Help my Grandfather find an old film

I am trying to help my grandfather find a movie. This is second-hand information.

He knows the film is old saw it as a young man. Definately pre-1970
He thinks the movie is Black-and-white

Basic plot:
Some soldiers need a place to hide and go into a bunker. (update: might not be soldiers it could be just people) The bunker locks behind them. They are in the dark.
Bunker turns out to be a huge storage area (maybe German). With tunnels. There are a lot of food, candles, and even some bike inside.
He remembers they raced the bike in it, there was a huge circle they could do it in.

He remembers that the candles started to run out.

And that is it.

Any help on trying to find this movie for him, would be greatly appreciated.