haven’t seen the vids but would agree with Atlaz, that sounds more like the LSP end of the seagull run.
Tank traps is the logical progression from that though. To LSP, take 2nd left (I think) which climbs slightly and then turning is on the right at the crest. Starts off twisty through the tres, drops and then climbs, twists some more and then enters a sort of gully with the concrete blocks and railway sleepers embedded which gives it its name. Dumps you onto the long fireroad that runs from LSP to the manhole cover above the jump gully.
Wouldn’t normally give location of trails away so readily but the BOB / Gorrick trail crews were working on TT 2 weeks ago and it needs wheels now to help to bed it in. So go looking.