FEATURED PROJECT: Inter-Column Underslung Girder System

The Honolulu Authority Rail Transit (HART) project will provide approximately 22-miles of above ground light rail capabilities to residents and visitors of Honolulu, spanning from East Kapolei to Ala Moana. As part of this massive project, TMF was contracted to manufacture (3) sets of Underslung Girder Systems designed to assist with the installation of pre-cast concrete decking. Despite the size/girth of the individual components, it was designed to be quickly disassembled and reassembled for the progressive construction of the concrete rail structure. Each system included the following main components:

• Box Girders & Trusses – these acted as a large gearbox of sorts, it housed the circulating chain which allowed the trolley above to move the rails)
• Pier Anchoring System – these were the Ram Assemblies, L-Brackets and Pier Brackets which ‘hugged’ the vertical concrete piers and supported the Box Girders and Trusses above

In total, roughly 1,500-Tons of fabricated steel was required. Thompson’s scope also included all painting, supply of the gearboxes/chain drive system, and all load testing. The load test (in particular), was a job all on its own. It required fixtures which rivaled the size of Pier Anchoring System. Due to the ‘girth’ of the structures and the load test/deflection requirements, a custom hydraulic system had to be developed as no other reasonable means/methods existed. Between the structural design of the load-test frame and the design of the hydraulic system, the load-test scope on this project is a reminder of highly creative folks that work at TMF, and the strategic alliances we have with our outside service providers.

start/completion date
First & Second Set
June 2012 – Feb. 2014

Third Set
Feb. 2015 – June 2015