Transcript Three Point Seat Belts on Coaches

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 killed
Kempsey 1989, Two Buses, 35 bus occupants killed
Australian Design Rule
• Australian Design
68Rule 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 1994. 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
ADR 68 Dynamic
Test
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ADR68 Dynamic Test
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are needed to see this picture.
• Initial
concerns
about
cost
and
weight
of
Design of Seats
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 threepoint 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
NHTSA
Crash tests
of school
Crash
Tests
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.
• 1997 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