There are millions of anti-personnel mines scattered around the world, many are in villages and in surrounding agricultural areas.
The present methods for the location of these include metal detectors, hand rakes, sniffer dogs or probing the ground with wooden sticks. Removal involves the equally hazardous procedures of uncovering the mines and their safe disposal.
While anti-vehicle mines are frequently removed by large, flail-type machines based on military tanks or earthmoving machines, these are not suitable for working in small areas.
A faster, more mechanised method of finding and digging up anti-personnel mines is envisaged based on the use of conventional agricultural machines that are common in many of the mined areas.
A project along these lines, titled “Agriculture technology for humanitarian demining”, is being run by a group based in the Department of Mechanics and Machine Design at the University of Genoa, Italy and led by Dr Emanuela Cepolina.
Several other groups and individuals in Italy and Europe are involved, including the Italian Ministry of Economic Development and the Italian Institute of Foreign Trade which funded the present project. I am involved as a consultant for the agricultural engineering aspects of the project.
The project involves the development of a prototype of a small remotely controlled power unit based on a 60kW, 4WD agricultural tractor. Work is also progressing on associated tools for clearing undergrowth and digging up the anti-personnel land mines. The complete unit is not expected to cost more than €50,000.
The project’s name LOCOSTRA is a contraction of “low cost tractor” and a pun on the Italian word for locust – “locusta”. The present work in Italy involves developing blast-resistant wheels, the remote controls, and armouring.
The wheels are designed to withstand the detonation of 200g TNT without damage that would halt operations. They consist of heavily braced dishes with an attached steel tread and a pneumatic or solid rubber wheel in the hub. They are designed to allow blast ventilation and prevent shock transfer to the bearings and chassis.
The same blast-resistant wheels are mounted at the front and rear. On soft ground, it is anticipated that the tread on these wheels may need to be replaced after five blasts. On hard ground the loss of the tread should not have any great effect on mobility.
The work I am undertaking in Australia is the development of prototype tools for digging under the mines and bringing them 100mm to the surface. The tools are based on 400mm cultivator sweeps which are filled in behind the mounting lug and incorporate a comb made from 10mm steel bars spaced at 40mm and mounted at the rear. This gives a 30mm gap which is smaller than the minimum dimension of the mines.
The present work on the evaluation of the tools in up to three different soil conditions is intended to explore the digging and sieving functions of the tools and not their ability to resist the blast from a mine.
Depending on the soil conditions, a small number of tools will be mounted on a rigid tine cultivator and attached to the rear of the tractor via a category 1 linkage and vertically controlled by depth wheels. The development of other digging and sieving tools may be necessary to suit various soil conditions which occur where the units are used.
It is also planned to develop front mounted tools for clearing grass, brush and other growth or obstructions which would hinder the digging and lifting operations.
It is anticipated that these components will be brought together in Jordan for final assembly at the regional centre for demining under the auspices of the University of Jordan. They will be tested in the field in the first half of this year.
If successful, further funds will be sought to manufacture a number of the units to be used where appropriate around the world.
This project, with the objective of helping to rid the world of this human curse, is humanitarian engineering at its best.
by Ross Macmillan
Ross Macmillan is a senior fellow in agricultural engineering at the University of Melbourne.
The remote-controlled tractor with armouring around conventional wheels.
Prototype steel wheel rim showing non-critical damage after a controlled explosion.
Tools and layout of simulated mines for digging trials in Australia.
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