4/21/2023
It couldn’t come soon enough for the weather-hardened crew at Middle Dam to finish up for the winter season and turn their taillights to the project.
This winter’s scope of work was in the Sluice Gates area, consisting of all new upstream concrete aprons, a new concrete pier wall, replacing a wooden gate, installing new bridge sub-structure steel, almost 70’ of new concrete pile cap, miscellaneous steel plating work, and more. Efforts by Todd Leighton helped finish off the season by installing 40,000-pounds of new hemlock boards and timbers for the new downstream apron where we installed the new gate, as well as installing temporary stop log slots in the South Spillway to prepare for next winter.
After working hard through brutally cold temperatures, to get as much done as possible during the lake drawdown, the crew was able to get themselves into a position to head out before the ground completely turned to mud. It’s without hesitation to say, we’ll be letting the road dry out before coming back for the next phase of construction this summer… and maybe for some fresh air and fish too.
A job very well done this winter folks. We’ll be looking forward to see what you make of the project in the coming summer! Check the back page for some pictures on the project’s progress.
6/16/2023
After a spring hiatus, we return to Middle Dam this summer for another phase of the multi-year rehabilitation project. This summer we have a good deal of concrete work to perform. For a good portion of the season we’ll be focused on the south side apron and wall. Our Middle Dam crew will also have work on Pier #4 & #5 upstream and downstream ballast. We’ll spend some time reconstructing the downstream end of Pier #2, and we’ll also work on an apron extension for sluice gate #3, before vacating the site in early fall.
9/1/2023
Over the past few weeks, the crew at Middle Dam has been performing a couple of distinct jobs on the dam.
Approximately 30-ft of pier on Middle Dam’s Pier 2 (not to be confused with a job at BIW of a similar name) was removed its end, as result of rot compromising the supporting logs. Between Piers 1 and 2, timbers were laid cross-hatched with rocks in between the layers (a.k.a., timber cribbing) for the apron, in preparation of laying down the final stripping. This will ensure the water moving through the dam will travel far enough away from the base of the dam to eliminate the chance it might later undermine and compromise the structure.
The south spillway also received some attention, as more rotting timbers were discovered at various parts along the pier wall. Those were removed and replaced with wood blocking and shims for the time being. The long-term plan, however, is to inlay concrete blocking to refill the gaps left behind and increase the structural integrity of the pier’s wall.
After the concrete is placed and winter begins to set in, the crew will be able to turn their attention to the old wood bulkheads. Those are scheduled to be removed and replaced with new steel gates that will help to make the dam operate more effectively.
11/17/2023
As some of you know, this rehab project has been multiple years in the process and is now into the second half of the scheduled work. This summer, the crew replaced the old downstream aprons between piers 1 and 3 with fresh timber cribbing and boards. The project then moved over to pier 3, where the crew made a beautiful concrete placement on the south side. Last week, you saw the pictures of the crew’s work to make the placement on the north side of pier 5, which yielded another great product, despite the crew needing to improvise to set the forms.
Another challenge was to get the concrete to the right spot. The bull work of Tucker Chute and Cam Mason to wheel loads of concrete, proved to make quick work of the pour. Below the gate house, Todd McKellick and Leon Ouellette ensured the concrete found its way into every nook and cranny of the form, with a baby-butt smooth finish on top. Matthias Mason also played a key role, making sure communication was clear and the concrete wasn’t delivered below too fast, as well as jumping in to deliver 5-gallon buckets of concrete down to Leon and Todd as the concrete approached the top of the form.
Trailing behind this concrete crew and working diligently along the spillway between piers 2 and 3, were Jacob Parise and Dan Pelletier. These two were tasked with cutting off the protruding end of the bolts anchoring the steel plates lining the spillway walls to the metal bracing that was placed inside of the existing piers. After the bolts were cut off, these two then welded the remaining exposed bolt to the steel plates to ensure there would be no leakage and provide top level integrity.
Away from the dam, Del Bryant prepared the nearby laydown yard with load after load of steel beams and piping that will be used when the crew shifts over to the next phase of this project in the winter. The plan is to change over the wooden baffle wall to steel plates to have a stronger and longer-lasting seal to force the water through the deep gates. This work is expected to begin in mid-December as long as the lake water levels are low enough to allow work to commence safely.
A job is never complete without a leader, and we want to take a moment to recognize long-time Site Superintendent, Paul Walker. His steadfast dedication to safety, quality, professionalism, and integrity, as well as the professional development opportunities he provides to those who work around him, is beyond reproach. Paul, thank you for over 38 years of service to the company, the countless memories made, and dozens of jobs you have seen through. Here’s to another one!
3/22/2024
Things were very busy onsite this past week with the rain coming down, snow melting, and water coming up. Even with these pressures, Dylan Wike and Paul Walker have been integral in guiding the crew to get this done.
Rewinding back to the thick of winter, the crew started out in the Shoal Gates area replacing the baffle wall at each of the six gate locations. The existing structure consisted of stacked, pre-cast concrete logs, situated so that when the gates are closed, water can be held back above the gate elevation. The concrete logs were deteriorating, leading to a lot of leakage. A monorail system was installed to hoist each of the concrete logs out and then placed into a cart to get them out of the gate house for disposal. Steel plates with channel iron supports were then welded in place, to act as the new baffle wall.
Moving into mid-January, when the lake was finally low enough to install stoplogs in the North and South Spillways, a 12-week work window was opened and so began demolition of the six existing wood bulkheads and their aprons — three in each spillway at opposite ends of the dam. Once demolition was completed, piezometers (an instrument used to measure the pressure of groundwater in dams, pipes, and other conduits) were placed and embedded with steel and rebar preparation for concrete. A placement of approximately 1,800-square-feet was made to create the new 13”-thick concrete apron. As soon as the concrete was cured enough to walk on, the crew started on the installation of the four new steel bulkheads, and demolition of the rusty steel plating on the abutments, which will also to be soon replaced. Simultaneously, preparation and placement of a new concrete pile cap in the South Spillway began, as well as the new stoplog slots and bridge support steel in both spillways. To no one’s surprise, most of the work involved design revisions and onsite ingenuity, as most of the existing conditions were not as expected.
Luckily, the concrete portion of this winter’s work scope has been completed before the unseasonably warm weather we’ve had for the beginning of March turned the 16-mile, dirt access road into Middle Dam to mud. Another result from the warm weather and rain, was a hit to the overall work schedule, as the need to button up everything 3 weeks early and turn two of the old bulkheads slots into operable gates, as they were not scheduled for installation until the end of March. Fortunately, after three years onsite, all of the extra material to build temporary gates to put in the gate slots was onsite and could accommodate the lake to coming up, keeping the crew ahead of the drastically accelerated schedule. The focus will now be on completing the plating and structural steel at higher elevations from scaffolding, as the water rises from below. It seems inevitable this will add another winter of work at Middle Dam, but the plan is to stay onsite and finish up what can be done through the end of March, until we’re back to kick off the next phase of the project early summer.
6/28/2024
We’ve been quiet with the Middle Dam crew as of late, but that doesn’t mean they haven’t been busy. In the spring, they spent some time replacing the roof of the gatekeeper’s house, and, lately, they have been working on the concrete for the aprons and walls of the downstream deep gate.
Last week alone, a total of 70-cubic-yards were placed in three of the five apron sections, which is the largest placement (to date) on the project. For the placement, another prime example of teamwork was on display, as Project Managers Tom Norton and Peter Poor each sent some of their crew to the site — Middle Dam’s Project Manager, Hannah Gallant had the following to say:
We all were thankful to borrow some additional manpower from other jobsites for the day, which helped everything go smoothly.
This placement included the aprons adjacent to the piers, that will act as the foundation of the new walls that are now being worked on. Once the forms and rebar are set for those walls, nearly 100 cubic yards of concrete will be placed! Normally, the three hour trip from the concrete plant makes larger placements at Middle Dam difficult, but Shay Flagg’s smooth operating of the 300-ton Linkbelt crane, combined with the new 3-cubic-yard concrete bucket, should allow this placement to move right along.
Another large batch of concrete will make its way down Fish Pond Road to Middle Dam near the end of July, as the last two of the five apron sections will be placed, as well as two 50’+ wall sections. The consolidation of these placements is going to take a coordinated effort from everyone and call on the many years of expertise Site Superintendent Paul Walker to make this a success.
That will finish out the summer concrete scope, which will shift the work to installing two upstream pier noses (as mentioned earlier, these will be built in the Fab Shop), as well as finish up some replacing and securing some structural steel and preparing the stoplog panels for the upcoming fall-winter work scope in the upstream deep gate area.
