What takes 18 months to plan and five minutes to complete?
A: Installing new transmission lines across Interstate 90 in Massachusetts (aka the Mass Pike). Months of planning and preparation by Transmission Line Services (TLS) and other teams culminated in the recent successful installation of conductors and shield wire across the Mass Pike and Route 20 in Charlton, MA. This activity is part of a larger project to run 18 miles of transmission line in this area.
A Process Hazard Analysis, a risk analysis tool used to work out the worst things that could happen so plans can be made to assure they don’t, is a requirement for several types of projects – driving over gas lines, operating helicopters near transmissions lines, and running wires across major highways, to name a few. This is done well in advance and repeated immediately prior to the activity to make sure nothing has been missed.
About 18 months prior to the execution date TLS reached out to the Department of Transportation (DOT). The following requirements had to be met:
- A traffic management plan detailing how drivers would be alerted to the traffic constraints that would result when the lines were brought across the highway needed to be developed and approved.
- Signage had to be set up along the route about 10 days in advance, warning people that work would be getting underway and when to expect delays.
- Trucks and equipment needed to be in place along with barricades to catch the wire so it didn’t fall onto the highway and into traffic.
- Light stands needed to be set up to illuminate the work, which was scheduled from midnight to 3:00 a.m., to minimize the traffic impacts.
In addition to the DOT requirements, the MA State police were contacted to manage the massive traffic stop, which required cruisers positioned five miles out in both directions to slow approaching cars. More cruisers would be at the crossing point to stop traffic at the key moment so the wire could be safely pulled across the four lanes of highway.
Since there was very limited time to make the crossing, everyone had to be fully aware of the plan and do their part.
And they did! It began with a midnight review of the PHA and culminated with the wire crossing at 3:00 a.m. Everyone was in place. On the National Grid side four supervisors and 25 line workers all worked to make this happen according to plan, reviewing the safety briefs and assuring all personal protective equipment was in place. When traffic was stopped a rope was walked over to the crew from the opposite side of highway. They met in the middle median where the rope was attached to the wire. It was connected to the equipment that would pull it across from one side of the road to the other, then elevate it and attach it to the pole providing a clearance of about 60 feet. Once the line was safely elevated and attached, the police drove off and traffic resumed normal speed. The process took about five minutes to complete. Everything went according to plan and everyone was kept safe throughout the process.
Quite an accomplishment!