Auto Extrication: School Bus Anatomy

School Buses exist throughout every community in the United States and even more I suburban areas where students use the transportation to get to their schools. According to statistics from the National Highway Traffic Safety Administration (2011) there were over 370,000 fatal motor vehicle traffic crashes and of those, over 1,200 were classified as school transportation-related (NHTSA). Only eight percent of those victims were occupants of school transportation vehicles but by understanding the anatomy and features of a standard school bus, it may assist with how fire/rescue units operate on scene. An incident that involves a school bus may have one patient or several and this potential stresses why it is important to be prepared to handle the situation as a mass causality incident, MCI. Whether the passengers are young or old it is important to know the exits of the vehicle and the capabilities of the vehicle to make more exits if needed.

Photo 1This photo shows the orientation of an adult passenger when sitting in a normal position. Notice the three reinforced ribs on the side of the bus and how they line up on a person. The top rib is just under the shoulder, the middle rib is inline with the seat, and the bottom rib is just above floor level.

Photo 2School bus accidents have the potential to be deemed as MCIs. This may require a mutual aid response from other fire/rescue agencies to assist with stabilization, patient care, and removal. Note the use of the emergency exit window, a short roof ladder can be affixed to the opening to create a stable ramp for a stokes basket. Using an A-frame ladder may also assist with operating with height to make certain cuts in the process.

Photo 3The reinforced and colored ribs on the side of a bus are used as reference points for the seating area. When in tact it allows for the energy of an impact to be dispersed to the entire side of the vehicle rather the direct impact area.

Photo 4The cutaway of the sidewall of the bus shows how thin the material is on interior/exterior walls and in between there is a packed insulation. Note the triangular form of the reinforcing ribs and how thin all of the material is.

Photo 5Once the insulation is removed the vertical reinforcement that makes up the window frame continues through the body. Note again the reinforced ribs.

Photo 6The cut away of the vertical posts when cut by a sawzall.

Photo 7When using hydraulic cutting tools the brute force will cause the metal of the sidewall to become mangled and may make the operation a bit tougher. Once the area begins to open up the tool may not have enough space to continue fitting through the cut area. A good alternative is using finer tools such as sawzalls and circular saws.

Photo 8Once the exterior layer is removed the more rigid kick paneling may be also removed in order to fully open up a section and gain access below the seating level.

Photo 9This photo shows the top notch of the steel frame of the vehicle. On the sidewalls are removed this area will be exposed. The frame, as in most vehicles, is not designed to by cut easily due to the integrity of the material. This frame (as seen at the bottom half of photo 8) is the location where other smaller vehicle may become wedged under in a multi-car motor vehicle incident.

Summary:

  • Understand the capabilities of your tools.
  • Thin metal will shred and turn to “swiss cheese”.
  • These incidents may range from simple to very complex so be aware and prepared.
REFERENCE:
NHTSA, HTTP://WWW-NRD.NHTSA.DOT.GOV/PUBS/811396.PDF

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