METROTRANS CORPORATION Download PDF Report
The Metrotrans Corporation submitted a model Classic 24' Raised Roof, diesel powered 15 seat/25-foot bus, for a 5 yr/150,000 mile STURAA test. The odometer reading at the time of delivery was 1,858.0 miles. The testing started on June 1, 1998, and was completed on August 7, 1998. 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 June 10, 1998 and was completed on July 29, 1998.
The first segment of the Structural Durability Test was performed with the bus loaded to a GVW of 13,570 lb. The number of standing passengers was reduced from 6 standees and two wheelchair positions, to 0 standees and one wheelchair position (600 lb per. wheelchair position). This reduction in passenger weight was necessary to avoid exceeding the GAWR (9,450 lbs.) of the rear axle. The middle SLW segment was performed at the same 13,570 lb. The final segment was performed at a curb weight of 10,690 lb. 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), were found to be readily accessible and no restrictions were noted. The only restriction noted during testing was in gaining access to the fuel filter.
The Reliability Section compiles failures that occurred during Structural Durability Testing. Unscheduled breakdowns are classified according to subsystems. The data in this section are arranged so that those subsystems with more frequent problems are apparent. Failures are classified according to the severity as defined in Section 2. The test bus encountered no Class1 or Class 2 failures. Of the remaining seventeen reported failures, eight were Class 3 and nine 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 18.13 seconds.
The Shakedown Test produced a maximum final loaded deflection of 0.461 inches with a permanent set ranging between -0.001 to 0.004 inches under a distributed static load of 9,075 lb. The Distortion Test was completed with water leakage observed during all positions of testing at the top door seal of the handicap door and above the driver where the cab meets the body. The results of this test are indicated on the following data forms. All subsystems operated properly. The test bus was not equipped with any type of tow eyes or tow hooks; therefore, the Static Towing Test was not performed. The Dynamic Towing Test was performed by means of a front lift tow. Due to the lack of tow eyes or tow hooks, therefore the towing interface was accomplished by placing wooden beams under the frame and attaching chains to the front axle. Rear towing is not recommended. No problems, deformation, or damage was noted during testing. The Jacking and Hoisting Tests were also performed without incident. The bus was found to be stable on the jack stands, and the minimum jacking clearance observed with a tire deflated was 8.70 inches.
A Fuel Economy Test was run on simulated central business district, arterial, and commuter courses. The results were 7.17 mpg, 7.57 mpg, and 13.53 mpg respectively; with an overall average of 8.42 mpg.
A series of Interior and Exterior Noise Tests was performed. These data are listed in section 7.1 and 7.2 respectively.