DTW started out developing and making low-cost demining equipment, initally prodders,
helmet visors and personal protection for the Mine Action Group, Cambodia. These
designs and staff were transferred to a local company which currently employs 30
disabled people and the products are exported world-wide.
The Mark 5 braille writer can be produced for $100 to $150, or about one-fifth the cost of other commercially available machines.
It went on to design, develop and manufacture the Tempest controlled vegetation and
tripwire clearance machine. Seventeen machines are now in use on demining operations
worldwide. Four more are about to be built for MAG. They cost $105,000 each. A fully
equipped portable workshop is available for $30,000 more.
The Tempest sells for one-third the cost of commercially available machines. It is
radio-controlled from up to 400 metres away, can remove thick vegetation up to three
metres high and small trees. It can safely explode anti-personnel mines but would
probably be overturned by an anti-tank device; this has never actually happened,
as pre-clearance surveys generally determine the type of mines laid, and also because
the unit weighs 2.4 tonnes, while anti-tank mines are designed to be set off by much
The 36-chain flail head has an intelligence which, if the load becomes too great,
diverts power from the wheels or tracks to the flail and adjusts the forward speed,
so that more power is available to cut into vegetation. A cutting rate averaging
20,000 square metres per month is achievable. After the vegetation clearance, two-person
detection teams move through the minefield marking explosive devices for later defusing
While the Tempest is DTW's high-profile attention-grabber, it represents a relatively
small proportion of the product portfolio.
The workshop has developed and is manufacturing a unique low-tech towed grader for
maintenance of rural roads; a portable mechanical braille writer; collapsible walking
sticks for the vision impaired; and a range of modern lightweight wheelchairs.
All of these were developed on submitted specification or request for a specific
solution to a problem, for use in poor countries, are quality guaranteed and sell
at prices attractive to donor sponsors.
The "Cam-Grader" features a significant number of used Toyota Camry components
and is seen as having sales potential in many countries. It is designed to be towed
by a 35 horsepower agricultural tractor and has been successfully field-tested for
six weeks in Svey Rieng. Three more units have been pre-sold for $2,500 each and
are under construction for delivery to villages in Takeo, Siem Reap and Kampong Speu
It has no mechanical gearing nor hydraulics, yet the blade has four-way pitch, angle,
height and tilt adjustment. A Khmer team headed by West German-educated engineer
Soeur Phal Khun (using CAD) designed and built the grader from a request by the UN
Office for Project Services, which put up $6,000 development capital.
"The gravel roads are being built or improved but they are difficult or costly
for villagers to maintain," he says. "The Cam-Grader can reshape the road
for runoff and fill potholes in four passes. It can grade about eight kilometers
per day. A typical road needs maintenance about four times per year.
"Most areas have agricultural tractors, which often sit idle outside the rice-paddy
plowing season. The grader is suitable as a business investment by a tractor owner,
or by a village group."
Richard Pullen says there are almost unlimited opportunities in developing countries
for DTW to start similar production units and receive royalty payments in exchange
for quality control assistance until handover to a local organisation.
"Unfortunately there is nothing to stop anyone copying our products. Our advantage
is we're six months ahead, we guarantee quality, we have credibility on the Third
World market, and we can produce much cheaper."
The mechanical braille writer is another DTW success story. It is a significant improvement
on its wooden braille predecessor which, although very cheap, had functional flaws.
The UK Department for International Development funded development of the improved
writer using machined parts which could be locally produced in developing countries.
Other development partners were the British Embassy, Krousar Thmey (Cambodian school
for vision impaired, French-run), Dark and Light (Holland), and Sight Savers International.
The developed and tested Mark 5 writer can be produced for $100 to 150, or about
one-fifth the cost of other commercially available machines. The project manager,
Harold Pearson, says DTW is planning to set up a regional production workshop in
Cambodia, where local vision-impaired people can be trained and employed in the manufacturing.
The current production line aims to produce 40 units to meet anticipated demand after
being promoted at a vision-impaired trade fair in Capetown in December.
The machine doesn't yet have a trade name; Pearson will run a competition among the
associated NGOs to find one.