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The impact dynamics of full-scale heavy-vehicle rollover events were quantitatively evaluated. Videotapes of a variety of rollover events were collected. One tractor-semitrailer combination was rolled by a sudden steer, two combinations rolled after a barrier impact, and one straight truck was pulled down an embankment. The videotapes were analyzed to estimate the vehicles' roll rates and their vertical velocities upon striking the ground. These experimental values corroborate the results of vehicle dynamic simulations that had been previously conducted to replicate actual rollover crashes. Those crashes were the subject of an NTSB Special Investigation Report that examined the crashworthiness of cargo tank trucks carrying hazardous materials.

A program has been completed to evaluate ultra-low sulfur diesel fuels and passive diesel particulate filters (DPFs) in truck and bus fleets operating in southern California. The fuels, ECD and ECD-1, are produced by ARCO (a BP Company) and have less than 15 ppm sulfur content. Vehicles were retrofitted with two types of catalyzed DPFs, and operated on ultra-low sulfur diesel fuel for over one year. Exhaust emissions, fuel economy and operating cost data were collected for the test vehicles, and compared with baseline control vehicles. Regulated emissions are presented from two rounds of tests. The first round emissions tests were conducted shortly after the vehicles were retrofitted with the DPFs. The second round emissions tests were conducted following approximately one year of operation. Several of the vehicles retrofitted with DPFs accumulated well over 100,000 miles of operation between test rounds.

A commercially available axial piston water hydraulic pump (Danfoss PAH 10) was evaluated under a range of pressures, speeds and fluid temperatures. Three candidate fluids were used in this evaluation: filtered tap water (as a baseline), a mixture of tap water and polypropylene glycol based antifreeze, and finally a mixture of synthetic seawater and polypropylene glycol based antifreeze. The effect of the fluids and temperatures on the pump efficiency was observed. The evaluation provides the basis for the design of a non-polluting variable flow water-antifreeze hydraulic power source.

The ability of performance-based brake testers (PBBTsa) to accurately determine the braking capability of commercial vehicles was investigated through a field study of over 2,800 trucks and buses. Under certain conditions, good agreement was found between the observation of brake-related defects by visual inspection and the measurement of weak brake forces by a PBBT. It was determined that the PBBTs' assessment was an independent measure of a vehicle's as-is braking capability, and should not be expected to correlate well with a visual inspection under any condition. It was also determined that predictions of stopping capability should be possible combining the PBBT results of the brake force and axle load measurements with certain assumptions regarding brake application time and road/tire coefficient of friction.

The objective of this project, which is supported by the U.S. Department of Energy (DOE) through the National Renewable Energy Laboratory (NREL), is to provide a comprehensive comparison of heavy-duty trucks operating on alternative fuels and diesel fuel. Data collection from up to eight sites is planned. This paper summarizes the design of the project and early results from the first two sites. Data collection is planned for operations, maintenance, truck system descriptions, emissions, duty cycle, safety incidents, and capital costs and operating costs associated with the use of alternative fuels in trucking.

Experimental research on an integrated Bosch reactor and water-vapor electrolysis unit for oxygen recovery from carbon dioxide is described. A principal feature of the integration is the use of regenerable solid absorbent for periodic water-vapor transfer in a gravity-independent manner to avoid gas-liquid separation problems. The carbon dioxide reduction subsystem was based on batch-wise operation of two Bosch reactors to permit periodic shutdown for carbon removal. Experimental results are presented on operation of the Bosch reactor which include catalyst activation, recycle rate, recycle gas composition, reactor temperature, catalyst consumption, packing density of carbon and life of reactor materials during extended operation. Experimental data are presented on the solid-absorbent unit with silica gel and synthetic zeolites for removal of water vapor from the Bosch reaction and for water-vapor feed to an electrolysis unit.

After several alternative procedures were investigated for preparing chromium-plated zinc die castings for painting, one procedure proved best for contaminated chromium surfaces. This procedure included six steps: (1) alkaline spray cleaning, (2) electrolytic alkaline cleaning, (3) rinsing with high-purity water with a specific resistance of 500,000-700,000 ohm-cm, (4) immersing in chromic acid solution (0.05 oz/gal) at 150 F for 2 minutes, or treating cathodically in 0.7 oz/gal of sodium dichromate with a current density of 0.05 amp/sq ft for 30-60 sec, (5) rinsing with high-purity water, (6) forced-air drying with filtered air at 15 psi. Good adherence was obtained by following these procedures and painting with a single coat of acrylic or alkyd-resin paint. Other preparation procedures resulted in inferior paint adherence.