7367-7373 Derailment Case

NEW YORK STATE PUBLIC TRANSPORTATION SAFETY BOARD RAIL SAFETY SECTION PTSB CASES #7367 AND #7373 INVESTIGATION OF TWO DERAILMENTS INVOLVING THE MTA - LONG ISLAND RAIL ROAD ON #73 SWITCH IN JAY INTERLOCKING, JAMAICA, NEW YORK ON JANUARY 23, 2003 AND JANUARY 25, 2003 SYNOPSIS On Thursday, January 23, 2003 eastbound equipment train #3800 derailed in the Jay Interlocking which is located in Jamaica, Queens, New York. The rear wheel set on the third car and the lead set on the fourth car derailed as they passed over #73 switch. Two days later, on Saturday, January 25, 2003, eastbound equipment train #8738 derailed four wheels on the lead truck of the first coach car (the second car in the consist) as it too passed over #73 switch. Neither train was carrying passengers at the time it derailed. In both cases, at least one car passed over #73 switch before the derailments occurred. Both derailments caused moderate damage to the track and car equipment. The cause of the derailments was not determined until after the second derailment on January 25, 2003 when the investigation discovered that a newly installed switch point on #73 switch's right hand switch point was not manufactured to the correct specifications . The defective switch point and its companion stock rail were installed one day before the first derailment on January 22, 2003 . INVESTIGATION Accident Scene : The Jay Interlocking is located west of Jamaica Station, in Queens, New York. The station and interlocking is one of the railroads busiest hubs with all trains routed through this interlocking going to the various branch lines . The speed limit throughout the interlocking is 15 mph. The #73 switch is a left hand, straight split switch with a Sampson undercut point. Number 73 switch rests on a 1 .8 percent descending grade sloping towards the station and is on a 4 degree curve to the left. A super- elevation of one inch exists between the rails of the diverging routes. On January 22, 2003, a work order was completed by LIRR Track Department personal which included replacing the right side sections of the #73 switch including the thirty-nine foot-long right hand straight stock rail and a 16'- 6" right hand curved switch point. Accident Descriptions : First Derailment - January 23, 2003 At approximately 6 :51 a.m., train #3800 made up of eight M-3 type coach cars and carrying no passengers, left from track #17 at Penn Station heading to Long Beach Station. The trip prior to Jay Interlocking was normal and uneventful . Train #3800, traveling east at approximately 13 mph, entered Jay Interlocking on main track #4 and was routed by the operator in Jay Tower via #73 switch to Jamaica Station track #6 . As the train approached the station platform, the engineer received a derailment hand signal from a track worker in the interlocking and a simultaneous radio message from the Jay Tower operator to immediately stop the train. The engineer applied the train's emergency brakes in response to the communications received. As the B-end truck of coach car #9252 negotiated the left turnout of #73 switch, the wheel flange of the first south wheel climbed the right hand switch point resulting in the wheel riding up on top of the rail . The wheel traveled across the top of the rail for a distance of approximately two feet, then dropped to the south side of the turnout rail, adjacent to the insulated joint at the south heel block, approximately 12 feet past the switch point. The following set of wheels took the same route as the first wheels to derail. Simultaneously, the left hand side wheels of the B-end truck dropped inside the gauge. The B-end truck of the following coach car #9251 also climbed the right switch point causing the wheel to ride up and across the rail, dropping to the south of the turnout at about the same spot as the first truck to derail. The train traveled approximately 150 feet before stopping causing significant damage to the track, railroad ties, third rail, third rail protection boards, switch mechanisms, and signal wires. Car equipment damage included damage to the two trucks, wheels, and undercar equipment of coach cars #9252 & #9251 . The track and third rail damage caused by the derailment was repaired, and the switch and surrounding track was returned to service at 4:03 p .m. that same day. The Railroad estimated that there were over thirty train movements made safely across the #73 switch from the time the new switch point was installed until the first derailment. The coach cars (#9252 & #9251) involved were taken out of service and sent to a Maintenance Facility for further inspection and repairs . The weather at the time of this incident was partly cloudy and cold, with a temperature around 10 degrees . Based on a review of all track measurements, equipment measurements and operating moves, no conclusive decision as to why the train derailed was determined and the track was returned to service after all repairs were made. Second Derailment - January 25, 2003 At approximately 7:14 p .m., eastbound train #873 8, carrying no passengers, left the Morris Park Yard bound for Speonk Station. The train consist was made up of a duel power locomotive (#401) pulling four C-3 type coach cars. The train was routed through Jay Interlocking over switch #73 in a facing move for Jamaica Station track #5 . The engineer was operating from the locomotive and was traveling at approximately 13 mph as the train approached the station. The engineer stated that after passing over the #73 switch, he felt the train shake violently and he immediately applied the emergency brakes. As the wheels of coach car #4005 passed over the switch, the wheel flange of the B-end truck climbed up onto the right hand switch point, similar to that of the derailment two days earlier. Investigation showed that the wheels dropped off the track adjacent to the #2 switch rod, approximately two feet from the end of the switch point. All four wheels of the B-end truck on coach car #4005 dropped to the ground on the south side of the turnout rails. The derailment caused minimal damage to the B-end truck, wheels, drawbar assembly and undercar equipment of coach car #4005. Track damage was also termed as minor. The equipment was sent to a Maintenance Facility for repair. The #73 switch was immediately taken out of service and an in depth investigation ensued. The weather at the time of both derailments was clear and cold, with the temperature around 30 degrees. Derailment Investigation: The initial investigation after the first derailment on January 23, 2003 did not find a definitive cause for the derailment . Post accident measurements taken by the LIRR Track Department showed that the track gauge through the turnout was within LIRR standards for Class I track. The track profile and alignment leading up to and beyond #73 switch also met with LIRR standards. The Railroad's Track Geometry Car tested the tracks in the interlocking one week prior to the first derailment with no exceptions taken. Since all measurements taken met with LIRR track specifications, and there was nothing which indicated a problem with #73 switch, the investigation shifted from a track related problem to a potential car equipment problem involving the wheels or trucks. The suspected equipment problem was short lived however and, after the second derailment on January 25, 2003, the investigation shifted back to the track and particularly #73 switch. Wheel markings left in grease that was applied to the right hand switch point after the first derailment indicated that the point of derailment was at the switch point. At this time, a decision was made to replace the switch point and stock rail that was only installed just three days earlier on January 22, 2003 . On January 26, 2003, the recently installed 3 9' section of the right hand straight stock rail and the 16' 6" right hand curved switch point of the #73 switch was removed and replaced. A visual inspection of the right hand curved switch point after it was removed showed that the switch point taper appeared to be different from the other switch point being installed. The point taper appeared too thick, instead of the knife edge taper that was normal for this type of switch installation. The excessive thickness of the switch point caused a narrowing of the gauge at the critical point where the wheels deflect past the switch point on to the diverging route. The narrowing ofthe gauge, along with a combination of track geometry, local gradient, and track super-elevation all contributed to allowing wheel climb on the right hand curved switch point at slow speeds. Split Switch Design: A switch point is used to deflect the wheels of a train from the tracks upon which they are riding to the tracks of a diverging route . Switches are designated either right-handed or left handed, as determined by which way the equipment diverges. The switch points are the movable rails of a turnout which actually cause the train's wheels to diverge. To protect the switch point from wheel batter, the companion stock rail is milled away and the switch point is beveled to fit snugly against the milled area of the stock rail. This style of switch point is known as a Sampson undercut. A bend in the stock rail is made on the turnout side at a predetermined distance in front the switch point. This measurement is referred to as the vertex distance .

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