Designline USA, LLC Download PDF Report
DesignLine USA submitted a model Enhanced Electric, diesel-powered 38 seat (including the driver) 42-foot bus, for a 12 yr/500,000 mile STURAA test. The odometer reading at the time of delivery was 10,254 miles. Testing started on May 13, 2011 and was completed on June 8, 2012. 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 May 27, 2011 and was completed on November 7, 2011. Note: extended testing of 1,500 miles for a new model cooling/circulating unit for the combiner was performed from March 25, 2012 to June 1, 2012.
The interior of the bus is configured with seating for 38 passengers including the driver. Free floor space will accommodate 43 standing passengers resulting in a potential load of 81 persons. At 150 lbs per person, this load results in a measured gross vehicle weight of 44,060 lbs. Note: at GVL the load is 1,060 lbs over the rear axle GAWR and 2,400 lbs over the GVWR. The first segment of the Structural Durability Test was performed with the bus loaded to a GVW of 44,060 lbs. The middle segment was performed at a seated load weight of 37,670 lbs and the final segment was performed at a curb weight of 31,810 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.
Effective January 1, 2010 the Federal Transit Administration determined that the total number of simulated passengers used for loading all test vehicles will be based on the full complement of seats and free-floor space available for standing passengers (150 lbs per passenger). The passenger loading used for dynamic testing will not be reduced in order to comply with Gross Axle Weight Ratings (GAWR’s) or the Gross Vehicle Weight Ratings (GVWR’s) declared by the manufacturer. Cases where the loading exceeds the GAWR and/or the GVWR will be noted accordingly. During the testing program, all test vehicles transported or operated over public roadways will be loaded to comply with the GAWR and GVWR specified by the manufacturer.
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 failures. Of the 51 reported failures, three were Class 2, 27 were Class 3 and 21 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 test is to be performed up to a maximum speed of 50 mph. This test vehicles top speed is 40 mph. The fitted curve of velocity vs. time is attached, followed by the calculated gradeability results. The Stopping Distance phase of the Brake Test was completed with the following results; for the Uniform High Friction Test average stopping distances were 28.15’ at 20 mph, 57.65’ at 30 mph, and 95.56’ at 40 mph. Note: data was obtained to a speed of 40 mph. The test bus could not obtain the maximum test speed of 45 mph; therefore, there is no data at that speed. The average stopping distance for the Uniform Low Friction Test was 22.39’. During the Stability phase of Brake Testing the test bus experienced no deviation from the test lane but did experience pull to the left during both approaches to the Split Friction Road surface. The Parking Brake phase was completed with the test bus maintaining the parked position for the full five minute period with no slip or roll observed in both the uphill and downhill positions.
The Shakedown Test produced a maximum final loaded deflection of 0.162 inches with a permanent set ranging between 0.001 to 0.005 inches under a distributed static load of 29,325 lbs. The Distortion Test was completed with all subsystems, doors and escape mechanisms operating properly. Water leakage was observed during the test at the 2nd window left side and at the roof antenna seal.
The Static Towing Test was performed using a target load (towing force) of 38,172 lbs. All four front pulls were completed to the full test load with no damage or deformation observed. The Dynamic Towing Test was performed by means of a front-lift tow. The towing interface was accomplished using a hydraulic under-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 3.63 inches.
A Fuel Economy Test was run on simulated central business district, arterial, and commuter courses. The results were 5.17 mpg, 9.04 mpg, and 6.03 mpg respectively; with an overall average of 6.07 mpg. Note: this bus has an electric motor for its final drive. The motor draws power from a battery pack, backed up by a diesel turbine. During fuel economy tests, the turbine gets turned on and off, depending on the state of charge of the battery packs. Thus a combination of two sources of power, namely diesel fuel and battery power are used during tests. The consumption of both these sources is recorded during the fuel economy tests and is presented in the report for the two clockwise and the two counterclockwise runs. The conventional fuel economy summary sheet is not included because the calculations therein are based only on diesel consumption.
A series of Interior and Exterior Noise Tests was performed. These data are listed in Section 7.1 and 7.2 respectively. The Emissions Test was performed. These results are available in Section 8 of this report.