82 FR 38989 - Addressing Electrode-Induced Rail Pitting From Pressure Electric Welding

DEPARTMENT OF TRANSPORTATION
Federal Railroad Administration

Federal Register Volume 82, Issue 157 (August 16, 2017)

This document provides notice of FRA's intent to issue a Safety Advisory alerting railroads, contractors, and the rail welding industry of the potential for electrode-induced rail pitting and fatigue cracking during the pressure electric rail welding process. Based on investigation and research, FRA believes improper electrode contact to the rail during the welding process can result in electrode- induced pitting that may lead to fatigue fracture and ultimately rail failure. The draft Safety Advisory includes recommendations to help the industry prevent electrode-induced rail pitting and to inspect for and then remediate such pitting if it occurs. FRA invites public comment on all aspects of the draft Safety Advisory.

[Federal Register Volume 82, Number 157 (Wednesday, August 16, 2017)]
[Notices]
[Pages 38989-38992]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2017-17285]


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DEPARTMENT OF TRANSPORTATION

Federal Railroad Administration

[Docket No. FRA-2017-0074; Notice No. 1]


Addressing Electrode-Induced Rail Pitting From Pressure Electric 
Welding

AGENCY: Federal Railroad Administration (FRA), Department of 
Transportation (DOT).

ACTION: Notice of draft Safety Advisory; request for comment.

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SUMMARY: This document provides notice of FRA's intent to issue a 
Safety Advisory alerting railroads, contractors, and the rail welding 
industry of the potential for electrode-induced rail pitting and 
fatigue cracking during the pressure electric rail welding process. 
Based on investigation and research, FRA believes improper electrode 
contact to the rail during the welding process can result in electrode-
induced pitting that may lead to fatigue fracture and ultimately rail 
failure. The draft Safety Advisory includes recommendations to help the 
industry prevent electrode-induced rail pitting and to inspect for and 
then remediate such pitting if it occurs. FRA invites public comment on 
all aspects of the draft Safety Advisory.

DATES: Interested persons are invited to submit comments on the draft 
Safety Advisory provided below on or before October 16, 2017.

ADDRESSES: Comments in response to this notice may be submitted by any 
of the following methods:
     Web site: The Federal eRulemaking Portal, 
www.Regulations.gov. Follow the Web site's online instructions for 
submitting comments.
     Fax: 202-493-2251.
     Mail: Docket Management Facility, U.S. Department of 
Transportation,

[[Page 38990]]

Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: Docket Management Facility, U.S. Department 
of Transportation, 1200 New Jersey Avenue SE., Room W12-140 on the 
Ground level of the West Building, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.
    Instructions: All submissions must include the agency name, docket 
name, and docket number for this notice, Docket No. FRA-2017-0074; 
Notice No. 1. Note that all comments received will be posted without 
change to http://www.Regulations.gov, including any personal 
information provided. Please see the Privacy Act Statement in this 
document.

FOR FURTHER INFORMATION CONTACT: Mr. Matthew Brewer, Staff Director, 
Rail Integrity Division, Office of Railroad Safety, FRA, 500 Broadway, 
Suite 240, Vancouver, WA 98660, telephone (202) 385-2209; or Mr. Aaron 
Moore, Trial Attorney, Office of Chief Counsel, FRA, 1200 New Jersey 
Avenue SE., Washington, DC 20590, telephone (202) 493-7009.

SUPPLEMENTARY INFORMATION: 

Draft Safety Advisory

    FRA routinely conducts investigations of railroad accidents to 
determine causation and any contributing factors to help the railroad 
industry implement corrective measures that may prevent similar 
incidents in the future. Over the past decade, FRA has investigated 
multiple broken rail accidents in which it found fractures in the rail 
web. Similarities in the fracture characteristics of the recovered rail 
fragments in some of these accidents have led FRA to conclude stray 
arcing may occur during the pressure electric welding process performed 
to create continuous welded rails.
    Pressure electric welding is the process of using a hydraulically-
operated welding head that clamps around two opposing rail ends, 
pressing an electrode on each rail, then hydraulically pulling the rail 
ends together while arcing current through the electrodes into the 
rails, causing them to essentially melt together to form a continuous 
rail. FRA believes stray arcing during this process results in the 
formation of electrode burns or pits on the web, head, or base of the 
rail. Fractures in the rail may originate from the electrode pits 
because they behave as stress raisers (also referred to as stress 
concentrations). Fatigue cracks often develop at locations of stress 
concentration. Once a fatigue crack initiates, the localized stress 
encourages the growth of the crack, which may potentially lead to rail 
failure. FRA believes electrode pitting may be a contributing factor, 
if not the root cause, in some accidents involving rail web cracking.
    Figure 1 below shows a photograph of a rail with electrode pits in 
the web. The location of these electrode pits, when they occur, is 
typically four to eight inches on either side of the weld. Electrode-
induced pitting from pressure electric welding may also occur in the 
head and base of the rail. At this time, it is unclear whether 
traditional ultrasonic rail testing can consistently detect electrode-
induced pitting.
    In 2016, FRA's Office of Railroad Safety requested technical 
support from The National Transportation Systems Center (Volpe) to 
study the fatigue and fracture behavior of rails with pitting from 
electrodes used in welding. Volpe enlisted technical support from the 
U.S. Army's Ben[eacute]t Laboratories (Ben[eacute]t) to conduct 
forensic examination of three rail sections with electrode-induced 
pitting in the web from the pressure electric welding process. FRA 
obtained these rails from members of the railroad industry. 
Ben[eacute]t's examination included fractography (the science of 
studying fracture surfaces to identify the origin and causes of 
fracture), metallography (the science of studying the microstructure of 
metals to provide information concerning the properties and processing 
history of metallic alloys), and testing to determine the chemical 
composition and tensile mechanical properties of the rail steel. 
Ben[eacute]t confirmed FRA's hypothesis that electrode-induced web 
fatigue cracking is a result of pitting caused by inadequate electrode-
to-rail contact.
    Specifically, Ben[eacute]t's metallurgical analyses concluded the 
cracking in the rail web originated from the pitting created by 
inadequate electrode-to-rail contact during the pressure electric 
welding process. The fractographic and metallographic examinations 
revealed evidence of fatigue cracking originating from the pitting and 
fast fracture once the fatigue crack reached a critical length. Figure 
2 below shows three photographs of the fracture surface of a crack 
found in one of the rails Ben[eacute]t examined. These photographs 
support the metallurgical evidence indicative of three stages of 
fatigue fracture: (1) Crack initiation or formation originating from 
the pitting; (2) crack propagation or growth by metal fatigue; and (3) 
final rupture or fast fracture. Figure 3 below shows photographs of the 
microstructure near the electrode pits in each examined rail, providing 
further evidence the cracking originated from the pitting created by 
improper electrode contact during welding.
    The results from the metallurgical analysis also suggested 
premature and sudden rail failure may result from high wheel-impact 
load (e.g., flat wheel), especially in cold-weather environments when 
the longitudinal rail force is tensile. Results from the chemical 
analysis and mechanical testing indicated the chemistry and mechanical 
properties of the rails selected for evaluation were within 
specifications the American Railway Engineering and Maintenance-of-Way 
Association (AREMA) published, except for the hardness measurements in 
one rail, which were slightly lower than the AREMA minimum. Hardness is 
a measure of the resistance of a material to surface indentation 
produced by a carbide indenter applied at a given load for a given 
length of time. The lower hardness in that rail, manufactured in the 
1950s, may be attributed to lower concentrations (compared to the other 
two rails) of alloying elements, specifically carbon, silicon, and 
chromium, which were still within AREMA tolerances. Testing of the 
chemistry and the mechanical properties revealed all three rails were 
made from standard quality steel containing no other defects except the 
electrode-induced pitting.
    FRA presented its concerns about electrode-induced rail pitting and 
fatigue cracking to the Railroad Safety Advisory Committee's Rail 
Integrity Working Group. FRA also advised the Working Group that FRA 
was considering issuing a safety advisory to ensure all parties are 
aware of the potential for electrode-induced pitting and fatigue 
cracking (as identified in the figures below) and the pressure electric 
welding process is performed properly. (FRA has posted a copy of this 
notice on its public Web site, www.fra.dot.gov, where you may view the 
figures below in their full resolution.)
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[GRAPHIC] [TIFF OMITTED] TN16AU17.003

BILLING CODE 4910-06-C
    Recommended Action: Based on the discussion above, and to prevent 
future electrode-induced pitting and fatigue cracking which may lead to 
premature rail failure, FRA recommends railroads, contractors, and the 
rail welding industry develop and apply appropriate methods to:
    1. Prevent electrode-induced rail pitting from occurring by:
    a. Reviewing proper pre- and post-weld procedures to avoid the 
development of electrode pitting;

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    b. Improving welder training programs to ensure consistency in 
welding procedures, especially for the pressure electric welding 
process; and
    c. Developing and scheduling appropriate pressure electric welding 
maintenance and rail testing programs.
    2. Identify electrode-induced rail pitting by:
    a. Inspecting the rail upon completion of welding, and reviewing 
the documentation in the weld report to help identify if pitting 
occurred;
    b. Visually inspecting existing welds for electrode-induced pitting 
during routine track inspections; and
    c. Considering alternative methods of identifying electrode-induced 
pitting, such as ultrasonic testing, machine vision, etc.
    3. Remediate any identified electrode-induced pitting by:
    a. Removing the section of rail containing electrode-induced 
pitting and re-welding the rail; or
    b. Developing and applying possible alternative methods to remove 
electrode-induced pitting, such as drilling, if electrode-induced 
pitting is found and the section of rail cannot be readily removed or 
re-welded.
    FRA requests public comment on all aspects of this draft Safety 
Advisory.
    Privacy Act Statement: Anyone can search the electronic form of all 
comments received into any of DOT's dockets by the name of the 
individual submitting the comment (or signing the comment, if submitted 
on behalf of an association, business, labor union, etc.). You may 
review DOT's complete Privacy Act Statement in the Federal Register 
published on April 11, 2000 (65 FR 19477), or you may visit http://www.regulations.gov/#!privacyNotice.

    Issued in Washington, DC, on August 10, 2017.
Patrick Warren,
Executive Director.
[FR Doc. 2017-17285 Filed 8-15-17; 8:45 am]
 BILLING CODE 4910-06-P