Thanks, hadn't seen it in this much detail before.There are two long pre-existing culverts, more like tunnels, running for over 200m right under the marshalling yard footprint. One is for the River Crane, and there’s a parallel flood relief tunnel as well.
You can see some internal photos and plan drawings in this article about the tunnels here. There’s a bit of metric/imperial exaggerated conversion going on, references to 750 yd, but the text has it 750 ft long.
The extent can just about be made out on the current Google satellite view, if you look for the tight bend in the river course.![]()
Feltham Cavalry Tunnel (40 acres) - Art of the State
Feltham Cavalry Tunnel aka Feltham 40 Acres Tunnel Known locally as Feltham Cavalry Tunnel or 40 Acres Tunnel there is an unlit culvert that runs for 750 yards under the former site of Feltham Marshalling Yards in West London. It runs adjacent to the redirected River Crane and was constructed to...www.artofthestate.co.uk
Bit of an update about the bridge in the video embedded in this tweet: