"During a quality assurance audit, we discovered that the welding work on the end frames of the CTA 5000 Series cars did not fully conform to the provisions of our 'assembly book' for those cars," Bombardier Transportation spokeswoman Maryanne Roberts told Railway Age Tuesday, June 11.
"We inspected the cars at our manufacturing plant in Plattsburgh, N.Y., as well as cars already delivered to Chicago, and determined that many of the approximately 275 cars already manufactured were nonconforming," Roberts said.
Bombardier inspectors discovered the problem last month, according to CTA officials interviewed by the Chicago Tribune. Bombardier and CTA already have agreed on a plan to correct the problem Regular shipments will total 20 cars per month, officials from both entities have said. CTA has ordered 706 Series 500 cars from Bombardier.
"Bombardier and CTA (have) worked closely together to establish a corrective action plan," Roberts said. "Car shipments resumed on June 5th. Bombardier will repair the cars already in Chicago beginning on or about July 8th."
CTA officials told the Tribune incomplete welds were found in 240 of the 250 rail cars delivered so far. Those cars will remain in service as the fleet is repaired; CTA said safety was not an issue, according to CTA and engineering consultant Parsons Brinckerhoff on the 5000 Series procurement, Parsons Brinckerhoff, determined.
Both CTA and Bombardier stressed that passenger safety was not at risk. "As the nonconformity would not result in a failure under the collision load cases described in the CTA 5000 Series Technical Specification and did not pose a risk to passenger safety, CTA kept the cars in service. However, car deliveries were halted while the production-related issue was fully investigated" Bombardier's Roberts said, adding, "The cars were 'over-designed' to ensure many years of reliable service at CTA, and the cars have been performing well in revenue service. "
Said CTA spokesman Brian Steele, "Computerized stress analysis verified that all the existing welds are sufficient to ensure the integrity of the rail cars under various load and collision test scenarios."
The fix mutually agreed to involves removing part of the rail car interior wall and installing a second bracket with welds, instead of fully disassembling the corners of the cars and adding a third set of welds to the existing brackets, Steele said. The result will be even greater structural protection, he said.
CTA and Bombardier unveiled the first new 5000-series car in November 2009, putting it into service on CTA’s Pink Line.