- Replace 100 feet of deteriorated 3-inch cast iron sewer later with minimal disruption at a Radisson Hotel- Grand Rapids, MI
- Contractor: McDonald Plumbing Grand Rapids, MI
- Customer: Radisson Hotel- Grand Rapids, MI
- Equipment: Grundotugger Lateral Pipe Bursting System with Fusion Equipment & Hydraulic Power Pack, TT Technologies, Aurora, Ill
Major renovations don’t necessarily mean major disruption. That was the case recently for a Radisson Hotel in Grand Rapids, MI. Major renovation and upgrade work was being done to the public areas of the hotel including the swimming pool and restaurant. As part of the project, the hotel’s sanitary sewer lines were also evaluated. Experienced utility contractor McDonald Plumbing, Grand Rapids, MI was contracted to televise the lines within the restoration area, and provided rehab or replacement services if necessary.
According to McDonald Plumbing Vice President Scott McDonald the lines were in fairly poor condition. He said, “The drains were cast iron and the bottoms were completely corroded away. They needed to be replaced. The normal course of action would have been to saw cut open the floor and hand dig the entire sewer lateral and replace it. But we wanted to find a less time consuming and more economical solution.”
Open cutting the floor would have meant a tremendous amount of restoration. The area would need to be re-concreted and the floor cover would need to be replaced. This would not only add cost to the project it would add a significant amount of time as well. McDonald looked at several options before talking with pipe bursting specialist Scott Redman with trenchless equipment manufacturer TT Technologies, Aurora, Ill.
McDonald said, “A portion of the line ran under a large section of decorative concrete. The restoration of that concrete alone would have easily doubled the cost of the project. Plus, all digging in the hotel had to be done by hand. It would have been a large undertaking to dig up that entire section of pipe by hand. We had been looking at trenchless bursting equipment for quite some time and this was an opportunity for us to really put the equipment to the test.”
Redman said, “While every lateral replacement situation poses its own unique challenges, a trenchless rehab option is almost always preferable. However, many trenchless options are not applicable to lateral replacement. Pipe bursting offers a viable solution for lateral replacement. Even though the area for this particular project was undergoing restoration, digging up the floor and the concrete areas was not necessary. Trenchless pipe bursting was definitely the right method for this particular project.” McDonald and his crew used a Grundotugger lateral pipe bursting system from TT Technologies.
Pipe bursting is well suited for lateral replacement. It is capable of replacing relatively small diameter pipe and allows for increase or upsize of the original host pipe diameter. That fact alone is extremely valuable on jobs where lines are being replaced because of capacity issues.
Redman noted that improvements in lateral bursting equipment have made the method accessible to everyone from specialty to general contractors. Redman said, “The new lateral bursting equipment is very portable, but doesn’t compromise on power. It’s also easy to use. Both static and pneumatic lateral bursting systems can be easily transported in most pick-up trucks. They only require a minimal crew compliment to operate. And they really get the job done well. With the big push for lateral replacement, the timing of some of this equipment couldn’t be better.”
On The Job
The McDonald crew prepared to replace the 100 feet of 3-inch diameter cast iron lateral by digging launch and receiving pits. A small launch pit measuring 5 feet by 5 feet was dug inside the hotel at the end of a hallway. A slightly larger receiving pit was dug outside of the building. The crew rodded the existing line and pulled back the winch cable for the Grundotugger that was positioned in the receiving pit. At the launch pit, a standard direct bolt expander was connected to the first section of 4-inch HDPE.
According to Redman there are several types of methods used for connecting an expander to HDPE. He said, “The direct bolt method is very common in main line bursting, but can also be used for lateral bursting. For difficult lateral projects, a pneumatic piercing tool can be used to assist bursting operations from the inside of the new HDPE, behind a direct bolt expander. A quick grip type expander connection is also common in lateral bursting, but does not allow the piercing tool assist option.” After the expander was in place, the winch line was connected.
The crew then connected the hydraulic power pack to the bursting unit. According to Redman the hydraulic system is a very important part of a static pipe bursting system. He said, “A proper hydraulic system can mean the difference between success and failure in the field. The system needs to be capable of handling foreign material and other contaminants found at every jobsite. Plus the hydraulic power pack needs to produce enough horsepower to meet the challenges of bursting. An electro-hydraulic system is the best option for hydraulic power. A simple industrial hydraulic system with a sequence valve design doesn’t survive long in the field.”
After all of the connections were made, bursting operations began with the bursting unit steadily pulling the new pipe through the existing line. As a section of pipe was installed, another section of pipe was fused on. Because the launch pit was located inside of the hotel within close proximity to the front desk, space was limited and the McDonald crew needed to fuse the new pipe together in 10-foot sections while bursting.
Within an hour the new HDPE was in place with minimal disruption to the hotel hallway. The McDonald crew tied-in the new HDPE and made the hotel connection. After the new lateral was tied into the system, crews set to work restoring the launch and receiving pits.
According to McDonald the hotel project supervisor was very pleased with the results of the bursting project. In addition, McDonald said he and his company have several lateral bursting jobs lined up and have since successfully completed several difficult lateral bursting projects.
He said, “We’ve had a couple of projects now that I’m not sure how we would have approached them without the bursting system. It’s been a very good investment and expansion of our service.”
Cleaner, June 2006