DENVER — The operator of an RTD R-Line train that derailed in late September was driving nearly four times the speed limit for the curve at Sable and Expedition and was inattentive, the agency found, according to documents declassified by the Colorado Public Utilities Commission.
The PUC on Wednesday agreed to declassify and release some of the documents related to the Sept. 21 derailment in Aurora as the Regional Transportation District prepares to restore service for the R-Line next week. Three people were taken to a hospital after the derailment.
The documents, including a corrective action plan, were submitted to the PUC along with the investigation report on Nov. 4 but were labeled “highly confidential.” The PUC approved the corrective action plans on Nov. 16.
The documents show the operator had the train going 38.8 mph into the 10-mph curve at South Sable Boulevard and East Exposition Avenue and before heading into the curve.
“Inattention by the operator and failure to operate the train in accordance with established rules by allowing the train to exceed the maximum posted track speed for both tangent and curve tracks,” was cited as one of the causes of the derailment.
The corrective action plan says the traffic alignment for the train in the area, which gave it exclusive right-of-way, contributed to the “operator inattentiveness.”
RTD is working with Aurora to redesign the train-traffic interface in that area, putting in place a stop-and-proceed area before the intersection, so trains will have to stop before entering the intersection.
The agency will also reduce the speed limit on the track approaching the intersection from 35 mph to 25 mph. RTD says it also plans to put more signage in ahead of the curve and put a radar sign farther north up the tracks to give operators more warning ahead of the curve.
RTD’s investigation found the severity of the hazard to be “catastrophic” – the most severe category, which could result in a person’s death or losses equal to or above $10 million, one of the documents says.
It found the probability of such an event happening again “remote,” or “likely to occur sometime in the life of an item.” On the risk assessment matrix, the corrective action plan found an overall risk level of “serious.”
RTD said last week that it plans to have service restored to the four-mile stretch of the R-Line between Aurora Metro Center and the 13th Avenue Station sometime next week. It says it has trained operators again on speed adherence and that R-Line operators would be trained on the stop-and-proceed and speed reduction before the line reopens.
This was the second derailmentin the area in the past four years. In January 2019, one person was injured when an R-Line train derailed on the same set of tracks while also going too fast around the curve.