R.H. White, Auburn, Mass. is a third generation family-owned construction company celebrating over 80 years in business this year. In addition to company sponsored special events planned throughout the year, R.H. White recently demonstrated the quality, innovation and capability that has brought the company to this heralded anniversary with a major pipe bursting project in Northbridge, Mass.
According to Project Manager Matt Gibbs, the project for Northbridge was significant for several reasons. He said, “The bursting project really represents what’s important about R.H. White. It was a challenging project that required skill, good planning and quality workmanship. On the other hand, it shows the company’s commitment to growth and new technology as it was our first pipe bursting project.”
In order to replace the over 3,100 linear feet of 12-inch cast iron main, R.H. White chose a 14-inch diameter Grundocrack Koloss pneumatic bursting system from TT Technologies, Aurora, Ill.
R.H. White was founded in 1923 by Ralph H. White. The company has survived the Great Depression and numerous recessions to become one of the largest and most accomplished contractors in New England. Beginning in ’23 as a primarily underground contractor, R.H. White expanded into building and mechanical construction. The building and mechanical divisions of R.H. White allowed the company to construct anything from a water and wastewater treatment facilities to medical clinics.
It’s the underground utilities division that is considered the cornerstone of the company. Starting over 80 years ago with horse driven trenching equipment, this division has grown and expanded to make R.H. White one of the foremost utility contractors anywhere. That skill and ability would be put to the test for the bursting project in Northbridge.
Each year cities and towns throughout the United States are seeing more administrative consent orders regarding the reduction of inflow into sanitary sewer systems. This was the situation faced by the city of Northbridge. Under the guidelines of an administrative consent order, the city would not be able to issue new building permits for a subdivision project until inflow was reduced to within certain guidelines. Replacing the 3,100 linear feet of trunk main along the Blackstone River was the key to this happening.
However, replacing that section of main would be an extremely difficult task. A traditional design and build project would have taken years to develop so the city looked to R.H. White for a solution.
Gibbs said, “Well we took a look at it and saw how difficult it was going to be. It was 3,100 feet of 12-inch cast iron that went through a swamp, beside a mill, by a railroad track and along a river. Actually much of the line ran directly underneath a historic cart path between the Blackstone River and the Blackstone Canal. During the early 1900s, the canal was used as a shipping lane and horses would pull barges through the canal while walking down the path. That’s also the time that they installed the cast iron sewer main. So there were some historic considerations as well. We needed a construction method that could operate within these parameters. We looked at trenchless pipe bursting.”
TT Technologies pipe bursting specialist Ric Micelotta said, “A traditional open cut project probably wouldn’t have succeeded in this setting. The working area was tight with only 25 feet on either side of the main at places. There were historic and environmental concerns as well. So preserving the area was a priority. Plus the line was undersized. Trenchless pipe bursting was a good choice for this project because it not only keeps disruption down to a minimum, it allows you to upsize.”
The project at Northbridge included bursting and replacing 3,100 feet of 12-inch cast iron sanitary sewer main with 20-inch High Density Polyethylene (HDPE). The R.H. White crew divided the project into sections, running typically from manhole to manhole. Certain provisions needed to be made before actual bursting work started. Gibbs said, “This was the main trunk line that fed the wastewater treatment facility so we needed to run a complete bypass. We used two 4-inch pumps to power the system. The bypass also needed to be operational 24 hours a day, throughout the project.”
Once the bypass was established, crews began bursting. Runs varied in length from 150 feet to 650 feet. The 14-inch diameter Koloss was equipped with a 24-inch diameter rear expander and a friction fit guide head. According to Micelotta, the guide head increases the tool’s effectiveness when bursting cast iron. He said, “The guide head helps out in several ways. First, it creates additional tool length allowing the tool to really get up inside of the pipe and break it from the insides. Second, it helps guide the tool through the existing pipe. And finally cast iron has a tendency to break into shards, in front of the bursting tool. The guide head helps protect the winch cable from the shards of cast iron.”
The bursting tool was guided through the host pipe by a 20-ton variable-speed, constant-tension dual-motor Grundowinch. In addition, R.H. White crews ran bentonite throughout the project to overcome difficult soil conditions that ranged, according to Gibbs, from sandy gravel to “muck.” Bursting times varied per the length of the run. Gibbs estimates, between set up and bursting, that crews averaged 200 feet or more per day, until they encountered the railroad track.
An Added Twist
One particular section of old pipe ran underneath a set of railroad tracks and posed a unique challenge. Gibbs said, “The history of it goes back to the early 1900s. There was no real easement there that was legally binding today. When we started on the project we figured the town of Northbridge would have to apply for a new easement underneath the railroad tracks. Initially we suggested bursting that section, but that idea was not accepted by the railroad. Then we came up with the idea to ram a casing around the existing pipe. This technique was agreed upon and fell within the guidelines of the existing centerline easement. We believe this solution saved everyone a year of negotiating a new easement.”
With the plan approved the R.H. White crew moved in and set up for ramming. The crew used a 14-inch Grundoram Koloss (the pipe ramming “brother” of the GrundocrackKoloss pipe bursting tool) to ram the 50-foot section of 36-inch diameter steel casing under the tracks. The ram was completed on grade, between two manholes, with perfect pitch and alignment. Crews then set to work removing the spoil from the casing as well as the old pipe.
According to Gibbs ramming was the perfect solution. He said, “Ramming the casing not only satisfied the easement issue, it satisfied other conditions of the project. There needed to be a sleeve around the new pipe. Once the casing was cleaned out, we were able to insert the new pipe without any problem.” The ramming was another first for R.H. White.
The Northbridge bursting project represented a major accomplishment. According to Micelotta, R.H. White’s performance deserves accommodation. He said, “The degree of difficulty on this project was very high. There were challenges everywhere. Upsizing a 12-inch line to 20 inches is always challenging, let alone in these conditions. Add to that the fact that this was not only R.H. White’s first bursting project, it included their first ramming project too, it really speaks volumes about the quality and competence of their crews.”
Gibbs said, “This was a first for the company. It was a pretty big undertaking if you look at the fact that this was 20-inch. We weren’t starting with an eight-to-eight. We did twelve-to-twenty. And I don’t believe anyone in this area has really tackled a bursting project of this length or this size. The project allowed us to expand our product offering and our capabilities. And that is always a positive thing.” Gibbs added that he looks forward to the possibility of more bursting projects in the future.
by Jim Schill
Trenchless Technology, September 2003