TRANSIT TRUCK TEST PROGRAM

THE PROGRAM DISCUSSED WAS ORIGINATED TO DETERMINE HOW THE OPERATIONAL CHARACTERISTICS OF A RAILED VEHICLE MIGHT BE IMPROVED. A PRIMARY OBJECTIVE WAS TO DEVISE A MEANS OF PROVIDING A GOOD RIDE FOR PASSENGERS ON WESTINGHOUSE COMPANY'S WABCO RAPID TRANSIT TRUCK THROUGH HYDRAIR SUSPENSION AND TRUCK COMPONENTS. THE REDUCTION OF WHEEL AND RAIL WEAR AND THE REDUCTION OF NOISE LEVEL WERE ALSO OF UTMOST INTEREST. ANOTHER MAJOR CONCERN OF THE PROJECT WAS THE INVESTIGATION OF THE REDUCTION OF NOSING OR OSCILLATION OF THE TRUCK ABOUT THE CENTERPIN THROUGH THE USE OF A TORQUE PROPORTIONING DIFFERENTIAL AND WHEEL TREAD SHAPE. THE COMPANY DETERMINED THAT TRUCK OPERATION COULD BE IMPROVED IN A NUMBER OF WAYS BY ALLOWING THE WHEELS ON AN AXLE TO ROLL AT THEIR DESIRED SPEED, ESPECIALLY WHEN OPERATING IN A CURVE. DIFFERENTIAL TESTS PROVED THAT, IN A RAIL SYSTEM, ONE WHEEL COULD TRANSMIT AT LEAST 3.4 TIMES THE TORQUE TO THE ADJACENT WHEEL WITHOUT ALLOWING THE OTHER WHEEL TO CHANGE ITS RATE OF SPEED. THE ADVANTAGES OF THIS CONCEPT ARE DISCUSSED. HYDRAIR SUSPENSION, BASICALLY A HYDRO-PNEUMATIC SPRING PRODUCING A NON-LINEAR SPRING RATE COMBINED WITH THE DAMPING WHICH OCCURS WHENEVER MOTION OCCURS, WAS APPLIED TO PROVIDE A STIFFENING ACTION WHERE THE LOAD INCREASES, THUS REDUCING THE ROLL TENDENCY OF THE CAR BODY AND PROVIDING A MORE CONSTANT NATURAL FREQUENCY BETWEEN THE EMPTY AND LOADED CONDITIONS. THE VERTICAL RIDE EXPERIENCED IN THE CAR WAS VERY STABLE PROVIDING VERY SMALL ROLL AND YAW AMPLITUDES IN THE LATERAL FORCE TO THE PASSENGER; THERE WAS PRACTICALLY NO PITCHING MOTION IN THE CAR. IN THE AREA DIRECTLY OVER THE CENTERPIN, HOWEVER, THE FLOOR WAS SUBJECT TO A VIBRATION STEMMING FROM THE SHRINKAGE OF A NON-STANDARD SUSPENSION BEARING. THE FAILURE OF THE SUSPENSION BEARING WAS NOT INHERENT IN THE DESIGN OF THE TRUCK OR OF THE HYDRAIR SUSPENSION SYSTEM PRINCIPLE. /UMTA/

  • Supplemental Notes:
    • PROJ NO CAL-MTD-2
  • Corporate Authors:

    Letourneau - Westinghouse Co

    ,    
  • Publication Date: 1966-7

Subject/Index Terms

Filing Info

  • Accession Number: 00241782
  • Record Type: Publication
  • Source Agency: Urban Mass Transportation Administration
  • Files: TRIS, USDOT
  • Created Date: Oct 9 1981 12:00AM