Honking big machine

A Honking Big Machine, or HBM, is a creative diversion of the engineers of New Babbage during the annual overhaul and maintenance period known as the Oiling Festival. A HBM is a device of dubious purpose. It is large, has moving parts, fits on a 24x24 meter base, has not more than 100 prims, and may or may not actually honk. 
History:
The HBM competition was initiated by Aeolus Cleanslate for the 2009 Oiling Festival.