DOT Should Keep Tank Responsibility
Feb 1, 2000 12:00 PM, Charles E Wilson
Once again National Tank Truck Carriers (NTTC) and the Truck Trailer Manufacturers Association put on an outstanding Cargo Tank Maintenance Seminar. Coverage of the meeting, which was held in late October last year, starts on page 56.
One of the stories in that report details an effort by the Department of Transportation to hand off responsibility to the American Society of Mechanical Engineers (ASME) for developing code tank rules. If adopted, that proposal holds profound consequences for the tank truck industry.
It seems very likely that cargo tanks of all types would be much more stringently engineered and could cost significantly more to manufacture and repair. DOT needs to take a long, close look at these potential impacts before making changes in the way the cargo tank rules are developed and modified.
For one thing, the current rules and the process for changing those rules seem to be working quite well. Cargo tanks built to the existing standard perform safely and effectively. According to a report prepared for NTTC by veteran tank design engineer Dave Fellows, more than 250,000 cargo tanks were produced over the past 48 years, and only a minimal number have experienced catastrophic failure. Three of the failed tanks were manufactured and stamped to the ASME code, Fellows wrote in the report. DOT's own research and analysis in recent years has demonstrated beyond question that the vast majority of product releases to the environment are in no way related to cargo tank construction, inspection, testing, maintenance, or repair.
The latest version of the cargo tank rules were adopted by the Research and Special Programs Administration (RSPA) just five years ago, and they seem to be working quite well. If they have any real weakness, it is inadequate or inconsistent enforcement by various state and federal agencies.
The rules require that cargo tank manufacturers must be registered with DOT, and their shops must hold an ASME "U" stamp for as long as they build specification cargo tanks. Many of these manufacturers also have obtained ISO 9001 certification.
Specification petroleum and chemical tanks must be built to DOT400-series standards. The "U" stamp, combined with the DOT400 code, requires that a manufacturer have a recognized quality and competent engineering system in place. This system is a very good guarantor of a safe, quality product.
Requirements for code tank repair operations also were made more stringent in the rules that were adopted by RSPA in 1995. Like tank builders, repairers and inspectors must be registered with DOT and are required to have a recognized quality system in place. Any repair shop that welds on a code cargo tank must have a current National Board "R" stamp.
The registration of cargo tank inspectors and repairers, coupled with DOT audits of these companies, has been a real success story of industry/government cooperation. As Fellows states in the NTTC report, there is no reason for DOT to abdicate its responsibility for oversight. DOT has tried to reassure the tank truck industry by stating that ASME has been instructed to develop a program that will transparently overlap the existing rules. DOT simply wants added safety through clarity of the design requirements, repair procedures, and quality inspections.
What DOT wants and what it gets may be two different things. For one, ASME has no real experience with the sort of elliptical tanks that predominate in gasoline hauling. Elliptical tanks don't fit within the pressure-vessel code that will form the basis for the ASME program. The industry is very likely to end up with heavier, round tanks for petroleum transport. Increased engineering requirements for other types of cargo tanks also are very likely. All of this means more expensive equipment with little or no real gain in safety.
Third-party inspection is an inherent part of ASME programs, and the engineering association wants to include the requirement in the program being developed for DOT. If ASME prevails on this point, only the third-party inspectors will benefit.
Third-party inspectors will earn up to $500 per visit to a cargo tank manufacturing plant or repair shop. Repair cycles will be longer, and a lot more paper records will be needed.
Industry associations have said that they will fight to stop this program from being adopted. We hope they win, because the program will be bad for the industry.
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