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Contributions from
the Column
Tribune
IMF is half-heartedly wooing emerging markets
Ancient technology offers new infrastructure in Africa
8-9/2006
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[ Appropriate technology ]
Old methods, new hope
Transport infrastructure needs to be improved in many African countries. A traditional way of building roads and bridges is proving useful in Rwanda – but it is from Europe and largely unknown in Africa. If one uses natural stone, infrastructure lasts long, construction creates plenty of jobs, and projects require relatively little capital.
[ By Rüdiger Behrens and Regina Poth ]
Rwanda is a small, densely-populated country with an average of 315 people per square kilometre – almost 50% more than in Germany. At the same time, Rwanda is an agrarian society with little urbanisation; some 90 % of the population live in villages. Many of them suffer from the poor transport infrastructure.
While Rwanda has around 14,000 kilometres of roads and paths, only seven percent are paved. The rest consists basically of stamped earth – muddy in the rainy season, and so dusty in the dry season, that it affects respiratory systems. Many roads are eroded so badly that one can only use them in off-road vehicles all year through. Some connections no longer exist, for instance, because bridges have collapsed.
Today, many villages cannot be reached by goods vehicles or ambulances, nor do residents have access to markets. They cannot buy goods that they do not make themselves, nor can they sell their own products. The country therefore desperately needs a fully-functional transport infrastructure, with bridges intact, for its development and the well-being of its people.
Local raw materials
Rwanda has no local tradition of constructing streets from natural stone, as has long been done in Europe. Nonetheless, this technique offers a number of benefits over tarmac roads and should be used systematically. To begin with, all necessary raw materials are available locally. In addition, only few machines are needed for construction purposes, but many people are employed. That is a major advantage in any economy that suffers from high unemployment and little purchasing power as does Rwanda. Furthermore, cobblestone roads can generally be repaired with locally available materials, and such streets last much longer than tarmac roads; they are thus much cheaper in the long run. To top it all, the invested money remains in the country, because local material and local workers are used. Therefore, such infrastructure projects support the national economy in more than one sense.
German development agencies are supporting the Rwandan government in its goal of creating as many jobs as possible in infrastructure projects. German agencies are directly involved in doing so. In the Construction Office in Kigali, the country’s capital city, experts from the German Development Service (DED) train local engineers, technicians and workers both in theoretical and practical terms. In another project, German Technological Cooperation (GTZ) is running in Gikongoro Province, demobilised soldiers are building infrastructure projects according to the principle “food for work”. Similarly, KfW development bank is involved in a project that will include cobblestone roads in Gisenyi Province.
In 2000, French consultants initiated the construction of a cobblestone road Kigali. Before, the methods had been unknown in Rwanda, and the first step was to train construction workers. Luckily, Rwanda has a tradition of building stone walls, so the actual techniques did not seem entirely exotic.
If one wants to build cobblestone roads, there are two work phases: manufacturing the cobblestones and laying them. Both are quite labour-intensive. At present, Rwandans employed in the construction of cobblestone roads even earn much more than ordinary builders do. Currently, 200 people are working at cobblestone construction sites in Kigali, and roughly the same number are involved in ancillary tasks. Cobblestones are produced at various quarries in Rwanda. The quality of a cobblestone depends on the type of rock and the skill of the worker. Some 730 people are currently employed in stone production, half of them as masons and the rest as unskilled assistants.
In other than employment terms too, it is fortunate that so many unskilled persons are needed in both phases. That not only creates jobs for demobilised soldiers, but also for widows and other victims of violence. In light of Rwanda’s traumatic recent past, building infrastructure thus offers a way for people to reconcile while working together.
The cobblestone roads built in the past few years are in good condition. They have settled a bit in some places, but that is typical of cobblestone roads, and there has been no serious damage. Even those routes that had to handle heavy traffic, which was diverted from a main road in Kigali for a number of weeks, are still in perfectly acceptable shape.
Saving wood
Generally, Rwandans used to make bridges from tree trunks. But the notorious energy crisis has made wood a scarce commodity. Therefore, natural stone is a promising alternative. Stones have been used to build arched bridges in Europe since antiquity. In a mountainous country like Rwanda, the necessary materials are easily available. Cement is also produced locally, so there is no need to import such goods as reinforced concrete. Again, local people are able to perform all tasks themselves. Unskilled workers from the villages break stones, masons build the bridges, and village carpenters make the simple scaffolding that is needed.
As soon as the mortar is dry, people can begin crossing small arched bridges. Generally, that is the case after about four days. One particular bridge – around six meters wide with around five meters of supporting framework – was finished in 45 days. If that bridge had been made with reinforced concrete, it would have taken three weeks longer. Once a natural-stone bridge has been correctly constructed, it requires very little maintenance. Its intrinsic weight helps it withstand floods and even makes them suitable for heavy truck traffic. The wooden scaffolding needed to set up the arches can be used time and again, and they can still serve as firewood in the end.
Obviously, asphalt roads and concrete bridges fulfil a much higher technical standard. But they do not last as long and require more capital. Raw materials and machines have to be imported, not to mention the technical expertise in many cases. In contrast, natural stone is a sound, affordable material for the entire secondary road infrastructure, both inside towns and in the countryside. Rwanda has understood that the lack of suitable roads is an obstacle to its development. At the same time, unemployment in the country is high. Rwanda is therefore right to using labour-intensive methods to expand its transport infrastructure.
Rüdiger Behrens
is a construction engineer and forestry
manager. He consults the GTZ project
in Rwanda’s Gikongoro Province.
Ruediger.Behrens@gtz.de
Regina Poth
is a construction engineer. She works
for the German Development Service (DED)
in Kigali.
regina_poth@web.de
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