ANCHORAGE (AP) -- A derailment and gasoline spill last week near Wasilla was caused by track flaws, according to the Alaska Railroad and its consultant.
The derailment came at a fairly sharp curve in the track after metal plates under the rail cut into the wooden ties on the outside of the curve, according to Gary Wolf, president of Rail Sciences Inc., which analyzed the accident for the railroad.
That cut in the ties allowed the rail to lean outward as the heavy tanker cars pushed against it.
Once the gauge -- the distance between the rails -- was wide enough, wheels on a 130-ton railcar dropped into that space and started bumping along on wooden ties and gravel.
Nine cars jumped the track, four of them gasoline tankers that tumbled down a 25-foot embankment. One of the 23,000-gallon tankers leaked nearly 600 gallons, state environmental officials said. The railroad maintains the spill was less than 100 gallons.
Spill cleanup has been completed, and the damaged track repaired, the railroad said.
The rail gauge has to widen about three inches for this type of derailment to occur, according to Wolf.
Deterioration of the ties over maybe 15 or 20 years took its toll on that particular section of track, said Loren Mueller, the railroad's new chief operating officer. He took the job in May.
''It's not anything that would jump out at an inspector,'' said Wolf, the consultant.
The curve was identified two years ago as one that needed straightening, according to Mueller. While the permits and other paperwork were being obtained, the railroad kept patching up the curve, he said.
A special electronic measuring car that checked the line in May identified the curve as a ''yellow flag'' spot because the track was too wide, Mueller said.
''We went up and regauged the track,'' he said.
Now, with expedited approval from the Federal Transit Authority, the curve is being rebuilt, reducing the curvature from 10 degrees to 3 degrees.
Work began Thursday on that curve and three others in the area. They are among 70 curves between Anchorage and Wasilla to be straightened with federal money.
Wolf, the consultant, said his company's analysis found no fault with the derailed train's rolling stock, and he said the engineer was ''doing it by the book.''
The train was rolling at a fairly consistent 22 mph, he said, on a stretch of track where the speed limit is 25 mph.
The July 12 derailment was the third accident and spill since last November for the railroad.
Gov. Tony Knowles ordered a safety investigation by four members of his cabinet. Results of that investigation are expected by mid-October.
Peninsula Clarion ©2013. All Rights Reserved.