|CERES No. 140 (FAO Ceres, 1993, 50 p.)|
A brief look at some low -cost transport options
By Peter Steele
Transport is all about people, especially at the local level, where community traditions may date back as far as memory reaches and the ways goods are carried may be based as much on cultural as on practical imperatives. It's surprising how rarely equipment and modes of local transport manage to transfer from community to community-even in the same region or country.
Yet there is no physical reason why what works in one place can't work just as well in another. Take, for example, the shoulder pole, used virtually everywhere in Asia. Why not try it in Africa, where it might save wear and tear on the neck vertebrae of women who have traditionally carried loads-sometimes very heavy ones-on their heads? Why wouldn't it be useful in a country like Burundi, where people can't afford motorized vehicles and the hilly terrain has limited road-building'? Burundi's roads are few and far between, and commercial transport is almost unknown. People walk long distances along tracks too steep and narrow for wheeled vehicles.
Easing the burden
There are, of course, only so many ways to carry goods on foot. The human frame isn't well adapted to heavy loads, whether on the head, back or shoulder, but there are ways of easing the burden.
The modern backpack places the load firmly on the lower waist by means of a wide belt. It has semi-flexible or firm support against the walker's back and permits loads equal to 25 per cent of a walker's weight. But such recreational equipment is expensive and beyond the reach of the developing world.
When a 1 2-year-old Kenyan girl weighing 35 kilograms carries a load of firewood home on her back, she uses a length of bark to bundle the wood into a pack and strap it to her back with a cord across her forehead. Walking in a stoop, she carries half her body weight for a kilometre or more. Her mother did the same before her. For 20 years she carried loads well in excess of her strength to save time and travel, and at the age of 30 she has the back of an old woman and a permanent deep crease across her forehead.
The head-loading already mentioned is even more common, especially for carrying water but also for such things as a single jug or bundle, which could as easily be carried by hand. Both men and women carry loads on their backs, but it is usually only women and children who carry things on their heads. They look elegant as they walk with head and shoulders gracefully erect, but the weight of the load can cause serious neck and spinal health problems later in life.
The traditional Asian yoke and shoulder pole are made of wood, often bamboo, the pole is usually 1.5 to two metres long and 40 to 60 millimetres in diameter in the centre, where it is carried, tapering to 30 to 40 mm at the ends. The carrier hangs loads of equal weight at each end to knee level and balances the pole across the shoulder where it flexes with each stride. With padding, 50 kg and more can be hauled for several kilometres. The pole is ideal for compact loads like liquids, which don't impede walking. And the carrier needs no help in picking up and setting down a loaded pole.
Non-motorized wheelbarrows, trolleys and pushcarts aren't used as widely as they should be because of cost, tradition and a lack of distribution and maintenance systems. In competition with the bicycle, the wheeled cart usually comes second.
Single-wheel transporters like wheelbarrows come in many designs. The Chinese wheelbarrow has a large central wheel, separate carrying frames on either side supported by twin legs and a handle at one end while other designs have a high-level deck above the wheel. These kinds of wheelbarrow can be operated by more than one person and can haul loads of 150 kg or more for short distances.
The wood or steel wheelbarrow manufactured for urban users and the construction industry is excellent for short distances on level or slightly sloping ground. A rubber-tired wheel with a central bearing improves load carrying and is a great advantage on soft ground. Depending on the size of the container, the wheelbarrow can carry 100 to 125 kg, but pushing is hard on the arms and back so it is usually used only over a few hundred metres.
Handcarts come with two, three or four wheels, with a flat, built-up or trailer deck, with bogies and/ or push-pull handles, and can carry loads of more than a ton. They compete so well with powered vehicles over short distances in towns that it is remarkable they have not replaced the pickup truck. Six workers with a strong handcart could easily provide reliable and prompt citywide haulage.
But handcarts have their disadvantages. Like the wheelbarrow, they need a good set of wheels, axles and bearings and usually can't be built locally. Often, wheels and tires must be imported. Handcarts also need roads with a hard surface at least 1 500 mm wide. They are less successful over tracks and steep terrain, where it is too difficult to negotiate passage. Here draft animals take priority.
From dogs to elephants
Traditional societies around the world have domesticated animals-from dogs to elephants-to provide transport. Motorized vehicles may dominate commercial land links between cities, but in the countryside it is still animals that count. Motorized vehicles can travel difficult terrain, but few societies can afford to buy and operate such equipment. The animal cart is a better choice for carrying loads from country to town over distance to 20 km, as in Lilongwe, Malawi, where ox carts dominate local transport.
Over the centuries, saddles, harnesses? panniers and carrying frames have been developed to suit the single pack animal and the needs of its owner. They are fitted to the animal-usually a donkey, mule, horse or camel-at mid-back with a central girth strap. Evenly balanced loads hang on either side, with an additional load built up between the two side loads. The lower the load the better for the animal's centre of gravity, which is important when walking hill tracks. People also ride animals with or without additional loads fitted in side panniers or behind the rider.
Pack animals are the most versatile of transporters-docile when well-trained, hard-working when well-fed and healthy and capable of carrying loads for almost unlimited distances. Mules can accommodate 50 to 60 kg and a camel two to three times that. Before trucks came on the scene, it was traditional for nomadic families in Mongolia to shift their entire households five or six times a year with a few pack horses, sledges and riders.
Like other forms of transport, animals need maintenance and inputs-traditional medicines and sometimes imported veterinary drugs, supplementary feed during the dry season or winter and leather, timber, fabrics and buckles for their fittings. But animals give special compensation. They become part of the family, capable of carrying a rider and load and finding their own way when the route is familiar and the rider tired. Try napping on a motorcycle!
Before the advent of the motorized truck, heavy goods wagons drawn by a team of oxen or horses dominated road haulage. Given firm, load-bearing pavements, the wagons moved much as truckers do today-and just as fast as a truck tied up in city traffic. Heavy duty animal transport on paved surfaces has all but disappeared, but lightweight transport is growing where animal carts are available and people can find the money to buy them. It is a question of credit and commercial development.
Lightweight animal carts are usually used with a single animal or a team of two. Donkey and ox carts are used throughout the world, horse-drawn carts less frequently, but the basic cart is much the same whatever the animal. A typical cart is made of timber with a flat deck fitted to a wooden sub-frame over the single axle. The animal is backed into a set of shafts and hauls the cart by means of a collar or yoke.
Design variations are almost limitless. A cart can be constructed completely of steel sheet on a steel frame. It can have a sprung axle with pneumatic tires and a hand brake. It can come covered to protect rider and goods. It can have a tip deck or slatted sides. It can have twin axles with the front axle connected to a draw-bar complete with central pivot steering. The design of axles and wheels ranges from the stub axle/motor car/pneumatic tire to oil-impregnated wooden blocks and split wood wheel. Researchers in institutes and artisans in workshops have combined to produce a multitude of novel ideas and designs. but most are available only locally because the financial returns from marketing them are limited.
A single-axle cart that weighs 200 kg unladen can carry up to one ton on a deck measuring 2.5 by 1.5 sq.m, exactly how much depends on the animals' power and the road surface. Clearly, a 500-kg ox can haul a heavier cart than a donkey with one quarter the body weight, and a bitumen road surface and pneumatic tires have a lower rolling resistance than steel wheels on packed earth. Wheels large in diameter can negotiate ruts and holes better than smaller ones and haul a heavier load. Animal carts usually need a track two metres wide, with a reasonably smooth surface cleared of rocks and trees. It helps if the width of the cart's axle is more or less the same as the axles of other vehicles using the track, especially if the road has deep ruts. Hills will be hard going for the loaded cart.
Pumping the pedal
Of all the simple transport machines in use throughout the developing world it is the bicycle to which most poor people aspire. And it is more or less within their reach. Two wheels provide a great deal of personal mobility at a proportionately low cost and can carry loads as well. Bicycles also have a good image. They are seen as advanced technology, post-traditional and status enhancing. Unlike the animal cart or wheeled hand cart, the bicycle provides speed and manoeuvrability and can travel on walking tracks in relatively open and flat country.
Of all the bicycle designs available, it is the traditional high frame, large wheel machine that sells best for serious transporting. Constructed around a heavy gauge steel diamond-shaped frame with steel wheels made of spokes and hub, fitted with pneumatic tires and brakes front and back, a bicycle can comfortably carry a rider and an additional 100 kg. A rear carrier attached to the subframe is a must. Front carriers or loading into the centre of the diamond-shaped frame are also practical but less common. If the bicycle is being pushed and access to the pedals is not essential, a sack of grain, a large quantity of wood or any other awkwardly shaped load can be wedged into the frame. As with a pack animal, the lower the centre of gravity of the load, the easier it is to balance.
Bicycle maintenance is available in small towns throughout the developing world. Most markets have a repair shop where artisans fabricate parts with a minimum of tooling, repair ancient and outdated parts when replacements are no longer available and fit new parts, often imported from India or China. Complete factories are shipped across the world and erected in isolated regions like the factory at Chipata in Zambia's Eastern Region, which is at the end of a long supply network and provides both employment and bicycles.
Fit another wheel to the bicycle, and it becomes a versatile load carrier-but is no longer a bicycle and loses much of the manoeuvrability of the two wheeled machine. Tricycles are essentially urban or industrial transporters and do the same work as hand and animal carte
Tricycles come in several forms with two distinct designs-single steering wheel/twin rear wheels or single rear wheel/twin steering wheels. The second version usually has a tray, box or platform out front and is steered by means of a bar, which pivots the entire axle, instead of a conventional bicycle handlebar and wheel. Because the load is over the steering wheels, this tricycle usually carries lighter loads than the tricycle with load-carrying platforms at the rear.
Tricycle people-carriers, better known as rickshaws, usually have a single rider in front to provide power and a covered seat across the back of the rear axle where two passengers can sit side by side. Whether people or freight, loads of up to 200 kg are commonplace. Tricycles need a smooth road surface and level terrain and do not mix well with motorized vehicles, which is why they are in a separate flow of traffic on main roads in the centre of Beijing. Tricycles are also expensive when compared to the conventional bicycle' often two to three times their cost, and conventional bicycle components are not always compatible.
Motorized vehicles are relatively new in the developing world. In most towns and villages people still remember the first car, truck or bus in the district and when the road was built. But commercial pressure, especially during the past 20 years, has made road vehicles appear synonymous with development and given road-building high priority despite the drain on limited national resources.
This is a mistake. Motorized vehicles don't make economic sense in many communities-and where is the foreign exchange to maintain roads and vehicles and buy fuel'? Tanzania's main highways, once adequate, are now appalling. In Cuba and Guyana, it is only the skill and ingenuity of the artisans in local repair shops that keep the aging fleet of cars and trucks on the road long past their expected life span. Georgetown probably has the world's best operational fleet of British cars, vintage 1960.
With conventional motor cars or trucks beyond their reach, many rural people have motorized with the motorcycle. Since the 1960s, Honda, Suzuki and Yamaha have become international symbols of speed and utility. The motorcycle and its two- or three-wheeled derivatives based on a chain-driven wheel and a small gasoline engine can go everywhere people want, whatever the terrain and climate, but it has its limitations.
Motorcycles are sophisticated machines and neither cheap nor simple to operate. To keep them running well, the motorcyclist needs access to a network of suppliers, including the manufacturer, national agents and fuel and oil companies. A rider can learn the rudiments of a motorcycle in a few hours, but it takes years to develop real driving and maintenance skills-and misuse and misunderstanding can quickly destroy a machine.
Motorcycles are ideal people-carriers. Most have two scats' one behind the other, and room for one or two more passengers balanced astride the fuel tank or squeezed in between the twin seat. As load carriers, however, they are less effective. Road machines don't function well at slow speed over unpaved ground, because air-cooled engines need a flow of air to maintain working temperatures. Higher speed brings its own problems if the ground is rough or a load is poorly positioned. Falls are common, damaging machines as well as riders.
Purpose-built panniers and rear load carriers resembling those used with bicycles are sometimes available, but most motorcyclists use only the small carrier supplied by the manufacturer. Loads are sometimes tied insecurely to the top of the tank or strapped perilously to the rider's back. A purpose-built load carrier, like a sidecar, works much better. A sidecar can accommodate two or three more people, or the same weight in freight. How much weight depends on how powerful the engine is and its design, but sidecars can work even with lightweight motorcycles or scooters.
There are other useful forms of transport, but major commercial vehicle manufacturers don't market most of them. Vehicles with three, four, six or more wheels or with tracks have evolved at local level. but because they rarely enter international markets, people who might find them useful in other parts of the world don't know they exist and can't demand their manufacture. It's a case of which comes first, the market or the product.
Exceptions include the tricycle, manufactured for farm and leisure use. A range of lightweight farm equipment has been developed to suit the power output and rear axle of the farm trike, and its wide, low-pressure tires cause little damage to the ground. The trike can go where the tractor cannot. With a tray at the rear, it can carry a bale or two of hay, fencing wire, a couple of dogs or an injured ewe. No wonder the machine is popular with New Zealand sheep farmers.
The four-wheel motorbike/tractor has a minor place on the farm, and three- and four-wheeled motorcycles have made their way to the atolls of Kiribati and other Pacific islands because they are relatively easy to unload and manhandle ashore. Two-wheeled motorcycles can pull trailers, but the larger three- and four-wheeled machines are better for pulling trailers. Usually constructed of aluminum on a box chassis to take full advantage of the limited power available, light trailers may weigh 175 kg and carry 350 kg.
Motorized platforms and containers have been developed for the construction industry and other specialized uses. These include the dump truck, which is a sort of motorized wheelbarrow. One design has a tipping container in front, a motor to one side of the rear alongside the driver, who should wear ear protection, and twin axles with steering wheels at the rear. The truck can be gas, electric, petrol or diesel-powered. A model with a petrol engine rated at 12 kW has a payload of 1.25 tons.
The dump truck may be too specialized to interest farmers in the developing world, but they should still know that it exists and have the option of buying it, just as they should know about and consider making use of the shoulder pole, wheeled carts, bicycles and tricycles. But spreading the word is the easy part. The problem is convincing people to try something new, even when the benefits would appear to be obvious. Experience shows you can shift ideas or equipment, but you can't always persuade people to give them a try. When it comes to transport, logic is often second-best to tradition. Commercial motivation and timing are important for the planning process, but so too are human foibles.