Superior Bus Design Presentation

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Bus design & safety 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 Ergonomy = Comfort

Presented by Ralph Hruschka MSc. Inventor & Consultant at KVM Ltd.

“Never design appearance only”

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 PROTECTOR-superior design from KVM Ltd.

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Case 1: Roll over accidents

Roof collapsed and disintegrated without safety concept

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

Gussets

Diagonals

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Case 2: Front impact accidents All pillars collapse forward – roof disintegrated without safety concept

The roof will move

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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

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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

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Case 3: Side impact accidents

Whole body bent & side wall collapsed without safety concept PROTECTOR-superior design from KVM Ltd.

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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 PROTECTOR-superior design from KVM Ltd.

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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 PROTECTOR-superior design from KVM Ltd.

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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

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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

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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

Side wall 50 mm

3 Seats = 1200 mm

Side wall 50 mm

150 mm maximum

150 mm maximum

Track width 2250 mm

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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

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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 PROTECTOR-superior design from KVM Ltd.

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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

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Door grab handles • •

Safety for passing persons and traffic Damage prevention

Groove mounting

Original CKD Dangerous protrusion

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Uppermost stair •

Uppermost stair not protruding into gangway

Dangerous interference

No interference

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Door locking mechanism •

Not protruding into door aperture

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Passenger seats safety • • • •

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

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Seat mounting • •

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

Side mounting: additional strength

Long lever

Short lever Floor mounting

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Passenger seats comfort • • • •

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

Legroom

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Front grille • •

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

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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] PROTECTOR-superior design from KVM Ltd.

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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]

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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

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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

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

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

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Windscreen • • •

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

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Number plate provision • •

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

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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

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Driver door • •

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

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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

Rearmost seat row •

Maximize leg room thru: Side view - Inclination of rear body backward - Seat rest of rearmost row to fit into shape of rear body

View from above

Lost space Inclination of rear body backward

Seat rest fit into body shape PROTECTOR-superior design from KVM Ltd.

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