At the early date, not quite four hours after this evening’s deadly Red Line collision, there is little information to be had at this point about the type and age of the cars involved in the crash. [UPDATE, 9:05 P.M.: Metro General Manager John Catoe said in a press conference that the last car on the stopped train was a relatively new 5000-series CAF-built car; the lead car on the moving train was a 1000-series Rohr-built car—-the oldest type in the system.] However, it is worth reviewing some historical criticism of the structural integrity of certain Metro cars levied in the past by the National Transportation Safety Board.

In January 1996, two trains collided at the Shady Grove station at between 22 and 29 mph; in that crash, the moving train “telescoped” 21 feet over the stationary train, “severely compromising the occupant volume of the striking car.” Almost nine years later, in November 2004, a Red Line train, its operator asleep at the wheel, slid backward and struck a train stopped at the Woodley Park station—-again, the moving train telescoped some 20 feet over the stopped one. According to the subsequent NTSB report [PDF], “Almost half of the passenger occupant volume of the striking car…was also severely compromised.”

Today’s crash, based on the extreme “telescoping” seen in photographs, seems to have taken place at higher speeds. But the survivability of the crash might have something to do with the type and age of the cars involved.

In response to NTSB questions about the 1996 incident, Metro conducted a review of its cars’ structural strength. This is how the NTSB, in the wake of the 2004 crash, described the response:

WMATA stated that its consultant determined that it was neither practical nor desirable to add underframe reinforcement and that such modification possibly could result in more injuries. WMATA also stated that it would have been impractical to modify the 1000-series Metrorail cars before they are scrapped and it would be prohibitive to modify the 2000, 3000, and 4000 series when they are refurbished. As a result of this response, the Board classified Safety Recommendation R-96-37 “Closed—Acceptable Action” based on the information that WMATA’s position on the existing fleet was reasonable and that the intent of the recommendation had been met.

Here was the NTSB’s recommendation on the Woodley Park crash, delivered in 2006:

Because the 1000-series, Rohr-built, passenger railcars, which will comprise 26 percent of the Metrorail passenger railcar fleet when all the cars are delivered, are vulnerable to catastrophic telescoping damage and complete loss of occupant survival space in a longitudinal end-structure collision (as occurred at the Woodley Park station), the Safety Board believes that WMATA should either accelerate retirement of Rohr-built railcars, or if those railcars are not retired but instead rehabilitated, then the Rohr-built passenger railcars should incorporate a retrofit of crashworthiness collision protection that is comparable to the 6000-series railcars.

Further conclusions: “The failure of the carbody (underframe) end structure of the 1000-series Metrorail cars may make them susceptible to telescoping and potentially subject to a catastrophic compromise of the occupant survival space” and “The failure to have minimum crashworthiness standards for preventing telescoping of rail transit cars in collisions places an unnecessary risk on passengers and crew.”

UPDATE, 9:10 P.M.: Interesting note from the 2006 NTSB report: “The 5000-series cars that have been delivered are equipped with an on-board event recorder system.”

UPDATE, 9:12 P.M.: Catoe: “I have no basis to suspend the use of 1000-series cars at this time.”

UPDATE, 6/23, 8:15 A.M.: NTSB’s Debbie Hersman this morning confirms that the the striking train was a 1000-series car and that the struck train was a mix of 3000- and 5000-series. She notes that the NTSB has “long been on record” about the crashworthiness of the 1000 series. “We recommended to WMATA to either retrofit those cars or phase them out of service,” she says. “Those concerns were not addressed.”

UPDATE, 6/23, 8:40 A.M.: More warnings from the NTSB, these from recommendations issued in 2006 [PDF], in response to the Woodley crash:

In WMATA’s March 2002 response to the Safety Board’s recommendation (R-96-37) to conduct a comprehensive evaluation of Metrorail cars and make modifications to improve their crashworthiness, WMATA stated that its consultant determined that it was neither practical nor desirable to add underframe reinforcement and that such modification possibly could result in more injuries. WMATA also stated that it would have been impractical to modify the 1000-series Metrorail cars before they are scrapped and it would be prohibitive to modify the 2000, 3000, and 4000 series when they are refurbished. As a result of this response, the Board classified Safety Recommendation R-96-37 “Closed—Acceptable Action” based on the information that WMATA’s position on the existing fleet was reasonable and that the intent of the recommendation had been met.

The Safety Board concluded that the failure of the carbody (underframe) end structure of the 1000-series Metrorail cars may make them susceptible to telescoping and potentially subject to a catastrophic compromise of the occupant survival space. WMATA’s evaluation, which determined that it was impractical to modify the 1000-series cars and their crashworthiness performance in collisions, in effect validates the scheduled retirement of the cars. Any replacement car should be designed with crashworthiness components for absorbing maximum energy in a collision and to transmit minimum acceleration to passengers without override or telescoping, as found in the current 5000-series railcars and specified for the 6000-series cars.

Again, the ultimate recommendation:

Either accelerate retirement of Rohr-built railcars, or if those railcars are not retired but instead rehabilitated, then the Rohr-built passenger railcars should incorporate a retrofit of crashworthiness collision protection that is comparable to the 6000-series railcars. (R-06-2)

Here is WMATA’s response, as contained in NTSB records:

WMATA does not plan to do a heavy overhaul on the 1000 Series, Rohr railcars. Instead WMATA plans to replace these railcars with the 7000 Series railcars on which design has already started. WMATA is constrained by tax advantage leases, which require that WMATA keep the 1000 Series cars in service at least until the end of 2014. The 296 Rohr railcars make up over a third of WMATA’s current rail fleet and have performed well for over thirty years. The railcars will be replaced around 2014. Current Situation: All WMATA rail cars are fitted with anti-climbers on the end of the cars. These are designed to engage during a collision and to reduce the tendency for one car to climb over the other. The newer 6000 design, while retaining the anti-climber feature, has included additional energy absorption in the front end of the car. That absorbs energy as its deforms and collapses in a higher speed collision. This type of design will be used on future procurements.

NTSB’s reply:

In view of WMATA’s response to the Board’s recommendation, it appears that further dialogue on this issue would prove futile. Consequently, we have no choice but to classify Safety Recommendation R-06-2 Closed Unacceptable Action.