About 12:10 a.m., on March 29, 1978, 4 locomotive units and 43 cars of St. Louis Southwestern Railway Company freight train SRASK derailed when they entered an 8° curve in the wye track at Lewisville, Arkansas. The body of the 13th car struck and ruptured the tank head of the 12th car, releasing vinyl chloride into the atmosphere. The vinyl chloride subsequently ignited and buildings within a 1,500-foot radius of the ruptured car were damaged. About 1,700 residents of Lewisville were evacuated. The engineer and two head brakemen were injured. Property damage was estimated to be $2,189,000. The National Transportation Safety Board determines that the probable cause of this accident was the failure of the engineer and other crewmembers to slow train SRASK for the 10-mph speed restriction through the wye track as required by the railroad's general orders. As a result of the train's high speed and consequent emergency brake application, the high rail in the curve moved laterally, allowing the locomotive to derail, and subsequently turn over, and the following cars to derail. The release and ignition of vinyl chloride from the ruptured tank car caused extensive damage to the train equipment and the adjacent industrial plant and buildings. 17. Key Words Railroad accident; derailment; freight train; tank head 19. Security Classification 20. Security Classification (of this report) UNCLASSIFIED NTSB Form 1765.2 (Rev. 9/74) (of this page) 18.Distribution Statement This document is available to the public through the National Technical Information Service, Springfield, Virginia 22151 21.No. of Pages 22. Price 23 NATIONAL TRANSPORTATION SAFETY BOARD WASHINGTON, D.C. 20594 RAILROAD ACCIDENT REPORT Adopted: December 7, 1978 ST. LOUIS SOUTHWESTERN RAILWAY COMPANY LEWISVILLE, ARKANSAS SYNOPSIS About 12:10 a.m., on March 29, 1978, 4 locomotive units and 43 cars of St. Louis Southwestern Railway Company freight train SRASK derailed when they entered an 8° curve in the wye track at Lewisville, Arkansas. The body of the 13th car struck and ruptured the tank head of the 12th car, releasing vinyl chloride into the atmosphere. The vinyl chloride subsequently ignited and buildings within a 1,500 foot radius of the ruptured car were damaged. About 1,700 residents of Lewisville were evacuated. The engineer and two head brakemen were injured. damage was estimated to be $2,189,000. Property The National Transportation Safety Board determines that the probable cause of this accident was the failure of the engineer and other crewmembers to slow train SRASK for the 10-mph speed restriction through the wye track as required by the railroad's general orders. As a result of the train's high speed and consequent emergency brake application, the high rail in the curve moved laterally, allowing the locomotive to derail, and subsequently turn over, and the following cars to derail. The release and ignition of vinyl chloride from the ruptured tank car caused extensive damage to the train equipment and the adjacent industrial plant and buildings. INVESTIGATION The Accident About 9:50 p.m., on March 28, 1978, St. Louis Southwestern Railway Company (SSW) train SRASK 1/, a northbound freight train consisting of 4 locomotive units and 116 cars, departed Shreveport, Louisiana, for Pine Bluff, Arkansas. Originating in Strain, Texas, on the Southern Pacific Transportation Company, SRASK was being operated as a run-through train at Shreveport, where a roll-by inspection disclosed no defects. A test for brake leakage was not performed. 1/ The letter "K" in the train identification indicates the presence of hazardous material cars in the train consist. Shortly after leaving Shreveport, the engineer closed the cab windows because of the cold weather. He later checked the train's speedometer and found it functioning properly. At Alden Bridge, 42 miles from Lewisville, Arkansas, a satisfactory stop was made by using the train's automatic air brakes. About 24 miles from Lewisville, the engineer radioed the conductor that they were passing a "hot box" detector. The conductor acknowledged the transmission and, after passing the detector, replied that it indicated a satisfactory journal box condition. At 12:02 a.m., when 6 miles from Lewisville, the rear brakeman in the caboose radioed the Lewisville operator to inform him that SRASK would arrive in Lewisville about 12:15 a.m. He also asked if the train would be able to continue through the Lewisville siding and onto the main track for Pine Bluff without stopping. About a minute later, the operator, after checking with the dispatcher in Pine Bluff, radioed that train SRASK could continue through Lewisville if it arrived before 12:15 a.m. The rear brakeman then radioed the information to the engineer and, receiving no reply, immediately repeated the message. This time, the head brakeman in the locomotive cab answered and said he understood the Lewisville operator's instructions. The engineer later said that he had been busy and, consequently, let the head brakeman operate the radio to respond to the rear brakeman. The engineer also stated that since he had 13 minutes to travel the 6 miles to Lewisville, he was in no hurry. According to the engineer, as SRASK approached the milepost sign indicating 1 3/4 miles to the Lewisville wye, the train was moving at 35 mph and he made a 6-pound service application of the brakes. This was the first brake application in about 23 miles, since near the hot box detector. While passing the Lewisville yard limit sign, about 1 mile from the wye, the train entered some ground fog; however, the engineer said he did not become disoriented. Believing the train was not slowing adequately for the 10-mph maximum authorized speed for the upcoming curve in the Lewisville wye, the engineer said he increased the brakepipe reduction to 15 or 20 pounds as the train passed a road crossing 3/5 mile from the wye. The engineer said that he made an emergency brake application about 1/2 mile from the wye but that a simultaneous emergency brake application had occurred automatically because of an explosion before the train derailed. The head brakeman stated that, as the train entered the patch of ground fog, he became disoriented and was not able to see the track until SRASK passed out of the fog about 1/5 mile from the wye. Estimating the speed at this point to be over 30 mph, which was too fast to safely traverse the wye curve, he immediately reached for the emergency brake valve. The train went into emergency before he could activate the valve, so he braced himself in anticipation of the locomotive rolling over. After the lead locomotive unit passed the wye switch and entered the 8° curve, the head brakeman felt the locomotive tip onto its left side and slide for about 50 feet. (See figure 1.) While trying to get out of the locomotive, the head brakeman |