Woonsocket Falls Dam
Woonsocket, Rhode Island

Work at the Woonsocket Falls Dam involved overhaul of gate operating machinery to include: disassembly, cleaning, inspection, reassembly, lubrication and testing of all gears, bearings, shafts, couplings, and motor brakes, and replacement of all seals and gaskets with new. Painting and refurbishing of tainter gates including replacement of gate seals, seal supports, seal retainers and all attachment bolts; replacement of wire rope anchor plates; replacement of wire rope and rope anchors including all sockets, clevises, and adjusting bars; disassembly, cleaning, inspection, reassembly, and lubrication of gate trunnion bearings; and painting and overhaul of mechanical gate operating machinery. Work also included: painting of all service bridge superstructure elements (beams, diaphragms, bearings) and railings on the deck, painting of all catwalk and machinery platform support elements; removal and replacement of all catwalk and machinery platform hand railings.

This project required design and construction of a cofferdam system to block river flow in order to adequately dewater each tainter gate sufficient for conducting all necessary work associated with the repair, rehabilitation, and inspection of each gate.  A unique steel sheeted cofferdam was designed for this purpose.  The cofferdam was supported by a single waler that spanned the gate opening above the water line, and the bottom of the sheets were anchored to an existing concrete slab by use of high strength bolts epoxyed into the concrete.  This work as well as the removal of stones and debris in front of gates in order to install the cofferdam system was accomplished by divers subcontracted for the work.  All of the cofferdam construction was accomplished with a crane mounted on a sectional barge located in the river upstream of the dam.  Work also included removal, disassembly, cleaning, and inspection of the tainter gate machinery for the 4 gates.  Machinery includes: enclosed speed reducers, worm gears and herringbone gears, open gear reducers, shafts, couplings, and brakes.  Our scope also required us to replace all lubricants, gaskets, packing, and seals; replace all rubber gate seals, steel support bars and angles, steel retainer bars and attachment bolts; replace all wire ropes, sockets, cable anchor hardware and welded steel cable anchor plates.  Additionally we were required to disassemble, clean, inspect, and reassemble 2 trunnion bearings on one of the gates.  Upon inspection of the gates in a dewatered condition some deteriorated steel was discovered and repaired prior to painting.