Metal structure near rear engine compartment.

[Honeydipped]

Hey folks, It has been too cold to work outside under the bus lately so I’m ripping up the inside. After taking the side panels off I stumbled across this metal structure near the rear engine compartment.

Circled in blue is closed off, but inside of it contains nasty looking insulation.

First, what is this? I’m assuming it’s some sort of structural support for the back end (maybe for accidents).

Second, would it be ok to cut a couple holes to reach in and rip the insulation out? I’d like to replace all insulation with XPS or spray foam. I can butt or lap weld pieces back over the holes I cut if need be.

Thanks for the help everyone!

 

[DeMac]

I have a similar structure in my RE. The steel plate on mine is to the outside of the angle or channel. Last three windows & tied into the engine craddle.
I vote 'No' on the cutting of the heavy plate. Being an RE, I believe it's to support the additional engine weight. Same reason for the shorter overhang/ long wheelbase.
Maybe expanding foam. (mixed reviews about corrosion, idk)
Foamboard on top for me.