Description
Those orange, plastic chimneys poking up along sidewalks and streets in Manhattan – or the obvious trickle of steam coming up from random manholes – represent steam leaks in the city’s underground steam system. Danella was hired to fix the leaks.
Project Details
- The four-year project started out as a two-year project in 2008; Danella won a re-bid to continue the project for two more years and started its third year in 2010.
- The steam leaks, which cut down on the efficiency of the system and can lead to explosions, are often difficult to locate because the system contains a pipe inside another pipe. If there is a leak in the middle of the block, the steam typically stays inside the outer casing until it gets to a manhole and comes up to the street. A specialized crew at Danella finds the exact location of the leak through exploratory holes and drilling. Danella welds and installs a new steel pipe to correct the problem.
- The job requires Danella to do more than find the leak and replace the broken pipes. Danella also performs asbestos abatement work if the old steam mains are covered in asbestos; the new steel, 30-inch diameter pipes are covered in a non-asbestos insulation. Danella also removes and rebuilds the old concrete housing around the pipes, and repairs manholes and puts in new valves as needed.
- Danella rotates six crews of six people each – three shifts in the day and three shifts at night – to get the job done.
Unique Challenges
The steam rehabilitation project requires highly specialized crews willing to work under extraordinary circumstances. “It’s like having miners, basically,” said Peter Mazzari, Vice President and Division Manager of Danella Construction Corporation of New York. Working nearly eight feet below street level, “the steam crews work in temperatures that reach 250 degrees, blowing hot steam. It’s brutal, especially in the summer, but that’s when we need to get the work done. The steam system supplies heat and hot water to Manhattan, and they don’t like to do steam shut-offs in the winter. We still do excavation work in winter, but we don’t shut the main off.”