geometry for high speed railways

7/30/2019 Geometry for High Speed Railways

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Geometry for High Speed Railways withSpecial Reference to Indian Railways

M. M. Agarwal *K. K. Miglani **

Synopsis : The High Speed Railway requires not only the sound

infrastructure of strong resilient track but also has to be supported with

properly designed track geometry. The paper covers most of the vital issuesconcerning track geometry viz curvature, cant, cant deficiency & cant excess,

cant gradient and ruling gradient etc and gives technical details about thesevarious parameters existing on high speed railways of world. Indian Railways

are planning to introduce high speed trains in some of its important sections

as per present planning of Railway Ministry. The authors have carefully

analysed the details of various parameters of track geometry existing onworld railways & have made some suggestions which may be helpful inintroduction of high speed trains in India.

1.0 Introduction

1.1 History of High Speed Railways in the worldThe Construction of first high speed railways started in 1959 in Japan

of Tokaido Shinkansen area. It started operations between Tokyoand Osaka on 1 Oct, 1964. Starting with nearly 45 million passengersper year, it now, annually carries well over 65 million passengers.Starting with the 210 kmph Tokaido Shinkansen in 1964, the now2,459 km long network has expanded to link most major cities onthe islands of Honshu and Kyushu at speeds up to 300 kmph.

The length of high speed lines in the world exceeding 250 kmph is

about 18000 kms.

* Formerly Chief Engineer / Northern Railway** Dy. Chief Engineer (TP) / Northern Railway, New Delhi


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Table 1 : Important High Speed Lines in the world exceeding

250 kmph.

Country Length of Details of Important Fast TrainHigh Speed

Lines (Kms)1) Japan 2678 'NOZOMI':AV speed 256 kmph,

Max speed limit 300 kmph.

2) France 1893 'TGV': AV speed 272 kmph,

Maximum speed 320 kmph.

3) Germany 1300 ICE: AV Speed 226 kmph &

Max Speed 300 kmph

4) Spain 1687 'AVE': AV speed 236 kmph &

Max Speed 300 kmph5) Portugal 3320

6) China 3120 High Speed C Class: AV speed

236 kmph & Max Speed 250 kmph

7) Belguim 830 Thayls: AV speed 236 kmph,

Max speed 300 kmph

8) Italy 890 Eurostar:AV speed 200 kmph,

Max speed 250 kmph

9) USA 360 Acela Express: AV speed 162kmph, Max. speed 250 kmph

10) South Korea 412 KTX: AV speed 200 kmph,

Max speed 300 kmph

11) Taiwan 245 Chiayi : AV speed 245 kmph,Max speed 300 kmph

Total World 17892 AV Speed varying 200-245 kmphMax Speed varying 250-350 kmph

Though the French hold the world train speed record of 574.8 kmph,set on 3 April 2007, a Japanese magnetic levitation train (maglev)achieved 581 kmph in trials.

2.0 Technical Requirement of High Speed Rail Corridors

i) Sound Infrastructure: Consisting of strong & resilient trackstructure, well compacted formation, well designed ballastedtrack or ballastless bed, properly designed bridges & tunnelsincluding approaches.


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ii) Proper Track Geometry: Consisting of smooth curves(horizontal & vertical) with well designed transition curves andsuperelevation ramp, proper cant excess & cant deficiency,correct spacing of track, well designed turnout etc.

iii) Motive Power & Signalling: Dedicated coaching stock, highpower traction & appropriate signaling technology.

iv) Misc issues: like grade separation, fencing, environmentprotection etc.

3.0 Track Structure on High Speed Routes:90% of the HS track in the world is on conventional ballastedstructure. French TGV marked a record of 525 KMPH on conventionalballasted track and conventional track is strong enough to bear thestresses of speed up to 300 KMPH. It is not the heavy structurewhich is required for HSR, but it is the High standard maintenancewhich is warranted for HSR. Track structures used over world railwayare as under.

Table 2: Track Structure for high speed Railways in world.

Component SNCF German Railway Japanese

Railway

Gauge 1435 mm 1435 mm 1435 mm

Rails UIC 54 and 60 kg. UIC 60 Kg UIC 60 kg

Rail Cant 1:40 1:40 1:40

Sleeper Concrete/ PSC/ PSC/

Wooden Polyurethane polyurethane

foam/glass fibre foam/glass fibre

Sleeper 1666 1724 1724Density

Fastenings TGV Nabla/ICE Leaf spring/ Leaf springs/

Vossloh wire spring ICE Vossloh

Double elastic rail fastenings are necessary for the concrete sleepertrack. Rubber pads are used as cushioning material between therail and sleepers fastened by leaf spring/ wire spring/ TGV Nabla/ICE Vossloh fittings for distribution of vertical load and for dampening

the vibrations. SNCF uses two types of rubber pads. Normal rubberpads of 9 mm thickness with a resistance of 90 KN/mm and softtype rubber pads of same thickness with low resistance of 56 KN/mm. Soft type rubber pads are mainly used for noise mitigation.


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Ballastless Track vis--vis Conventional ballasted TrackBallast less track is used in France in the underground sectionswhere trains run through at a speed of 220 kmph.

Certain railway (DB AG, FS, SNCF, JR) have developed high-speed

ballastless track. Experience shows that the maintenance costs areless on ballastless track than the costs of ballasted track (of theorder of 1/5th), due to the slower degradation of the geometricalparameters of these tracks.

The German experience shows that the cost of building ballastlesstrack is between 50 % and 75% higher than that for ballasted track.

There are certain advantages particularly easy maintainability &

increased service life, but no doubt the ballastless track is muchcostlier than ballasted deck. The management, therefore, has totake a conscious decision whether ballasted deck or ballastless trackhas to be adopted.

4.0 Geometrical Parameters of High Speed Railway LineThe main factors governing the standards required for the geometryof a high-speed railway is to ensure safety and comfort of passengers

duly keeping unbalanced lateral and vertical acceleration within limits.The various parameters, which affect passenger comfort and safety,are as under : -

i) Centre to centre Distance or Spacing of tracks

ii) Radius of horizontal curvature

iii) Max. cant, cant deficiency and cant excess

iv) Rate of change of cant and cant deficiency

v) Longitudinal grade or Ruling gradient

vi) Radius of vertical curve.

Let us discuss these items in detail:

4.1 Distance or Spacing of tracksWide spacing between the two adjacent lines is important for high-speed track because when two trains pass each other, in the opposite

direction, speed difference can be as much as 300 to 500 Kmph. Iftwo trains are too close together, there is burst of air pressure whenthey first pass and then a drop of pressure between the carriages.Although this is not enough to push the trains off the track, repeated


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stress on the windows may cause fatigue, which result in breakageof window glasses. Wider spacing between tracks has economicimplications. Studies show that an increase of 30 cm in the width ofthe subgrade would involve an increase in cost of the civil engineeringworks by 1%.

Minimum distance between track centre adopted by some of thehigh-speed networks using standard gauge is given as under:-

Table 3 : Minimum distance between tracks having standard Gauge

(1435 mm)

Country Minimum distance between track

250 Km/h 300 Km/h 350 Km/h

Italy 4.5 m 5.0 m 5.0 m

France 4.2 m 4.2 m 4.5 m

Spain 4.3 m 4.3 m 4.7 m

Germany 4.5 m 4.5 m 4.5 m

Belgium 4.2 m 4.5 m 4.7 m

Japan 4.2 m 4.3 m 4.3 m

4.2 Horizontal CurveThe most distinguished parameter for a circular curve is the radius,which is inversely proportional to curvature, k= 1/R. It is known factthat a vehicle running at a speed V in a curve with a radius R

undergoes a centrifugal lateral acceleration V2/R which results in a

number of undesirable effects.

Gentle curves become necessary in view of restriction on maximumvalues of cant deficiency and cant excess along with maximum speedof operation. The minimum radius of curvature for the high-speedlines on developed High Speed Railway networks generally variesfrom 4000 m to 7000 m for standard gauge.

The lateral acceleration, which is created by trains negotiating acurve is quite high and it can have adverse effects on safety & comfortof passengers.

The minimum radius of curvature existing in some of the high speedrailways of the world is given in Table 7. This radius for speeds upto350 kmph varies from 4000 m to 6500 m for standard gauge.


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4.3 Cant & Cant DeficiencyThe cant deficiency allowed in real train operations is determinedby the factors like, track construction (with respect to its ability toresist high forces), state of track components, track alignment (i.e.magnitude and shape of geometrical irregularities), type of vehicleand running gear, axle loads and unsprung masses, state ofmaintenance of the rolling stock and passenger comfort.

The lateral strength inversely varies with the axle loads as definedby Prud'homme formula. Track structure should be specially designed

to resist this heavy lateral force. Based on the comfort criteria, Cd

works out to about 150 mm for standard gauge (170mm for BG).

However over IR and various world Railways, we permit Cd up to100mm only. Considering the limiting values of 165 mm and 180

mm for Ca

& 100mm for Cd, the radii required for various speeds

are:

Table 4 : Radius required for various speeds with given

values of Ca

+ Cd

Speed in KMPH Radius in metres for Radius in metres for

Ca

+ Cd

= 265 mm Ca

+ Cd

= 280 mm

200 Kmph 2077 m 1965 m

250 Kmph 3245 m 3071 m

275 Kmph 3927 m 3716 m

300 Kmph 4672 m 4423 m

325 Kmph 5484 m 5191 m

350 Kmph 6360 m 6020 m

Cant DeficiencyThe uncompensated lateral acceleration, which is proportional tocant deficiency, should not be too large. The permissible cantdeficiency and the corresponding lateral acceleration for threedifferent categories of rolling stock based on experience accordingto Banverket, is given in table below.


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Table 5: Permissible cant deficiency and the corresponding lateral

acceleration.

Train Category Permissible Lateralcant deficiency acceleration

(mm)A) Conventional vehicles 100 0.65

with older running gearand freight train

B) Vehicles with improved 150 0.98running gear, accordingto approval

C) Vehicles with improved 245 1.60running gear and carbody tilt system

4.4 Transition curve and superelevation rampAccording to Banverket transition curves should be arranged withlinear curvature changes (clothoids) and superelevation rampsshould be arranged with linear changes of cant. The length of

transition curve is dependent on the allowed amount of jerk. Theallowed rate of cant deficiency is a question of comfort. In Sweden,used values for maximum rate of cant and rate of cant deficiency isshown in Table 6.

Table 6 : Maximum rate of cant and rate of cant deficiency

Train Category Maximum rate Maximum rate of cantof cant deficiency

A 46 mm/s 46 mm/sB 55 mm/s 55 mm/s

C 70 mm/s 79 mm/s

4.5 Cant, cant deficiency and cant excessThe recent research shows that the non-compensated lateralacceleration should not exceed 0.10 to 0.15 g according to comfortrequirements. SNCF allows a cant deficiency of 150 mm (exceptional

value 160 mm) and a cant excess of 70 to 100 mm (exceptionalvalues between 105 and 135 mm, in dedicated high-speedoperations, without freight trains).


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At SNCF the limiting value of cant is about 160 mm and exceptionally180 mm. A cant of 180 mm was utilized as limiting value at the high-speed line Paris-Sud Est. The cant is given to respect the limitingvalues of cant deficiency (150 mm) and cant excess (100 mm) in

France.4.6 Vertical CurvesIn vertical curves, if the vertical acceleration on a crest is too great,the loads on the vehicle wheels can cause the wheels to climb therail and thus cause a derailment. Furthermore, the resistance againstvehicle overturning at side-winds will be lower.

Summarising, the vital parameters of track geometry of high speed

railway are with a view to provide better safety & comfort topassengers. The technical details of these parameters are given intable 7.

Table 7 : Practices on some high speed railway systems in world.

COUNTRY FRANCE SPAIN GERMANY BELGIUM JAPAN

Design Speed (kmph) 300 350 300 350 300 350 300 350

Min R of 4000 6250 4000 6500 3350 5120 4800 4000

curvature (m)Max. 180 180 150 150 170 170 150 180Cant (mm)

Cant 85 85 100 65 130 112 100 50Deficiency (mm)

Max cant 35 35 12.5 25 40 40 15 -21 ---Gradient

Min. Vertical 16000 21000 24000 25000 14000 20000 20000 10000Radius (m)

Transition 300 350 360 460 408 476 420 ----

Curve length (m)

5.0 Tilting TrainsTo overcome the limitation of speed on account of tight curves whereit is not possible to cant the track, vehicles with tilting suspensionsystem having tilting mechanisms can be used. Trains that tilt cango up to 25% to 40% faster around curves than conventional trainswithout upsetting the passengers and this can significantly increasethe speed on existing lines. With tilting trains, Cd of up to 275mm is


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permitted on standard gauge. Tilting technology is used normallyfor speed exceeding 350 Kmph.

6.0 Turnouts for high speeds6.1 Factors affecting Turnout speed

When the speed on straight track is above 250 Kmph, high speedturnouts with speed on curved track from 80 to 100 Kmph arewarranted. Factors affecting design of turnout are

i) Entry from straight to curve without transition

ii) Lead curve without superovulation

iii) Entry from curve to straight without transition

iv) Kink in the turnout route at the toe of switch rail

v) Gap at the V of crossing

On turnouts, the magnitude of force primarily depends on switchentry angle. By reducing the switch angle, entry gets smoothenedand flange force gets reduced. Tangential types of switches are isthe answer to this and are being used over foreign railways for HSR.

Upgradation in turnout technology in the railway system has beenguided by the following considerations:

i) Higher speeds on straight and curved tracks with reasonablelevel of passenger comfort. Designs have been evolved for aspeed of over 220 Kmph on turn out track.

ii) Least life cycle cost with minimum traffic interruption for repairing.

iii) Track geometry maintainability comparable with the normal trackSafety and comfort.

iv) Planned maintenance without emergencies.

6.2 Type of Design for Turnouts

i) Flatter Switch entry angle by tangential layouts thereby reducingthe angle of attack and reduced lateral forces resulting inincreased passenger comfort.

ii) Movable nose crossing: Use of movable nose crossings housedin a specially designed cradle, thereby avoiding gap at crossing.

iii) Flatter angle of crossing: Use of flatter angle of crossing i.e. 1in 32 or 1 in 24 and 1 in 20 P&C (curved switches) permit higherspeeds.


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iv) Special rail profile section: Use of asymmetrical profile sectionZU- 1 in 60 kg forged to standard rail profile (UIC 60) at the end.

v) Spring operated switch setting device: Use of spring operatedswitch setting device to ensure proper flange way clearance.

vi) Speed rail pads: Use of specially designed synthetic rail padsfor reduced vibration of switch assembly.

vi) Miscellaneous factors like transition curves for improving therunning at curved track, continuation of canting of rails, use ofhigher UTS rails, use of non-greasing box plate, surface handingof load bearing areas & sophisticated filling technologies.

By above modifications, the forces, accelerations and rolling

movements, were less than the normally allowed limits. Further theactual sensation felt by the passenger was very good. Based on theabove data turnout for HSR 250 Kmph can be designed.

7.0 Level Crossing/Grade separationNormally level crossing is not suitable for high speed train operationand therefore, for road transport, either road over bridges or roadunder bridges needs to be planned. However, in unavoidable

circumstances, level crossings may be required. Then it must beinterlocked with the signals. Sophisticated arrangement ofinterlocking the signals of train with that of road transport with helpof video camera is used on JNR. Similar type of arrangements maybe made here also.

8.0 FencingIn high-speed lines, trespassing is very risky and thus not at all

permitted. Therefore, the entire high-speed track is to be providedwith fencing. It is noticed from the experience of high speed corridors,world around that at very high speeds, track ballast stones sometimesfly off and hits the surroundings. To avoid such incidences, trackfencing is required to be provided.

9.0 Introduction of High Speed Trains in India

9.1 High speed projects to be taken in IndiaThe Ministry of Railway in Railway budget 2010 has announced

i) Construction of high speed passenger rail corridors is anothertransformational initiative that Indian Railways will embark upon


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in the coming years. Indian Railways propose to go ahead indeveloping high speed corridors of 250 to 350 kmph speeds.

ii) High speed rail corridor should become a catalyst for India'seconomic growth, a stimulus for the development of satellite

towns and reduction of migration to metropolises. It is, thereforeproposed to set up a National High Speed Rail Authority forplanning, standard setting, implementing and monitoring theseprojects.

iii) Already six Corridors have been identified. These projects wouldrequire large investments and will be executed through PPPmodel.

The six corridors earmarked for high speed routes, where pre-

feasibility studies are being conducted, are as follows:

i) Delhi-Chandigarh-Amritsar (450 km approx.)

ii) Pune-Mumbai-Ahmedabad (650 km approx)

iii) Hyderabad-Dornakal-Vijaywada-Chennai (664 km approx.)

iv) Chennai-Bangalore-Coimbatore-Ernakulam (649 km approx.)

v) Howrah-Haldia (135 km approx.)

vi) Delhi-Agra-Lucknow-Varanasi-Patna (991 km approx.)

9.2 Benefits of high speed trainsA high speed railway system is, considered essential in India foravoiding congestion in cities, facilitating wider regional development,providing a thrust to economic growth and launching healthycompetition to civil aviation and to retain technological relevance.From the experience of many countries, high speed railway projects

can improve employment potential, human exchanges, regionaldevelopment and overall economic growth.

The main benefit a high speed railway line is likely to bring in Indianconditions are Saving in time (from 7 hrs. to 2.5 hrs.), Safety, EcoFriendly (high speed trains produce 7.7 times lower carbon emissioncompared to airlines and 4.5 times lower than cars), fuel efficient(energy consumption of high speed trains per passenger km is 3.5times less than the private cars and 5 times less than aeroplanes


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thereby making them highly fuel efficient), efficient use of land (highspeed trains require only 30% of the land than required byexpressways ), on board services ( catering, conferencing, comfort),connectivity of communication via wi-fi and easy connectivity.

9.3 Recommendations/suggestions of proposed high speedrailway & corridors on Indian Railway:

i) Basis for recommendationOut of six corridors, earmarked for high speed routes as broughtout earlier, the case studies of Mumbai-Ahmedabad has beenconducted by RITES. Based on the Rites recommendations andalso on the basis of experience of high speed railways for variouscountries in the world, the following suggestions/

recommendations are made for the high speed routes on IR.

ii) GeneralHigh speed rail system would require quality infrastructure andimproved rolling stock. It would require modern signalingtechniques and overhead current collection system to ensuremaximum safety of train operations on the new line. Followingin-built features are prerequisites for a high speed route:

a) A separate track with a minimum of curves and carrying noother traffic.

b) No level crossing.

c) Derailment guides.

d) Fences or walls for total isolation of the track from bothhuman and animal interference.

e) Ultra-modern electronic safety system that intervenes

automatically when speed limit is exceeded or distance topreceding train falls below safe limit.

9.3.1 Technical detailsTrack Structure: 60 Kg 90 UTS UIC continuous/long welded railswith 1660 concrete sleepers per km and a ballast cushion of 30 cmon well compacted formation.


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9.3.2 Present track geometry on existing railway routes.Indian Railways at present have the following parameters for variousitems of its Track geometry for Broad Gauge (1676 mm) as well asfor Meter Gauge (1000 mm).

Table 8 : Existing Track Geometry of B.G & M.G routes

Item Details of Parameters

B.G. (1676 mm) M.G.(1000mm)

1) Distance from centre to centre 5300 mm 3960 mmof track of double line section.

2) Minimum radius of the curve 175 m 109 m

3) Maximum Cant 165 mm (for A,B 90 mm (Normally

& C routes) 100 mm withpermission of CE)

4) Maximum cant deficiency 75 mm 50 mm(in normal cases)

100 mm(in special cases)

5) Cant excess 75 mm 65 mm

6) Maximum cant gradient 1 in 720 1 in 720

7) Rate of change of cant or 35 mm/sec 35 mm/seccant deficiency (Desirable)

55 mm/sec(maximum)

8) Maximum gradient * 1 in 100 1 in 100

9) Min. length of vertical curve * 4000 m 2500 m

* As proposed for LWR section

9.4 Proposed track geometry on high speed routes of IR

Geometrical track parameters for high speed routes have to be veryspecial because of the impact of high speeds. The following pointsrequire special consideration.

i) Distance from centre to centre of track on double linesection: For standard gauge (1435 m) the distance is varyingbetween 4.3 to 5.0 metres. The spacing of 5.30 metre alreadyexists on IR for new construction project and that appears to be

sufficient for speeds from 250 to 350 kmph.ii) Minimum radius of curvature: The radius of curvature for

various H.S. Railways of the world with speed of 350 kmph is


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varying between 4000 m to 6500 metres and 7250 metres forUIC. It is technically necessary to have a very flat curve for highspeeds in order to provide proper comfort to passengers. Thepresent standard of IR for 10 degree curve on BG (Radius 175m) will not be workable. Looking to safety & comfort for highspeeds, it would be desirable to have minimum radius of10,000m for IR.

iii) Maximum cant & cant gradient : Maximum cant adopted byvarious high speed railway systems is varying from 150 to 180mm, UIC standard is 140 mm. Limiting value of cant to beprovided is based on safety criteria along with reasonable levelof comfort for specified rolling stock.

Indian Railways are already permitting maximum cant of 165mm on Group A,B & C category of track. This can be increasedto 180 mm for improved vehicles of High speed railway. Thecant gradient should be more smoother and it is thereforerecommended that the same should be 1 in 1000 instead ofexisting particularly 1 in 720.

iv) Cant deficiency & cant excess : Conventionally Comfort

Criteria governs the decision of cant deficiency. The excessivecant deficiency causes heavy lateral forces on the track & thereare more likelihood of gauge widening & buckling. Therefore,the track needs to have more lateral strength. Indian Railwaysare already permitting cant deficiency of 100 mm and can remainthe same even for high speeds due to improved vehicles ofHSR on BG. Cant excess is recommended to be 100 mm insteadof 75 as existing at present on IR.

v) Vertical curve : A very smooth vertical curve is necessary forhigh speed railway to provide maximum comfort to passengers.The minimum vertical radius in various HSR system in the worldis varying from 20000 m to 25000 m.

Considering the comfort criteria for high speed trains, it isrecommended to have minimum radius of vertical curve as24000 m.


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vi) Ruling gradient or maximum gradient : Generally steepergradients can be allowed on high-speed lines in comparison toconventional lines as very high momentum of HS trains makesit feasible to negotiate steeper gradients. Practices followed bysome important H.S. Railways are as below.

Railway Practice being followed

1) SNCF (French Railways) Max. gradient on TGV is 0.35% to0.25% However transition betweentwo different gradients is alwaysprovided by a circular transitioncurve whole radius is more than12000m.

2) Japanese Railways The maximum gradient may attain0.15% as long as the average overa distance of 12 Km does notexceed 0.12%. Between twosuccessive gradients, a circulartransition curve is always provided.

3) DB German Railway 0.125% longitudinal grade hasbeen used.

It is suggested that Indian Railway having BG, which is wider thanstandard Gauge, should have 0.1% longitudinal grade i.e. 1 in 1000.


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The proposed parameters to be adopted on IR are as given inTable 9.

Table 9 : Proposed parameters for high speed railway for IR

Parameter Figures for UIC figure Proposedvarious High for H.S. for IRSpeed Railways Railwayof world

1) Min distance varying from 4.3 m -- 5.3 mbetween track to 5.0 m

2) Minimum radius varying from 4000m 7250 m 10000 mof curve to 6500 m

3) Max. superele- varying from 150mm 140 mm 180 mmvation (cant) to 180 mm

4) Cant deficiency varying from 50mm 65 mm 100 mmto 112 mm

5) Cant excess -- 80 mm 100 mmmaximum

6) Cant gradient 0.21 to 0.35 % 0.1 % or 1

in 10007) Minimum varying 20000 m to 24000 m

vertical radius 25000 m

8) Maximum 0.15 to 0.20 % 0.1% or 1gradient in 1000

9.5 Misc. technical features:

i) Motive Power & Signalling : Dedicated coaching stock, highpower traction & appropriate signaling technology.

ii) Turnouts for HSR projects: Special turnouts for HSR projectshaving speed in range of 80 to 100 kmph from curved trackshould be developed which can provide the reasonable level ofcomfort. For this purpose special sturdy high speed turnoutswith swing nose crossing, flatter switch entry angle, flatter angleof crossing and using special rail profile section should be used.Such design already exists for a speed up to 220 kmph in HSrailway system in world and IR can accordingly develop therequired turnout.


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iii) Tilting Train: Improvement of the conventional railway systemby the adoption of tilting train technology offers very limitedadvantage in the increase of speed only upto a maximum of 30percent. Otherwise also even on dedicated high speed corridors,tilting train technology should not be tried in the Ist stage on IR.

iv) Level crossing/ Grade Separations: For high-speed operation,all level crossings are required to be replaced by suitable gradeseparation works.

v) Fencing: On high-speed lines trespassing on tracks cannot bepermitted. Thus the entire high-speed line has to be fenced.

vi) Environmental issues: Due to increase in speed on HS lines

noise problem will also get intensified due to track noise,Pantograph noise & other such allied factors.

The measures adopted to reduce the noise are (i) Noise protectionwalls (ii) Noise protection embankments (iii) Covered sections (iv)Artificial tunnels for noise protection (v) High and modifiedmaintenance practices (vi) Modification in rolling stock (vii) ModifiedPantographs.

10.0 Final RecommendationsIndian Railway should immediately go ahead with the project ofintroduction of high speed railways on various assigned routes.There is rich experience available for high speed railways of theworld for all technical issues including track geometry. Certainrecommendations for track geometry are given in the para 9 aboveand IR can consider these suggestions for introduction of high speedson certain specified routes.

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geometry for high speed railways

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