The combat engineers, who do all the dirty work when it comes to destroying enemy fortifications and clearing mines, often get the short end of the stick when it comes to new equipment. This has something to do with the (false) concept that the engineers are "support" troops, even though they sometimes provide this "support" in front of friendly infantry, while getting shot at by the enemy (clearing mines, for example.) One piece of heavy equipment the engineers like is special engineer vehicles. One is the mobile bridge (AVLB) that can put a bridge across a gully or stream and allow vehicles, including M-1 tanks, to cross. But constantly changing priorities on building a new AVLB resulted in two AVLBs being service; the Wolverine and the Razorback. That would not be a big deal, except when the dust had settled, the bridge itself turned into two different pieces of equipment that could only be used on one AVLB vehicle (instead of being interchangeable). To try and deal with this problem, the Wolverine will only be used in division engineer battalions, while the Razorback will be used with engineer battalions at the corps or army level.