Allied Power Products, Inc. (APPI) recently designed a custom traction drive hoist system for the Washington Department of Transportation (WSDOT) to assist in removing paint from the suspension wires on the Tacoma Narrows Bridge.

After struggling to make an existing twin winch system work properly when raising and lowering a paint stripping tool, WSDOT site supervisors turned to APPI for help.

Specifically, WSDOT wanted to end the practice of cutting the wire ropes on the hoists each time they moved to a new suspension wire and at the same time make it easier and safer for workers to make each move.

After reviewing the application, APPI produced a purpose built traction drive hoist that uses a single, continuous loop of wire rope to make moving it quick and easy. 

Weighing 70 lbs, and with overall dimensions of 22” X 23” X 14” high, the prior problems with getting set up to work on a new suspension wire have been eliminated.

Equipped with a ¾ hp AC motor, the unit provides a maximum of 750 lbs of line pull at a speed of 16 feet per minute.  A hand held pendant was provided for operator convenience.