Skip navigation

DOT officials discuss diverse range of issues affecting tank truck industry

PHIL Olson, Research and Special Programs Administration (RSPA), reported that the agency is working with the Truck Trailer Manufacturers Association (TTMA) to develop a new recommended practice that would address overturn protection equipment to satisfy requirements by the National Transportation Safety Board (NTSB).

He and other Department of Transportation (DOT) officials discussed a diverse range of topics at the meeting, from an update on agencies' current organization, to wetline issues, to cargo tank maintenance, to security in the tank truck industry.

In other NTSB news, Olson said two investigations currently on the horizon include an MC307 multi-compartment tank failure that occurred in 2002 which has prompted concern about hidden corrosion. The other concern was sparked by a 2003 incident in which a pressure vessel ruptured while transporting anhydrous ammonia. These are likely to produce federal actions in the future.

Another subject of interest to DOT is new technology on hydrogen fuel cells. FMCSA is working with other agencies to determine the feasibility of converting vehicles.

“That feasibility study is taking a lot of our time and competes with other issues that might be more relevant to this in-dustry,” Olson said.

One subject definitely of interest to the tank truck industry is the wetline issue, which still is very much alive, according to Mike Stevens of RSPA. He said the NTSB wants equipment to be installed on petroleum tank trucks that would remove product from the wetlines. Currently, RSPA is evaluating what the cost would be to industry. “At this time, I really can't say much more on the rule-making process,” he added.

Cargo tank thickness

Joe Evans of FMCSA discussed cargo tank thickness testing. “The idea is to verify the shell and head thickness,” he said.

Among the requirements are periodic testing for corrosion — visible reduction in the material thickness of the wall itself or the internal valve. However, minor surface degradation that has no affect on the safety or service of the tank is not included.

Thickness tests are required every two years, but can be annually if cargo tank thickness is calculated to be less than minimum plus corrosion allowance.

If corrosion/abrasion is found during visual inspection, four readings will be necessary to estimate the average. If the result is less than 10 percent, then the tank will have to be tested internally.

As for equipment used in the testing — he said there are products that will measure to 2000th of an inch accuracy. However, the person using the equipment has to be trained and the equipment must be calibrated. If FMCSA inspectors arrive to inspect a shop, they will want to see the equipment, have a demonstration of its use, and see how it is calibrated, he said.

He advised that more than one reading must be taken, especially in the upper coupler attachment areas, where flexing occurs in the tank, and in sump areas. And, he emphasized that the exterior should be inspected because of spilled products that may have caused corrosion.

Tank linings

Danny Shelton, FMCSA, noted several federal issues. He pointed out that shops involved in installing tank linings must be DOT-registered. In addition, FMCSA wants to know about shops that are doing mobile testing and inspections.

The agency wants to be sure that registered inspectors have work experience on cargo tanks. However, he pointed out that they are not required to determine cargo tank structure integrity, “but they need to know if tank conforms to the specifications as much as possible.”

For vent pressure testing, he said that the devices must be removed from the tank for testing, and must be tested to manufacturer's specifications.

Leakage tests are now required on cargo tanks used to haul anhydrous ammonia, liquid petroleum gas, and those with vapor recovery used to transport distillate petroleum products.

Shelton emphasized the importance of documentation, noting the minimum thickness of shell and heads, location of defects, and method of repair.

Shelton also recommended the use of the RSPA Web site ( that covers 49 CFR hazmat regulations and has a hazmat table for reference of what products can be carried in what type of trailers.

On another topic, Evans addressed security issues for cargo tanks. He said that a group of industry and government representatives are examining ways to meet the new demands, including identification of risks, threats and vulnerabilities for explosives, inhalation of hazardous materials, and other high-hazard materials.

The group is examining the range of technologies available, which varies from the simple to the complex. Included are global positioning systems, panic buttons, biometric identifiers for drivers, intelligent onboard equipment, and untethered-trailer tracking.

Costs for these systems can range from a low of $250 to $800 to $2,500 per vehicle or per driver.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.