Go to the mobile version of this Web site.

Login | Contact Us | Site Map | Paid archives | Electronic edition | Subscription Questions | Extras

Home › News › Traffic

Insulator problems beset line

Devices have failed repeatedly on Southeast Corridor light rail

By Kevin Flynn, Rocky Mountain News (Contact)

Published February 26, 2008 at 12:30 a.m.

Text size  
Kelvin Hardemon rides a light-rail train to the Broadway station with his daughter, Mika Hardemon, 5, on Monday. Because of numerous failures of electrical insulators along the Southeast Corridor, RTD is in the process of replacing them along the entire length of the line.

Photo by Matt McClain / The Rocky

Kelvin Hardemon rides a light-rail train to the Broadway station with his daughter, Mika Hardemon, 5, on Monday. Because of numerous failures of electrical insulators along the Southeast Corridor, RTD is in the process of replacing them along the entire length of the line.

Since T-REX opened in November 2006, insulators that help suspend the contact wire over the light-rail trains have broken 27 time, causing power outages. Last week’s lasted 33 hours. While RTD doesn’t know the reason they are breaking, it is replacing all 2,000 insulators along the Southeast Corridor along I-25 and I-225 with a model from a different manufacturer.

Photo by John Sopinski © The Rocky

Since T-REX opened in November 2006, insulators that help suspend the contact wire over the light-rail trains have broken 27 time, causing power outages. Last week’s lasted 33 hours. While RTD doesn’t know the reason they are breaking, it is replacing all 2,000 insulators along the Southeast Corridor along I-25 and I-225 with a model from a different manufacturer.

More Traffic

More stories »

Map my news

The problem that shut down a portion of RTD's new T-REX light-rail line for 33 hours last week wasn't a fluke.

When an insulator that helps suspend the high-voltage power line over the train cars broke near the Southeast Corridor's underpass at C-470 - sagging the wire and causing a passing train to rip out support arms on a dozen poles - it was the 27th time an insulator has broken on the new corridor since T-REX opened 15 months ago.

In RTD's 14 years of running light rail on the Central Corridor downtown, the Southwest Corridor to Littleton and the Platte Valley spur to Union Station, it has never had a broken insulator.

Because of the T-REX problems, RTD already had decided before last week's outage to replace all 2,000 insulators, made by Kummler & Matter of Zurich, Switzerland, with ones made by Siemens of Munich, Germany. It placed the order three weeks ago and plans to have the swap completed by midsummer.

"We're going to replace them all," said Lloyd Mack, RTD's chief of rail operations. "I can't keep doing this."

The T-REX contractor, Southeast Corridor Constructors, noted that K&M insulators are used without any such problems on light rail systems in Sacramento and Bergen County, N.J.

The T-REX project was the first time RTD used K&M insulators. The Southwest and Platte Valley lines both used Siemens while the original 5.3-mile Central line used insulators made by IMPulse of Mount Olive, N.C., all without problems.

Tom Howell, project manager for Southeast Corridor Constructors, said the wire is still under warranty.

"We have changed out quite a few on I-225 where most of them are breaking," Howell said. "Right now we're working closely with RTD and the designer to find out exactly what is causing it. We'll make sure we take care of it and that it's 100 percent before we hand it all over."

There have been many minor electrical outages on the T-REX line due to broken insulators, but two stand out because of the level of service that was disrupted.

In February 2007 a broken insulator along the Interstate 225 stretch of the line between the Nine Mile and Dayton stations ground trains on that leg to a halt for two hours, then limited service to only one track ran for 10 more hours.

Last week's failure was the worst incident. A train headed back from Lincoln Station to the yard off Santa Fe Drive at 2:30 a.m. Thursday hit the broken stretch at 50 mph. The rooftop power collection device, called the pantograph, automatically moved upward to try to maintain contact with the wire, which had lost its tension. By doing so, it knocked the steel struts and support arms off 10 of the 12 poles it passed before stopping, ripping up 1,500 feet of wire.

It wasn't fully repaired until 12:30 Friday afternoon.

Experts don't know why the insulators are breaking repeatedly on the Southeast Corridor Â? the formal name for the T-REX line.

RTD, its contractor and K&M are looking into four possible causes - product defect, design flaw, incorrect installation and even residue from the salty liquid deicing solution magnesium chloride on the adjacent freeways.

The contractor doesn't have to look far to investigate workmanship during installation. The subcontractor that installed the power system, Mass Electric of Boston, was bought out during the project by the main T-REX contractor, Kiewit Construction.

The fourth potential cause, mag chloride residue, is controversial because that's what helps keep highways clear of ice. But traffic kicks up mist that floats the mixture in the air. Xcel Energy has blamed mag chloride residue on insulators for some outages caused by fires when electricity arcs over the salty connection.

flynnk@RockyMountainNews.com or 303-954-5247

Comments

  • February 26, 2008

    1:05 a.m.

    Suggest removal

    gwats writes:

    When searching for reasons any electronic system fails, you have to be thorough and extremely professional about your investigation. This isn't Political, this is business.
    We have to let RTD follow where the investigation leads them and trust them for now.

  • February 27, 2008

    4:18 a.m.

    Suggest removal

    mrfxx writes:

    I understand this is business, but I curious as to why Siemens (a foreign firm) was chosen over IMPulse (a US-firm) when the previous experience was that IMPulse insulators presented no problems either (after all, the article states the US-made connectors were used in the original central line - which has been in place the longest of the light rail "sections"). How much more expensive are the IMPulse insulators (assuming they are more expensive), is their availability limited from the US-based firm, or is the IMPulse warranty less than the Siemens insulators, etc?

  • February 28, 2008

    6:49 p.m.

    Suggest removal

    prk166 writes:

    gwats, the problem is the Siemens has a history of bribery in many places it conducts business in the world. I'm not saying that is the reason here but surely RTD is aware of this and understand there could be extra scrutiny because of it.

  • February 29, 2008

    10:23 a.m.

    Suggest removal

    cbx123 writes:

    mrfxx raise a very good point! These projects are built with lots of local and federal dollars and we should be looking at more ways of keeping these dollars in the the good ole USA through the Buy America act. In this situation look we first spent money with a foriegn entity which is having problems and now we are going to spend even more money overseas to hopefully correct the problem. We need to look at more home grown alternatives to our needs. If this issue was not looked at based on all available suppliers and best overall solution then the transit authorty's actions should be reviewed.

  • March 5, 2008

    10:24 a.m.

    Suggest removal

    Art writes:

    Have all of the outages taken place in the winter, after storms when the mag chloride is being applied? From this story it is not clear if they have all come in inclement winter weather or not. If they have then the mag chloride just may be the problem. It has been shown that mag chloride has a detrimental effect on the insulators along highways and it stands to reason that the insulators on the light rail would be subject to the same corrosive effects. Get rid of the mag chloride and see if the problems continue.