1. Trackwork With the original light rail construction in the 1980s, several phases of rail rehabilitation have been done to replace broken rail, damaged switch machines, worn track crossings, etc. Along with rehabilitation, improvements to add crossovers or special trackwork have been done to enhance operations. This type of rehabilitation and improvement work will continue throughout the alignment on a continual basis. This work will include investigations, analysis, recommendations and construction document preparation for construction contracts required for the rehabilitation or improvement of rail infrastructure. 2. Traction Power Substation (TPSS) VTA operates and maintains 34 traction power substations that convert incoming utility power to nominal 800-1500 Vdc output for distribution via feeders and the Overhead Contact System (OCS) to the Light Rail Vehicles (LRVs). The VTA substations are rated for continuous 1.5 MW – 3.0 MW operations and are equipped with four (4) to six (6) dc feeder circuit breakers. Many of the original substations have been replaced as part of previous state of good repair projects, however, the Tasman East, Capitol and Vasona lines will need rehabilitation in the near term. Other traction power substations may require rehabilitation of transformers, rectifiers, disconnect switches, etc. This work for the light rail traction power substation category will include investigations, analysis, recommendations and construction document preparation for construction contracts required for the rehabilitation, replacement, or improvement of traction power substations. 3. Overhead Contact System (OCS) The OCS for the VTA LRT consists of three (3) different types: 1. Simple Catenary Auto Tensioned (SCAT) is a single contact wire, suspended by hangers from a single messenger wire. The combination of these two wires istensioned at the end of each half tension section by a counterweight. 2. Single Wire Auto Tensioned (SWAT) is a single contact wire, tensioned at the end of a half tension section by a counterweight. 3. Single Contact Wire Fixed Termination (SCW) is a single wire, terminated to pole/poles or structure where tension varies as the temperature changes. The overhead contact infrastructure is in the process of rehabilitation of the older segments. Currently the Guadalupe alignment is under construction with wire, disconnect switch, and insulator replacement. The rehabilitation will continue with other sections over the next decade. In addition, there are occasional OCS rehabilitation needs in the light rail yard, at attachments to structure, etc. The engineering work for the OCS system will include investigations, analysis, recommendations and construction document preparation for construction contracts required for the rehabilitation, replacement, or improvement of the overhead contact system.
