THOMAS BUILT Download PDF Report
Thomas Built Buses submitted a model SLF 200/30 Foot, diesel powered 29 seat/30-foot bus, for a 12 year/500,000 mile STURAA test. The odometer reading at the time of delivery was 1,400.0 miles. Testing started on June 5, 2000, and was completed on January 12, 2001. 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 27, 2000 and was completed on January 2, 2001.
The first segment of the structural durability test was performed with the bus loaded to a GVW of 25,200 lbs. The middle segment was performed at a SLW of 21,750 lbs and the final segment was performed at a CW of 17,225 lbs. Durability driving resulted in unscheduled maintenance that consisted of a variety of subsystem failures. 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. Problems are listed by class as defined in Section 2. The test bus encountered no Class 1 or Class 2 failures. Of the twenty-nine reported failures, twelve were Class 3 and seventeen were Class 4.
The Safety Test, a double-lane change (obstacle avoidance ) test was performed safely 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 31.68 seconds.
The Shakedown Test produced a maximum final loaded deflection of 0.192 inches under a distributed static load of 21,375 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 as designed. Water leakage was observed during the test at the bottom of the left rear window.
The Static Towing Test was performed using a target load (towing force) of 20,670 lbs. All four pulls were completed to the full target test load with no damage or deformation observed. The Dynamic Towing Test was performed using a front flat tow. The towing interface was accomplished by using the manufacturer supplied tow eyes and tow bar. 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 3.1 inches.
A Fuel Economy Test was run on simulated central business district, arterial, and commuter courses. The results were 5.27 mpg, 4.98 mpg, and 9.08 mpg respectively; with an overall average of 5.87 mpg.
A series of Interior and Exterior Noise Tests was performed. This data is listed in Section 7.1 and 7.2 respectively.