Tank modifications, suspension maintenance, lighting top TTMA session
Feb 1, 2010 12:00 PM, By Rick Weber
NTTC Cargo Tank Maintenance Seminar...
Modifications require current code compliance. Examples: modified overturns on an MC307 tank must meet DOT400 series requirements; modifying a bumper requires DCE approval and DOT400 series compliance; and a DCE, RI, or AI should be able to describe the requirements of a modification.
“It's much easier to modify DOT400 series tanks vs MC300 series,” Plumski said.
Modification documents include:
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HM-183 forms. The VIPKTL test documentation notes changes made and tests required to certify changes, and has the signatures of the RI and CTMV owner.
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Supplemental Certificate of Compliance, describing the modification and documents DCE and including the approval of the responsible official and RI.
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ASME Form R2 for ASME trailer modifications. That includes a description of modifications, drawings, design certification with DCE signature, certificate of design change review with AI signature, construction certification with RI signature, and certificate of inspection with AI signature.
The owner of the CTMV must keep the ownership and repair/modification record throughout ownership and one year after ownership ceases. These documents include: COC, U1A (ASME), HM183 documents, supplemental COCs, ASME Form R2s, and records of repair.
Trailer Suspension Maintenance
Rick Rickman, Ridewell Suspensions
Rickman said the air springs, structure, and ride height should be inspected every 1,000 miles, and the bushings every 50,000 miles. Fastener torque should be tightened after the first 6,000 miles of operation and then every 50,000 miles.
“When inspecting air springs, check for proper inflation, look for chafing, and make sure everything is as should be,” he said. “Chafing is generally on the margins as it rides up and down on the piston. Make sure it's not rubbing on something, which generally is caused by inflation problems. If you're running it too high, you will get overextension of the air spring.”
He said bushing problems can arise from breakdown of the natural rubber over time or, in a severe application, by failure of the bond between the rubber and the metal inner sleeve. The bushings should be checked if any of these conditions are observed: uneven tire wear; abnormal forward-aft or lateral movement of the axle during operation; rapid degradation of wear washers; or abnormal noises coming from the suspension.
To check the suspension, insert the flat end of a pry-bar between the sidewall of the hanger and the eye of the beam. Applying moderate side load to the pry-bar, look for any relatively large or easy movement of the beam in relation to the hanger. A small amount of movement under load due to deflection of the rubber is normal and acceptable. Repeat the process on the other side of the hanger. If large or easy movement is noted, drop the beams down per the bushing replacement procedure for further inspection of the bushing, and replace if necessary.
“The bushings is a critical part of the suspension,” he said. “In fact, it is probably the most important part.”
A Lighting Technology Update
Brad Van Riper, Senior VP & Chief Technology Officer, Truck-Lite Co Inc
Van Riper said that since light emitting diodes (LEDs) were introduced in 1991, lumens per watt have increased on an exponential curve, and the output of LEDs is going to double every 18-24 months. By 2012, LEDs will feature 200 lumens per watt, and research and lab levels already have hit 249.
“An incandescent 60-watt light bulb produces about 820 lumens, so the LED is an extremely robust technology, and it's getting brighter,” he said.
He said a contract has been awarded to the University of Michigan Transportation Research Institute to develop a performance-based lighting standard to replace FMVSS 108.
“The current FMVSS 108 is an equipment-based standard, which means a vehicle is in compliance if the lights meet the SAE standards that are prescribed in the rule,” he said. “The idea with a performance-based standard will be a lot less design- restricted. If you want to create a new look for your trailer, you can combine devices to create a performance-based design.”
He gave some lighting updates specific to tank trailers:
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Explosion-proof lighting. “It has been something bantered about, but there are really no specific regulations related to lighting,” Van Riper said. “Truck-Lite has developed its own explosion-proof standard. We take a full wire harness and all lamps, place the assembly in a chamber, introduce a 5% propane environment, and operate the lighting assembly for a period of time. We do our own self-certification with an independent lab.”
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Clearance lamps, side markers, and identification lamps. He said there really is no difference between them. “They're all the same lamp,” he said. “It's a function of the location.”
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PC lamp. It is a combination clearance and side marker that has the ability to replace the two lamps with one lamp. “The PC is typically a front- or rear-mounted combination clearance showing the overall width of a vehicle, and a side marker showing the rear-most part of the vehicle. It's mounted on a 45-degree angle. There's a lot of confusion within fleets as well as OEMs about what the difference is.”
