[Federal Register Volume 65, Number 107 (Friday, June 2, 2000)]
[Notices]
[Pages 35418-35419]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-13838]


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DEPARTMENT OF TRANSPORTATION

Federal Railroad Administration


Notice of Safety Advisory 2000-2

AGENCY: Federal Railroad Administration (FRA), DOT.

ACTION: Notice of Safety Advisory 2000-2.

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SUMMARY: The FRA is issuing a safety advisory addressing recommended 
replacement of certain components in Harmon Industries' ``Electro Code 
4'' and ``Electro Code 4 Plus'' intermediate signal units.

FOR FURTHER INFORMATION CONTACT: William Goodman, Signal and Train 
Control Division, Office of Safety Assurance and Compliance, FRA, 1120 
Vermont Avenue, NW, Washington, DC 20590 (telephone 202-493-3625) or 
Mark Tessler, Office of Chief Counsel, FRA, 1120 Vermont Avenue, NW, 
Washington, DC 20590 (telephone 202-493-6061), e-mail 
``<a href="/cdn-cgi/l/email-protection#224f4350490c564751514e4750624450430c464d560c454d54"><span class="__cf_email__" data-cfemail="3954584b52174d5c4a4a555c4b795f4b58175d564d175e564f">[email protected]</span></a>'.

SUPPLEMENTARY INFORMATION:

Background

    On March 25, 1998, a Norfolk Southern Corporation (NS) freight 
train collided with a Consolidated Rail Corporation freight train in 
Butler, Indiana. The post-accident investigation of the accident 
revealed that an intermediate signal in the vicinity of the accident 
would randomly go dark. While it has been determined that the signal 
malfunction did not contribute to the accident, the malfunction was 
further investigated by the FRA, the National Transportation Safety 
Board (NTSB), NS and Harmon Industries (Harmon), manufacturer of the 
signal control equipment.
    The investigation revealed that certain modules in Electro Code 4 
and Electro Code 4 Plus intermediate signal units can contribute to 
intermittent dark signal occurrences.
    On May 15, 1998, Harmon, through its Electro Pneumatic Corporation 
subsidiary, issued PIA [Product Improvement Announcement] 98-101 in 
which it recommended an upgrade to the ``211S, 211SRP, and 212A'' 
modules that are used in Electro Code 4 and Electro Code 4 Plus 
Intermediate signal units. Harmon offered to supply upgrades to the 
listed modules at no charge through December 31, 1999.
    In its Product Improvement Announcement, Harmon discussed the 211S, 
211SRP and 212A modules:

211S and 211SRP

    The 211S and 211SRP modules are DC to DC converters that are 
used in Electro Code 4 and Electro Code 4 Plus Intermediate signal 
units. These modules provide isolated battery for signal lighting 
circuits and are located in the top of the chassis housing behind 
the front panel. A resistor in the module's mid stage driver circuit 
may be subject to excessive heating due to heavy lamp load and/or 
continuous duty cycle of the lamp-lighting circuits. Eventually this 
resistor can fail open. In the event this circumstance occurs, 
excessive noise can be passed through the converters to the balance 
of the lamp lighting circuits. Random noise on a lamp output can be 
interpreted by the dual microprocessors as false energy. In 
response, the processors will reset, resulting in a dark signal for 
a period lasting approximately 40 seconds. Ultimately, the 
processors will attempt to reinitialize the converters and restore 
the signal lighting. The frequency of the dark signal occurrence 
depends on many

[[Page 35419]]

variables and may be recognized many times during a single day, or 
sporadically during the course of one or several months.

212A

    The 212A module is also part of the signal lighting circuits 
within Electro Code 4 and Electro Code 4 Plus equipment. AC signals 
from the processor modules are combined on the 212A to provide the 
excitation voltages to the 211 converter modules. It has been 
recognized that several of the electrolytic capacitors on the 212A 
modules have failed, resulting in symmetry distortion of the AC 
signal passed to the 211 modules. This distortion may exaggerate the 
noise condition as described with the 211S and 211SRP above.

    Harmon further stated that ``[on the 211S and 211SRP modules, 
several components in addition to the resistor described above, will be 
replaced and added to the base design. This upgrade offer applies only 
to 211S and 211SRP converter modules * * * manufactured between March 
1994 and March 1998 * * * ''

Recommendation

    In recognition of the need to assure safe reliable railroad signal 
operations, FRA strongly recommends that:
    1. Each railroad having a signal system which uses any ``Electro 
Code 4'' or ``Electro Code 4 Plus'' Intermediate signal unit 
immediately identify each 211S, 211SRP, and 212A module within their 
signal system.
    2. Each railroad replace or upgrade every 211S, 211SRP, or 212A 
module within their signal system as soon as possible.
    3. Each railroad having 211S, 211SRP, or 212A modules contact 
Harmon Industries Riverside Operations, Attention Repair and Return, 
7337 Central Avenue, Riverside, California 92504, phone no.: 800-854-
4752 for further information pertaining to upgrades.

    Issued in Washington, DC on May 25, 2000.
George Gavalla,
Associate Administrator for Safety.
[FR Doc. 00-13838 Filed 6-1-00; 8:45 am]
BILLING CODE 4910-06-P


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