Title: Bus design
1Bus design safety
PROTECTOR superior design from KVM Ltd.
- ACCORDING TO SPECIFIC KENYAN REQUIREMENTS
- LEGAL BACKGROUND (The Traffic Act KEBS bus
standard), - AVAILABILITY OF MATERIALS TECHNOLOGIES,
- ROAD CONDITIONS
Guide lines for Design Passenger safety Staff
safety Traffic safety Functionality Aerodynamic Er
gonomy Comfort
Never design appearance only
Presented by Ralph Hruschka MSc. Inventor
Consultant at KVM Ltd.
2Safety critical features
- 1) Roll over protection, 2) Front impact
protection, 3)Side impact protection, 4)
Passenger door, 5) Door hinge cover, 6) Passenger
seats, 7) Seat mounting, 8) Front grille, 9)
Gangway, 10) Cross members, 11) Side wall
diagonals, 12) X-Members, 13) Door grab handles,
14) Uppermost stair, 15) Door locking mechanism,
16) Front bumper, 17) Rear bumper, 18)Rear
overhang, 19) Rear glass / emergency exit
Moto Every feature that will save a life must be
realized
3Case 1 Roll over accidents
Roof collapsed and disintegrated without safety
concept
4Roll over protection
- To reinforce the strength in between side walls
and the roof - Prevention of a passenger cabin collapse sideward
5Case 2 Front impact accidents
All pillars collapse forward roof disintegrated
- without safety concept
The roof will move
6Front impact protection
- Option 1 Diagonal column to stabilize the roof
thru directing the impulse force into the lower
body - Column out of two strong tubes
- Zig-zag interconnection in between bars
- Correct angle from roof to column
- Correct angle from column into body
Stabilizing column
Impulse force diverted into body
7Front impact protection
- Option 2 Stabilize the roof thru reinforced
pillars
Roof
Fixed side glass
Sliding side glass
Stabilized side pillars
Disadvantage reduces size of glasses
8Case 3 Side impact accidents
Whole body bent side wall collapsed without
safety concept
9Side impact protection
- Option 1 triangular vertical reinforcement
inside legroom
Side reinforcement triangular in legroom
Side reinforcement triangular
No reinforcement at floor mounting
Disadvantage disturbing in the legroom
10Side impact protection
- Option 2 (recommended) triangular vertical
reinforcement underneath floor
Side reinforcement triangular underneath floor
Gives structural strength against side impact and
roll over
11Side impact protection
- Option 3 (recommended) triangular reinforcement
longitudinal inside floor level
View from above
Cross member
Impact force
Cross member
Side bent thru impact without reinforcement
Side reinforcement triangular longitudinal
12Number of cross members
- Enough for strength and safety according to load
class (min. 4 for 26-seater, max. 8 for
71-seater) - Not more than necessary weight and cost
relevant - Welding joints fist grade and verified
13Gangway and seat arrangement
- Width of gangway recommended is 450 mm (Class IV,
above 40 passengers) - and 350 mm (Class III, 26 40 passengers)
- This requires for 3X2 seat arrangement a vehicle
track width of 2250 mm or correctly curved side
pillars
Gangway 450 mm
2 Seats 800 mm
3 Seats 1200 mm
Side wall 50 mm
Side wall 50 mm
150 mm maximum
150 mm maximum
Track width 2250 mm
14Side wall diagonal setting
- Structural strength against rattling, cracks and
bending - Prevent share force in an accident
Wrong cutting share force
Correct prevent share force
15Passenger door
- Dimensions according to KEBS
- Minimum height 1650 mm
- Minimum width 650 mm above 700 mm
- 1st step height maximum 460 mm above ground
- Function according to European Safety
regulations - In case of a panic after an accident the
passengers want to press outward - The passenger door must swing outward otherwise
it becomes a death trap
Death trap inward swing door
Outward swing door
Outward sliding door or pantographic
16Door hinges
- Protruding hinges like at the drivers door must
have a cover to protect against sharp corners - Passers by on foot or passing vehicles will be
cut by sharp corners
Option 1 Hinge cover
Option 2 Hidden hinges
17Door grab handles
- Safety for passing persons and traffic
- Damage prevention
- Groove mounting
Original CKD
Dangerous protrusion
18Uppermost stair
- Uppermost stair not protruding into gangway
Dangerous interference
No interference
19Door locking mechanism
- Not protruding into door aperture
20Passenger seats safety
- No sharp corners
- No protrusions
- Made out of round tubes
- Width of seat frame 400 mm per seat
21Seat mounting
- Strength increased thru short lever and
additional stiffness - Seat anchoring forward and sideward stronger
Side mounting additional strength
Floor mounting
22Passenger seats comfort
- Dimensions
- Seat rest height inclination
- Seat base height inclination
- Head rest cover
Legroom
23Front grille
- Loose grille gets lost if not ALLWAYS locked and
will endanger traffic - Front grille must be fixed to body thru hinges
24Front bumper
- Prevention of damages thru road conditions
- Creating sufficient air flow to radiator
- Access to towing hook
- Rounded curvature to support comfortable handling
- No sharp corners to prevent accidents
Original CKD bumper Formula r(fr)x(fr)mm/m
25Rear bumper
- Prevention of damages thru road conditions
- Access to towing hook
- Rounded curvature to support comfortable handling
- No sharp corners to prevent accidents
Formula r(re)x(re)mm/m
26Rear overhang
- To ensure comfortable vehicle handling (stability
on the road) the rear overhang can be maximum - 60 of wheel base measured behind rear axle to
rear bumper
wheel base
60 of wheel base
27Rear glass / Emergency exit
- Access size according to legal regulations
- Safe opening function
- Cost saving shape
- Recommended flat to save costs
Unnecessary waste of material and money very
difficult to replace
28Functional bus design
- Part 2 FUNCTIONAL features
- 20) Hump, 21) Windscreen, 22) Number plate
provision, 23) Passenger door position 24) Side
glasses
29Hump
- Only small vehicles can be built like Formula 1
cars - Big vehicles require specific aerodynamic shape
to reduce air resistance - Lower air resistance will reduce fuel consumption
Eddies at sharp corners increase air resistance
Front hump eliminates eddies
Joint at roof bow
30Windscreen
- Cost reduction recommended laminated, two piece
flat glasses - Reduction of braking thru stones high lower end
- Reduction of heat low upper end
31Number plate provision
- To accommodate square long type
- Protection of number plate lamp no protrusions
32Passenger door position
- 1st step height 460 mm maximum recommended
behind front axle - Creating space for air duct
- Air duct is disturbing in leg room
- Shortest way for air intake required
- Vibration buffing in between engine and body
33Driver door
- Dimensions similar to CKD
- Avoid additional weight and stress to the hinges
34Comfort in bus design
- Part 3 ERGONOMY COMFORT features
- 25) Tool box, 26) Parcel rack, 27) Leg room 28)
Arm rest, 29) Rearmost seat row
35Rearmost seat row
- Maximize leg room thru
- - Inclination of rear body backward
- - Seat rest of rearmost row to fit into shape
of rear body
Side view
View from above
Lost space
Inclination of rear body backward
Seat rest fit into body shape