A battery-powered hobgoblin repair cart with a tunnel-filling debris-scoop portal that hurls everything on a track to the trainyard or the abyss.
The Interdiction Rapid-Response Railway Repair Cart is the workhorse cleanup vehicle of the Hobgoblin Interdiction Team — and the linchpin of Carl's end-of-line rescue. Found never-used at station 75 (ten of them), each is a battery-powered flatbed with a raised driver cabin and, crucially, a wide front debris-scoop that projects a mobile portal filling the entire tunnel ahead: switchable between "trainyard mode" (safely relocating live trains and passengers) and "abyss mode" (dumping wreckage into the pit). It runs up a line at five times a subway's speed on battery or third-rail power, and dials any of ~100+ destination lines via a DungeonWerx portal selector.
Its cruel lock: it starts only with a pair of gnoll LEFT hands on two far-apart sensors, forcing Carl to harvest the indestructible Growler Gary. Carl's plan sends two carts down each of three lines — one in abyss mode to clear the track of ghouls and wrecks, then one in trainyard mode fifteen minutes later to teleport the stranded crawlers to safety. (Its worn cousin, the smaller Auxiliary cart, needs no gnoll and just ferries personnel.)
A metal-bodied rail cart about twice a normal cart's length, three axles, open seating and cargo bed, a ladder-accessed raised driver cabin, and a wide ground-hugging squeegee-like blade across the front that emits a frosted tunnel-filling portal.
The portal-scoop repair cart that powers Carl's mass evacuation of crawlers stranded at the abyss.