How did mobile X-ray units work?

A tent was attached to the back of a van with a table where stretchers could be placed and the X-ray machine was set up next to this table. It was linked to the vans engine which powered the X-ray machine, while the equipment for processing the X-ray film was set up inside the van Though mobile X-ray units weren’t as efficient as static units they wee useful in identifying shrapnel, bullets and preventing wound infection