Fenagh is pleased to be involved with a project that’s poised to permanently improve the public transportation in Boston.
The Green Line Extension involves the construction of 6 new train stations that will open up travel to the communities of Somerville, Cambridge, and Medford. While these areas have been historically underserved in terms of public transportation, the new stations will allow for 50,000 more passenger trips per day, reducing vehicles on the road and related air emissions. Overall, this expansion is expected to cost around $2.3 billion with the goal of having the service up and running by late 2021.
What’s unique about this job?
Compared to other projects Fenagh works on, this project involves many railroads, railroad specialists, and railroad-specialized equipment. All of this is complemented by railroad specialized specifications, plans, standards, and construction techniques. The novelty and history of these processes are not lost on our inspectors.
“This job is Quality Control (QC), whereas much of the work we do is Quality Assurance (QA). Here we are working deeper in the “interior” of the job, doing tests and inspections while the QC/QA are still being ironed out, and often working on what those QC processes will be and will not be. Were this a cake, I am around for the baking, rather than the usual QA where I am around for just the icing and decoration.”
Fenagh has done field inspections on all the rail welds involved in this project, including:
Flash Butt Welds:
This is a type of resistance weld that does not use any filler metals. The Flash Butt welds are tested by the Magnetic Particle method, a non-destructive testing process used to detect surface and shallow subsurface discontinuities in ferromagnetic materials like iron, nickel, cobalt, and some alloys.
Thermite welding, also known as exothermic welding, is a welding process that utilizes molten metal to permanently join conductors. The thermite welds on the Boston Green Line Extension project were tested ultrasonically. This method tests for internal discontinuities like shrinkage cavities and microporosity that could affect the mechanical properties of welds, such as their fracture toughness and fatigue strength.
Fenagh’s scope of work on the Boston Green Line Extension project doesn’t stop there. We have also sampled and tested, often at a very frequent schedule, the stone, aggregate and soil materials used throughout this job. We have also sampled and tested concrete and grout used for bridge repairs, as well as inspected structural steel installations used for bridge repair. Going forward, we will inspect the concrete, steel, soil material and compaction for project retaining walls, rail stations, overpass and underpass structures.