It's apparently nitro fuel tubing, although I've never seen anyone use black fuel line in an rc car, and I've never seen these dimensions.
https://www.ebay.com/itm/401073783505
As far as I can tell, it's one ladder with 3 sections. Some kind of pulley system mounted to the side, a pair of spiked feet that digs into the ground and a pair of long support legs that can fold out from the sides. A short section is mounted to the truck and can tilt up. The final section seems to be mounted to the tilting bit and can slide out and down towards the ground. I think the ladder is then just strapped to this sliding section.
I'm having trouble finding reference material of it in use, but here's one image.(Image of aftermath of house fire, noone physically harmed)
https://www.folkebladet.no/nyheter/a...leks%20Olsborg
Better image of the truck mounted section extended, and a video that I just now discovered of that part being retracted by a firefighter:
https://www.sa.no/varteig/nyhet/matt...n/s/5-46-50230