In Reply to: Re: Moto-Tug Serial Numbers (BNO 40 XXXX) posted by Jim.UT on December 20, 2009 at 20:27:05:
If the Navy system was the same as the Army, the serial number is associated with when the unit was ordered, and assigned in a block of numbers equaling the total number of units ordered, not when it was made. Usually, the numbers were assigned to a particular unit sequentially, and the most recent unit had the next highest serial number. In this case, the order was approved by the Navy in 1940, and the tugs could have been manufactured at any time after that approval. Thus, a tug made in 1941 or 1942 would still have a serial number of BNO 40 XXXX, but the XXXX number would be higher as time went on.