They are small trailers with a panel intended to be fed with a 4 wire single phase feeder.
Unless some "illegal" modifications are made, the frame of the trailers as well as all grounded receptacles will be "floating" as it will not be bonded back to the MDP via a grounding conductor.
In other words, in a worst case, the frame of the trailer could become energized at up to 120V to ground.
This doesen't even take into account the places that the bare "neutral" conductor comes into contact with the lightning protection conductor as well as the 1/2" EMT or anything else that it may inadvertantly touch providing more than one path to ground for the neutral current etc...
Truly unbelievable!
