The dam over the Winooski River is being rehabbed: the old shot concrete surface has to be removed using concrete saws and jackhammers.
Some projects require a little bit extra. Extra knowledge, extra skill, extra attention. It’s for that very reason that Pizzagalli Construction Company created its “Special Projects Division.”
The special projects division of Pizzagalli focuses on niche areas such as power generation, oil and gas production, and other areas that require a high degree of expertise, and enables the company to focus on a wide range of various sized projects, which include areas like waste water treatment plants, semi-conductor plants, hospitals and schools.
In July 2010 Pizzagalli began a project to resurface the exposed 2,000 sq. ft. (186 sq m) of a dam’s surface for the Green Mountain Power Corp. in Middlesex, Vt. This project involves the repair and resurfacing of the original dam that was built for the power corp.’s hydroelectric plant. The facility was originally constructed in 1928.
The dam, which spans the Winooski River, is approximately 55 ft. (17 m) high; the length of the spillway (dam) is 280 ft. (85 m). It received a facelift with a new surfacing of shot concrete in 1980, but the forces of erosion, freezing and thawing have much of the new surface disintegrating.
Approximately 6 in. (15 cm) of old shot concrete resurfacing must be removed, plus 4 to 6 in. (10 to 15 cm) of the original structure, to make way for the new resurfacing. When completed the new dam surface, made up of 80 cu. yd. (61 cu m) of concrete, will be constructed from cast in place concrete reinforced with rebar.
To remove the shot concrete facing that had been applied to the surface of the dam in the 1980’s Pizzagalli is using concrete saws and jackhammers.
“When we were originally studying how to approach this job one of our thoughts was to use remote controlled mini excavators with hydraulic hammers to break away the shot concrete surface. However, by the time we factored in the costs of stronger scaffolding to support the excavators and the rental cost for renting the highly specialized remotely controlled hydraulic excavators with hammers, from a cost standpoint we were better off using laborers with handheld power saws and jackhammers,” said Justin Reed, project manager.
“We have run into a couple of challenges from the start with this job, the first of which was bidding the job itself. The job was bid in March and with the spring runoff and heavy rains there was several feet of water flowing over the dam, obstructing the view of much of what we needed to see to prepare our bid. We did the best we could with the limited visibility, fortunately for us we hit the mark on what was needed to be done and the project is working out just fine for us.”
“The other challenge was getting the scaffolding generators and other needed materials down to the base of the dam and removing the demolition debris back up to the top as we broke loose the shot concrete surface of the dam,” Reed continued.
The base of the dam, where most of the work is taking place, cannot be accessed by any type of equipment — all materials, tools, etc. have to be lowered from the top of the dam. Adding to the challenge was the fact that the top of the dam was not easily accessible to bring in the type of crane necessary for these types of picks. Any equipment going through the dam had to be transported through a tight residential area, through a road that in places is no wider than 13 ft. (4 m), and had large trees growing in very close to the sides of the road.
“It was obvious that a crane was the tool to use, but finding a crane that could access the job site and give us the amount of reach we needed was the challenge. In most cases you would use a lattice boom crane, but having to transport the crane through a small residential area and then down a winding overgrown path that only offered 13 feet of clearance was a challenge,” Reed said.
“Our company has a long standing relationship with Woods CRW and their crane experts in Burlington, Vt. They worked closely with us to identify that the specs of the Link-Belt TCC750 could accomplish what we were looking to do. The telescopic boom and the adjustability built into the track system made this crane the obvious choice.
“Transport into the site was relatively easy and setup was a breeze. If we had had to use a lattice boom crane there would have been no place or room to lay the booms down and we would have been looking at about four loads to bring it in versus just two with the Link-Belt TCC750. From the tip of the extended crane to the bottom of the dam is about a 200 foot drop and we are bringing materials in and out all day. The entire setup works flawlessly.”
Link-Belt TCC750 Fits the Bill
With an adjustable track width the Link-Belt TCC750 can be contracted to a width that does not exceed 11 ft. 5 in. (3.5 m). The total length of the crane, when ready for transport, is 45 ft. (13.7 m) and 10 ft. 9 in. (3 m 22.9 cm) high. The entire crane can be transported in two loads.
With the configuration at this site the crane has 150 ft. (45.7 m) of boom and was handling 4,000 lbs. (1,814 kg) loads at more than a 100-ft. (30 m) radius.
The Link-Belt TCC750 used on this project:
• Has 115.6 ft. (35.2 m) of main boom and extends another 35 ft. (10.6 m) with a lattice fly.
• Has all hydraulic pilot operated controls
• Because of the telescopic boom, the boom completely retracts to the length of the crane (approximately 45 ft. [13.7 m])
• The width of the crawler tracks can be extended out and retracted back in from 17 ft. (5.1 m) to 11 ft. 5 in. (2.6 to 4.3 m), making the crane transportable into tight spots. Load charts are available for 11 ft. 5 in., 14 ft. 11 in. (4.3 m 2.6 m) and 17 ft. of track width.
Pizzagalli Construction Company
Pizzagalli’s corporate headquarters are in South Burlington, Vt.; it also has offices in Portland, Maine, and Garner, N.C. The 100 percent employee-owned company handles as much as $300 million worth of construction projects a year, most occur up and down the east coast, east of the Mississippi River.
For more information, call 802/651-1378 or visit www.pizzagalli.com.
Wood’s CRW Corp. is a customer service driven, heavy construction equipment distributor founded in 1961 in South Burlington, Vt. It is the Link-Belt crane distributor for New England and New York. (Excluding New York City and Long Island).
For more information on the TCC750 Please, call 802/658-1700 or visit www.woodscrw.com. CEG