Accident No: | DCA-05-FR-002 |
Location: | Pico Rivera, California |
Date and time: | October 16, 2004 9:40 a.m.1 |
Company: | Union Pacific Railroad |
Property Damage: | $2.7 million |
Injuries: | None |
Fatalities: | None |
Accident Type: | Derailment |
About 9:15 a.m., ZLAMN-16 departed eastbound from Los Angeles enroute
to Yuma, Arizona, with a final destination of Marion, Tennessee. The engineer
said that he had no difficulties with either the brakes or slack action
and the train handled as expected for a train of that size. As the train
approached Bartolo Junction on the single main track, a clear3
signal indication was displayed. The train was traveling 57 mph when, the
crew said, the lead locomotive rocked a little from a dip on the engineer’s
side. As the crew was talking about this event, the train air brakes went
into emergency application and the lead locomotive came to a rough stop.
The engineer immediately contacted the dispatcher while the conductor checked
on the condition of the train. The engineer relayed information to the
dispatcher from the conductor that 3 locomotives and the first 11 cars
had derailed and that local residential structures appeared to be involved.
The second locomotive was the easternmost piece of equipment to derail.
Emergency response personnel arrived within minutes.
The derailment occurred on the UP Los Angeles Division, Los Angeles
Subdivision. The UP designated the track as Class 5,4
authorizing maximum speeds of 70 mph for passenger trains and 65 mph for
freight trains. The UP timetable established train directions for this
subdivision as east and west. The train involved in the accident was moving
northeasterly. A residential area was adjacent to the tracks on the northwestern
edge of the derailment. An embankment for the 605 Freeway curved in front
of the accident site and bordered the eastern edge.
In the area of the derailment, the main track was constructed of 133-pound
continuous welded rail (CWR). The rail was laid on 8 1/2- by 16-inch double
shoulder tie plates. Four cut track spikes in each tie plate affixed the
rail to treated timber crossties. There were 24 crossties for each 39 feet
of rail. Longitudinal rail movement was controlled through base-applied
rail anchors. Each tie was box anchored in the area of the initial point
of derailment (POD). The anchors contacted the respective crosstie at each
location. The track structure was supported by crushed granite ballast
that was generally 12 inches deep and between 1 1/2 to 3 inches in diameter.
The cribs were full and clean. Ballast extended beyond the ends of the
ties. There was no vegetation in the ballast section or along the immediate
right-of-way. It had been raining in the area before the derailment and
during the on-scene phase of the investigation; however, there was no standing
water near the POD.
The initial POD was at an insulated joint on the south rail at milepost
(MP) 11.34. The joint was composed of two 133-pound rails and a pair of
6-hole joint bars with associated hardware and bonding material. Both joint
bars were broken and the end faces of both rails exhibited visible evidence
of having been deformed by impact.5 The rail
ends, attached broken bars, and the supporting tie plates were sent to
the National Transportation Safety Board’s Materials Laboratory in Washington,
D.C. Starting on November 4, 2004, the track components from the accident
were examined in the Safety Board’s laboratory; representatives from the
Federal Railroad Administration (FRA) and the UP were present.
The Materials Laboratory report6 on the
examination of the joint pieces is in the Safety Board’s public docket.
The evidence indicates that there were slowly growing fatigue cracks in
both joint bars and that at least part of each fatigue crack had been visible
on the lower outer portion of the bar for some time before failure. (See
figures 1 and 2.)
Figure 1. West rail portion showing the fractured
ends of the joint bars, a fracture between the first two bolt holes of
the south joint bar, and rail batter.
The initial cracking in the south joint bar was between the first and second bolt holes from the center of the joint and was associated with an indentation in the bottom outside corner of the bar. The metallographic evaluation of the deformation could not determine whether the damage had occurred while the joint bar was being manufactured or at a later time.
Figure 2. East rail portion showing the fractured
end base of the north joint bar.
The epoxy bead along the top of the joint bars was missing from the
center sections of the bars, indicating that the joint was older and was
experiencing relative movement between the rail head and the bars. The
joint bars were still securely bonded at the ends, indicating that the
joint bars were not moving laterally, but were bending cyclically in the
middle under the weight of passing trains.
Preaccident Inspections and Reports
The UP had used its track geometry car to inspect the area on September
4, 2004, and had not noted any exceptions7
for the immediate area of what later became the POD. In a separate UP report,
the crossovers at MP 11.3 had been identified in April 2004 as “Areas That
Need Surfacing;” however, the area was not resurfaced before the accident.
The FRA-required inspection8 for internal rail
defects was performed at the accident location on September 21, 2004. The
minimum inspection requirement was once a year. However, the UP had done
two other internal inspections in the previous year on January 28,
2004, and on May 20, 2004. No rail defects were reported for the area in
the vicinity of the POD. Title 49 CFR 213.237 further stipulates, “(b)
Inspection equipment shall be capable of detecting defects between joint
bars, in the area enclosed by joint bars.” This required inspection can
detect internal defects in rail, but does not identify internal defects
in joint bars. The UP conducted an ultrasonic test of the noninsulated
joint bars in that area on July 2, 2004. No defects were reported.
According to representatives from the FRA, the California Public Utilities
Commission, the UP, and joint bar manufacturers, current technology will
not allow an in-service joint bar to be completely inspected for internal
defects. Over time, both dye penetrates and magnetic particle inspections
proved ineffective in field use. Transducer applied ultrasonic imaging
is generally used throughout the rail industry as the best available means
of testing. However, the shape of the joint bars and rails make some areas
inaccessible. Moreover, removing joint bars for testing is time consuming
and it introduces new load dynamics into the system when they are reassembled.
Class 5 track requires9 a visual inspection
of the track structure by a qualified track inspector. This inspection
must be performed at least twice weekly with a minimum of 1 calendar day
between the inspections. Records maintained by the UP indicated that the
required inspections were routinely performed and logged. Federal and State
inspectors stated that they routinely observed UP track inspectors conducting
these inspections.
Two days before the accident, an FRA track safety inspector, a California
Public Utilities Commission track safety inspector, the local UP track
inspector, and a UP manager of track maintenance inspected the Los Angeles
Subdivision main track between MP 32.46 and MP 10.30. This inspection included
the joint that would be involved in the accident. Portions of their inspection
were done from a Hy-Rail vehicle and portions were done on foot. The inspectors
reported that they stopped and did a walking inspection of the Bartolo
Control Point, and then they Hy-Railed over the insulated joints at MP
11.34, the POD. As they departed, they continued their visual inspection
from the moving vehicle. Minor defects10 were
noted at MP 11.40 and MP 11.50, but no defect was reported at MP 11.34.
UP records indicate 102 trains passed over the track at MP 11.34 between
the time of the inspection and the time of the derailment. None of these
trains reported a track defect in the area.
The locomotive engineer of the last train to successfully pass over
the track was interviewed after the accident. He said that he had stopped
his westbound train at the end of the multiple main track to wait for the
passage of an eastbound train moving from the single main track to an adjacent
multiple main track. He stated that he had felt a “small bump” as he started
his train moving near the west end of Bartolo Junction, but that he had
not believed it was significant enough to report.
Postaccident Testing
Postaccident track geometry measurements were made by the parties to
the investigation. Fifteen stations were established at 15-foot 6-inch
increments.11 Station 1 was set at the POD.
The group summarized its factual findings as follows:
Joint Bar Inspections
Joint bars are subject to routine visual inspections only as part of
an overall track structure inspection. The FRA allows visual inspections
to be conducted from a moving vehicle, as in the case of this accident.
The Safety Board addressed the need for periodic on-the-ground inspections
of rail joint bars during its investigation of the derailment of a Canadian
Pacific Railway freight train on January 18, 2002, near Minot, North Dakota:15
Visual inspection from a moving vehicle is inadequate because, for example, a track inspector checking the accident location from a vehicle traveling west to east would be able to see only the tops of the joint bars on the north rail, and the outside joint bar on the south rail would not be visible at all. Even those joint bars that can be partially seen by an inspector may have small fractures or fatigue cracks that are extremely difficult, if not impossible, to see from a moving vehicle. Instead, to adequately visually inspect joint bars, an inspector must dismount the vehicle and conduct an up-close, on-the-ground inspection of both the field- and gage-side bars for small hairline cracks. The joint bar fatigue cracks that eventually fractured and led to the Minot derailment were externally visible over a length of 1.9 inch on the gage-side bar and 0.8 inch on the field-side bar. An on-the-ground, visual inspection of this joint bar would almost certainly have detected the larger crack, which should have led to replacement of the joint bar before it failed and caused a derailment. A secondary benefit of on-the-ground rail joint inspection in CWR territory is that the inspector could assess the rail joint gap as well as look for evidence of bent or loose bolts.
The FRA’s regulations regarding CWR are silent on inspections of joint bars. Although, by definition, CWR joints are welded rather than being bolted with joint bars, in practice, a length of CWR can have numerous joint bars where rail plugs have been added to replace defective rail sections. Although FRA regulations state that cracked or broken joint bars shall be replaced, they do not provide any guidance on finding such joint bars. Defects such as fatigue cracks develop and grow over time until, as in this accident, the bar can no longer support the load and fractures. With the proper frequency and type of joint bar inspections—specifically, on-the-ground visual inspections—these defects can be detected, and the defective bars can be repaired or replaced before their minor defects lead to complete failure and a possible derailment. Moreover, as noted previously, on-the-ground visual inspections can detect rail gaps, loose bolts, poor joint support, or other conditions that can be corrected before cracking develops. Unfortunately, a railroad can meet existing FRA CWR regulations without an effective joint bar inspection program.As a result, the Safety Board concluded in the same report, “FRA requirements regarding rail joints in CWR track are ineffective because they do not require on-the-ground visual inspections or nondestructive testing adequate to identify cracks before they grow to critical size and result in joint bar failure.” On March 15, 2004, the Safety Board made two recommendations to the FRA on this issue:
R-04-01
Require all railroads with CWR track to include procedures (in the programs that are filed with the FRA) that prescribe on-the-ground visual inspections and nondestructive testing techniques for identifying cracks in rail joint bars before they grow to critical size.
R-04-02The CWR track involved in the Pico Rivera accident had all the inspections required by the UP and the FRA. In some instances, the inspections were done more frequently than required. Nevertheless, the inspections failed to detect the developing problems and prevent the ultimate failure. Additionally, during the 2 days after the last inspection, more than 100 trains passed over the insulated joint bars without either discovering or reporting a defect. Trains traversed the area after the insulated joint bars were completely broken, as evidenced by the rail batter in both directions.16
Establish a program to periodically review CWR rail joint bar inspection data from railroads and FRA track inspectors and, when determined necessary, require railroads to increase the frequency or improve the methods of inspections of joint bars in CWR.
Probable Cause
The National Transportation Safety Board determines that the
probable cause of the derailment was the failure of a pair of insulated
joint bars due to fatigue cracking. Contributing to the accident was the
lack of an adequate on-the-ground inspection program for identifying cracks
in rail joint bars before they grow to critical size.
Adopted: May 31, 2005
1 All times in this brief are Pacific daylight time.
2 The cargo was resin, 18 kilograms; sulfuric acid, 6 liters; and butane lighters, 1 kilogram.
3 A clear signal indicates that a train may proceed at track speed unless otherwise restricted. Trains receiving a clear signal will not be diverging at the next signal location and will not have a signal more restrictive than approach at the next signal.
4 The Federal Railroad Administration (FRA) has established minimum inspection and maintenance standards according to various classes of track. Maximum track speeds and other requirements are based on the designated class.
5 “Batter” is generally used by the rail industry to describe this type of damage: a particular type of deformation that happens when wheels pass over the end face of a rail in an area where the rails are separated by a greater distance than is normal.
6 National Transportation Safety Board’s Materials Laboratory Factual Report No. 05-017 dated March 4, 2005.
7 Exceptions are conditions that fall below the minimum standards defined by the FRA for the designated class of track.
8 49 Code of Federal Regulations (CFR) 213.237(a).
11 Four stations form a 62-foot chord.
12 Station 15 was 62 feet west of the beginning of the curve or tangent to spiral.
13 This portion of the project is reportedly being conducted together with the Burlington Northern and Santa Fe Railway on high tonnage coal routes to accelerate the test cycle.
14 Both the FRA and the UP state that they have representatives on this committee.
15 National Transportation Safety Board, Derailment of Canadian Pacific Railway Freight Train 292-16 and Subsequent Release of Anhydrous Ammonia Near Minot, North Dakota, January 18, 2002, Railroad Accident Report NTSB/RAR-04-01 (Washington, DC: NTSB, 2004). Paragraph excerpts are from pages 55 and 56.
16 Rail signal systems are designed to
provide broken rail protection, but because the break was within an insulated
joint, the safeguard was not activated.