Document ID: FRA-2017-0074-0003
Agency: fra
Document Type: Notice
Title: Addressing Electrode-Induced Rail Pitting from Pressure Electric Welding
Posted Date: 2018-07-27T04:00Z

[Federal Register Volume 83, Number 145 (Friday, July 27, 2018)]
[Notices]
[Pages 35699-35702]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-16022]

[[Page 35699]]

=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Railroad Administration

[Docket No. FRA-2017-0074, Notice No. 2; Safety Advisory 2018-01]

Addressing Electrode-Induced Rail Pitting From Pressure Electric 
Welding

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

ACTION: Notice of Safety Advisory.

-----------------------------------------------------------------------

SUMMARY: FRA is issuing Safety Advisory 2018-01 to remind 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.

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: On August 16, 2017, FRA published a notice 
of a draft safety advisory in the Federal Register to address 
electrode-induced rail pitting from pressure electric welding and 
seeking comment on the issue. 82 FR 38989. FRA noted its investigation 
and research into the issue demonstrated that improper electrode 
contact to the rail during the welding process could result in 
electrode-induced pitting that may lead to fatigue fracture and 
ultimately rail failure. As a result, FRA's draft safety advisory 
contained specific recommendations to help the industry prevent 
electrode-induced pitting.
    FRA presented the information contained in the draft safety 
advisory to its Railroad Safety Advisory Committee's (RSAC) Rail 
Integrity Working Group. Subsequent RSAC discussions and comments 
submitted by the Association of American Railroads (AAR) indicated that 
the rail industry agrees with FRA's concern that stray arcing can 
result in the formation of electrode pits and that fatigue cracking can 
then develop from these electrode pits. AAR noted, however, that FRA's 
draft safety advisory did not present any information to support a 
finding that rail failures from electrode-induced rail pitting are a 
wide-spread problem. Further, AAR noted that its member railroads 
report they have seen no indications of a systemic problem involving 
electrode pitting, and that railroads and welding companies have 
procedures in place to prevent electrode pitting and remediate it when 
it does occur. Accordingly, AAR asserted that FRA should not issue any 
recommendations burdening the industry such as those included in the 
draft safety advisory.
    After consideration of AAR's comments and input from RSAC 
discussions, FRA agrees with AAR's position that, although stray arcing 
during the pressure electric welding process can result in the 
formation of electrode burns or pits on the web, head, or base of rail, 
and that fatigue cracking can develop from those burns or pits, 
railroads and welding companies have procedures in place addressing the 
issue of electrode pitting. Accordingly, in issuing Safety Advisory 
2018-01, FRA has not adopted the specific recommended actions listed in 
its draft safety advisory and instead intends Safety Advisory 2018-01 
to merely remind railroads, contractors, and the rail welding industry 
to be diligent in complying with existing practices and procedures 
designed to prevent electrode-induced pitting in rail and to mitigate 
the pitting when it does occur.

Safety Advisory 2018-01

    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. 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 may 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. 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 the 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

[[Page 35700]]

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 recognizes that the industry already has practices and 
procedures in place to avoid electrode pitting during the pressure 
electric welding process. Therefore, FRA is issuing Safety Advisory 
2018-01 to remind railroads, railroad employees, railroad contractors, 
and welding companies and their employees of the importance of 
complying with those procedures to prevent electrode pitting and, 
ultimately, to prevent rail failures. (FRA has posted a copy of this 
notice on its public website, www.fra.dot.gov, where you may view the 
figures below in their full resolution.)
 BILLING CODE 4910-06-P

[[Page 35701]]

[GRAPHIC] [TIFF OMITTED] TN27JY18.329

[[Page 35702]]

Ronald Louis Batory,
Administrator.
[FR Doc. 2018-16022 Filed 7-26-18; 8:45 am]
 BILLING CODE 4910-06-C