Question for electricity experts (light rail)

This morning (8 Oct) if you looked off the south edge of the south platform at Newark Broad, west of the station building, you saw a pit maybe 9 feet deep, 25-30 ft by 45-50 ft at the bottom. The bottom was sandy dirt, with a grid of half-inch copper cables running N-S and E-W over the whole pit, spaced 2-2 1/2 ft apart. (Not rigidly fixed-- just lying in the dirt.) They were thermite-welding (?) the intersections to (maybe?) the tops of what may have been vertical rods pounded into the dirt.

So presumably this is something to do with grounding the rails of the light-rail. Do other light-rail systems have such things? Did old streetcar systems? Sometimes, sometimes not, never? Is it a new requirement that all new systems must have?

That's done at a substation to provide a good station ground as well as a ground for lightning protection. Don't know if a substation is planned for there, or if power will be fed from the main line.

One further thought. Trolley lines often had problems with return current straying from the rails and passing through water and gas pipelines, which could cause corrosion of the pipelines. As good ground at strategic points, such as you describe, might mitigate that problem.