The number sequences are math problems. 85^2=7225, 95^2=9025, etc.

Likely whoever was on duty did mental math as a way to pass the time while bored. The other doodles, such as the car, reinforce that theory.

The drawing of the old car is fascinating, whether it means anything or not.

It's most likely just graffiti, or a quick math problem as /u/Dire88 suggests. Anything that was meant for permanent consumption in that compartment would have been on a plaque or stenciled onto the wall.

Some of it may well have been done by workers in the shipyard working out their interpretation of the blueprint for the placement of ductwork, plumbing or such. That combined with doodling. Where it appears to be directly on the primer, not on the finish coat of paint it seems to imply that this was done during construction or an overhaul, rather than while in active service.