accurate & real time is one of the most important

‘parameter’ for data logging and diagnostics.

� We request RDSO to include this parameter as a

mandatory clause for Data Logging & Diagnostics i.e. a

verifiable or able to calibrate “accurate & real time”

shall be provided in the data logging & diagnostics

module or unit.

Cl. 5.16.2(a) has been

modified suitably.

Further Cl. 6.18 shall be

modified to incorporate

provision display of real

time on SDMI.

8. 6.16 Fail safe relay shall be used for performing

emergency brake operation. The status of this

relay shall be continuously monitored & any

change in the status shall be logged with date &

time.

Hytronics Is the presence of only one relay for the emergency brake

compliant to the SIL-4 of the entire onboard system?

In our opinion the relays for such function should be

redundant.

The entire TPWS (on-

board system as well as

track side system) has to

be SIL-4 compliant as

specified in Cl. 4.19


9. 6.18 Driver’s indication-cum-control panel:

Each driving cab/ each driving position (where there is

only one cab in the locomotive having two driving

positions) shall be provided with Driver’s interface to

TPWS. It shall consist of:

6.18.1 One of the following types of Driver’s

indication-cum-control panel as indicated by the

purchaser:

6.18.1.1 Simplified Drivers’ Machine Interface

(SDMI), which shall be user friendly, easy to operate,

shall be as per layout drawing no. Annexure-I & shall

have at least followings:

(i) Audio warning & visual indications for warning

over speed, Service & Emergency Brake applications.

(ii) Display of current mode of the system, current

speed of the locomotive, target distance, target speed

and release speed, when necessary.

(iii) Suitable switches/ buttons for the driver to carry

out required operations like Start-up, change of mode,

alarm resetting, acknowledgement, over-ride

operation etc.

(iv) Any other indications, buttons and switches as

necessary for the operation of the system & to meet

requirement of this specification.

6.18.1.2 CENELEC standard Drivers’ Machine

Interface (DMI), which shall be user friendly, easy to

operate, shall be as per UIC/UNISIG specifications &

shall have at least followings:

(i) Audio warning & visual indications for warning

over speed, Service & Emergency Brake applications.

(ii) Display of current mode of the system, current

speed of the locomotive, target distance, target speed

and release speed, when necessary.

(iii) Selection menu for the driver to carry out

required operations like Start-up, Selection/change of

mode, alarm resetting, acknowledgement, over-ride

operation etc.

(iv) Any other indications & selection menu as

necessary for the operation of the system & to meet

requirement of this specification.

(v) Selection menu to select/ enter the minimum

train parameters to select the configuration of

different predefined train characteristics.

Hytronics Could the SDMI or DMI be a “touch-screen” monitor? SDMI shall be as per Cl.

6.18.1.1 and Annexure of

this specification.

DMI shall be as per

UIC/UNISIG specifications as

mentioned in Cl. 6.18.1.2.


10. 7.7 Manufacturer shall guarantee availability of

spares throughout the life of the equipments

Hytronics We request RDSO to specify the Time period for

availability of spares, as it is a very important commercial

requirement.

The manufacturer shall

specify the expected life

of equipment as

mentioned in Cl. 11.5

11. Not

applicable

Language of the equipments/tool Hytronics Which is the language for the equipments (i.e. DMI) and

tools?

English as mentioned in

the drawing of SDMI.

12. - - - - - - HBL Currently TPWS only prevents Signal Passing At Danger

(SPAD). TPWS is reliant on the signaling system for

prevention of SPAD. In case of failure of the signaling

system, TPWS would not be in a position to prevent

collisions if two trains are found to be on the same track.

Provision to be made in the TPWS specification for

prevention of collisions in case of failure of signaling

system.

Cl. 1.2 may be referred

for the purpose of TPWS.

Other features are not

considered as part of

TPWS at present.

13. - - - - - - HBL TPWS cannot work reliably in Automatic Block Sections of

the Railway network. In an Automatic Block Section the

locomotive pilot has an authority to proceed in a restricted

speed even if the signal ahead indicates RED aspect. Any

human error when exercising these discretionary powers

vested in the locomotive pilot might lead to collisions.

TPWS specification to include provisions to prevent

collisions incase of human error in Auto-Block sections.

This is covered in Cl. 5.11

14. - - - - - - HBL TPWS should have comprehensive collision prevention

features over and above SPAD.

Cl. 1.2 may be referred

for the purpose of TPWS.

Other features are not

considered as part of

TPWS at present.


15. - - - - - - HBL TPWS specification requires each of the sub-systems

constituting TPWS should be interoperable with makes of

other vendors. TPWS uses LEU and Balise for passing the

“Movement Authority” information to the on-board

system. LEU and Balise are expensive equipment and

constitute to significant cost of the overall TPWS. If the

LEU and Balise specifications are issued by RDSO with

interface requirements clearly defined for the following:

a. LEU and Balise

b. Balise and On-board system

Low cost indigenous LEU and Balise with the same Safety

Integrity Levels and interoperable with the existing TPWS

sub-systems can be built, thereby reducing the cost of the

system significantly.

The interface

requirements are as per

ETCS/ERTMS

specifications as specified

in Cl. 2.1 & 4.1.

16. MOM

dt

20.10.2010

Modification in the target distance bar to show target

distance upto 1500m in place of 1000m at present.

The target distance bar

with 1500m is shown in

the drawing.

17. MOM

dt

20.10.2010

For audio alarms, volume control shall be provided with

fixed minimum level so that alarm is audible even at

minimum setting of volume control.

Cl.6.18 may be modified

suitably.

18. MOM

dt

20.10.2010

Provision for display of date and time alongwith

arrangement for setting the clock is required on SDMI so

that the events logged in EVC are recorded with correct

date and time.

Cl.6.18 has been

modified. Provision of

real time & date has been

made in OBC/ JRU in Cl.

5.16.2(a). Therefore, only

display of date & time is

incorporated. Provision of

setting of time from SDMI

not considered as Driver

is not supposed to modify

the time set in OBC/JRU. .

19. MOM

dt

20.10.2010

The five types of alarms are basically information to the

loco pilot and are different. However, display of contextual

information alongwith alarm and otherwise is

recommended on SDMI.

Cl.6.18 may be modified

suitably.


Remarks on Draft TPWS specification RDSO/SPN/183/2010 ver -2 (dt. 24-12-2010)


from


1. ----- ----- PS & EMU Simulated test for functioning of the TPWS with

traction system brake system needs to be included.

Included in STR.

2. ----- ----- PS & EMU The interface protocol for interface with the

existing software control traction and brake system

to be spelt out.

The interface is not through

software & therefore, no

interface protocol is

required.

3. ----- ----- PS & EMU Clause for field trial to be included. While granting the type

approval, the field trial is

given as per ISO procedure.

4. 6.6 The on board as well track side systems of TPWS shall

be immune to following interference currents

generated by locomotive/EMU etc.

SN Interference Current Overal

l Limit

1. Psophometric current AC

traction

10.0A

2. Psophometric current DC

traction

2.0A

3. DC Component in AC mode 4.7A

4. Second Harmonic

Component(100 Hz) in AC

traction

3.0A

5. 1400Hz to 5000 Hz 400mA

6. More than 5000Hz upto

50000 Hz

270mA

7. 50 Hz component in DC

mode

2.4A

PS & EMU In clause no. 6.6, the value of second harmonic

component (100 Hz) in AC traction to be changed to

8.5A as confirmed by you.

Agreed.

5. ----- ----- PS & EMU Since lots of Relays/ contactors are installed in

EMUs, the energy stored in the coil of relays/

contactors may cause EMI/EMC interference. The

manufacturer shall acquaint themselves with the

control system of EMUs and may carry out the

Cl. 6.9 modified to cover the

requirement.


EMI/EMC measurement before finalizing the

scheme for EMUs.

6. ----- ----- PS & EMU The brake interface and equipments requirement

and its validation shall be included in the scope of

the TPWS system supplier. This is based on the

experience on the present system.

Brake interface is part of

TPWS as mentioned in Cl.

4.1 (ii) h. As mentioned in

Cl. 4.19, the entire TPWS

including brake interface

shall be SIL-4 validated.

7. 2.1 Electrical

DTE

SN no. 12 is repeated. Corrected.

8. 3.3.10 National Values: These values are the values of

different parameters such as maximum permitted

speed, speed in shunting mode, speed in OS mode,

overlap distance, permitted roll away/ reverse

movement distance etc. which are based on ules of

train operation.

Electrical

DTE

In last line of paragraph, the word ‘ules’ shall be

corrected as ‘rules’.

Corrected.

9. 3.3.13 Overlap Distance: The length of track in advance of a

stop signal, which must be kept clear, either for clearing

the stop signal next in rear or for the purpose of

granting permission to approach. The overlap distance

may be different for different types of signals &

signalling.

Electrical

DTE

Definition of overlap distance is not very clear. This

may be looked into and corrected.

The definition is correct.

10. 4.3 The On board equipment of TPWS shall work on the DC

power supply available in the locomotive.

Electrical

DTE

The range of DC Voltage of locomotive battery may

be specified for diesel and electric locomotives. For

electric locomotives, the DC power supply can

varies from 70V-136V.

The Range is specified in

cl.6.12 which is from -77V to

132V (i.e. -30% to +20% of

110V as nominal supply).

11. 4.6 TPWS shall be suitable for all types of EMUs, MEMUs,

DMUs, electric and diesel locomotives, including all

types of microprocessor based locomotives, running on

Indian Railways.

Electrical

DTE

TPWS shall also be suitable for Distributed Power

wireless control of locomotive (Locotrol). This

provision should be added.

Corrected.

12. 4.20 The system shall be compatible & interoperable with the

existing TPWS on Indian Railways. The supplier manufacturer

shall also submit certificate mentioning the systems working

on world railways with which their system is interoperable.

The certificate shall include systems of those manufacturers

also whose TPWS are already working on IR.

Electrical

DTE

Slash (/) between word supplier and manufacturer

in second line is required.

Corrected.


13. 4.21 (i) The size of the entire on-board equipment

(excluding SDMI/DMI) which is to be provided

inside locomotive’s machine room shall not be

more than 1350 x 560 x 550 mm (Height x width x

depth). The SDMI/DMI to be provided in Driver’s

cab shall not exceed in size by 360mm x 450mm x

150mm (Height x width x depth).

(ii) Suppliers shall specify the number of sub-systems

in which their On-board system can be split.

Supplier shall also submit sizes of such sub-systems.

Electrical

DTE

The size mentioned in this class cannot be

accommodated in various types of electric locos.

The constraint of space is most severe in WAP4 type

of loco for which the tentatively identified available

space locos has already been advised to signal Dte.

In view of this following rewording of clause is

necessary.

(i) There is severe constraint of space in the

locomotives and therefore the equipment shall be

compact & modular in design with possibility of

distributing it into sub-systems to facilitate its

accommodation in the locomotive.

(ii) The space tentatively identified for TPWS is to

the tune of 500DX550WX750H mm &

300DX500WX800H mm in two separate portions.

However, the supplier is advised to make a visit to

any loco shed under advice to RDSO to have an first

hand idea of space availability in WAP4 locomotive,

where the constraint is most severe.

(iii) The supplier shall specify the number of sub-

systems in which their On-Board system can be split.

The supplier shall also submit the sizes of such sub-

systems.

(iv) Due to space constraint, mounting of complete

system or one or more of its sub-systems under-

slung on locomotive frame can also be considered.

Supplier shall specify which of their sub-systems are

suitable for under-slung mounting.

(v) It shall be the responsibility of

supplier/manufacturer to identify space in the

locomotive for installation of on-board equipment

of TPWS. The installation of on-board equipment of

TPWS in space so identified shall not adversely

affect the access to the loco equipments for

maintenance/operation purpose. The supplier

/manufacturer shall obtain RDSO approval for space

so identified for fitment of on-board equipment of

TPWS prior to manufacture/supply.

(i) Agreed

(ii) This need not be

mentioned in the spec.

The max size of TPWS is

covered in cl.4.21(i).

Further availability of space

is covered in next para.

(iii) Covered in cl 4.21(ii)

(iv)This aspect is already

covered in (i) & (v) of the

comment.

(v) Agreed


14. 4.23 The on board system shall be upgradeable to ETCS/

ERTMS level-2 with additional hardware & changes in

the software. The supplier to give details of such

additional hardware & changes in the software.

Electrical

DTE

Rewording of clause as under is suggested.

“The on board system shall be upgradeable to ETCS/

ERTMS level-2 with minimal addition of hardware &

changes in the software. The supplier shall give

details of such additional hardware & changes in

the software.”

Minimum can not be

quantified, hence not

included. The next line is

corrected.

15. 5.1 Healthy condition of system: A steady lit green light

indicating that TPWS is in working condition shall be

available in the cab or on the driver’s indication -cum -

control panel. This TPWS healthy indication light shall

extinguish when any fault is detected by TPWS and

immediately “TPWS faulty” red light shall be lit and

audible alarm shall sound to attract attention of driver

(which shall stop on acknowledgement by the driver). In

such case, Emergency brake shall be applied by the

TPWS and the train shall be able to move only after the

TPWS is isolated. However, the “TPWS faulty” red light

shall remain lit till such time fault persists.

Electrical

DTE

As soon as TPWS becomes faulty, it ceases to

monitor the over-speeding by loco pilot. Once the

loco-pilot acknowledges the TPWS faulty condition,

why should there be need for applying emergency

brake and stops the train for isolating the TPWS.

This will result in unnecessary detention. In TPWS

faulty condition, if the driver acknowledges the

fault, its isolation in running condition should be

possible. Clause shall be reviewed accordingly.

Due to fail safety, EB

application will be there.

However, if isolation is

performed during EB

application, then brake shall

be released & Driver can

pickup speed.

16. 5.3 Calculation of Speed: The speed of the train shall be

calculated accurately based on the data from two

separate dual (minimum) channel speed sensors fitted

over two independent axles of the locomotive. There

should be provision for wheel slip & wheel skid

correction keeping existing automatic wheel slip

protection device if provided on the locomotive

functional. Manufacturer/supplier shall submit the

details of any other technology used for speed sensing

and for wheel slip/skid correction. Calculation of speed

shall be with an accuracy of ±2% subject to maximum of

±2 kmph.

Electrical

DTE

It seems that provision of separate dual channel

speed sensors fitted on two independent axles of

locomotive has been kept considering the

arrangement followed by M/s Ansaldo. Meaning of

‘dual channel’ is not clear and can be interpreted

differently by different vendors. Moreover, M/s

Ansaldo could not furnish so far any international

spec/guidelines in support of speed sensing

methodology adopted by them. In view of above,

rewording of clause as under is suggested.

“The system shall incorporate the necessary

hardware and software module for accurate

calculation of the train speed duly accounting for

wheel slip/skid corrections. Manufacturer shall

submit the details of the speed calculation module

along with the supporting international

standards/practices being followed world over for

same. Calculation of speed shall be with an accuracy

of ±2% subject to maximum of ±2 kmph. Further,

the variation in wheel diameter due to normal wear

during time period between two loco maintenance

Corrected.


schedules shall not affect accuracy beyond the limits

specified above.”

17. 5.8.1 TPWS shall continuously compare the current speed of

train with the permitted speed at all locations in all

those modes in which speed monitoring is available

except for release speed monitoring. A warning must

be given to the driver to enable him to react and avoid

intervention from TPWS before the application of

service brake. The following actions shall be taken by

TPWS depending upon the difference in current train

speed & permitted speed:

SN Current

train speed

if exceeds

the speed

permitted

at the

moment

(kmph)

Warni

ng to

the

Driver

Comma

nd for

traction

cut-off

Braking/

Brake

Comma

nd

Event

logging

Electrical

DTE

1. Column 2 heading is not very clear. It should be

reworded as under

“Difference of current train speed and the permitted

speed, if the current train speed exceeds the

permitted speed at the moment.”

2. SN 2 of Column 5: Withdrawing of the command

after speed has reduced to or below the permitted

speed will cause further drop in speed due to

substantial brake release timings. This has been

actually observed in trials of existing TPWS. The

clause can be reworded as under.

“Service brake command applied by the TPWS. The

service brake command will be withdrawn at

appropriate point of time, considering brake release

time, so that actual train speed does not fall more

than 10 kmph below permitted speed before the

traction is available” As option of EB above +10

kmph speed shall be available there is no

infringement of safety in above.

1. It is changed to “Current

train speed exceeds the speed

permitted at the moment , by”

2. As the brake release time

would be different for

different types of stock &

may also be different at

different point of time for

the same stock, it would not

be appropriate to take this

into consideration for a SIL-

4 system.

18. 5.10.1 The TPWS equipment shall have provision to enable

passing of a manual stop signal (without calling on

signal)/ IB Signal/ Gate Signal at ON by carrying out EOA

override operation on the SDMI/DMI. The EOA

override operation shall be done by the driver after

following the procedure as prescribed in relevant paras

of G&SR for passing such signals at ON. This override

operation shall be possible at only after the train has

come to a stop. The override control must be protected

against inadvertent operation. This action shall be

logged by the system.

Electrical

DTE

The word ‘at” in row 6 after the word “possible”

shall be deleted.

Corrected.

19. 5.10.2 If Manual Stop Signal is at ON but its calling on signal

is OFF, the system shall permit passing of such signal

without EOA override operation. However, on passing

such signal, a visual indication shall be lit up on the

SDMI/DMI & TPWS shall request for an

acknowledgement from the driver. If driver doesn’t

acknowledge within 5 secs, the service brake shall be

Electrical

DTE

In 3rd row from bottom, the basis for “(which can

be in multiples of 5 kmph)” is not understood. This

shall be deleted.

This is as per ERTMS

requirement.


applied till driver acknowledges. However, if while

passing such signal, the speed of the train is more than

the speed configured in the system to be followed after

passing such signal then brake shall be immediately

applied to bring the speed to the restricted speed

configured in the system, without waiting for driver’s

acknowledgement. The indication shall remain lit up

until the train passes the switchable/ signal balise (not

the in-fill balise) connected to next signal ahead. This

indication reminds the driver that he should proceed

ahead cautiously at the specified restricted speed as

per G&SR. The driver shall pass such signals at ON after

following the procedure as prescribed in relevant paras

of G&SR & follow the restricted speed as defined in

G&SR. In case the train speed exceeds the restricted

speed configured in the system, TPWS shall take action

as described in para 0 above. Provision should be made

in the system to enable changes in the configured

restricted speed limit to any value (which can be in

multiples of 5 KMPH) at a later date to comply with the

changes in Operating Rules of the Indian Railways.

20. 5.12 Balise Tracking / Balise Linking: The TPWS equipment

shall be capable of identifying missing balise and give

suitable visual indication to driver accordingly. This

event shall be logged by the system. The System shall

be capable of taking following actions under such

condition:

(a) Apply service brake to bring the train to a halt;

(b) Apply emergency brakes to bring the train to a halt.

Purchaser shall select one of the actions as mentioned

in (a) & (b) above, to be taken by the system in case of

missing balise.

Electrical

DTE

1. As the driver is not supposed to constantly look

at TPWS’s DMI while driving and therefore

whenever attention of driver is to be attracted, an

audio alarm along with visual indication is

necessary. Thus word “audio

&” shall be added before word “visual” in 2nd line.

2. Last 2 lines shall be reworded as under “The user

shall be able to select one of the actions as

mentioned in (a) &

(b) above, to be taken by the system in case of

missing balise. Necessary interface shall be provided

for such selection by authorized user.

1. Corrected.

2. Such type of action is

chosen by the zonal railway

at the time of installation of

the system.

21. 5.13 Brake application:

5.13.1 The system shall generate service &

emergency brake commands according to the situation

and apply respective brakes of locomotives in one of

the following manners:

5.13.1.1 On the locomotives not provided with

Electrical

DTE

Add clause 5.13.1.3 as under.

5.13.1.3: The provision of brake interface and its

development in association with respective brake

manufacturers shall be in scope of supply of TPWS.

However, in case RDSO has already finalized a brake

interface for a particular class of loco, same shall be

Brake interface is part of

TPWS as mentioned in Cl.

4.1 (ii) h. As mentioned in

Cl. 4.19, the entire TPWS

including brake interface

shall be SIL-4 validated.


electronic/ microprocessor controlled brake system, the

brake commands of TPWS shall be interfaced to the

existing brake system of the locomotive either

pneumatically or electrically (like in EMU/ MEMU etc.)

and shall apply the corresponding brakes.

5.13.1.2 On the locomotives provided with electronic/

microprocessor controlled brake system, the brake

commands of TPWS, through an electronic/ electrical

interface, shall be given to the existing brake control

system of locomotive and based on these commands

given by the TPWS, the existing brake control system

shall apply the corresponding brakes.

provided by the manufacturer.

22. 5.13.4 A non-resettable type electro-mechanical counter shall

be provided to record in the form of counter reading,

the instances of application of emergency brake and

this record shall not be affected by interruption of

power supply to the system.

Electrical

DTE

The specification is silent under following condition

of emergency brake application:

In case TPWS system applies EB while approaching

Red signal and the Red signal turns to Green while

approaching and TPWS has captured the Green

aspect then whether it is required to Stop the train.

In such situation brake release should be possible

without waiting to stop the train after

acknowledgement by loco pilot in order to reduce

detention. However, counter must be incremented

for each EB application by system. A new clause for

this scenario shall be included.

Once the movement

authority is updated by

picking up the off aspect of

the signal, EB shall be

released & train can pickup

the speed.

23. 5.15.14 Reversing- In this mode, the driver is permitted to

change the direction of movement of the train and

drive from the same cab. This mode shall be permitted

by trackside.

Electrical

DTE

REVERSING: The sentence “This mode shall be

permitted by Trackside” is not clear. Does it imply

that trackside balise shall not prevent reversing of

loco? Shall it permit reverse movement within two

signals or beyond that also? Clause needs

elaboration.

Normally, the train is not

allowed to be reversed

beyond a certain distance

treating it as Roll Back which

is not permitted. However,

where the reversing is

permitted, that will be

defined by the balises.

24. 5.16.1 System shall be provided with diagnostic functions,

which can be accessed through PC/ laptop, and a

standard interface cable connected to the diagnostic

interface of train borne computer and track side

equipment to download or upload data. Memory

capacity of system shall be sufficient to keep log of

minimum last one-week train running data. The

Electrical

DTE

The period of data log should match with schedule

inspection interval during which the data log shall

be generally downloaded for analysis. The

periodicity of minor schedule inspection is 90 days

for 3-phase locos and 45 days for conventional

locos. Therefore the memory capacity sufficient to

contain data log of minimum last 90 days shall be

As per ERTMS requirement,

the period of storing the

data has been defined as 24

hour data in case of

accident and one week data

for assessing the

performance of driver.


memory shall keep log on First-In-First-Out basis. specified.

25. 5.16.2 Diagnostic/Analytical software will be provided to

analyse the events logged in Log File. Diagnostic

software shall perform following minimum functions:

e) it shall be possible to download data of logged

events and selectively sort this data regarding

emergency brake application, service brake

application, speed overshoots of more than 5 kmph

than permitted speed, missing balise, defective

telegram, passing of manual stop signal at ON, train

trip etc. Every recorded event shall be with real date

and time stamp of OBC/ JRU and the balise ID.

f) it shall be possible to download data of failures of

sub-systems .

g) it shall be possible to download and display different

Balise telegrams and parameters of vehicle data.

h) The downloaded log shall be in standard file format

like text, html, excel etc.

Electrical

DTE

New clause (e) shall be added as under.

(e): It shall be possible to identify the failure of line

side equipments by analysis of data log.

The onboard shall log data

as mentioned in Cl. 5.16.2

(a), the missing balise,

defective telegram from the

trackside. It cannot log the

diagnostic data of track side.

26. 6.6 The on board as well track side systems of TPWS shall

be immune to following interference currents

generated by locomotive/EMU etc.

SN Interference Current Overal

l Limit

1. Psophometric current AC

traction

10.0A

2. Psophometric current DC

traction

2.0A

3. DC Component in AC mode 4.7A

4. Second Harmonic

Component(100 Hz) in AC

traction

3.0A

5. 1400Hz to 5000 Hz 400mA

6. More than 5000Hz upto

50000 Hz

270mA

Electrical

DTE

The SN shall be brought in front of heading. Not clear.


7. 50 Hz component in DC

mode

2.4A

27. 6.11 The On Board Computer (OBC) shall be capable of being

connected to driver’s SDMI/DMI provided in each cab/

each driving position (where there is only one cab in the

locomotive having two driving positions) of the

locomotive. It shall be interfaced with Driver Control

Switch so that at a time only one SDMI/DMI is active &

other gets locked. On EMU/MEMU/DMU, OBCs with

individual driver’s SDMI/DMI shall be provided in each

of the driving cabs. The train characteristics, wheel

diameter etc. shall be loadable into OBC through the

respective ports on the OBC module using special

software tool.

Electrical

DTE

Provision of RTC in OBC shall be specified. Covered in Cl. 5.16.2(a).

28. 6.15 The system shall facilitate programming of braking

characteristics of the system. It shall be possible to

program on board computer via diagnostic PC for date,

time, wheel diameter, number of impulses per wheel

revolution, emergency braking deceleration rate,

maximum vehicle speed etc.

Electrical

DTE

The clause shall be reworded as under.

“The system shall have facility for entry/setting of

various parameters, required for its functioning, in

on-board computer during initial configuration

through LAPTOP/PC”.

This is modified as:

“It shall be possible to

program various parameters

in on board computer

required for its functioning

via diagnostic PC. The data

for example, may include

date, time, wheel diameter,

number of impulses per

wheel revolution,

emergency braking

deceleration rate, maximum

train speed etc.

29. 6.16 Fail safe relay shall be used for performing emergency

brake operation. The status of this relay shall be

continuously monitored & any change in the status shall

be logged with date & time.

Electrical

DTE

The word “Fail safe relay” should be qualified. The

sentence as under is suggested to be added at the

end.

“Here, Fail safe relay means that the arrangement

will be such that failure of relay or its associated

wiring will be on safer side i.e. system shall

command EB in such failures.”

Corrected.

30. 6.18.1.1 Simplified Drivers’ Machine Interface (SDMI), which

shall be user friendly, easy to operate, shall be as per

layout drawing no. Annexure-I & shall have at least

followings:

Electrical

DTE

As point of intervention for SB/EB depends on train

formation, it is desirable that train formation as

entered in the system is visible on DMI/SDMI so

that any discrepancy in same is noticed by the

Agreed.


(v) ---

(vi) ---

(vii) ---

(viii) ---

(ix) ---

driver and corrected at once.

Suitable clause shall be added in this regard.

31. 6.18.2 Where required by the purchaser, an atleast 8 position

switch to select the configuration of different train

characteristics predefined based on maximum

permissible speed, train load, brake characteristics &

any other relevant considerations.

Electrical

DTE

Provision of 8 position selector switch was finalized

by IRPMU in the present contract. This switch only

caters to the requirement of passenger trains.

Moreover, the selection can only be made based on

4 predefined passenger train configurations at 110

kmph and 130 kmph speed. As the specification is

generic in nature, therefore, provision for setting of

various combinations of freight trains is also

required to be made at this stage. It is further

noticed that train parameters could not be yet fine

tuned and tested for many of these combinations.

Based on the understanding of the system gained

so far, it is imperative to enter exact train formation

in the system so that calculations of point of

interventions for SB/EB are appropriate and do not

result in premature application of SB/EB.

Therefore, provision of entry/selection of exact

train formation should be provided on both DMI as

well as SDMI. For this purpose provision of an

alphanumeric keypad should be made. The steps

for train formation entry should be on following

pattern.

(i) Select type of service: Passenger or Freight or

Light engine

(ii) Select type of coach/wagon

(iii) Enter no of coach/wagon.

(iv) Go to step (ii) or complete the entry

The clause should be modified accordingly.

Provision of alphanumeric

keypad with SDMI will

increase its size which is

already quite big. For

requirement of more than 8

options, it is preferable to

go for DMI.

32. 7.1 The MTBF of each sub-system of track side as well as

On board system shall be as under:

Sub-System Minimum MTBF

(Hrs.)

OBC with JRU 25,000

Electrical

DTE

The basis of MTBF mentioned for various sub-

assemblies is not clear.

Further, the definition of failures and provision for

logging of failures shall be incorporated.

The data is based on a

report of analysis got done

by M/s Ansaldo for TPWS in

India. However, overall

MTBF figures are also


SDMI/DMI 20,000

BTM 25,000

Balise Antenna 1,00,000

Speed & Distance

Measuring Unit

25,000

TIU 15,000

LEU 60,000

Balise 1,00,000

included in the clause.

33. 8.3 Train borne (external) equipment shall have minimum

protection code of IP 67.

Electrical

DTE

The word ‘train borne’ shall be replaced by “on-

board”.

Shall be corrected.

34. 8.5 The design of on board & track side systems shall take

into account switching transients that may occur, in

either the system or out side, of any magnitude, upto

and including interruption due to short circuit of 25 KV

system. The design shall also take into account supply

related supply related surge & transient.

Electrical

DTE

The word “supply related” is repeated. Same shall

be corrected.

Shall be corrected.

35. 9.3.3 For on board system, following tests shall also

constitute type tests:

(a) Performance Test as per clause 10.2.2 of IEC 60571

(b) Cooling Test as per clause 10.2.3 of IEC 60571

(c) Dry heat test as per clause 10.2.4 of IEC 60571

(d) Damp heat test as per clause 10.2.5 of IEC 60571

(e) Supply over voltage, Surges and electrostatic

discharge test as per clause 10.2.6 of IEC 60571

(f) Transient burst susceptibility test as per clause

10.2.7 of IEC 60571

(g) Insulation test as per clause 10.2.9 of IEC 60571

(h) Salt mist test as per clause 10.2.10 of IEC 60571

(i) Vibration and shock test as per IEC 61373

(j) Water tightness test for on board external

components as per clause 10.2.12 of IEC 60571

(k) Tests for reliability of electronics used in rolling stock

as per RDSO specification no. ELRS/SPEC/SI/0015 of

Oct 2001.

Electrical

DTE

Visual Inspection as per Clause no 10.2.1 of IEC

60571 shall be added.

Visual inspection is defined

in cl 10.2 which is

considered better than IEC

clause.


36. 11.0 (ii) Verification and validation of safety, reliability &

availability etc. as per relevant standards (SIL 4 or

equivalent) from reputed agency having experience in

this field. The agency to be engaged for validation shall

be got approved from RDSO. The certificate alongwith

proof of safety report or its equivalent safety report or

its equivalent giving complete tests & their results that

have been undertaken by the manufacturer or

independent safety assessor shall also be submitted.

Electrical

DTE

The meaning of following is not clear.

“….The certificate along with proof of safety report

or its equivalent safety report or its equivalent

giving complete tests & their results that have been

undertaken by the manufacturer or independent

safety assessor shall also be

submitted.”

This shall be elaborated for clarity.

Cl. 11.1 (ii): Language

corrected.

37. 11.1 Manufacturer shall furnish following informationat the

time of initial type approval:

Electrical

DTE

the word ‘informationat’ shall be corrected as

‘information at’

Corrected.

38. 11.6.2 The braking algorithm along with input parameter shall

be supplied by the manufacturer/supplier & got

approved from RDSO before its implementation in the

section.

Electrical

DTE

In view of experience of existing system, rewording

of clause as follows is suggested.

“RDSO shall supply the data of weight, rotating

mass, and Braking effort of various types of locos,

coaches and wagons. Values of EBD, SBD and max

acceleration with +- 10% accuracy for different train

formations shall also be supplied by RDSO. The

working out of correct train parameters shall be the

responsibility of the supplier based on this

information. The braking algorithm along with the

input parameter values for various train

configurations shall be furnished & demonstrated to

the satisfaction of RDSO by the

manufacturer/supplier before implementation in

the section.”

Corrected.

39. ---- Electrical

DTE

(i) The option of deciding between SDMI and DMI

has been left to the purchaser. Why such an option

has been kept and how the user will decide is not

clear?

It is for the purchaser to

decide as per requirement.

40. ---- Electrical

DTE

(ii) Suggestions/ comments of Rlys, particularly NR,

NCR & SR, who have experience of the TPWS

system, should also be invited.

The comments of Rlys S&T

deptt. were taken at Signal

Standards Committee (SSC)

meeting. The remarks from

Electrical department of

Railways shall be obtained

by concerned directorate of

RDSO.


41. ---- Electrical

DTE

(iii) Comments of TPWS manufacturer’s world over

may give useful inputs. Procedure for revision of

specification, as per ISO guidelines, calls for

involvement of vendors in finalization of revision.

The comments of firms was

included in the specification

as circulated to Electrical

and PS & EMU dte.


Other changes in draft TPWS specification RDSO/SPN/183/2010 ver -2 (dt. 24-12-2010)

SN Clause No. Clause Details of specification no.

RDSO/SPN/183/2010 Ver.-1

Reason for change Modified clause

1. 5.8.1

Serial no. 3

of table

Current train speed if exceeds the speed

permitted at the moment (kmph): Above 10

kmph

Warning to the Driver: Continuous audio &

visual warnings

Command for traction cut-off: Yes

Braking/ Brake Command: Emergency brake is

applied till the train is brought to a halt. The

emergency brake gets released when train stops.

Event logging: Yes

While controlling the speed, the TPWS

should apply EB to reduce the speed

below permitted speed.

Current train speed if exceeds the speed permitted at the

moment (kmph): Above 10 kmph

Warning to the Driver: Continuous audio & visual warnings

Command for traction cut-off: Yes

Braking/ Brake Command: Emergency brake is applied by

the TPWS. There shall be following two programmable

options for release of emergency brake

(a) When the current train speed is reduced to or below

the permitted speed.

(b) When train comes to a halt.

Purchaser shall program one of the above options as per

requirement

Event logging: Yes

2. 5.13.4 In case of emergency brake application, it shall

not be possible to release brake until the train

stops. In such cases, the brakes can be released

only after the train has stopped. In case of Train

Trip (Clause Error! Reference source not found.),

in addition, acknowledgement from Driver is also

required for releasing the emergency brake. A

non-resettable type electro-mechanical counter

shall be provided to record in the form of

counter reading, the instances of application of

emergency brake and this record shall not be

affected by interruption of power supply to the

system.

Changes made due to above reasons. A non-resettable type electro-mechanical counter shall be

provided to record in the form of counter reading, the

instances of application of emergency brake and this

record shall not be affected by interruption of power

supply to the system.

3. 5.16.2 (a) it shall be possible to download data of logged

events and selectively sort this data regarding

emergency brake application, service brake

application, speed overshoots of more than 5

kmph than permitted speed, missing balise,

defective telegram, passing of manual stop signal

at ON, train trip etc. Every recorded event shall

be with date and time stamp and the balise ID.

Provision of real date & time has made

in OBC/JRU

it shall be possible to download data of logged events and

selectively sort this data regarding emergency brake

application, service brake application, speed overshoots of

more than 5 kmph than permitted speed, missing balise,

defective telegram, passing of manual stop signal at ON,

train trip etc. Every recorded event shall be with real date

and time stamp of OBC/JRU and the balise ID


4. 6.20 Line-side Electronic Unit (LEU) shall also conform

to the latest specifications issued by UIC/UNISIG

and shall be suitable to work with Indian

Railways’ Signalling System. LEU shall be

capable of receiving minimum 10 signal inputs. It

shall be capable of delivering minimum four

separate channels so that at least four data

balises may be driven upto 2500m. The

manufacturer/ supplier shall mention the

maximum number of inputs & maximum number

of channels an LEU can handle.

Interconnecting cable alongwith balise

makes the standard interface for the

LEU.

Line-side Electronic Unit (LEU) shall also conform to the

latest specifications issued by UIC/UNISIG and shall be

suitable to work with Indian Railways’ Signalling System.

LEU shall be capable of receiving minimum 10 signal

inputs. It shall be capable of delivering minimum four

separate channels so that at least four data balises may be

driven upto 2500m. The manufacturer/ supplier shall

mention the maximum number of inputs & maximum

number of channels an LEU can handle. Balise controlling

interface cable shall meet the requirement mentioned in

UNISIG specification for balise.

5. 6.27 (New

clause)

For monitoring the health of LEUs. The Manufacturer/ supplier shall submit the health

monitoring scheme of LEUs.


Remarks on Comments received on TPWS Draft specification RDSO/SPN/183 ver-2 (dt. 15-03-2011) sent by email on 18 & 22/03/2011

Sr No

Clause No.

Clause Details Comments From

Comments & Suggestions RDSO’s Remarks

1 2.1 This specification requires reference to the latest approved documents on ETCS/ ERTMS of UNISIG, EEIG, UIC, EC and EU, together with the following documents –

ALSTOM Under clause 2.1 it is mentioned that”…… latest approved document on ETCS/ERTMS of UNISIG, EEIG, UIC,…..”, however this is not sufficient to identify and achieve the interoperability. Therefore, we suggest that RDSO specification shall mention the document reference. “TSI conventional Rail/European commission Decision 2006/679/EC of 28.Mar. 2006 concerning the technical specification for interoperability relating to the control command and signaling subsystem of the trans-European conventional Rail system” and the purchaser as per clause 14.0 shall mention each time the exact versions of those documents referred in RDSO specification at the time of tender, for example “SRS 2.3.0 d full annex A” of European commission Decision 2010/79/EC of 19.oct.2009” in the tender document, which is the latest as of today.

No change is required in the clause. This clause mentions about the documents to be referred to. Clause 4.1 clearly indicates that generally system shall be as per latest approved FRS & SRS for ETCS Level-1.

2 3.3.10 MTBSF: Mean Time between such failures which require restart/ maintenance/ repair of system.

ALSTOM Under the clause 3.3 Definition, MTBSF is defined. We will appreciate you modify this definition to make it in line with its original meaning as “Mean Time Between Service-affecting Failures” with mission interruption.

No change is required in clause. The definition given in the specification is considered clear.

3 4.1 ii) b)

General Requirement: on board- system ALSTOM Under the clause 4.1.ii).b), the existing sentence “juridical Recorder unit(JRU) for data logging for diagnostics & Investigation “ shall be modified as juridical Recorder unit(JRU) for Investigation and Data Recording unit for diagnostics”. So that it makes it clear the request of two functions (juridical and Diagnosis).

Clause has been modified. Data logging for diagnostics & for juridical purpose has been made separate. Corresponding change has been done in Cl. 14.

4 4.1 i.b) 4.1 ii.a) 4.1 ii.d)

Line side electronic unit (LEU) with minimum 2 out of 2 hardware architecture & diversified software, its power supply & interfacing system with signaling. On Board Computer (OBC) with minimum 2 out of 2 hardware architecture & diversified software. Balise Transmission Module (BTM) with minimum 2 out of 2 hardware architecture & diversified software.

ALSTOM In these mentioned clauses, the specification is modified to specify beyond the ERTMS/ETCS requirements. Now with this modification the specification will call for specific architecture “2 out of 2 hardware architecture & diversified software” We would appreciate that you maintain an open architecture and not privilege any. The requirement of cenelec SIL 4 justified by a product safety case endorsed by an ISA shall be enough to assure a wide competition.

Clause has been modified. The architecture has been made open.

5 5.16 Data Logging & Diagnostics

ALSTOM We appreciate that JRU is included in clause 4.1.ii)b), however we found the specification reference to JRU and functional requirement were missed out under the clause 5.16. Therefore can we suggest modifying the title of clause 5.16 as “juridical recording, Data Logging and Diagnosis”. We would also suggest that under clause 5.16 to add, “JRU shall be compliant to the UNISIG subset 026 and 027 and the memory shall be crash protected”.

Clause has been modified according to changes in Cl. 4.1 ii) b)

6 4.1 i.b) Line side electronic unit (LEU) with minimum HYTRONIC We request this clause be modified as: Line side electronic unit Clause has been modified. The


Sr No

Clause No.



2 out of 2 hardware architecture & diversified software, its power supply & interfacing system with signaling.

S ENTERPRIS

ES

(LEU) with minimum 2 out of 2 hardware architecture & with common or diversified software, its power supply & interfacing system with signaling. Notes: 1. CENELEC specification/permits the use of common software. 2. Clause 7.1b of RDSO/SPN/192/2005 specification for Electronic

Interlocking permits Common software. 3. Clause 7.1(a) of draft spec-EI for BIG Yards-

RDSO/SPN/271/2009 permits common software.

architecture has been made open.

7 4.1 ii.a) On Board Computer (OBC) with minimum 2 out of 2 hardware architecture & diversified software.

HYTRONICS

ENTERPRISES

We request this clause be modified as: Line side electronic unit (LEU) with minimum 2 out of 2 hardware architecture & with common or diversified software, its power supply & interfacing system with signaling. Notes: 1. CENELEC Specifications /permits the use of common software. 2. Clause 7.1b of RDSO/SPN/192/2005 specification for Electronic

Interlocking permits Common software.


8 4.1 ii.d) Balise Transmission Module (BTM) with minimum 2 out of 2 hardware architecture & diversified software.

HYTRONICS

ENTERPRISES

We request this clause be modified as: Notes: 1. CENELEC specification/permits the use of common software. 2. Clause 7.1b of RDSO/SPN/192/2005 specification for Electronic

Interlocking permits Common software. 3. Clause 7.1(a) of draft spec-EI for BIG Yards-

RDSO/SPN/271/2009 permits common software.


9 4.20 The system shall be compatible & interoperable with the existing TPWS on Indian Railways. The supplier/ manufacturer shall also submit certificate mentioning the systems working on world railways with which their system is interoperable. The certificate shall include systems of those manufacturers also whose TPWS are already working on IR.

HYTRONICS

ENTERPRISES

We request this clause be modified as: The System shall be compatible & interoperable with the existing TPWS on Indian railways. The manufacturer shall submit a certificate stating that their system is interoperable with all other systems which are manufactured as per UNISIG/ERTMS Specification. Notes: 1. The current RDSO specification is depending on

ERTMS/UNISIG specification. Please refer to clause 2.1

Agreed. The clause has been modified.

10 6.20 Line-side Electronic Unit (LEU) shall also conform to the latest specifications issued by UIC/UNISIG and shall be suitable to work with Indian Railways’ Signalling System. LEU shall be capable of receiving minimum 10 signal inputs. It shall be capable of delivering minimum four separate channels so that at least four data balises may be driven upto 2500m. The manufacturer/ supplier shall mention the maximum number of inputs & maximum number of channels an

HYTRONICS

ENTERPRISES

We request provision to be made in this clause for: a) Locating LEU in centralized Cabin/Relay Room. b) Locating LEU at Signal Post/Distributed architecture. c) This will facilitate use of LOW Power, reduce number of balise

channels and it will be more economical. Notes: 1. Recently Railway called 2 Tenders for this equipment i.e.

Eastern Railway & IRPMU (NCR). 2. In IRPMU (NCR) Tender, Provision was made to Locate LEU’s

for both at Centralized location and at Signal Post i.e. distributed locations.

No change is required in the clause. This shall be as per the scheme/ quantity given by the purchaser.


Sr No

Clause No.



LEU can handle. Balise controlling interface cable shall meet the requirement mentioned in UNISIG specification for balise.

11 3.3.11 National Values: These values are the values of different parameters such as maximum permitted speed, speed in shunting mode, and speed in OS mode, overlap distance, permitted roll away/ reverse movement distance etc. which are based on rules of train operation.

Siemens Ltd The Examples are not clear: “maximum permitted speed” of what? E.g. in SR mode or unfitted mode speed? “Overlap distance” is not at all part of National values as defined by UNISIG. Proposal: These values are the values of different parameters such as speed in shunting mode, speed in OS mode, permitted roll away/ reverse movement distance etc. which are based on rules of train operation.

The terms given are for example only to define National values. The values of the parameters as required by the system shall be supplied by the purchaser.

12 4.1 i.b) 4.1 ii.a) 4.1 ii.d)

Line side electronic unit (LEU) with minimum 2 out of 2 hardware architecture & diversified software, its power supply & interfacing system with signaling. On Board Computer (OBC) with minimum 2 out of 2 hardware architecture & diversified software. Balise Transmission Module (BTM) with minimum 2 out of 2 hardware architecture & diversified software.

Siemens Ltd General safety requirement should not predict architecture solution to achieve the safety. It is the task of the safety case to show and prove safety. The way of doing so is usually described by CENELEC (EN 50126; EN50128; EN50129). The use of 2 out of 2HW together with diversified SW is a mark of e.g. SIL 5 development which seems here beyond common railway requirements. SIL 4 is usually achieved by the use of 2 out of 2 HW “OR” by the use of diversified SW. Proposal: for all above items i)b/ ii) d: change “&” to “or”



Siemens Ltd Balise Transmission Module (BTM) is not a defined component by UNISIG or an interoperable constituent of its own etc., it belongs in general to the onboard constituent. According EN50159-1 the reference architecture for the transmission system defines: the non safe part of transmission system (usually antenna, receiver and so on belongs to that part). The safe part of the transmission system performing the safe transmission functions and he safe application functions part (usually performed by the EVC). The safe part will be performed usually with a 2 out of HW or with diversity SW. So Balise transmission at onboard does have non-safe and safe parts. Proposal: Delete ii) d:”….with 2 out of 2 hardware architecture & diversified software “ behind”…..(BTM)”


14 4.1 i.a) Switchable balises – This balises are interfaced to signal aspect through LEU. The telegrams/ data transmitted by these balises

BOMBARDIER

Please change as below "This balise are interfaced to signal aspect through LEU / object controllers of CBI (where CBI's are installed) such that balises can be

For standardization, only one mode of interfacing has been defined in the specification.


Sr No

Clause No.



depend on the aspect of the signal. These are provided at a location near the signal. The Permanent Speed Restriction & track topography related information is also transmitted by these balises within the telegram/data related with signal aspect.

directly driven by object controller eliminating the requirement of LEUs in that area". The telegrams / data transmitted.........signal aspect.

15 4.1 i.b) Line side electronic unit (LEU) with minimum 2 out of 2 hardware architecture & diversified software, its power supply & interfacing system with signaling.

BOMBARDIER

Our LEU is not based on CPU architecture the LEU is SIL 4 approved and has reliability figures as mentioned in the clause 7.1. The safety in Bombardier LEU is achieved as under: The LEU 2000 output interface is implemented on the balise driver board. Each balise driver board contains one output channel for one balise. Each balise driver board consists of a logic unit and one balise driver unit. Based on the combination of input signals from the lamp detector boards, the logic unit selects the corresponding telegram from the memory and through the balise driver unit the selected telegram is repeatedly sent to the balise. The LEU 2000 is designed to handle three independent hardware failures without a hazardous situation occurring. This is achieved by dividing each logic unit into four independent blocks; A1, A2, B1 and B2, see Figure below:

The dissipated power in each lamp/control signal load is measured independently in the four detectors on the lamp detector board. The measured power is used to determine whether the signal lamp (or control signal) is on or off. The results are then transmitted separately as logical values (1=ON, 0=OFF), to each logic block on the balise driver board.



Sr No

Clause No.



The selected telegram that is sent to the balise is assembled from four quarters sent by the four ASICs in a specific order, one after the other. In this regard, the synchronization of the four ASICs, sending one quarter of the telegram each, is the key process that results in a stream of bits that reconstructs a complete and coherent balise telegram on the output line, from the LEU 2000 to the balise. If there is an error, the function is disabled.

At any time, a given logic block (A1 for instance) “knows” only two quarters of the selected telegram: the quarter that it sends and the quarter that it checks (coming from B2 in this example). However, the logic block A1 is totally “unaware” of the information sent by the logic blocks A2 and B1. When the balise does not receive a telegram from the LEU 2000, it will transmit an internally stored default telegram, which is a fixed telegram, with information indicating that no telegram has been received from the LEU 2000. Each balise driver board is programmed individually i.e. it is possible for one LEU 2000 to control several completely different balise groups, based on information from several signals. We request RDSO to only mention the safety integrity level achieved by equipment shall be as per clause 4.19 & availability shall be as per 7.1 of RDSO/SPN/183/2010 Ver-2 Draft specification. RDSO shall not mention about the safety concept but shall mention about achieving the safety and availability.


Sr No

Clause No.



Hence; we request to modify the clause and remove “2 out of 2 hardware architecture & diversified software” requirement.

16 4.1 ii.a) On Board Computer (OBC) with minimum 2 out of 2 hardware architecture & diversified software.

BOMBARDIER

We request RDSO to only mention the safety integrity level achieved by equipment shall be as per clause 4.19 & availability shall be as per 7.1 of RDSO/SPN/183/2010 Ver-2 Draft specification. RDSO shall not mention about the safety concept but shall mention about achieving the safety and availability. Hence; we request to modify the clause and remove “2 out of 2 hardware architecture & diversified software” requirement.



BOMBARDIER

We request RDSO to only mention the safety integrity level achieved by equipment shall be as per clause 4.19 & availability shall be as per 7.1 of RDSO/SPN/183/2010 Ver-2 Draft specification. RDSO shall not mention about the safety concept but shall mention about achieving the safety and availability. Hence; we request to modify the clause and remove “2 out of 2 hardware architecture & diversified software” requirement.


18 4.17 The TPWS track-side system shall interface with the signalling system without affecting normal working & safety of signalling system. It shall take input regarding signal aspect through potential free contacts of the Lamp Checking Relays (ECRs).

BOMBARDIER

We request you to consider other solutions such as direct control of balise with object controllers wherever possible. Hence, request you to add " In case of interlocking renewal the balise can also be controlled directly by the object controller system of the interlocking"

For standardization, only one mode of interfacing has been defined in the spec.

19 5.14 Isolation of TPWS: On board system shall have provision for isolation to cater for failure situation which shall result in disconnection of the system from the locomotive braking system. This shall be indicated to the driver by means of a visual indication which shall be available even if SDMI/DMI has failed. To avoid accidental/ unwarranted use, the isolation arrangement of the equipment must be protected and sealed. Isolation of system must be recorded by the system as well as recorded in a non-resettable veeder counter.

BOMBARDIER

During isolation of the onboard system (by mean of Isolation Switch) all connection to the brake system will be bypassed and additional EB SIFA valve will be energized by the vehicle battery. Isolation of the system is indicated to the driver by means of a dark DMI. However if this is not considered as sufficient, an additional contact can be implemented into the isolation switch and an alarm lamp can be then lit. Isolation switch can be sealed to prevent unauthorized isolations. All isolation will be recorded by proposed JRU and the stored data inside JRU can not be erased nor manipulated by unauthorized personnel. Hence, we propose to eliminate the requirement of non-resettable veeder counter.

The requirement is based on clause no. 4.1.6.3a of ETCS FRS ver.4 .50. The clause details as “A clear indication shall be given to the driver, that ETCS has been isolated, even if the normal ETCS DMI is defective.” Indication of TPWS isolation is required even in case of DMI/SDMI failure e.g. blanking of DMI screen. Non-resettable counter is also necessary so that even without downloading the data from JRU, number of EB application cases could be known.

20 5.16.1 System shall be provided with diagnostic functions, which can be accessed through PC/ laptop, and a standard interface cable

BOMBARDIER

Trackside Diagnostics: The need and level of diagnostic functions is to some extent depends

The clause has been modified for clarity & sub-clauses made separate for On-board & track side


Sr No

Clause No.



connected to the diagnostic interface of train borne computer and track side equipment to download or upload data. Memory capacity of system shall be sufficient to keep log of minimum last one-week train running data. The memory shall keep log on First-In-First-Out basis.

on the LEU implementation. Bombardier’s implementation is based on PCB's with ASIC's instead of microprocessors and software which creates a more reliable product and reduces the need for those maintenance functions that normally are required for microprocessors based system. The diagnostic functionality in the Bombardier LEU is performed by a separate LEU monitoring board that can provide information to e.g. an external SCADA system. The LEU monitoring board is normally offered as an option since the MTBF of LEU is over 800,000 hrs in combination with no need for preventive maintenance which makes it possible to achieve the customer availability requirements also without monitoring board.

equipments.

21 5.19 Interoperability: The On Board system of a manufacturer shall be compatible & interoperable with Balise of another manufacturer & vice versa. Similarly, Balise and LEU of different manufacturers shall be interoperable with each other.

BOMBARDIER

Please add "Valid for systems and products delivered in compliance with identical versions of the UIC/UNISIG specifications". Also we would like clarify that interoperability is only achieved if the products are compliant with the same version of the UIC/UNISIG specifications.

The interoperability with the TPWS systems existing on Indian Railways has to be ensured.

22 6.18.2 Red light & Green light indicating respectively the faulty & healthy condition of On Board TPWS. Non-resettable type electromechanical counter for recording the cases of emergency brake application.

BOMBARDIER

The Red light & Green Light functionality shall be removed as this functionality is achieved via DMI during the Start of Mission phase. The onboard system will automatically undergo start up healthy tests. All tests are initiated automatically and if some part of the system is found faulty, a faulty message will be displayed on the driver’s DMI. The onboard system will not be ready for operation and must be maintained. On the other hand if all start up tests are successful, this will also be indicated on DMI and the Driver will be allowed to start the operation. During the train run, if some onboard fault occurs this will also be immediately indicated on the DMI and an alarm will be given to the driver. The system will also automatically apply brake, which can be released when the train has fully stopped. Further action depends on the type of fault, however if the fault does not recover, the driver has to switch OFF the onboard then the DMI becomes dark as a best indication to the driver that the onboard system is not working. In stead of a mechanical counter Bombardier proposes the use of JRU to register any type of emergency brake application (authorized and non authorized actions). JRU is also an integrated standard part of any ERTMS system and have excellent data storage functionality. The stored data inside JRU cannot be erased nor manipulated by unauthorized personnel.

The requirement of ‘TPWS Healthy’ & ‘TPWS Faulty’ indications is in addition to the indications existing on DMI/ SDMI. These additional indications shall be prominent & will immediately attract the attention of the Driver. Therefore, the requirement as mentioned in the clause is considered necessary.


Sr No

Clause No.



Thus any additional components as mechanical counters can be avoided ensuring better system reliability. Hence, we propose to eliminate the requirement of Red/Green Light and electro mechanical counter.

23 6.6 The on board as well track side systems of TPWS shall be immune to following interference currents generated by locomotive/EMU etc.

The track side system shall be immune to electro-magnetic interference generated by thyristor / chopper-controlled locomotives, traction return currents.

BOMBARDIER

Please change to " Trackside System shall comply with EN50121-4 standard"

The requirements mentioned in this clause are for the conditions prevailing over Indian Railways and therefore, should be complied.

24 7.7 Manufacturer shall guarantee availability of spares throughout the life of the equipments.

BOMBARDIER

We propose to specify the number of years for which the spares would be required.

Availability of the spares is to be guaranteed for the life as submitted against Cl. 11.5.

25 11.1 ii) The certificate of verification and validation of safety, reliability & availability etc. as per relevant standards (SIL 4 or equivalent) from reputed agency having experience in this field. The agency to be engaged for validation shall be got approved from RDSO. The certificate of proof of safety giving complete tests & their results that have been undertaken by the manufacturer or independent safety assessor shall also be submitted.

BOMBARDIER

Please change as "Any reputed ISA shall be used for getting" the certificate of verification & validation of safety, reliability & availability etc. as per relevant standards…...RDSO shall be informed in writing while engaging the agency”…….....submitted.

The change requested is not acceptable. The agency shall be engaged with the approval of RDSO only.

26 4.1.(i)b 4.1.(ii)a

(Safety Architecture and compliance) Line side electronic unit (LEU) with minimum 2 out of 2 hardware architecture & diversified software, its power supply & interfacing system with signaling. On Board Computer (OBC) with minimum 2 out of 2 hardware architecture & diversified software.

ANSALDO The target safety level of TPWS is SIL4. This can be achieved in various ways with 2oo2 or 2oo3 hardware redundancy and common or diversified software. Ultimately the product will have to meet SIL4 safety requirements following CENELEC specification EN50126, EN50128 and EN50129, validated by a third party. The above mentioned clauses have specifically mentioned about diversified software.



Sr No

Clause No.



4.1.(ii)d

Balise Transmission Module (BTM) with minimum 2 out of 2 hardware architecture & diversified software.

We suggest this should be left open mentioning as “common or diversified software”.

27 5.3 Calculation of Speed The system shall incorporate the necessary hardware and software module for accurate calculation of the train speed duly accounting for wheel slip/skid corrections. Manufacturer shall submit the details of the speed calculation module along with the supporting international standards/practices being followed world over for the same. Calculation of speed shall be with an accuracy of ±2% subject to maximum of ±2 kmph. Further, the variation in wheel diameter due to normal wear during time period between two loco maintenance schedules shall not affect accuracy beyond the limits specified in this clause.

ANSALDO According to UNISIG subset 041 on Performance Requirements for Interoperability, clause : 5.3.1.2 states that Accuracy of speed known on-board : Value ± 2 km/h for speed lower than 30 km/h, then increasing linearly up to ± 12 Km/h at 500 km/h.” With reference to the UNISIG specification mentioned above, we request you to kindly amend the description of the clause accordingly.

The requirement was there in ver-1 of the specification also. No other vendor has given any comment on this requirement. The requirements as mentioned in the clause should be complied with.

28 6.2 Protection of cards from dust All the cards shall be suitably protected, enclosed and provided with mechanical dust proofing covers to avoid dust ingress and then mounted in a robust metallic housing so that entire assembly is capable of withstanding shocks, vibrations, electromagnetic induction and electrical surges etc.

ANSALDO The component density of the PCBs used for TPWS is quite high and it needs some air Circulation to avoid hot spots. Enclosing the PCBs inside a mechanical enclosure will Trap the heat inside. Protection of the modules from dust and EMI/EMC may be achieved at the rack and Cabinet level. Thus it is suggested to keep the implementation open for the supplier to Satisfy the requirement.

The clause has been modified.

29 6.7 Electromagnetic compatibility Electromagnetic compatibility of the entire On-board equipment as well as track side equipments including interlinking cables shall comply with European Standards EN50238 for Railway Applications – Compatibility between rolling stock & train detection system and EN 50121 for Railway Applications – Electromagnetic Compatibility, as applicable. Adequate provisions should be made in the design for suppression of internal transients, spikes and to withstand external transients, spikes and surges as per limits laid down in IEC-60571.

ANSALDO

The clause mentioned about EMC compatibility referring to both EN50238 and EN50121. Please clarify which specific requirements you would like to have for Compliance.

The clause is modified as under: ‘Electromagnetic compatibility Electromagnetic compatibility of the entire On-board equipment as well as track side equipments including interlinking cables shall comply with European Standards EN 50121 for Railway Applications – Electromagnetic Compatibility and On-board equipment shall also comply with EN50238 for Railway Applications – Compatibility between rolling stock & train detection system. Adequate provisions should be made in the design for suppression of internal


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transients, spikes and to withstand external transients, spikes and surges as per limits laid down in IEC-60571.’

30 8.1 PCB Layout The PCBs shall meet the requirements clause 6.8 of RDSO/SPN/144/2006.

ANSALDO

Clause 6.8 of SPN/144/2006 speaks about the PCB layout, track widths and separation. Considering the component density, both track width and separation are decreasing Without degradation of the performance of the module. Considering the present day technology, it is suggested to keep the clause open Without specific reference to SPN/144/2006.

Cl. 6.8 of RDSO/SPN/144/2006 does not mention about track width & separation.

isolation of tpws - indian railwayrdso.indianrailways.gov.in/works/uploads/file/reasoned document...

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