NORTH AMERICAN BUS INDUSTRIES Download PDF Report
North American Bus Industries, Inc. submitted a model 40C LFW CNG, CNG powered 40 seat/40-foot bus, for a 12 yr/500,000 mile STURAA test. The odometer reading at the time of delivery was 183.0 miles. Testing started on January 21, 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 was started on February 10, 2000 and was completed on September 9, 2000.
The first segment of the Structural Durability Test was performed with the bus loaded to a GVW of 36,930 lbs. The middle segment was performed at a SLW of 30,850 lbs and the final segment was performed at a curb weight of 24,950 lbs. Durability driving resulted in unscheduled maintenance that consisted of a variety of subsystem failures. These unscheduled maintenance breakdowns can be found in a complete and detailed listing of scheduled and unscheduled maintenance, which is provided in the Maintainability section of this report.
Accessibility, in general, was adequate, 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 also listed by class as defined in Section 2. The test bus encountered no Class 1 or Class 2 failures. Of the sixty-one reported failures, forty-nine were Class 3 and twelve were Class 4.
A Double-Lane Change (obstacle avoidance) Test 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 33.07 seconds.
The Shakedown Test produced a maximum final loaded deflection of 0.261 inches with a permanent set ranging between -0.002 to 0.005 inches under a distributed static load of 31,125 lbs. The Distortion Test was completed with all subsystems, doors and escape mechanisms operating properly. Water leakage was observed throughout the test at most windows on both sides of the bus. All subsystems operated properly. All four front pulls of the Static Towing Test were performed to the target test load of 29,940 lbs. No damage or deformation was observed. The test bus is not equipped for rear towing; therefore, a rear test was not performed. The Dynamic Towing Test was performed by means of a front lift tow. The towing interface was accomplished with a hydraulic under 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 also performed without incident. The bus was found to be stable on the jack stands. The minimum jacking clearance observed with a tire deflated was 4.4 inches.
A Fuel Economy Test was run on simulated central business district, arterial, and commuter courses. The results were 0.54 M/lb, 0.74 M/lb, and 1.02 M/lb respectively; with an overall average of 0.68 M/lb.
A series of Interior and Exterior Noise Tests was performed. These data are listed in Section 7.1 and 7.2 respectively.