Up shit creek without a paddle? Why not use a Zagreb Excavator, the perfect way to paddle that canoe, or in this case, a barge. This must have been a makeshift situation, because this can't be safe enough for everyday locomotion.
Think of it this way: excavators similar to that weigh around 35-40 tons. I wouldn't want to be putting even more downward pressure on that sucker while floating on a barge. Personal safety aside, hope this guy has good insurance, because an excavator can cost more than $300K.
Zagreb Excavator [Neatorama]