R. Zoppo Corp’s work at the Woonsocket Falls Dam consisted of refurbishing the tainter gates, which included: replacement of gate seals, seal supports, seal retainers and all attachment bolts; replacement of wire rope and rope anchors including all sockets, clevises and adjusting bars; disassembly, cleaning, inspection, reassembly and lubrication of gate trunnion bearings; overhaul of gate operating machinery to include: disassembly, cleaning, inspection, reassembly, lubrication and testing of all gears, shafts couplings and motor brakes and replace all seals and gaskets with new. R. Zoppo Corp. acted as a subcontractor to Watermark, Inc. who oversaw our work along with a painting subcontractor.
We were required to design and construct cofferdam system to block river flow in order to adequately dewater each tainter gate so that we could conduct 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 using high strength bolts epoxyed into the concrete. This work, as well as the removal of stones and debris in front of gates to install the cofferdam system, was subcontracted out to a diving team. All of the cofferdam construction was accomplished with a crane mounted on a sectional barge located on the river just upstream from the dam. Our scope of work also included removal, disassembly, cleaning, and inspection of the tainter gate machinery for the four (4) gates. Machinery included: enclosed speed reducers, worm 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; and replace all wire ropes, sockets, cable anchor hardware and welded steel cable anchor plates. Additionally, we were required to disassemble, clean, inspect and reassemble two (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