While I was waiting for my neighbor, an electrician, to get home I went to see what would happen if I unplugged the dryer. The washer and dryer are in a closet that is not much bigger than they are. You can't just pull them out of the closet (as I found out) since the water and power lines are not long enough for that. I was able to pull them out enough to create a space behind them. I lowered a small chair down there with a belt, squeezed over the top of the washer and dryer (they are stacked front loaders), and got down on the other side. Unplugging it did absolutely nothing, but now I know how to get back there. This will be useful in a real emergency someday I am sure.
My neighbor was able to quickly determine the problem. The power cable was flakey (and was too small anyway) at a previous splice point. We re-spliced it and power is now fine. It took him all of about 10 minutes to locate the problem. It was actually pretty easy it was hot and steam was rising from the old splice point. The neutral on one of the phases had finally come apart. Turing the 2 phase dryer on provided a neutral path for the broken phase. The previous electrician never did figure this out. I even suggested the cable might be the problem and we should just replace it. He thought that would be a waste.
My neighbor is going to help me replace the cable with one that can safely hold 60 amps and the can be disconnected more easily. It will also go from the meter to the stern where the barge circuit breaker is; the stern of the barge is nearest the meter. The cable currently goes from the meter, along the dock to the bow, under the water, into the boat where it runs back to the stern and into the box. The new cable can be about 20 feet and have plenty of slack. The old cable is at least 100 feet.