9/28/2022
Things down on the Saco River are looking up, literally, as the 110,000-pound runner was recently hoisted out of its position in the dam and moved out of the housing. It and a handful of other parts are now prepared for off-site testing, machining, and alignment while the crew continues working on some of the smaller parts.
Working alongside MasterCraft and HydroTech, our crew of millwrights, welders, carpenters, and laborers started the project in mid-August and are well on their way to replacing the runner seals. In the past month alone, they have removed the oil head, excitor, upper guide bearing, thrust bearing, upper bridge and rotor. Next up is removing the lower bridge and continuing down until they reach the runner seals.
With everything on schedule, these guys are setting themselves up nicely to have another happy customer by the end of this project. Well done!
8/25/2023
It had been nearly 20 years since the last time this generator had been ser-viced, so it’s been no small task for Phil Lacy and his mechanical guru crew to tackle. They have been busy bees these past couple of weeks, with some major moves happening on the replacement of key components.
Their first task was to disassemble the rotor enclosure that has housed the piece since it was removed last year. After doing so, Prime Electric arrived on site to do a thorough cleaning of the unit and prepped it for reinstallation. Westbrook, ME-based Bracket Machine returned the wicket gates to the site and those were rein-stalled as well as the head cover be-ing replaced to hold all of gates in place. The outer head cover was then installed in preparation of the refur-bished Kaplan runner being moved into the powerhouse when it arrived.
The guys were able to receive the shaft on Saturday 8/19, but the runner was delayed until Tuesday 8/22. When the runner did arrive, it was no small feet to move it down the steep embankment to the powerhouse, but the guys and truck 23 (24’ flatbed, dubbed “an oldie, but a goodie” by PM Ben Thone) were more than up to the task. Even with this small delay, the inner head cover and runner have since been installed, with the shaft and operating rod to be installed early next week.
With the station projected to start generating power by December 1st, the team is on the path to success!
12/22/2023 (Completion)
Two weeks ago, the guys who had been dealing with the Cataract hydro-turbine replacement got a welcome sign of getting the project that much closer to completion — running the unit at 100% load!
Because this mark was reached, the crew has been able to pack up and demobilize, leaving Peter Poor and the Fish Passage crew with a little less company.
However, no project comes without some kind of hurdle to overcome, and Cataract is no different. In this case, the unit back-fed some of the electricity and caused some of the electrical systems to fail and become unusable. This certainly throws off the date in which we can finally say, “job complete.”
Once those electrical problems are fixed, the unit will be ready to produce power to the grid and the station can begin to monitor the unit for any vibrations. Those measurements can then be used to calculate the balancing the unit will need in order to perform at peak efficiency. The balancing will reduce the wobble of the unit, as even the smallest amount of displacement can create the most devastating of effects on the unit, or more…
The balancing will certainly come with challenges of its own, as the additional weight cannot be slapped on anywhere or the risk of cavitation will increase dramatically. If cavitation does occur, the efficiency and power output of the unit will be greatly reduced until rectified.
In order to properly balance the unit, the team will need to return to the site at a future date and interpret some of the measurements and calculations made to determine how much and where the additional weight should be placed on the runner (see picture).
While the job is still technically not complete, it’s more than appropriate to acknowledge the work the crew has done with a quick excerpt form project manager Ben Thone:
“This was a long, hard project — no doubt about it. Those who endured through the hurdles at this Brookfield site are worthy of significant praise. Job well done.”
