Presentation on theme: "Three Point Seat Belts on Coaches - The First Decade in Australia Michael Griffiths Road Safety Solutions Sydney Michael Paine Renae Moore."— Presentation transcript:
Three Point Seat Belts on Coaches - The First Decade in Australia Michael Griffiths Road Safety Solutions Sydney Michael Paine Renae Moore
Background International “harmonization” has obvious benefits but it can also lead to widespread adoption of the lowest common denominator and stifle innovation Sometimes it takes prominent media coverage to provide the motivation to go beyond “feel good” safety standards - such a situation occurred in Australia in the late 1980s. Early in 1989 Australia was in the process of harmonizing with European coach occupant regulations (ECE Regulation 80) - “Compartmentisation” at 10g (no seat belts)
Coach Crashes in 1989 Late in 1989 two horrific coach crashes in New South Wales led to demands for improved bus occupant protection Crash investigations revealed that ECE Regulation 80 protection would have done little to prevent fatalities in these severe crashes. Three point seat belts able to withstand 20g deceleration were needed. Grafton 1989, Bus & truck, 18 bus occupants killedKempsey 1989, Two Buses, 35 bus occupants killed
Australian Design Rule 68 Australian Design Rule 68 - developed as a result of these crash investigations - requires three point seat belts mounted on seats (not bus frame). Applies to all Australian coaches built from July Route service buses are exempt Dynamic test with 20g deceleration. Seat assembly must withstand loads from restrained occupant and an unrestrained occupant striking the rear of the seat.
ADR 68 Dynamic Test
Design of Seats Initial concerns about cost and weight of ADR 68 seats have proved to be unfounded. RTA Crashlab assisted with the development and testing of prototype seats. Innovative designs were developed that were similar in weight to the replaced seats McConnell Seats
Retro-fitting Seat Belts ADR 68 has led to strong consumer demand for three- point seat belts on coaches used for charter and excursions. A significant industry has developed for fitting ADR 68 seats to older buses.
Retro-fitting Seat Belts A National Code of Practice is being prepared to ensure that these installations meet the same high standards as new coaches Proposed that it will require: Ban lap belts Any seat belt must be integrated 3-point proven to 20g (best solution is ADR68 seats) Will also apply to small buses
Bus Crash Tests NHTSA Crash tests of school buses confirmed the high crash pulses in severe impacts. This full-frontal barrier test at 50km/h is equivalent to a head-on crash between vehicles of similar mass travelling at 60km/h Crash pulse exceeded 12g This supports the 20g estimate for 100km/h head-on crashes
Exposure to severe crashes 29% of fatal bus crashes in Australia are head-on Australian coaches have a relatively high exposure to head-on crashes with other heavy vehicles travelling at 100km/h 10g restraint systems could be expected to fail in these crashes - resulting in severe injuries
Crash Experience with ADR 68 Fortunately, there are only a few cases of coaches built to ADR 68 being involved in severe crashes Tenterfield, NSW: 47 of 52 passengers were wearing three point seat belts and had no serious injuries. Unrestrained relief driver asleep in bunk and child sleeping in aisle were killed. Estimated 6g offset frontal crash.
Small Buses Cranfield Impact Centre studied 25 minibus crashes and conducted eleven crash tests Recommended ADR 68-like requirements and concluded that "Provided a satisfactory restraint system is fitted to these seats, the passengers [in these seats] have the opportunity to survive exceedingly severe impacts...”
Small Bus Cranfield research confirms the need for 20g restraint systems in small buses (in any case the delta V is likely to be higher than for large buses) ADR68 seats have been successfully installed in several popular models of small bus in Australia. Coaster with ADR68 seats
Small Bus Crashes NHTSA found rollover risk is 3 x higher with a laden small bus. Structure usually adequate so seat belts can be highly effective in rollovers of small buses. Recent fatal rollover crash in Australia showed seat belts would have been highly effective No seat belts 2 ejection fatalities
Conclusions These standards set world leading practice for bus occupant protection at 20g 15 years of development has resulted in seats which are economical and lightweight (no longer any economic reason for regulating lesser protection) Retrofit cost is approx US$750 per seat (Original equipment cost is less) Remaining challenge is better wearing rates