Reminds me a little of some jokes played on young officers on joining their cavalry regiment. Troop sergeant sends the young fellow newly arrived and keen to muck in with the chaps off the tank park straight to the Quarter Masters dept for a 'Long Weight' (near universally translated into said young officer standing around a stock room for several hours whilst the QM staff reassure him that he's going to get a long wait).
Others I've heard included sending an officer off for a can of camouflage paint; a can of tartan paint; a 'new bubble please, sir' for the spirit level thing that levels the gun during checks, etc.
My firm favorite, however, involves an unsuspecting soul being placed at the end of the main armament barrel, whereupon he's asked to take the weight of the gun as it's depressed by a gunner inside using the manual controls (ie, tank not on; done using hand cranking). The brief to the young 'un is that they need to wiggle the gun in order to get the 'Giggle Pin' out for cleaning. Slowly the gun is depressed, and the officer shoulders more and more weight until he has to call for help, at which point the Giggle Pin is released.
All very silly.