[The End 007]

You could make a construction chinook or something along those lines that flies out and lowers workers from a winch down over the constuction site, similar to the kind of casket things you have on the sides of tall buildings for window cleaners, it lowers down and allows them to work. That would avoid the problem of having to have either two dozers or a strange looking dozer that has to be amphibious. The only problem I foresee is that construction chinooks could then fly over to the enemy base being able to avoid all terrain and just get straight there.