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RAMPS. LEONARDO AWARD PROJECT. The ramp is a plane passageway connecting two different levels. Ramps are indispensable for wheelchair users, but not only wheelchairs have wheels. Everyday tasks, such as to push a buggy, a trolley, a bike, towing a luggage need ramps, as well.
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RAMPS LEONARDO AWARD PROJECT
The ramp is a plane passageway connecting two different levels. Ramps are indispensable for wheelchair users, but not only wheelchairs have wheels. Everyday tasks, such as to push a buggy, a trolley, a bike, towing a luggage need ramps, as well. Even if one actually have nothing on wheels, the ramps are more comfortable than stairs for walking on it, especially if somebody uses walking frame, cane, crutch (these people are the “ambulant disabled”). Nevertheless ramps are comfortable and safe only if some simple but important rules are met. The necessary width of a ramp depends on the expected traffic on one hand and on its length, on the other hand. The first is easy to understand: the minimum width must be enough for a wheelchair. No less is the requirement, if you use crutch, walking frame, or you have luggage. More space is necessary if traffic from opposite direction is expected. What about the length? The longer the ramp, the higher the risk that somebody is coming from the opposite direction. Self intended, wider ramp is necessary in a park, at a railway station, at the entrance of a public building or a shopping centre, while the minimum can be accepted in a home. There are indoor and outdoor ramps. As far as the size and geometry are concerned, the rules are the same. The difference is in the floor covering: outside the water diversion, the problem of frost and snow are important safety aspects.
The slope of the ramps must not exceed 5%, thus 5 cm height difference for 1 m length. Exceptionally 8% may be accepted if the length is less, than 2,12 m, It means that the height difference must not exceed 17 cm. It is easy to understand, that considerable force is necessary to drive up a manual wheelchair on a steep ramp – and the wheelchair user may have powerless arms or hands. It should not be forgotten that driving down on a steep ramp is risky: the brake of a manual wheelchair is for to make fast the wheelchair, but not for slow down it. Less known is that the wheelchair cannot move on a steep ramp even if it is a short one. The footrest is typically in a height of 7 cm, it may impinge the ramp. This problem is frequently forgotten in the case of a short ramp, e.g. a curbed ramp on the street
The footrest is typically in a height of 7 cm, it may impinge the ramp. This problem is frequently forgotten in the case of a short ramp, e.g. a curbed ramp on the street
You can say that the footrest should be in a higher position. But it may be ergonomically false, uncomfortable, or the seat should be in a higher position, as well and the gravity centre of the user will be higher – this is not without risk from the point of view of his/her balance.
Even if the footrest is in a higher position, on a steep ramp a wheelchair user may lose his/her balance. The gravity force, starting from the centre of gravity (one may estimate, it is somewhere in the stomach in case of manual wheelchair) must impinge the soil between the wheels, otherwise the wheelchair capsizes.
Xx,jpg (not available now) Photo of wheelchair user with safety belt You are right saying, that bending forward the gravity force vector may be kept between the wheels, so the risk of the balance may be avoided, however there are disabled people, whose seating is not stable. They must use safety belts and cannot apply this trick. Only a strong assistant may prevent the casualty, pushing and balancing at the same time the wheelchair – but even this is risky, if the surface is slippery, e.g. on an outdoor ramp. Xx,jpg (not available now) Photo of wheelchair user with safety belt
A long and steep ramp is risky when driving downwards: the wheelchair may accelerate, its brake is for to make fast the wheelchair, but not for slow down it. The landing may become an accident, as shown on the next slide.
Driving up on a long ramp is exhausting, Downwards it may be risky: any device on wheels may accelerate, majority of them does not have brake or the brake is for making fast the device. Therefore at every 50 cm height difference – in other terms at every 10 m of length – a horizontal platform must be provided. The length of this horizontal place should be minimum 1,50 m. If you suppose, that the wheelchair user change the mind and intend to go back, the width of this horizontal place must facilitate the turning: the diameter of a turning circle is 1,50 m for a manual and 1,70 m for an electric wheelchair: this is the necessary width. Would be the height difference great, it is not likely that we have enough place to provide a straight ramp in one direction. For example: if the height difference is 2 m, the length of the ramp should be 2 : 0,05 = 40 m plus 3 x 1,5 m horizontal platform, in total 44,5 m ! In such a case the ramp should be built in zigzag. The direction can be changed at the horizontal platforms, as shown on the next slide
At each change of the direction and/or at each 50 cm height difference a horizontal landing area must be provided.
The other side of the coin is, that in each case when the direction is changed, a horizontal platform must be provided. Without them an uneven surface would evolve, not a plane. Having in mind that a wheelchair has 4 wheels, from which 3 define a plane, the fourth wheel would be float in the air, making the manoeuvrability risky if not impossible. The wheelchair can move safely only on a plane (the last may be horizontal or sloping).
The same is the risk on a curved ramp. Even if it seems to be elegant, it must not be applied.
Horizontal platform is needed where some manoeuvre is necessary, e.g. at an entrance door
A nice but bad solution – a curved (and to steep) outdoor ramp (narrow for horses and carts, not usable for wheelchairs).
Although the width is enough for a car, it does not meet the expectation of wheelchair users.
A non-usable and risky indoor ramp: curved pathway, sleepy floor covering, lack of handrails, lack of visual or tactile marking disturbing reflection on the glazing,…..even if the designer thought, it will be eye-appealing.
Additional ramp with horizontal platform at the change of direction
A massive ramp, with interim horizontal platforms, marked with (estimate the height difference, in comparison with the stairs)
A pair of handrails is to be provided (for walking people and for wheelchair users, children, short people)
Along the edge of the ramp wheel guard or a rail should be provided.
The wheel guard is not for wheels only but to prevent the sleeping down of crutches and to provide a line which can be touched by white cane.
Indoor and outdoor environment must be safe, comfortable and usable for anybody. The ramps are used by people with visual impairment, even by blinds. They do not see well or at all the edges of the ramp. High, contrasting colours and change of pavement, floor covering (called tactile information, perceptible through the shoes and with the tip of the cane) are necessary in each case when the slope changes in order to prevent the loss of balance and causalities.
Instead of marking the whole surface the ends of the ramp, the landings may be marked. The marked area must be longer than a step, to guarantee the “information transfer”. Besides of tactile surfaces coloured strips mark the edge of the ramp as well as the ends of the handrails.
Examples of visual and tactile marking of ramp (this ramp must be completed with wheel guard or one more rail at a height of max. 30 cm. Imagine a blind person: what can be touched with the cane? Imagine the tip of crutch, slipping out!
Outdoor ramps are exposed to rainfall therefore water diversion should be provided. Nevertheless the cross slope must not exceed 2 %, otherwise the manoeuvrability of the wheelchair becomes critical. At the landing the water should be collected. The openings of the grating should be smaller than the tip of the white cane or the width of the wheel.
The distance must be less than the width of the wheel and should be perpendicular to the direction of driving
Due to snow or ice an outdoor ramp may become slippery wintertime. Even if it is provided with a canopy, driving rain or snow may fall onto it. The safest – no doubt, expensive – way to keep the ramp dry is its heating. Heating can be provided either with electric cables or with tubes (like floor heating), in both cases embedded in concrete. Possibly even temperature distribution on the surface is required, therefore the distance between the cables/tubes is limited and they should not be to close to the surface. Reinforcement or metallic mesh over them promote the lateral heat flow, thermal insulation below them decreases the heat losses towards the soil. In case of tubes their network should be connected to the heating system of the building with a heat exchanger and the energy carrier must be antifreeze liquid.
