Low Idle Research Articles

Assessment of Ergonomic Exposures among Operators of Construction Equipment

Although numerous studies have shown an association between operation of heavy construction equipment and symptoms of musculoskeletal disorders, very little research has been performed that objectively characterizes the exposure of operating engineers to ergonomic hazards. The objectives of this study were to evaluate: 1) the vibration at the seat/operator interface (X, Y, and Z axes); 2) the transmissibility of vibration in the Z-axis; 3) the psychophysical ratings of vibration level and vibration discomfort; and 4) the postural requirements of the job. The results of this study indicate that the digging operation had higher levels of total weighted acceleration than high or low idling. The transmissibility data showed that the seat was amplifying vibration particularly in the lower frequencies. The seats in the equipment demonstrated that they may not be sufficient in protecting operators from long-term effects of vibration exposure. There was high positive correlation among the subjective ratings (vibration discomfort and vibration level), but moderate positive correlation between subjective ratings and quantitative vibration levels. The postural evaluations revealed that the operators were required to assume awkward postures of the neck, shoulder, and trunk while performing their jobs.

Gaseous and Particulate Emissions From Diesel Locomotive Engines

Steady-state gaseous and particulate emissions data are presented from two 12-cylinder diesel locomotive engines. The two laboratory engines, a EMD 645E3B and a GE 7FDL, are rated at 1860 kW (2500 hp) and are representative of the majority of the locomotive fleet in North America. Each engine was tested for total hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NOx), and particulate. Emissions were measured at all steady-state operating conditions that make up the eight discrete locomotive throttle notch positions, plus idle, low idle, and dynamic brake. Emissions are reported for each engine with two different diesel fuels: a baseline diesel fuel with a sulfur content of 0.33 weight percent, and a commercially available low-sulfur diesel fuel with a sulfur content of 0.01 weight percent.

Developmental Study of Impulse Type Oil Turbine

To take out mechanical power from high pressure oil, an impulse type oil turbine of a construction similar to the Terry steam turbine was developed on the basis of the fundamental experiment and the study of the performance of a test turbine. The turbine mainly consists of a nozzle, a turbine wheel with many deflection grooves and several fixed deflection boxes. Comparing with a positive-displacement type oil moter, the oil turbine has such features as feasibility of high rotational speed, low idling resistance, simple construction etc. As the fundamental experiment, a static test of two-dimensional deflectors was carried out and design data for a deflector with minimum losses were obtained. Based on the data obtained from the above, a test turbine was built, and its performance was measured at different rotational speeds and also at different jet velocities. From this study the limit of performance of an impulse type oil turbine was clarified, and the necessary data for designing an efficient oil turbine were obtained.

Developmental Study of Impulse Type Oil Turbine

To take out mechanical power from high pressure oil, impulse type oil turbine of a construction similar to Terry steam turbine was developed on the basis of the fundamental experiment and the study of performance of test turbine. The turbine mainly consists of a nozzle, aturbine wheel with many deflection grooves and several fixed deflection boxes. Comparing with positive-displacement type oil motor, the oil turbine has distinguished points such as feasibility of high rotational speed, low idling resistance, simple construction etc. As the fundamental experiment, the static test of two-dimensional deflection grooves was carried out and design data for deflection groove with minimum losses were given. Based on the data obtained from the above, a test turbine was built, and its performance was measured at different rotational speed and also at different jet velocity. From this study the limit of performance of impulse type oil turbine was clarified, and the necessary data for designing oil turbine were obtained