Bus design

1
Bus 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.
2
Safety 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
3
Case 1 Roll over accidents
Roof collapsed and disintegrated without safety
concept
4
Roll over protection

• To reinforce the strength in between side walls
  and the roof
• Prevention of a passenger cabin collapse sideward

5
Case 2 Front impact accidents
All pillars collapse forward roof disintegrated
- without safety concept
The roof will move
6
Front 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
7
Front 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
8
Case 3 Side impact accidents
Whole body bent side wall collapsed without
safety concept
9
Side 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
10
Side impact protection

• Option 2 (recommended) triangular vertical
  reinforcement underneath floor

Side reinforcement triangular underneath floor
Gives structural strength against side impact and
roll over
11
Side 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
12
Number 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

13
Gangway 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
14
Side wall diagonal setting

• Structural strength against rattling, cracks and
  bending
• Prevent share force in an accident

Wrong cutting share force
Correct prevent share force
15
Passenger 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
16
Door 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
17
Door grab handles

• Safety for passing persons and traffic
• Damage prevention
• Groove mounting

Original CKD
Dangerous protrusion
18
Uppermost stair

• Uppermost stair not protruding into gangway

Dangerous interference
No interference
19
Door locking mechanism

• Not protruding into door aperture

20
Passenger seats safety

• No sharp corners
• No protrusions
• Made out of round tubes
• Width of seat frame 400 mm per seat

21
Seat mounting

• Strength increased thru short lever and
  additional stiffness
• Seat anchoring forward and sideward stronger

Side mounting additional strength
Floor mounting
22
Passenger seats comfort

• Dimensions
• Seat rest height inclination
• Seat base height inclination
• Head rest cover

Legroom
23
Front grille

• Loose grille gets lost if not ALLWAYS locked and
  will endanger traffic
• Front grille must be fixed to body thru hinges

24
Front 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
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Rear 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
26
Rear 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
27
Rear 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
28
Functional bus design

• Part 2 FUNCTIONAL features
• 20) Hump, 21) Windscreen, 22) Number plate
  provision, 23) Passenger door position 24) Side
  glasses

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Hump

• 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
30
Windscreen

• Cost reduction recommended laminated, two piece
  flat glasses
• Reduction of braking thru stones high lower end
• Reduction of heat low upper end

31
Number plate provision

• To accommodate square long type
• Protection of number plate lamp no protrusions

32
Passenger 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

33
Driver door

• Dimensions similar to CKD
• Avoid additional weight and stress to the hinges

34
Comfort in bus design

• Part 3 ERGONOMY COMFORT features
• 25) Tool box, 26) Parcel rack, 27) Leg room 28)
  Arm rest, 29) Rearmost seat row

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Rearmost 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