title: technology advancements in the field: stringless ... · title: technology advancements in...

March 2-4, 2016 Salt Palace Convention Center Salt Lake City, Utah

TRACK C: AIRSIDE ENGINEERING WORKSHOP: 2

Title: Technology Advancements in the Field: Stringless Paving

Speaker: Gary L. Mitchell, P.E., ACPA

Date: March 2, 2016

March 2-4, 2016 Salt Lake City, Utah

Stringless slipform paving technology

www.acpa.scholarlab.com

http://www.acpa.scholarlab.com/


Already being done at numerous airports around the country

501-4.8 Placing concrete. -- a. Slip-form construction. The

concrete shall be distributed uniformly into final position by a self-

propelled slip-form paver without delay. The alignment and

elevation of the paver shall be regulated from outside reference

lines established for this purpose.


Introduction – What is Stringless Paving?

Alternative to conventional stringline paving.

Uses electronic guidance systems to replace pins, sensors, and “stringline.”

Electronic guidance system controls elevation and steering of the paving machine(s).

Sometimes referred to as 3D paving.


Combinations of these technologies.

Robotic Total Stations.

Laser surveying.

Global Positioning Systems.

3D models.

The concepts are similar, but there are options for the technology employed


Timeline of Development

1990

2000

2010

1990’s – Earthwork Controls Developed and Refined

1999 – First Paving, Curb & Gutter (Alabama)

2000 – First Street (Iowa)

2003 – First Highway (Belgium)

2001 – First Airfield Paving (Various)

2000’s – Paver Controls Refined

2013 – Use is Growing

2004 – First Published Research (Iowa)


• Step 1 – Create survey control network.

• Step 2 – Collect field survey data of existing surface.

• Step 3 – Design pavement/create 3D model; convert data for machine inputs.

• Step 4 – Transfer simplified model to the paving machine, set up 3D instruments, tie into controls; then pave.

STEP 1 STEP 3 STEP 4 STEP 2


Similarities and Differences


Accurate Surveying is Required!

Both stringless and stringline paving methods require establishing a control network (or reference) for accurate paving.

A string control method requires more labor intensive surveying to transfer the plan geometry to the grade.

Stringless paving requires additional equipment, training and 3D data to build the pavement to plan.

Both methods work and the accuracy of either starts with the survey controls!


Engineering plan and profile is transferred to grade by a survey crew for stringline-controlled paving.

Basic Differences – Use of Technology

– How design data is used. – The number of surveyed control points needed to

control the paving machine. – The opportunities for survey error. – The trueness of the line and grade that the machine

follows.

Engineering plan and profile is converted to 3-D model for stringless paving machine control.


Benchmark

Control Points (Paving Hubs–Pins)

Stringline survey crew must set up each paving hub individually for stringline-controlled paving. There are many chances to introduce or compound errors.

Survey Reference Point Working With Stringlines Requires Many Steps


Stringline Surveying – Setting Grade on the Stake.


Field Surveying and Set-up Requirements for Stringless Paving

Establish Control Network: – Control points established

from field surveying. – 2 person crew. – Control points tied to

known benchmark(s). – Should be positioned:

• Out of way of any operations.

• Where they will not be bothered by the public.

• To allow instruments for machine control to see at least three control points at all times.


The Typical Steps Working With Stringless Paving

1. Surveying control point locations in the field at about 250 ft intervals for total station control and even greater intervals for laser or GPS control.

2. Placing each control point.

3. Performing automated surveying of the project site to build the terrain model.

4. Developing 3D model from plans.

5. Error-checking the 3D model.

6. Setting up instruments on the grade and tying them into at least three control points for paving.

9. Moving machine into position & checking (validating) the pan elevation using the instruments before paving.

10. Checking radio and/or laser communication between instruments and paver.

11. Moving the instruments along the grade as paving progresses.


Benchmark

Control Points

The stringless survey crew must plan the location of control points. The number depends on terrain, urban development and instruments (total station, laser or GPS)


Time Efficiency Improvements with Stringless

– Reduces field surveying. – Eliminates labor intensive

stringline surveying for hubs and stakes.

– Eliminates need for string line, stakes and accessories.

– Reduces opportunities to introduce surveying errors.

– Reduces overall preparation time on the grade.

These efficiencies will save construction costs while the technology will improve paving quality!


Spatial Requirements Reduced with Stringless

– A string-controlled operation requires about 5 feet clearance on each side: • 3 ft. for paver track and workers.

• 1 ft. for hubs and stringline stakes.

• 1 ft. for safety devices

– A stringless operation requires 1-2 feet less clearance on each side.

– Benefits: • Increases phasing and traffic control

pattern considerations.

• Improves project feasibility.

• Provides safer access to grade for crew and trucks.

Stringless technology helps increase feasibility of concrete paving in tight areas.

5 ft.


Machine Control Improvements with Stringless

– Places engineer’s design directly into machine(s).

– Controls elevation, slope, and steer of machines with truer input.

– Reduces or eliminates cords created by stringline hubs/pins.

– Reduces wave patterns introduced by improperly tensioned stringline sensors.

The control points that link the 3D model to the real world are the key to paving accuracy.


Sensors for Controlling Machine Elevation and Position.

Stake

Stringline

Elevation Sensor Touches Top or Bottom of String

Steering Control Sensor Touches Inside of String

Grade Stake


Sensors for Controlling Machine Elevation and Position.

Sensors Require Hand Tuning to

Get Accurate and Smooth Paving

Results


Stringlines represent the pavement using a series of cords. The cords are easy to see in this curve – even with a close staking interval.


These cords are built into the pavement, as can be seen here with cords in a horizontal curve.


Stringless technology represents the pavement using mathematical equations representing tangents and curves (a “true” profile).

Smooth Curve


Eliminates cords in vertical curves.

Eliminates stringline factors affecting smoothness: o Sag (stringline expansion in hot weather).

o Push up (improperly tensioned sensors).

o Deviations from loss of contact.

o Bumps from knots/splices.

o Crew fidgeting with sensor controls.

Sensor Follows Sagging String

Sensor Pulls String if Not Properly Tensioned

Sensor Looses Contact


Quality and Process Control Benefits with Stringless

More precise machine control (digital) to much smaller increments.

Better and more consistent ride quality.

Control over material quantities and costs.

Lower yield loss.

Control of horizontal and vertical curves is significantly more accurate to the plan – arcs are paved versus a series of cords!


Stringless control of thick airport paving.


What’s Required to Transition to Stringless?

Contractor:

– Capital expenditures.

– Investment in control (control points).

– Understanding line-of-sight for instruments.

– Understanding weather and environmental considerations for total stations, lasers and GPS.

– Learning curve/training – dedication of trained personnel to run stringless operation and work with 3D model.


What’s Required to Transition to Stringless?

• Owner/Agency:

– Acceptance – allow its use.

– Adopt end-result mindset (specifications) for thickness, smoothness.

– Provide (or validate) control points.

– Provide plans and CAD files to contractor for use in creating 3D model.

– Learning curve/training for field inspection or construction management staff.


Title: Technology Advancements in the Field: Stringless Paving

Speaker: Chad Ackley, P.E., CHA Consulting, Inc.

Date: March 2, 2016


Introduction

• Stringless technology/automatic grade control from the design engineer’s perspective

• Review of recent runway rehabilitation at Myrtle Beach International Airport using this technology

• Lessons learned

• Look ahead


MYR – Runway 18/36 Rehabilitation


MYR Project Overview

• Single runway airport

– (9,500 feet x 150 feet)

• 12 taxiway connectors

• Former USAF base

• Multiple pavement sections (asphalt and PCC); runway extended twice since original construction

• PCC ends structurally deficient for A320 and A321

• Non-standard longitudinal and transverse gradients



• P-401 Asphalt Overlay

• Variable depth milling

• Two variable depth leveling courses

• Uniform 2-inch surface course



• Tourism major component of the local economy

• Off-season and off-peak construction – September, 2014 to March, 2015

• Night work only – Weeknights: 10:45 PM – 6:45 AM

– Weekends: 11:45 PM – 5:30 AM

– Runway open to traffic during the day

• P-401-4.1 Weather Limitations – Surface temperature of underlying course (45 degrees F)

– Wilmington, NC terminal stopped shipping PG 76-22 binder for the surface course (too stiff to pipe in cold temps)



• This job demanded speed and efficiency

• Stringless paving was key! (…else we may still be paving…)


Design Considerations

• Five surfaces

– Existing Surface

– Milled Surface

– 1st Lift Surface

– 2nd Lift Surface

– Finished Surface

• What’s the best way to present the information to the contractor?

– Contractors want the digital design files

– Release disclaimer

[‎1/‎19/‎2016 1:55 PM] Bravo, Laura:



• Contractor imported our design elevations from MS Excel into their Carlson Takeoff Suite software

• We were able to compare each surface before construction started • Makes it easier on contractor, but ensures correct transfer of data



As-built final surface compared very well to design surface; no payment adjustments


Lessons Learned

• Night construction = terrible project photos

• Temporary pavement markings

– Saved time each night by outlining using Polaris Brutus with spray can mounted to machine control equipment


Lessons Learned

• Expand the survey area – Automatic grade control equipment doesn’t like being near the edges

of the survey data

– Contractor recommended 300-400 feet of additional survey beyond the limits of construction

• AutoCAD drawings – presentation vs. functionality – Annotated/blocked/hatched features in AutoCAD do not show up on

machine control equipment in the field

– Redraw symbols (to scale) using polylines


Going Forward

Where do project digital files (*.xml, etc.) fit into the discrepancy chain?

AE firms: is our product transitioning away from paper plans to the digital design model?


Going Forward

• How does your QA/QC reviewer ‘check’ a digital file?

• Where to focus design efforts in plan production? – Paper

– Digital

– How will that work with FAA specs like P-152 (cross sections)?

• When do we distribute the digital files? – After contract award

– During bidding?


Going Forward

• Automatic grade control equipment is here to stay – As design engineers, we need to learn out to handle this

technology advance practically, professionally, legally and within our E&O guidelines


Title: TECHNOLOGY ADVANCEMENTS IN THE FIELD STRINGLESS PAVING

Speaker: Robbie Pope, PE at GOMACO Corp

Date: March 2, 2016


Presentation Outline

What is 3D stringless paving?

Benefits of using 3DMC.

What technology is currently in the market?

Why are contractors moving away from traditional paving methods?

What infrastructure does a contractor need in place to implement

stringless technology?

What happens once the 3D technology is purchased and in place?

Workflow of Stringless Paving


What is 3D Stringless Paving?

Question:

What is Stringless Paving?

Answer:

A 3D Machine Control system that simplifies jobsite logistics, reduces costs and improves quality and safety

Question:

How does it work?

Answer:

It uses a variety of sensors and surveying instruments to monitor your machine’s real-time positions compared to a digital model to automatically control the movements of steering and elevation.



In short it removes the guidelines that traditionally run the length of the jobsite and replaces that with survey instruments and a virtual stringline.



A Brief History of Stringless Paving First machine automated tests using total stations occurred in Germany in 1997.

First construction application was high speed railway paved in Germany in 1998.

First road in USA both graded and paved without stringlines was on Sept. 14 1999 in Ida Grove Iowa.

Stringless Use on Airports Military RAF/USAF Fairford (UK); USAF Kirtland (NM, USA); USAF Lakenheath (UK); Belle Chasse Naval Reserve New Orleans, LO (USA); Homer Regional Airport, LO (USA); Travis USAF Cal USA; El Centro Cal, USA; Virgin Galactic Spaceport, New Mexico; Jacksonville USAF, Florida; Tulsa Air National Guard, Oklahoma;

Civil Zurich & Basel International (Switzerland); London Heathrow & Stansted, Edinburgh Intl., Farnborough, Luton Intl. (UK); Paris Charles de Gaulle (France); Atlanta Hartsfield Jackson Intl., Baton Rouge; St Louis, Missouri; Indianapolis, Indiana; Toulouse (France); Chicago O’Hare; Guadeloupe (Caribbean); Paris Orly (France); Charlotte, NC, USA; JFK Airport, New York, USA; Fort Lauderdale-Hollywood, Florida, Dallas Love Field; BWI, Baltimore International



Partial List of North American use of Stringless Paving Projects State Company Project NY Coldsprings, Surianello, Tutor Perini 90, JFK MI Toebe, AJAX 196, 75, 10, DTW PA Golden Triangle WV Hiway paving MD Cherry Hill Construction Andrews AFB IN Primco, Milestone, Walsh, FWI 69,31,24,IND IL Walsh, D's construction, MCI, ET Simonds 80,74,57,94,ORD KY Harper 416 WI Walsh 94 MO FWI, Millstone Bangert STL, 70, 270 AR Weaver Baily, Harper XNA Airport (NW Arkansas) TX MCM, HRT JV, Texas Sterling, Granite, Lonestar,Kiewit DAL, HRT, City streets in Lubbock, 26, 114, 635, Burleson (NTTA Chisholm Trail) GA Scruggs, MCI, APAC, Kiewit 75, ATL, 85, 92 SC Zachary, MCI, Lane 385, AFB in Charleston, 20 NC Hiway Paving, Zachary, Lane, Archer Western/Walsh Raleigh Durham toll road, CLT, Apex VA Hiway Paving FL Pepper, Kiewit, Archer Western, Head Inc Jacksonville AFB, FLL Airport, 95 LA Kiewit AFB OK Head inc. Tulsa Air National Guard KS Ideker Highway 24 NE Paulsen, Hawkins US-35, US-30, I-80, City streets IA Manatts, MCI, Flynn, Croell, MFT I-80, I-29, 680, I-35, HWY-20, 380, DSM, OMA, ALO, multiple county roads CO Kiewit NM Montoya Space port, 64 AZ Southwest, RL Wadsworth, Kiewit/Sundt 101 UT Provo River constructors JV, RL Wadsworth, Wadsworth Brothers Orem I-15, Logan US-10 ID CPC OR CPC CA Baldi Brothers, CC Meyers El Centro AFB, Travis AFB, 132, 4 NV Southwest Reno HI Baldi Brothers AFB Hawaii TN APAC Memphis Airport Alberta Flatiron Ontario Coco, O'leary 402 Quebec EBC Mexico Cemex


Benefits of using 3DMC

A 3DMC system simplifies jobsite logistics, reduces costs, improves quality and safety

Removes stringlines and pins from the jobsite

• Removes installation, maintenance & removal costs

• Increases work safety, especially at night

• Removes down time from stringline breaks/bumps during production

Puts the 3D job design directly onto the machine

• Eliminates survey setup errors in stringline influences

• No waiting for setting-out before production

• No dependency on setup – work wherever you have 3D data

• Increases productivity, quality and performance bonuses

Controls height, slope (and steer) of machines

• Delivers a precisely-constructed product

• Optimises amount of new material needed

• Reduces over-trimming/milling, overpouring

• Improves concrete yields and material cost savings


Logistical Advantages During and After Construction

Roadway is now open

Trucks no longer need to back up so far

No “Gates” in wireline needed

Better versatility moving through site

No lost time to tear down of wireline

Benefits of using 3DMC

Wireline Clearance

Track grade now only needs to be the width of the actual machine profile, allowing this technology to be used in much tighter spaces and confined areas.


Technology in Market Today

All 3 major developers of survey instruments have 3D Slip-Form Paving solutions.



Overview of the instrument technology types

offered and their applications

Total Station

accuracy +/-0.001’

*line of sight

Slipform Pavers

Trimmers

Milling Machines

Curb & Gutter

Asphalt paving

Millimeter GPS

accuracy +/-0.01’

*with good satellite signal

Slipform Pavers

Trimmers

Milling Machines

Curb & Gutter

Asphalt paving

GPS RTK

accuracy +/-0.1’

*with good satellite signal

Slipform Paver**

Placer/Spreaders

Follow-up Machines

Curb & Gutter Steering

Asphalt Paving Steering

**used only in mixed modes with

other sensors on fill-in lanes


There are many different sensor choices and many different applications for each sensor

TPS

VS

GPS


Choose your sensors wisely!

SO


Why Contractors use it?

are expensive, time-consuming

and error-prone to install

are easily damaged before and

during paving

are easily misaligned (errors

increase costs)

are a significant site safety hazard

interfere with site logistics,

increase concrete delivery time,

haul costs, and reduce

productivity.

greatly increase pre-production

planning & surveyors workload

Because stringlines…


Why Contractors use it?

Good site engineers/surveyors are hard to find, and expensive

Stringlines don’t always ‘model’ the concrete design accurately

“Go in, pave & get out” ability minimizes machine standing time – ideal for

time-critical paving operations (e.g. ‘live’ airports, roads)

Estimated 50% survey cost reduction - one surveyor or engineer

manages the 3D system

Estimated 20% productivity increase (up to 50% in complex areas)

Direct construction from CAD design – no intermediate rework

One 3D model for trimming and paving = material cost savings

Advantages the paving contractors are seeing in implementing 3DMC


Contractor Infrastructure Required


3D Sensors – Total Stations

1” accuracy total station

Fully robotic operation

Automatic prism tracking

Simple setup and position fix

Can be used for any surveying tasks

10-12Hz measurement rate

Backlight & heater for night operation

Typical working Range ± 300ft

Tracking accuracy ±0.01 at 300ft


Components Leica PaveSmart


Machine GPS

Supports GPS & GLONASS systems for

maximum operational time

Simple setup and position fix routine

Identical user interface to TPS – no

extra training required

Can be quickly removed from machine and used for any site surveying tasks

True 20Hz measurement rate

Typical Tracking Accuracy:

Position ±0.03FT

Height ±0.06FT

3D Sensors – GPS (for machine steer option only)


Components Leica PaveSmart



Machine

Computer

Radios

Slope Sensor

360⁰ Prism

Total Station #1

(Guidance)

Total Station #2

(Guidance) Total Station #3

(As-builts)

Survey

Control

Point

360⁰ Prism

Slope Sensor

Survey

Control

Point


PZL-1 (Positioning Zone Laser) Transmits Unique Laser Zone

Signal 500 Foot Diameter Auto-Leveling 4 Channel Operation Alkaline Batteries, NiMH

Rechargeable, & External Power

mmGPS Transmitter


• PZS-MC (Positioning Zone Sensor for Machine Control)

Receives & Decodes the Laser Zone Signal

360o beam Detection Rugged, Shockproof Design IPX6 Waterproof DC8V~DC32V Power Supply

mmGPS Machine Sensor

Used in 2D & 3D applications Touch screen Windows XP Operator selectable views

GX-60

3DMC User Interface


Total Station Option

GX-60 Display • LCD Color Touchscreen

Machine Prism • integrated GPS+ antenna

Machine Radio Long range Bluetooth

PS-101 Total Station • 1” (arc-second) resolution • +/- 3mm at 100m • Fully Robotic



Trimble PCS900

Consists of:

CB460 Display

• Color screen

SPS930 Total Stations

• 1” accuracy

• +/- 3mm at 100m

Machine Radio

MT900 Active Prism

MS992 GPS Receiver Head

Dual-Axis Angle / IMU Sensor



Now what do we do with it?

We just bought all this stuff and nobody knows how to use it!!

Tips for Successful Implementation

Contractor Buy-In Training

• Provided by vendors on customer jobsites around the world

Experience • Many field procedures are new compared to using string

• It is a repetitive skill but the learning curve is not steep

Adoption • Field crews must fully adopt to be successful

Role changes • Added responsibilities for foreman/groundman

• 3DMC interface replaces wands for making real-time steering and grade changes

• Replace stringline crew with Field Tech • Crew member dedicated to setting up survey instruments and QC checks

• Data Prep - may be done in-house or contracted out

Equipment and Training up to date • Market is frequently changing/updating and releasing new products


Now what do we do with it?

We just bought all this stuff and nobody knows how to use it!! How can the owner/agent get involved in the construction process?

Tips for Successful Implementation

Agency Buy-In Knowledge

• A basic understanding of the process

Quality Control (includes both before and

after pave) • Check sub-grade before paving

• Verify digital model before paving

Field Verification • Obtain their own survey instruments for

QA/CQ

• Use Contractors instruments for QA/QC

Additional tools • Utilize other tools such as real-time

smoothness indicators and auto-survey &

as-built functions


Before you order the Concrete Trucks!

1) Establish Control FIRST! 2) Maintain control network and have quality check continuously throughout

the entire time frame of the project! 3) Know or define where the existing project (roadway) is today X,Y,Z 4) Know where the proposed project will be upon completion (model of

proposed) – Your yield is at stake! 5) Do a quality check BEFORE you pave! (i.e. dry run the machine) 6) Make corrective actions to the surface prior to paving if necessary!

Preferable Pre – project check list!

Workflow of Stringless



Stringless Paving vs Wire

Working with Stringline…

Inspect design – calculate setting-out lists for each lane

Setup a total station, survey each hub or pin position with total station (or GPS if accuracy isn’t important!)

Hammer (or drill) in each pin, minimum 1 line for each lane of concrete/asphalt

Check pin alignment & adjust if required

Survey and set stringline height on each pin (min. 2 men)

Install & tension clamps and stringlines

“Eyeball” & adjust stringlines before paving

Move machine into position, set sensors to stringline

Check machine position relative to stringlines

Start Production, monitor machine position

Ensure (or hope!) nothing disturbs or damages stringlines during paving/milling…

Reference

Point

Walk left 5ft!

Walk right 1ft!

Up a bit!

Down a bit!

STOP!

Reference

Point



Data Prep is Crucial

Don’t let it scare you – the 3D model is simply a digital representation of the stringline

The virtual stringline model now becomes one of the most important aspects of paving

The success of accurately and smoothly paving depends on the quality of the digital model

Built from Alignment Data, Profile Data, and Template Data

Built from Horizontal and Vertical Curves

Built from Station, Offset, and Elevation

Will the Owner/Agent/Designer provide this data?

How do we model the paving?

Grading model are typically for use with GPS guided machine – accuracy required ~ 0.1ft

Grading models are surface based and 2D linework is only for reference

Paving models are for Total Stations or Lasers – accuracy required ~ 0.01ft

Paving models are based on alignments (means paver steering is also automated)

Paving Models vs. Grading Models


Design software has different

tools for creating 3D Data

These packages are used by

designers from all aspects of

Owner/Agents

These packages below export generic formats that the manufacturer software can recognize

Linework = .DXF Surface= .XML Alignment Models= .XML



Surface Model Quality Assessment

Basic steps in prediction analysis on 3D model An example of how to preview theoretical smoothness of a 3D model

Open digital model in CAD software

Sample from 3D Polyline/Surface

Build Profile

Sample from Profile

Isolate data for ProVal

Create a Project

Add data from model

Run ride quality and/or smoothness quality

Make adjustments if necessary and run the check again


Quality analysis is more than just a overall number Look closer at the data to analyze for problem areas, specifically bridge ties, transitions into existing pavements and joint matching

– Overall the 3D Model looked reasonably good – IRI less than 30

– A closer look at the numbers in the continuous analysis shows problem areas where grinding may occur.

– Learn to use the different ProVal tools effectively so that we can better analyze our 3D models



Calibration Why and when to Calibrate?

Why?

• Precise paving

• Optimal machine performance

• Optimal concrete thickness & cost savings

• Prism locations, relative to Mould “Origin” , must be determined

• Slope sensors must be accurately adjusted (relative to machine & each other!)

When?

• At first installation (commissioning)

• At EVERY subsequent change of the machine (width change, disassembly/reassembly)

Risks if ignored?

Mis-matched slope sensors can cause machine “twisting”

• Poor concrete surface finish

• Risk of structural damage to machine (leg barrels, tracks are stressed) “jumpy” machine

Machine will not pave at correct elevation or position



Practical Issues… In the field!

How do we know what is going on without seeing the stringlines?

How do we know where we are in reference to the model?

What is the contractor doing to verify placement?

How does the Owner/Agent get involved in the Quality Process?



Field Adjusting the Machine on the fly

If position needs horizontal adjusting…

…just like stringline control

we can adjust position at

front and rear independently,

without stopping the paver

If the level needs vertical adjusting…

…just like stringline control

we can adjust all leg heights,

and draft independently,

without stopping paving

Digital Offsets, no hand cranking and

forgetting

Real-time steering and grade adjustments are easy


Practical Issues Moving the Robots (‘Leapfrogging’)

Maximum Range Robot-to-Paver is <= 300FT (*depends on conditions)

We don’t need to stop the paver – all done on the fly

Before maximum range is reached, move 3rd Robot to new position &

setup (Position & Orientation Fix).

Press ‘Swap Robot’ on computer

System switches control from #2 (or #1) to #3 Robot automatically

Move ‘old’ Robot to new position, setup and repeat procedure

Ensure enough Reference Points visible for Setup (Position & Orientation Fix)

* temperature, humidity, air quality



“Leapfrogging” Part 1 All Theodolites in “Start” Position

TS #3

TS #1

TS #2


“Leapfrogging” Part 2 Move Theodolite #3 ahead, Setup, Transfer Control (#2-#3)

TS #3

TS #1

TS #2


`


TS #3

TS #1

TS #2



Please feel free to contact me at ay time by any of the listed means below:

Robbie Pope, PE

GOMACO Corporation

3D Controls Engineer

(712) 371-3991 Cell

[email protected]

mailto:[email protected]

title: technology advancements in the field: stringless ... · title: technology advancements in...

Documents