There are safety systems built into every Blue Bird school bus. There are a couple of safety features integral to all Blue Bird school bus construction that should be kept in mind: the Colorado Rack Test and the Kentucky Pole Test. We want you to understand what they do to make the school bus safer, and why every school bus should be built this way.
Colorado Rack and Kentucky Pole Tests were not invented by or exclusive to Blue Bird. Some will downplay the importance of these critical structural benefits and will fall back on compliance to Motor Vehicle Safety Standards. When transporting our most precious cargo, our children, Blue Bird does not settle for minimum construction standards. Both Colorado Rack and Kentucky Pole Tests were developed because minimum FMVSS standard testing, according to Blue Bird, should be taken a step further.
Colorado Rack Test
All Blue Bird buses are Kentucky Pole tested and designed to keep all passengers safe by providing structural integrity to minimize outside intrusion.
The Colorado Rack Test was developed before most FMVSS implemented April 1, 1977. On September 11, 1971, a school bus in Gunnison, Colorado, was involved in a single-vehicle rollover crash, resulting in numerous injuries, as well as the death of 8 students and 1 adult. The structural damage to the school bus included a collapse of the roof at the bottom of the passenger windows. The Gunnison Watershed School District contracted with the Department of Mechanical Engineering, University of Colorado, to perform an engineering analysis of the crashworthiness of existing school bus body designs and to develop test criteria for evaluating those designs. As a result of the analysis, the University recommended a testing procedure currently referred to as the ‘Colorado Rack Test’ to verify the structural integrity of a school bus body design.
The Colorado Rack Test simulates a rollover crash by applying a constant load (based on the weight of a fully loaded bus) along the full length of the school bus body. The analysis determined that the worst location of load during rollover was in the region with the greatest curvature, so the Colorado Rack Tests requires the load to be applied to the bow immediately above the passenger windows. The test requires the application of two loading cycles to determine permanent deformation of the body structure. The Colorado Rack Test requires that a school bus body, when subjected to the prescribed load for 2 cycles, cannot deflect more than 5 1/8 inches measured diagonally. Each emergency exit of the bus (pushout windows, emergency doors, etc.) must meet FMVSS both during the full application of the load and after release of the load to insure that the emergency exits will be functional in the event of a rollover crash. This test is more severe than related FMVSS. In the mid-1970s, when FMVSS specific to school buses were underdevelopment for April 1977 we stripped down the bus construction to fully comply with the imminent standards. After all federal validation we decided to test Colorado Rack Test to see if the new federal regulations would meet the requirements. To our surprise, they do not meet. It is our belief the test developed by the University of Colorado is a better representative of the dynamics occurring in a vehicle rollover and needs to be provided with all school bus construction and why Blue Bird builds it with every school bus as standard construction.
Kentucky Pole Test
The Kentucky Pole Test was developed as a joint effort by the Kentucky Governor’s Task Force on School Bus Safety in 1989-1990, and is designed to verify that interior panels above the passenger windows will not separate and expose sharp edges in the event of a crash. The Kentucky Pole Test simulates a crash in which a school bus rolls over and strikes the roof against an object such as a tree or pole, and is a derivative of the Side Intrusion Test (which is included in the National School Bus Specifications & Procedures). The Kentucky Pole Test requires that when the school bus roof immediately above the passenger windows is impacted by an 8” diameter ‘pole’ with sufficient force to cause the roof to bend into the passenger compartment between 8 -10 inches there can be no separation of the body panels.
All school buses should be designed to keep passengers in the passenger compartment and provide structural integrity to minimize outside intrusion. There are numerous incidents every year which these construction standards will minimize injuries. We believe our children deserve this level of protection.