ANCHORAGE (AP) -- Most of the railroad fuel tank cars in Alaska were overhauled during the summer to reduce the risk of derailments and spills, Alaska Railroad officials said.

Nearly three-quarters of the fuel tank cars underwent major repairs on wheel and suspension systems.

Alaska Railroad Corp. officials say the overhaul work will greatly reduce the risk of derailment since the fuel tank cars will ride more smoothly along the rail line.

GATX spent more than $825,000 on the repair work on its entire fleet of 275 tank cars. The Chicago-based company leases fuel cars to Williams Alaska Petroleum Inc., said George Lowman, GATX's vice president of corporate communications.

Williams Alaska leases another 134 fuel tank cars owned by ITLX, according to Jeff Cook, vice president of external affairs for Williams.

Those cars were not scheduled for maintenance this summer, Cook said.

Fuel shipped from the Williams' North Pole refinery to Anchorage averages about 100 rail cars a day. The bulk of the rail cars -- some 80 a day -- carry jet fuel to be used at Ted Stevens Anchorage International Airport, according to Cook.

Seven GATX workers spent seven weeks replacing wheels, axles and ''trucks,'' the assemblies which hold the wheels, Lowman said.

Part of the work consisted of fitting wedges -- which act as shock absorbers -- into the trucks. The wedges provide a dampening effect over bumps and keep the wheels from bouncing off the track and derailing a train, Alaska Railroad officials said.

The Alaska Railroad inspected the fuel tank cars last spring and found that many of them needed repair or replacement.

''Wheels wear down,'' Lowman said. ''It's like putting new shocks and tires on your car.''

Lowman said maintenance on the fuel tank cars is regulated and required by the federal government.

''A lot of effort goes into the safety of railroad fuel cars,'' Lowman said, adding that GATX's entire fleet in Alaska is in ''first-rate shape.''

Depending on the condition of the track, wheels on fuel cars last anywhere from 200,000 to 250,000 miles, Lowman said.