SUPREME CORPORATION Download PDF Report
The Supreme Corporation submitted a model Trolley, diesel powered 30 seat/36-foot bus, for a 10 year/350,000 mile STURAA test. The odometer reading at the time of delivery was 2,203 miles. Testing started on June 8, 2000 and was completed on November 3, 2000. The Check-In section of the report provides a description of the bus and specifies its major components.
The primary part of the test program is the Structural Durability Test, which also provides the information for the Maintainability and Reliability results. The Structural Durability Test started on June 15, 2000 and was completed on October 25, 2000.
The interior of the bus is configured with seating for 30 passengers including the driver. Additionally, free floor space will accommodate 28 standing passengers resulting in a potential load of 58 persons. At 150 lbs per person, this load results in a total vehicle weight of 27,900 lbs and exceeds the GAWR (10,000 lbs) of front axle. In order to avoid exceeding the axle weight rating, ballast simulating 13 standing passengers (1,950 lbs) was removed. Elimination of the 13 standing passenger positions resulted in an adjusted gross vehicle weight of 25,850 lbs. The SLW segment was performed at 23,700 lbs and the final segment of the test was performed at a CW of 19,200 lbs. Durability driving resulted in several failures that required unscheduled maintenance. A description of failures, and a complete and detailed listing of scheduled and unscheduled maintenance, is provided in the Maintainability section of this report.
The components covered in Section 1.3 (Repair and/or Replacement of Selected Subsystems) along with all other components encountered during testing were found to be readily accessible and no restrictions were noted.
The Reliability section compiles failures that occurred during structural durability testing. Breakdowns are classified according to subsystems. The data in this section are arranged so that those subsystems with more frequent problems are apparent. The problems are listed by class as defined in Section 2. The test bus encountered no Class 1 or Class 2 failures. Of the 17 reported failures, 7 were Class 3 and 10 were Class 4.
The Safety Test, a double-lane change maneuver, was safely performed in both right-hand and left-hand directions up to a maximum test speed of 45 mph. The performance of the bus is illustrated by a speed vs. time plot. Acceleration and gradeability test data are provided in Section 4, Performance. The average time to obtain 50 mph was 25.33 seconds.
The Shakedown Test produced a maximum final loaded deflection of 0.265 inches under a distributed static load of 21,750 lbs. The test resulted in essentially no permanent deflection of the structure. The Distortion Test was completed with all subsystems, doors and escape mechanism operating properly. No water leakage was observed during the test. The test bus had no tow eyes or tow hooks; therefore, the Static Towing Test was not performed. The Dynamic Towing Test was completed by performing a front lift tow. The towing interface was accomplished by using a hydraulic, under-wheel lift. The bus was towed without incident and no damage resulted from the test. The manufacturer does not recommend towing the bus from the rear; therefore, a rear test was not performed. The Jacking and Hoisting Tests were performed without incident. The bus was found to be stable on the jack stands and the minimum jacking clearance, measured with a tire deflated, was 6.0 inches.
A Fuel Economy Test was run on simulated central business district, arterial, and commuter courses. The results were 3.77 mpg, 4.60 mpg, and 7.76 mpg respectively; with an overall average of 4.70 mpg.
A series of Interior and Exterior Noise Tests was performed. This data is listed in Section 7.1 and 7.2 respectively.