Dupont Industries Inc. Download PDF Report
Dupont Industries Inc. submitted a model CT-181, diesel powered 33 seat bus, for a 12 yr/500,000 mile STURAA test. The odometer reading at the time of delivery was 11,608 miles. Testing started on August 25, 2000 and was completed on March 23, 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 was started on September 18, 2000 and was completed on February 28, 2001.
The interior of the bus is configured with seating for 33 passengers including the driver. Free floor space will accommodate 29 standing passengers resulting in a potential load of 62 persons. At 150 lbs per person, this load results in a calculated gross vehicle weight of 30,550 lbs. The first segment of the Structural Durability Test was performed with the bus loaded to a GVW of 30,550 lbs. The middle segment was performed at a seated load weight of 26,150 lbs and the final segment was performed at a curb weight of 21,450 lbs. Durability driving resulted in unscheduled maintenance and failures that involved a variety of subsystems. A description of failures, and a complete and detailed listing of scheduled and unscheduled maintenance 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 listed by class as defined in Section 2. The test bus encountered no Class 1 or Class 2 failures. Of the twenty-four reported failures, fifteen were Class 3 and nine were Class 4.
The Safety Test, (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 30.17 seconds.
The Shakedown Test produced a maximum final loaded deflection of 0.129 inches with a permanent set ranging between 0.000 to 0.004 inches under a distributed static load of 23,250 lbs. The Distortion Test was completed with all subsystems, doors and escape mechanisms operating properly. No water leakage observed throughout the test. All subsystems operated properly.
The Static Towing Test was performed using a target load (towing force) of 25,740 lbs. Both front and rear pulls were terminated during the 20° upward pulls due to deformation of surrounding structures. The Dynamic Towing Test was performed by means of a front-lift tow. The towing interface was accomplished using a hydraulic-lift wrecker. 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, and the minimum jacking clearance observed with a tire deflated was 7.5 inches.
A Fuel Economy Test was run on simulated central business district, arterial, and commuter courses. The results were 3.37 mpg, 3.66 mpg, and 5.36 mpg respectively; with an overall average of 3.87 mpg.
A series of Interior and Exterior Noise Tests was performed. These data are listed in Section 7.1 and 7.2 respectively.