Operations Strategy

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Rollovers Seatbelts
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What is a ROLLOVER?
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• What is a ROLLOVER?
• a single vehicle incident
• vehicle rolls 90 deg or more
• driver looses control

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Does PDO have many ROLLOVERS?
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Rollovers

• PDO many rollovers every year!

2000 2001 2002 2003 2004 2005 2006 2007 td
Rollovers 43 33 22 22 21 45 54 45
Km 118 123 133 139 145 151 161 175
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Rollover !!
19-Oct-2007 on the way to Bahja Driver
        seatbelt minor injury Passenger
Seatbelt minor injury Passenger  NO seatbelt
- DEAD
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9-Sept-2007 on the way to Haima Driver
        NO seatbelt - DEAD Passenger NO seatbelt
- DEAD Passenger Seatbelt minor injury
Rollover !!
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Rollover !!
2-Aug-2007 Qarn Alam Driver died no
seatbelt head crushed under vehicle
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23-Oct-2006Marmul-Thumrait 7 km before Harweel
junction Driver 39 yrs old, died Speed at least
140 km/hr PDO Spec vehicle tampered! Seatbelt
did not help anymore
Rollover !!
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150 km/hr
March/2001 Maqbool Faisal Died
Rollover !!
Tyreblew
Anything that goes wrong at high SPEED is a BIG
problem!!
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Straight blacktop Fahud-Nahada
Veered off to the rightOvercorrected, rolled
4xClassic S patternNO rollover bar
30/Oct/01 LTI Permanent Total Disability
Rollover !!
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Blacktop road Fahud- Nizwa
20/Nov/01 Fatality LTI
Rollover !!
Car moved right at high speed. Driver over
corrected and got into an S patternRolled
Flipped.
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2 man came out alive. They were wearing their
seatbelts. 1 man DIED. He was NOT wearing his
seatbeltNO Seatbelt DEATH
Nimr to Muscat 13th June 98
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What would you prefer? a Rollover or a Head on
Collision
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• Rollovers are killers!

Video 1 Video 2
No of accidents
No of death
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• Common features of rollovers
• Speed (80 km/hr can be too fast !!)
• Mostly 4 WD (high Centre of Gravity cars)
• Most on straight roads
• Most classic S curves
• Many on blacktop roads at high speed
• Few tyre blow-out, junction/speed

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• Why does a vehicle roll ?
• How many rolls will it do ?
• Simply Physics !
• Understand the physics
• to understand the controls

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• We have a vehicle at speed why does it roll?

Centre of Gravity
M mass (kg) v speed (m/s) g
gravitational acceleration
Gravity Force GF M x g ( constant)
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• Why does it roll?.... Because of centrifugal
  force!

Centre of Gravity
M mass (kg) v speed (m/s) r turn radius
(m) g gravitational acceleration
Mv2 CF ------- r
Centrifugal Force (CF)
Gravity Force GF M x g ( constant)
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• Why does it roll?.... Because of centrifugal
  force!

Centre of Gravity
M mass (kg) v speed (m/s) r turn radius
(m) g gravitational acceleration
Mv2 CF ------- r
Centrifugal Force (CF)
CF increases with- v higher (higher speed)- r
smaller (sharper turn)
Gravity Force GF M x g ( constant)
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• We have a rolling vehicle at speed
• How many rolls will it do ?

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• We have a rolling vehicle at speed
• How many rolls will it do ?
• Kinetic Energy ½ Mv2
• This energy is dissipated during the rolls
• More energy more rolls!
• Energy goes up with the square of the speed!

M mass (kg) v speed (m/s)
Km/hr Energy in of 100 km/hr
80 64
100 100
120 144
140 196
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• Next 4 slides
• 2 RTAs are shown
• they are almost the same
• compare them
• see what the differences are
• discuss why the outcome was different

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25/2/2003
14/3/2003
140 km/hr
80 km/hr
2 Black Top Roads2 Cars driving
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25/2/2003
14/3/2003
80 km/hr
140 km/hr
2 Tires blown
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25/2/2003
14/3/2003
140 km/hr
80 km/hr
2 Rollovers
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25/2/2003
14/3/2003
Passenger25 years old (drivers son) Very badly
Injured Will he ever recover?
Driver Minor scratches and bruises
140 km/hr
80 km/hr
Driver Dead
1 Dead1 Badly Hurt
No Injury
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• 2 RTAs
• what differences?

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• The difference is
• Speed
• ( kinetic energy)

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• Rollovers happen when combining
• - (high) speed - sudden change of direction -
  (braking when changing direction)
• ALL caused by THE DRIVER! .

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• The classic S curve rollover

Mistake 1 lost concentration / tyre blow
car moves slowly to the right
(or left) Driver suddenly realises this !!
Mistake 2 pull hard left could roll here
already
Roll?
Mistake 3 pull hard right
Roll!!
Mistake 4 braking turning at
the same time
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• A rollovers happens when combining
• - (high) speed - sudden change of direction -
  braking when changing direction
• ALL caused by THE DRIVER! .
• He does this because of
• Lack of concentration and suddenly appearing
  other road users
• Tiredness (falling asleep)
• Entering a dust cloud
• Tyre blowout (not often)
• Mechanical failure (not often)

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• The classic S curve rollover
• How to avoid it !!!

Mistake lost concentration / tyre blown
car moves slowly to the right (or left)
Good re-action Roll-out into the desert. Do
NOT pull your steering wheel. Hold it tight and
straight with 2 hands. Brake slowly to full
STOP. Do NOT panic.
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• 4WD and Rollovers
• Are they better or worse than 2WD ?

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• 4WD are great cars
• strong (we think)
• goes anywhere (almost)
• never get stuck
• sit high (good view)
• powerful feel good (macho?)
• comfortable
• carry big loads / many passengers
• BUT.

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• But 4WD
• High CoG sensitive to rollovers
• Heavy poor braking
• Steering/cornering not great
• False sense of security invulnerable at speed
• Powerful fast much too fast for handling
  ability

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Centre of Gravity
High CoG
Would you drive these cars in the same manner
when taking a corner or bend ? Of course NOT
!4WD High CoG car adjust your driving speed.
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• When driving (especially for 4WD)
• Adjust your driving style.
• Speed
• Steering no sudden direction changes
• Braking earlier, more distance
• Keep heavy loads low NOT on the roof!
• Keep loads balanced centre/middle.
• Passengers are load they change the stability of
  the car.

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• How can you prevent Rollovers? Remember the
  Physics!
• Speed Slow down !
• Turn not turning
• Wrong reaction? Train yourself NOT to
  oversteer roll out straight and NOT to
  brake!
• Turn not getting surprised
• Lack of concentration? Concentrate!
• Tiredness? STOP, rest, have a nap!
• Dust? Do NOT enter the dust cloud!
• Other road users? Drive defensively
• Tyre blowouts? Check condition, pressure
• Lower COG Use a 2WD instead of a 4WD Load
  cars low and centred

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• I am in a rollover !
• WHAT will protect me?

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• I am in a rollover !
• WHAT will protect me?
• roll-bar
• seat belts

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• Seat belt in a rollover
• Keeps you
• INSIDE
• the car

Video 3 Video 4
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M mass (kg) v speed (m/s)
Seatbelt physics Kinetic Energy ½ Mv2 F
x d This energy is dissipated by braking
(force F) over a distance (d)
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M mass (kg) v speed (m/s)
Seatbelt physics Increase the stopping distance
(d) Reduce the force on the body (F)
Force on 50 kg body (kgf)
G-Force on a body
Stopping Distance (m) Stopping Distance (m) Stopping Distance (m) Stopping Distance (m) Stopping Distance (m) Stopping Distance (m)
1 0.5 0.1 1 0.5 0.1
Speed (km/hr) Stopping Force (kgf) Stopping Force (kgf) Stopping Force (kgf) Stopping Force (g) Stopping Force (g) Stopping Force (g)
40 300 600 3,100 6 12 62
60 695 1,390 6,950 14 28 139
80 1,240 2,500 12,400 25 49 247
100 1,900 3,900 19,300 39 77 386
120 2,800 5,600 27,800 56 111 556
V5
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• Seat belt
• The UNBELTED person

Video 6 Video 7 Video8
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(No Transcript)