Limitless Power in a Limited Space


Think, for a moment, about the amount of electricity that would be required for underground transit tunnels.

You’ve got the lighting systems along the walls, ventilation to ensure there’s clean air, and rail communications systems. On top of all this, you need to supply power for these systems over massive distances covered by the transit line.

When you travel through Crosstown tunnels in 2021 though, you’re not going to see dozens of power lines running the walls. In fact, you won’t see much at all outside of tracks, trains and the overhead power for the LRVs. That’s because the bulk of the Crosstown’s electrical conduits will be encased in concrete – in duct banks that run through the tunnels alongside the tracks.

Duct Banks

“Within these duct banks, we run conduits of varied sizes, covered in either steel or PVC piping,” says Norm Langerhorst, Transit Systems Project Manager. “Because of fire regulations, we encase the conduits in a protective concrete coating, which protects them in the event of a fire or other emergency.”

On top of all this, the tunnel’s real-estate needs to be kept in mind. Trains need a certain amount of clearance on both sides for sway (side-to-side movement). Essentially, when building a duct bank within the tunnel, a generous space for trains must be accounted for, where no structures can be built. Considerations like these result in duct banks that are well-planned and occupy as little space as possible. 

Duct Banks 2

Constructing duct banks in the tunnels requires skill and expertise. Just because something seems simple and isn’t visible doesn’t mean that it’s easy – sometimes the simplest things require the most attention.