Regional Seminar Proceedings 1990

THE OPTIONS FROM OXCARTS TO TIPPER TRUCKS

4.1 ANIMAL HAULAGE

Amongst the participants, the experience with animal haulage was mostly with donkeys rather than oxen. In Makete, Tanzania they have successfully gravelled a section of road using a donkey with panniers hauling gravel up to a distance of one kilometre (km). They have calculated that in equivalent costs 1 tractor and trailer is equal to thirty donkeys.

If a roads programme is to look at the possibility of using animal drawn carts the following must be considered.

• Will the cart and the animals be owned by the roads programmes?
• Will the carts only be owned by the programme and the animals hired from local farmers on a daily basis?
• Will the carts only be owned by the programme and the animals hired from local farmers on a contract basis with a fixed rate per trip depending on the haulage distance?
• Will the animals and the carts be hired by contract from local farmers/ businessmen?

The contracts listed above include the excavation, loading, hauling, off loading and spreading of the material. From the trials in Tanga where the project owned some of the donkeys, they would recommend that the animals, at least, should be hired on a contract basis. It may be advantageous for the programme to purchase the carts as they can be specifically designed for roadworks. Farmers may have difficulty in securing credit to buy carts and this could prove a stumbling block to the introduction of animal haulage in certain areas.

The roads project in northern Zambia are purchasing donkeys and requested any available information on harnesses.

4.2 EQUIPMENT CHOICES FOR ROADS PROGRAMMES

Before deciding on the haulage equipment to order for roadworks several factors must be taken into consideration:

(i)The haulage distances from sources of good material to the road sites. The World Bank has given the following guidelines on haulage distances:

(ii) The haulage needs of the different sites in the region.

(iii) The possibility of using equipment produced in the country where the work is to be carried out.

(iv) The ease of repair and stocking of spare parts if the same vehicles and equipment are ordered.

(v) The possibility of using container tippers

(vi) The possibility of hiring private contractors, either businessmen with trucks or farmers with tractors. Suitable trailers may have to be provided for the tractors by the programme.

4.3ADVANTAGES AND DISADVANTAGES OF USING CONTRACTORS FOR HAULAGE

The advantages for the roads programme is that they do not need to purchase expensive equipment, they do not need to keep large stocks of spare parts, they do not need a large mechanical workshop, also vehicles assigned to the raods programme are not available to be diverted into other activities.

The disadvantages of using contractors are if insufficient vehicles are available, if the rate set by the region or government for haulage is uneconomic and therefore uninteresting to the private sector, and the need for close supervision to ensure that the correct quantities of gravel are being delivered and properly placed on site.

4.4 TRACTOR TRAILER COMBINATIONS

All the participants had different experiences of using a variety of tractor and trailer combinations. The tractors ranged from 45 to 80 horsepowere (hp) with the simplest mechanics to sophisticated hydraulics and 4 wheel drive. The trailers ranged from 2.8cum to 4.5cum in capacity, with either single acles, single axles with twin tyres or double axles.

The size and sophistication of the tractors purchased depended on the job to be done,and the facilities for maintenance. In Mozambique an 80hp, 4 wheel drive tractor was used for rolling and grading but a 48hp tractor was used with the single axle 3cum trailers.

In general participants were not in favour of double axle trailers as previous experience had shown them to be difficult to manoeuvre and too heavy to towing by normal agricultural tractors. In Tanzania, Valmet Tractors are readily available and familiar to the mechanics as they are assembled in the country. Although they may not be as powerful as other makes, their availability and the availability of spare parts may be a consideration when deciding on which tractor to use. An interesting alternative tractor, which must be imported, is the Tugwell 480 which is designed for Africa using no hydraulics, and a mechanical spring rather than electric starter.

The largest problem faced by all participants was finding a reliable supplier within the Southern and Eastern Africa region of a well designed, well manufactured trailer. Certainly countries such as Kenya and Tanzania could support manufacturer with sufficient orders once a good trailer had been produced. Kenya have had great difficulties with their trailers and Tanzanian projects are still trying out various designs. The most promising is RRM Mbeya's newly purchased trailer manufactured in Zimbabwe, but this has not been in operation long enough for assessment.

Many participants felt there was a need to gather together a list of the types of tractors and trailers in sue with comments on their performance, individually and their suitability as tractor trailer combinations.

4.5 TIPPERS AND CONTRAINER TIPPERS

An alternative to tippers or flat bed lorries is the container tipper. It has been successfully used in projects in Somalia and Thailand. The container tipper gives one truck multipurpose possibilities for all phases of the road construction including use as a water tanker.

Some participants were concerned about the efficiency of loading tippers by hand and the alternative expense of a mechanical loader. It was pointed out that the ease of loading by hand is determined by the setting up of the gravel pits and Lesotho LCU had no problem with efficient hand loading of tippers. In Tanga they used wheelbarrows to load the excavated gravel into the tippers. Leaflets on contrainer tippers are available from ILO Geneva.

4.6 AGREED PLANS FOR ACTION, HAULAGE OF MATERIALS

NOTE: Trailers are also discussed in Session 6 of this report, under the heading of "Site Visit".