DAIMLER BUSES NORTH AMERICA, LTD Download PDF Report
Daimler Buses North America Ltd. submitted a model Orion VII EPA 10 CNG, CNG-powered 43 seat/41-foot bus, for a partial STURAA test in the 12 yr/500,000 mile test category. The Federal Transit Administration determined that the following test would be performed; 1. Maintainability, 3. Safety, 4. Performance, 6. Fuel Economy, 7. Noise Test and 8. Emissions Test. Testing started on October 27, 2011 and was completed on December 23, 2011. The Check-In section of the report provides a description of the bus and specifies its major components.
The interior of the bus is configured with seating for 43 passengers including the driver. Free floor space will accommodate 34 standing passengers resulting in a potential load of 77 persons. At 150 lbs per person, this load results in a measured Gross Vehicle Weight (GVW) of 43,130 lbs. Note: at GVL the load is 440 lbs over the front GAWR, 150 lbs over the rear GAWR and 590 lbs over the GVWR.
It should be noted that, after the test was completed, DBNA notified the Bus Research and Testing Center that they had changed the bus configuration to include Michelin XZU tires (versus originally equipped Goodyear G152 tires). This change effectively increases the Gross Vehicle Capacity to 15,660 lbs for the front axle and 27,760 lbs for the rear axle as opposed to the capacities indicated on the VIN plate of the bus delivered for testing (14,748 lbs front axle and 27,702 lbs rear axle). Notwithstanding the above tire change, the bus delivered for testing was tested in accordance to FTA standards utilizing the GVWR as indicated on the bus VIN plate.”
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 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 37.41 seconds. The Stopping Distance phase of the Brake Test was completed with the following results; for the Uniform High Friction Test average stopping distances were 33.10’ at 20 mph, 66.59’ at 30 mph, 113.64’ at 40 mph and 141.29’ at 45 mph. The average stopping distance for the Uniform Low Friction Test was 32.89’. There was no deviation from the test lane during the performance of the Stopping Distance phase. 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.
A Fuel Economy Test was run on simulated central business district, arterial, and commuter courses. The results were 0.61 M/lb, 0.65 M/lb, and 1.05 M/lb respectively; with an overall average of 0.70 M/lb.
A series of Interior, Exterior Noise Tests and Emissions Testing were performed. These data are listed in Section 7.1, 7.2 and 8. respectively.