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Reason for gearbox failure is a top priority

A new gearbox is slated to arrive at the Princeton Municipal Light Department wind site within the week, and it will be a three- to four-day project to replace the failed equipment and get the south turbine running again.

The gearbox and a container of tools have been in storage in Boston since arriving in May, waiting for technicians from Fuhrlaender that will make the repair. Fuhrlaender manufactured some of the turbine, but not the gearbox.

The highway department did work on the access road prior to the arrival of two cranes. One of the two cranes needed has to be assembled on site, PMLD General Manager Brian Allen said at the May 23 meeting of the light commissioners. The larger crane is needed to lift the 37-ton gearbox off the truck and another crane is needed to assist with installation.

The old gearbox will be returned to Germany to be analyzed to find the reason for its failure.

By mid-June the blades of the turbine should be spinning again, depending on the weather, according to Allen. Work on the windmills comes to a stop when winds are more than 10 miles per hour.

The trip to Germany for the old gearbox will take about three weeks. “I’d guess it will be mid-July before they actually start tearing it apart,” said Allen. PMLD will send an expert in machines and machine design to Germany to watch the dismantling of the gearbox.

“Fuhrlaender is out of this once the gearbox is up and running,” said Allen. “They don’t have a fish in the pan. The manufacturer of the gearbox will have to pay for it if it’s a manufacturing problem.”

Commissioners met Rick Stockhaus, who works for a defense contractor designing machines and fixing them. “I feel your pain here,” said Stockhaus. “You need someone there who will speak for you. I’d like to get a full set of drawings so we can see what’s inside the high speed section of the gearbox.”

“I’d like to see photographs as it’s taken apart,” said commission chairman Scott Bigelow. “They could have put in parts made for the tropics and we’re at the top of a mountain.”

“When this is opened up who makes the ruling on culpability,” asked Sam Cobb Lane resident David Nichols.

Along with guidance from Stockhaus, Allen wants the right to have a private laboratory check it. Travelers Insurance Company, which PMLD has a policy with regarding the equipment failure and for loss of revenue because of the turbine being off line, and Lumis Construction, the firm that oversaw installation of the wind turbines in October 2009, may also send someone to witness the gearbox autopsy, according to Allen.

“It’s not just out eyes on this,” he said. “We’re not going to take their word, unless of course they say it’s their fault. It’s in their best interest financially to say it’s not their fault. So we have to be vigilant.” Westminster Road resident John Mollica asked if any analysis had been done to see if wind shifts could have put additional stress on the gearbox.

Nothing out of the ordinary was found prior to the failure of the equipment, according to Allen.

The problem was found in August 2011, when an oil sample showed pieces of ground-up metal from the teeth in the gearbox. The turbine was shut down and has been out of commission since.

At the time, then-manager Jonathan Fitch said the gearbox was under warranty, but PMLD officials have since learned PMLD was a third party to the warranty. The two 1.5-megawatt turbines on 215-foot towers were installed in October 2009 and became fully operational in January 2010. Cost to install the windmills was $7.3 million, and the turbines have a life expectancy of 20 to 25 years.