Denton County Transportation Authority (DCTA)

Rail Project

Denton and Carrollton, Texas

LTK is assisting the Denton County Transportation Authority’s (DCTA) efforts to bring a 21-mile rail passenger service between Denton and Carrollton, TX.  LTK’s support services cover the self-propelled diesel multiple unit (DMU) vehicle acquisition, operations, and signal system design. CA1-DCTAmap

The DCTA Rail project will connect Denton, TX with the Dallas Area Rapid Transit System (DART) light rail.  The newly constructed line utilizes a mixed corridor of infrequent freight rail service and rails-to-trail occupancy.  DCTA Rail has an across-the-platform connection with the DART Green Line, scheduled to open in December 2010, at Trinity Mills (one of DART’s Carrollton stations).  DCTA Rail has three stations in Lewisville and two stations in Denton.  Rail freight service will continue on the line between Carrollton and Lewisville with temporal separation.

DCTA Rail’s primary objective is increasing mobility into the Dallas Metro area through coordinating service with DART.  Thus, the system design foundation is light rail technology adapted to a modest passenger base on an FRA regulated rail line.  The resulting system concept is 20-minute bi-directional peak period service plus mid-day and evening service utilizing diesel multiple units.  LTK is supporting DCTA through the following tasks, focusing on cost-effective engineering solutions:

  • Provided passenger rail vehicle technology review encompassing new and second-hand self propelled vehicle choices.
  • Developed new vehicle procurement technical specifications.
  • Assisted DCTA in the development of procurement documents and manufacturer negotiations.
  • Completed the signal system design to eliminate schedule delays due to meets and incorporate over 40 road crossing installations.
  • Developed an operating plan for the varying train performance characteristics of interim and new vehicles.
  • Guided passing siding locations and length to minimize running time delays and minimize vehicle fleet.
  • Assisted in vehicle maintenance facility design, advising on recommended support equipment, space requirements, and layout.


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NJ Transit

NEC Middle Zone Train Performance/Signal Capacity Analysis

Newark, New Jersey

Working with NJ TRANSIT Rail Service Planning and Equipment Engineering, LTK is assisting the railroad in quantifying capacity differences between existing Jersey Arrow III Electric Multiple Unit (EMU) and ALP-46 push-pull consist with multi-level coaches.  This analysis focuses on the critical “Middle Zone” segment between Midway and Union Interlockings on the Northeast Corridor (NEC). LTK is also assisting NJ TRANSIT in quantifying various levels of potential signal system upgrades in this segment that would mitigate any losses in capacity due to train performance as part of support of overall strategic fleet expansion plans.

CA2-NJTMiddle.jpgNJ TRANSIT’s RAILSIM database was used to compare morning peak hour Middle Zone capacity under current fleet assignments versus replacement of the Jersey Arrow III portion of the fleet with ALP-46 and Multi-Level coaches (and using dual ALP-46 locomotives for longer trains).  The analysis shows that the current morning peak hour schedule for Track 1 operation in the Middle Zone exceeds the practical capacity of the signal system.  With maximum train lengths already operated in this segment, NJ TRANSIT serves the high ridership between Jersey Avenue and Metropark through operation of peak period trains at reduced speeds to optimize throughput.

Depending on the train consist, stopping pattern and routing, the most constraining Middle Zone signals can be found at County Interlocking or at Lincoln Interlocking, with Clear (green) signal clearing times in the range of 8 to 9 minutes.  These clearing times are unusually long because the signal system is designed for 90 to 110 mph maximum train speed and there are multiple closely-spaced stations.

Working with Amtrak, NJ TRANSIT is pursuing resignaling of this territory using additional cab signal aspects to improve capacity.  The current signal installation does not include any cab signal aspects between Approach Medium (120 code, or 45 mph) and maximum authorized speed (90 to 110 mph, depending on location) whereas new designs will support intermediate 60 and/or 80 mph cab signal aspects.

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Minnesota Department of Transportation

Northstar Corridor Project

Anoka County, Minnesota

When evaluating service on the Northstar Corridor, the Minnesota Department of Transportation turned to LTK Engineering Services for expertise. The firm developed operational concepts and assisted with reviews and determinations of rail capacity improvement. Staff members provided maintenance facility layout and design while also working with MinnDot during a difficult site selection process. LTK served as a facilitator for a variety of other potential challenges.

CA3-MNNorthstarThe Northstar Corridor, which extends some 80 miles between downtown Minneapolis and the city of St. Cloud, Minnesota, is one of the fastest growing in the nation. It is served by interstate and state highways, and the transcontinental mainline of the Burlington Northern Santa Fe Railway. The objective of the Northstar Corridor project is to define an appropriate commuter rail service to link the two terminal cities and intermediate communities.

Working in the preliminary engineering phase of this project from 1999 to 2001, LTK developed and evaluated alternative operating plans and service concepts; analyzed alternative track configurations; evaluated the operating implications of alternative station locations; and provided conceptual signal layouts, together with the associated cost estimates.  Rolling stock options appropriate to the operating concepts and consistent with demand forecasts were analyzed, with fleet requirements identified, and a conceptual car and locomotive design framework prepared. Alternative maintenance and operating facility sites were evaluated, and a maintenance facility design consistent with the rolling stock concept, including storage yard and access trackage, was prepared. The firm also evaluated and recommended appropriate car and locomotive technology for this service.

Infrastructure cost estimates provided by LTK included components, labor, materials, engineering services, as well as overhead and expenses. These estimates focused on the extensive improvements to the Burlington Northern Santa Fe infrastructure required to accommodate fast and reliable commuter rail frequencies on a busy freight mainline, as well as on the signaling and track requirements unique to the commuter rail operation itself. The improvements addressed were interlockings, automatic signal locations, passing sidings and grade crossing protection. Cost estimates for the fleet of cars and locomotives required to operate the service, and the maintenance facility and yard, also were prepared.

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