Crane Institute of America

Seeing Cranes Everywhere

Wood CraneLOWRESA wooden girder bridge crane that could have been manufactured around the turn of the last century was spotted by a CIA instructor while on vacation. Shelburne Farms VT, a model for sustainable farming, once had horse drawn carriages that were used to transport guests to their inn. When these carriages needed repair the body was lifted off the undercarriage using a wooden girder, top running, and dual drum, manually powered and operated bridge crane. Ropes were reeved over two large wooden sheaves, one controlled bridge travel and the other controlled hoisting. The large diameter sheaves provided the leverage required to lift and move the carriages. Two wooden hoist drums, one on each side of the carriage, were used to lift the carriage body; the holding brake or dog manually engaged one of the sheave spokes preventing it from turning. It is not known who designed and manufactured the crane.  VT was home to many early inventors including the Fairbanks Brothers and Frank Strong who invented scales for weighing large objects. This crane would be typical of other engineered products they would have made with available technologies of the time.

If reliability is a key factor and the crane does not have to operate often or quickly nothing is more reliable than manually operated. The pump room crane in the City of St Petersburg water treatment plant is probably 100 years old and the ultimate in reliability. It has manual bridge and trolley travel where the operator pulls the chain in the direction they want the crane to travel. It has a 2 speed manually operated wire rope hoist. By pulling the chain on a large sprocket the hoist moves fast and by pulling the chain on a small sprocket the hoist moves slowly.

http://www.shelburnefarms.org/