Project Name: PMO Effort for SW Moody Ave Street Reconstruction and Streetcar Project
Abstract: This paper seeks to provide insight and guidance on the design, testing and installation of a new type of running rail used on streetcar projects. Problems experienced with 112 Tram rail installed on the SW Moody project are discussed.
Project Phase(s): Design and Construction
Category: Schedule and Cost
The SW Moody Streetcar Project was completed and opened for service in November 2011. The Project constructed approximately 3,200 linear feet of double track alignment including Overhead Catenary System (OCS), train control, and communications facilities along SW Moody Avenue from approximately SW River Parkway to SW Gibbs Street. SW Moody Avenue includes three traffic lanes, dual streetcar tracks, and pedestrian and bicycle facilities. The roadway was elevated 14 feet above current street level which allows for the redevelopment of adjacent brown fields to offer “tuck under parking” without disturbing capped contaminated areas. The elevated street also integrates mixed-use developments with street-level transit facilities, which encourages transit ridership and reduces auto trips. New construction will increase roadway capacity and introduce urban development standards, such as fiber optic, sewer, storm water, and water infrastructure to support future development.
The initial trackway design specified girder rail (Ri59) for the new track installation. However, the FTA would not permit the use of non-domestically produced rail on Transportation Investment Generating Economic Recovery (TIGER) funded projects. The project team was faced with replacing the Ri59 rail with 115RE rail which they did not want to use due to concern about the flangeway width.
The project team discovered that many European rail transit systems use LK-1 block rail especially on low clearance bridges and underpasses. LK-1 has a height of only 72mm (~3-inches) and has the desirable girder rail type flangeway and similar strength characteristics as Ri59 girder rail. ArcelorMittal, a US manufacturer, expressed an interest in rolling the LK-1 rail in their Steelton, PA plant. During rolling minor changes were made to the LK-1 shape increasing the flangeway width by a few millimeters, and the final rail was called 112 Tram rail. ArcelorMittal produced and shipped approximately 200-tons of 112 Tram rail to the SW Moody project. The 112 Tram rail was approximately 10% more costly than 115RE rail.
Due to the distinctive block or square shape of 112 Tram rails, no Association of American Railroads (AAR) type insulated joint (IJ) was readily available, so the project team designed a unique bolted plate IJ for 112 Tram rail. The PMOC recommended that the new IJ design be exposed to rigorous AREMA type testing protocols, but the team indicated a lack of time and funds to perform AREMA testing and chose to follow their own testing procedures. The newly designed IJ’s were installed at 10 locations throughout the project in the spring/summer of 2011. Streetcar operation was started on the new trackway in November 2011.
Sometime prior to January 11, 2012, a rail break occurred in the 112 Tram rail at a number of IJ’s, and the PMOC was asked to investigate. The PMOC again recommended the newly designed joints be thoroughly analyzed to determine failure mode and that the new design be tested according to AREMA or AAR protocols. The project team decided against performing any investigation and followed their own testing procedures developed by in-house staff.
During the January site visit, the PMOC was approached by a Portland Bureau of Transportation inspector who commented that the contractor who installed the 112 Tram rail had difficulty bringing the rail to its neutral temperature because it was encapsulated in elastomeric material. During cool temperatures heat is applied directly to the rail head to raise the rail’s temperature to its neutral temperature point prior to welding. Thermite weld kits were used to join the rail strings since a fusion-butt welding process had not been developed in time for the rail installation.
The PMOC contacted the SW Moody Project Manager by email asking several questions about what had occurred. She responded promptly indicating that the IJs (at this time there were four) had failed. According to her, the weld failed. On January 26, the SW Moody Project Manager indicated that the new design would be tested to failure by the fabricator Liberty Steel. The PMOC recommended that an independent testing lab be used to retain independence of the testing process, and that the City of Portland (COP) should consider removing and replacing all the IJ’s on the project with the new design.
Results of the IJ testing were received at the April 27, 2012, team meeting in Portland. Rather than use a standardized testing protocol recommended by the PMOC (based on AREMA) the team elected to use a testing procedure developed by their in-house staff.
In mid June 2012, the PMOC observed the installation of the new IJ’s. The trackway repair work was completed at the end of June. The contractor demolished the existing concrete track slab to the sub-grade. New reinforcing steel and dowel bars were installed to re-establish the foundation for the new track slab containing the new IJ. The many phases of IJ replacement include: concrete demolition, 112 Tram rail placement, rail welding, reinforcing steel placement, negative return junction box placement, and concreting of the track slab with embedded IJ.
In late February 2013, the PMOC visited the site and discovered three of the previously repaired IJ’s had failed and the rail head exhibited signs of cracking. At this time the PMOC recommended further analysis and a thorough investigation be performed into the failure mode.
The PMOC is concerned that the new IJ installations installed in June 2012 were unable to withstand what appears to be thermal stress occurring in the rail. Without removal and thorough testing of the failed IJ’s it will be impossible to determine if the new breaks are the result of a poor IJ design, thermal stress, or improper rail installation. Although breaks in the rail are not readily visible in the other seven locations, doesn’t necessarily mean they haven’t also failed. The PMOC recommended a thorough analysis and investigation into the failure mode on all 10 IJ’s that were repaired in June 2012.
There is still some uncertainty regarding the cause of the 112 Tram rail breaks that have occurred in the SW Moody trackway. It could have been the temperatures when the 112 Tram rail was installed versus the winter temperatures which could have caused a thermal stress, the design of the IJ’s, the manufacture of the rail, or the installation of the rail. The PMOC recommends further evaluation and testing of the 112 Tram rail be performed by an independent testing agency.
When breaks occur they cause an interruption in service, which is a cost to the COP who provides alternative ways (bus, bridge, etc.) for moving patrons through the system. The first breaks were discovered in January 2012, and after repair were still occurring in February 2013.
The recent IJ rail breaks (in January 2013) are an indication that the team isn’t employing a rigorous and thorough testing regime of the joint before its installation and quality assurance and control efforts. The PMOC recommended both prior to the first installation and after the January 2012 break that an industry accepted testing protocol be used based on established industry practice and experience.
A properly designed and constructed rail system is important to the streetcar operation to prevent interruptions in service and additional cost to the agency to provide alternate transportation for patrons.
Don Carnell, PE
1616 East Millbrook Road, Suite 310
Raleigh, NC 27609