The 1,480 KW Collins project located on the Chicopee River between Ludlow and Wilbraham, MA is an example of constructive reuse of a low-head, breached mill dam. Swift River Company searched among Europe's most innovative turbine manufacturers to select 2 ESAC bulb turbines designed and built in France. The advantage of the bulb for the Collins site is that bulb require no powerhouse; controls and switchgear are located in a small building well above the river flood levels and therefore the full crest length of the dam is available to spill water in case of flood flows.
In flood Collins bulb turbines as safe and continue to generate, flashboards are lowered
The site was hard to permit because houses were built in the flood plain upstream after the dam was breached. However, by using the existing forebay as an additional spillway on the right side of the river and also designing three 4 foot high sections of hinged flashboards that are lowered during floods, the site was approved by the local conservation commission, the state dam safety agency and by federal fish environmental agencies. For 35 years Collins has operated above its design output level and few unplanned outages.
Key Benefits of Bulb Turbines
Bulb turbines where both the turbine and generator are housed under the water behind the dam are ideal for this application because:
The hydraulic operators lift the hinged flashboards to 4 feet, but could be replaced with inflated runner crest gates
Preparing to remove the bulb top so the gearbox can be extracted from the nose cone.
Installing the refurbished gearbox after 45 days at Electro Mechanics in Springfield, MA
The top of the bulb is the last component for the crane to lift back to the flume location in the river
Swift River Hydro Operations has skilled mechanics and operator who have worked on SRC's turbine generators for years. Preventative maintenance is a key to sustaining the high availability record that SRHOCO is renowned for achieving. In 2011, SRHOCO rebuilt the control building with a new roof, insulated siding and air conditioning to limit humidity.
Bulb turbines located in dam with 3 sections of hinged flashboards