Photos 3 & 4
I took many photos of the submerged remains but the two that I think are most interesting and perhaps the first time ever photographed are Photos 3 and 4. Photo 3 shows a sliding wood input gate in the arched cavern at the bottom of the impounded Northwest Park side’s stone abutment. When this input gate was opened, it allowed water to flow in the penstock and turn the turbine/generator remains seen in Photo 4. A penstock is simply a conduit to channel water. With a 27-foot head of water, one can imagine the tremendous and efficient hydraulic force that went through gate to feed that turbine. It was a remarkable engineering accomplishment in its day.
Photo 5: Oil City dam under construction, 1891. WHS collections 2009.1.9.
This 1891 view shows the dam under construction. It was taken slightly downstream from the dam’s abutment and reveals the logs and trap rock that made up the dam and impounded the water.
Photo 6: Abutment remains, 2009. Photograph by author, 2010.58.31.
I took this image in 2009 slightly upstream from the dam’s abutment. It shows that the logs and trap rock are still holding up well. The submerged logs are over 120 years old and well preserved. The trap rock used possibly came from the abundant basalt quarries on nearby Metacomet Ridge.
At the conclusion of the Rainbow Dam’s repairs in 2009, the great watershed of the Farmington River soon refilled the Reservoir and now only the Oil City stone abutments are visible. Submersion will help preserve these remains. Perhaps in many years to come the Reservoir’s impounded water will be again drained and the thrill of seeing the remains between the abutments will once again be a treasured event for industrial archaeologists.
Rainbow Reservoir can be reached by a short hike in Windsor’s Northwest Park or by boat from a state boat launch in the Rainbow section of town.
By Jim Trocchi, volunteer.
Top image: the Oil City dam before 1897. WHS collections 19184.108.40.206.
- Roth, Matthew. An Inventory of Historic Engineering and Industrial Sites. Society of Industrial Archaeology, Houghton, MI, 1981.