Drivers, when arriving at the bridging site were also trained to drop their loads of bridge parts using this same layout.
With LOTS of training, Engineer Units could build a typical Bailey Bridge very rapidly, even in the dark, even “under fire” from the enemy.
Engineer units regularily practice “speed building” by holding BRIDGE GALLOPS. Engineer units, would take turns building a bridge, the next unit moving over it, building another bridge, and so on. This method of training developed the speed necessary to build these bridges as quickly as possible.
From the table below, a typical 80 foot single-single bailey bridge could be built (with manpower only) in TWO hours
https://archive.org/stream/ost-military ... 2/mode/1up