Content Manager posted on January 01, 2009 21:14
January 2009 NRA News
by LCDR Christian Schomaker
The submarine tender USS Frank Cable (AS-40) suffered a boiler casualty while pier-side in Guam in December 2006. The Cable, equipped with two boilers, was conducting steam testing of boiler safety valves when two steam generating tubes failed in boiler number 1A. This failure caused a sudden increase in steam pressure that ruptured the boiler’s casing. Hot, saturated steam exploded out of this rupture and filled the upper level of the fire room, killing three Sailors and injuring two others instead of safely venting through the exhaust stack.
Naval Sea Systems Command’s Ship’s Support Engineering Services (NAVSEA SSES) immediately began an investigation to determine the root cause. This investigation determined that corrosion caused the failure in the steam generating tubes and that fabrication errors 26 years earlier rendered the boiler’s casing unable to withstand the sudden increase in steam pressure.1
SSES’s solution was to inspect and clean all steam-generating tubes and to reinforce the boiler casings on all 24 of the boilers in service fleet-wide. These boilers are common on submarine tenders and LHA and LCC amphibious ships. The cost for this repair is estimated at $24 million. Repair efforts would require one month pier-side for each ship.
NAVSEA maintains a stable of experts whose specific industry technical expertise and knowledge exceeds normal NAVSEA competencies. This stable of experts is comprised of engineering duty officers (EDOs) of the Navy Reserve, and their program name is NAVSEA Technical Authority Support (TAS). VADM Kevin McCoy, the Chief Engineer for the Navy at the time of the incident, decided to employ two Navy Reserve EDOs of the Technical Authority Support program to investigate the Cable’s boiler casualty in January of 2008. CDR Phillip Burnside, a Ph.D. in Mechanical Engineering, a structures expert, and resident of Avon, Indiana, received orders to active duty to conduct an analysis of the Cable’s boiler casualty. CDR Burnside is also a combat veteran from a 2006 tour in Baghdad, Iraq. He was joined on active duty by LCDR Brandon Larson of Cincinnati, Ohio, a licensed Marine Engineer/Professional Engineer. Their analysis and recommendations would provide VADM McCoy a second opinion.
Burnside and Larson’s analysis concurred with all of the SSES’s findings but provided a different solution significantly. These highly skilled Navy Reservists determined that corrosion was, indeed, the cause of the steam-generating tubes failure, and the boiler casing on the Cable was manufactured incorrectly. Inspection and cleaning of all steam-generating tubes was recommended by both the SSES report and the Burnside and Larson report. Casing repair, however, is where Burnside and Larson diverged from the recommendations of the SSES. Burnside and Larson recommended visual inspection of the suspect areas on all 24 of the boilers in the Navy fleet. If fabrication errors are found, further inspection using ultrasound imaging equipment would detail the scope of required repairs.2
Burnside and Larson’s recommendations were accepted by NAVSEA and implemented throughout calendar year 2008. This solution provided a cost savings of approximately $23 million and a reduction in a ship’s operational availability of only five days vice 30. If operationally necessary, completing these repairs at sea is possible if the subject ship is equipped with two shafts or another boiler without fabrication discrepancies.
According to CDR Burnside, their analysis would cost approximately $250,000 if completed by a civilian firm. Completing this analysis required approximately nine days of service for both Burnside and Larson at a total cost of approximately $10,000.3 Computer modeling through NAVSEA was utilized in the analysis. Combining the expertise of these Navy Reserve Engineering Duty Officers with NAVSEA’s technology saved the Navy $240,000 during production of this essential product.
At the time of this article’s publication, no other boiler fabrication deficiencies have been found. CDR Burnside and LCDR Larson have been nominated for the Navy and Marine Corps Commendation Medal.
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References:
1 NAVSSES Report “Failure Analysis Report of Superheater Support Tubes from USS Frank Cable (AS-40), Ser 615/07-169 of 11 June 2007.”
2 NAVSEA TAS Report “Structural Analysis and Recommended Repairs Concerning the USS Frank Cable (AS-40) Boiler Casualty of December 2006.”
3 Compiled from Navy Reserve Order Writing System’s Budget Estimator Application.