Metro's mixing of signal part brands could have caused crash, maker tells NTSB
Thursday, February 25, 2010
Metro's decision to mix different brands of signaling equipment -- despite a warning from one of the manufacturers -- could have caused the June crash that killed nine people, a senior engineer with the company said Wednesday at a federal safety hearing.
Five days before the accident, Metro crews replaced a key piece of equipment with one from another manufacturer. After the equipment was replaced, the circuitry malfunctioned, and no one at Metro detected the problem, investigators have said.
The National Transportation Safety Board, which is conducting a three-day hearing into the accident, plans to issue a formal finding on the cause by mid-June. Information released by the board has pointed to possibly faulty and aging equipment in the failure of the automated crash-avoidance system. But the information on the signaling system attempts to shift blame to Metro's maintenance, testing and installation procedures. Alstom, the equipment manufacturer, like Metro, potentially faces millions of dollars in liability judgments from victims' lawsuits.
"Alstom believes that the use of third-party components . . . presents, not only a customer quality issue, but also constitutes a serious and increasing risk to overall signaling system safety," wrote Alstom, which makes much of Metro's train detection equipment, in a Sept. 7, 2004, letter. Neal Illenberg, Alstom's site safety officer, said the letter was distributed to "hundreds of" customers, including Metro.
In the letter, Alstom said the use of non-Alstom components, without "rigorous industry design and safety standards," had resulted in a series of failures in track switch machines, a different kind of system, and had resulted in operational problems, including a freight-car derailment. Alstom warned against mixing components across all train control systems.
The information was disclosed as Illenberg questioned Metro witnesses Wednesday. Parties to the investigation, such as equipment manufacturers, are allowed to examine witnesses. The hearing, which is scheduled to end Thursday, is exploring what happened and examining broader issues of safety and oversight.
A copy of the letter and the 24-page distribution list obtained by The Washington Post shows that 19 Metro officials were on the list, including Harry Heilmann, then a supervisory engineer. Heilmann retired Feb. 1 as an assistant chief engineer for Metro but is testifying on Metro's behalf.
Asked about the letter, Heilmann said, "I'm not familiar with that correspondence."
In addition, Illenberg said an Alstom employee gave an oral warning to another Metro engineer about the risks of mixing equipment from different manufacturers during discussions about an engineering bulletin issued on the topic in October 2006. The bulletin gives instructions about installing equipment made by Union Switch & Signal in track circuits made by GRS, the company that Alstom took over. Union Switch & Signal is now Ansaldo STS USA. Alstom and Ansaldo are the two major companies that make this type of equipment.
The Metro engineer, Johann Glansdorp, "was told Alstom would not consent with the mixing of equipment," said Illenberg, the lead Alstom representative for the investigation. During the overnight shift June 16, Metro replaced the component as part of an upgrade of its aging track system.
Illenberg said the specific risk associated with using non-Alstom equipment is that it would require boosting the power level of the device. That, in turn, could increase the potential for a signal malfunction that could prevent the system from detecting a train on the tracks, causing a crash, according to industry sources.
Illenberg also quoted interviews that federal investigators conducted with Metro maintenance employees who voiced concerns about the compatibility of the mixed equipment. The NTSB released transcripts of those interviews this week.