I have two cars transporting submarines.
Both use smallish toy submarines.
My next project is to build an Reynolds Aluminaut experimental deep diving sub used to recover items from the sea floor. The real sub is 51ft long and about 8 feet in diameter, not an unreasonable size to be carried by rail.
The Reynolds Aluminaut is made mostly from aluminum and I retired from ALCOA which bought Reynolds Metals several years ago. A similar sub was used to recover a lost H bomb in the cold war.
Charlie
Real Aluminaut sub now in Museum
Model of Aluminaut sub ( not my yet not built model ! )