Comments on the "Detonation" Approach
Daniel Wolf and Steven Barmazel discussed the Public
Health approach to demining in an article entitled "The
Necessity of Implementing a Public-Health Approach to
Humanitarian Demining,"1 making some very valid points.
However, Robert Keeley points out some problems with this
approach that he feels need to be addressed before this method
can be successful.
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by Robert Keeley, Asian
Daniel and Steven are right to
point to the ideal of a Level Two Survey that defines the boundary of a
contaminated area and properly reduces the area that is believed to be
contaminated, so that the area freed up by the process is cleared to the
same level of confidence as could be expected by a clearance process.
This does seem to be a way to improve the overall cost benefit of mine
action, rather than simply hunting for mine fields. However, I’m not
sure that this approach automatically endorses the Level Two Survey
technique that they promote in their article, and I’d like to discuss
these points in more depth.
A Common Approach
First, I’d like to endorse the inclusion of this
type of cost-benefit analysis approach. Belinda Goslin and I helped
introduce similar ideas in Croatia in 1996 (with the help of
Norwegian-Croat public health specialist Branko Kopjar), and since then,
I know that several other people have considered this issue, such as
Eric Filipino in his recent publication at GICHD, "A Study of
Socio-Economic Approaches to Mine Action." (I wish that it was on a
website somewhere, as it would be easier for other people to get copies
I raise these examples not to make any sort of
"Yah boo, we thought of that before you did!" comment, but
rather to make the point that many people in many places have similar
ideas. Although it could be an example of "if you put enough
chimpanzees in enough rooms with enough typewriters, eventually you’d
get a copy of Hamlet" I hope these examples of "parallel
processing" really mean that many of us are thinking the same sort
of thing, which (hopefully) means that we are making some sort of
The public health/socio-economic/cost-benefit
analysis approach also applies to the areas of R&D—many of the
cries in the separate article in the same edition about the DTIF
conference1 bring eerie feelings of déjà vu when I read about
the eternal question of balancing resources for R&D against
allocating some of these resources for projects using existing methods.
The cost-benefit question will come up again later in these notes.
It was the point about using "detonators"
as a Level Two Survey technique that caught my eye. First, we need to
unpick the linguistic confusion—as Oscar Wilde said, the English and
Americans are "two nations separated by a common language,"
and to us users of British English, a "detonator" is what, I
believe, those on the other side of the pond call a "blasting
cap." I’m assuming that Daniel and Steven are talking about the
use of a mechanical impact device (such as a flail or roller) to
initiate mines—so perhaps "Level Two Survey by Detonation"
would be a term we could all agree on. Sorry to be so picky, but in my
experience of the last 10 years in this industry, it’s always worth
the effort to get the definitions correct as early on as possible!
This basic idea—that you drive a machine in as far as possible
until something goes bang, then use the location of the bangs to
define the perimeter—has been around for a while. We were certainly
talking about it in UNPROFOR (the UN mission in Bosnia and Croatia) and
the follow-on humanitarian demining missions with representatives of NPA
and Technopol in 1995–6. The Slovak manufacturers of the Bozena, and
both Hendrik Ehlers of MgM and David Hewitson of ELS have
been conducting work on the same ideas for years now (another example of
parallel processing). The motivation for this technique was simple:
bayoneting our way in from the Croatian coast wasn’t an option, and
how could we use machines that had already failed as total
clearance devices to help reduce the total area that we might
have to clear? In other words, could machines, used in this way, help us
improve the overall cost-benefit ratio of demining and help us target
our resources against priority targets more effectively?
I think that, five years later, the answer is still—at
best—"Yes, well, maybe," and so I don’t think it’s fair
for Daniel and Steven to state so categorically that "mechanical
detonators are more than adequate for this task" or that
"mechanical detonators allow quick area coverage…thus increasing
survey speed while reducing cost." I’ll explain why I think this
There are two main problems with such enthusiastic
and categorical endorsements of the "Level Two Survey by
Detonation" technique. These are:
• The machines do not detonate 100 percent of the
mines—let alone UXO—that they cross.
• Machines are not necessarily more cost effective.
Not 100 Percent Effective
This first came up in my experience in Kuwait, though
some of the lessons (not) learned by others in Afghanistan were directly
relevant. The representative of a company selling and operating machines
on contract in Kuwait endorsed the use of a flail machine for clearance
of a beach mine field, even though one of the junior managers of the
company who hired the flail had personal and unsatisfactory experience
with the same machine used in this way in Afghanistan. He said that the
machine had failed to detonate at least 50 percent of the PMN2 mines it
had encountered there—and as many readers will be aware, the PMN2
includes a cunning mechanism that was intended to protect the mine
against explosive overpressure. The junior manager postulated that the
flail would have the same problem against the Italian VS-50 mines in the
beach mine field in question, as the VS-50 has a mechanism with a
similar protective effect. He suggested that the soft sand and the
smaller mine size would exacerbate the problem. He then went on to prove
this by disarming some VS-50s, removing the main charge, painting the
mine bodies orange and replacing the detonators. He then re-armed the
mines and invited one of the flail crews to drive over the mines—50
percent did not detonate. Now, only a small sample was used—he had had
to recover the mines himself and therefore only had four—but, given
that the aim was to remove ALL of the mines, this gave serious room for
doubt. I won’t go on with this story (which had a sad ending) except
to say that a similar test based on this story, which we conducted in
Cambodia, with a different flail, had very similar results against the
PMN2, corroborating the Kuwait and Afghanistan experiences and helping
us prevent injury in that case.
Rollers proved even less effective in Croatia, where
they had the unexpected side effect of knocking down crops on top of
mines and masking the mines from the rollers when they passed over them.
These results, and others elsewhere, have led us all away from the idea
of using rollers and flails as "one stop shops" in the
demining process. However, the point of these examples in the context of
these notes is: if we can’t be sure that the first bang made by the
machine is as a result of it successfully detonating the first mine that
it has passed over, how do we then use this result to determine the
boundary of the contaminated area?
It has been suggested occasionally (though not in Daniel and Steven’s
article) that the number of passes made by the machine can increase the
effectiveness of the result, but let’s be clear that that is not
a valid conclusion to draw in this case. If the mechanical impact isn’t
going to set off the mine because of a protective mechanism in the mine,
then more repetitions of the same technique do not guarantee an eventual
success. We are not hammering in a six-inch nail! In fact, if anything,
this is more likely to disrupt or mechanically destroy the mine (perhaps
a good result in itself, but also contributing to the uncertainty about
where the edge of the contaminated area is). There is also the problem,
rarely encountered in the land of brochures and sterile trials, that we
are not demining football pitches and that the ground in mine fields is
Mines at the bottom of
undulations (see Figure 1) aren’t going to be hit by the wheels or
hammers, no matter how many times the machine drives over them, and the more
energetic techniques—such as flails or soil mills—can even
contribute to burying the mines further by redistributing soil on top of
them. Furthermore, anyone who has ever had to supervise any sort of
construction plant will know that it seems to be impossible to make the
plant operators drive in a straight line (construction engineers all
over the world believe that bulldozer operators are united in a common
bond to knock over all the site markers that the engineers put up on a
construction site), and this problem is only exacerbated by the use of
remotely operated plants, so we really can’t be sure that the machines
have covered all of the ground that we want them to (see Figure 2).
The Cost-Effectiveness of
The second problem with Daniel and Steven’s
endorsement of "Level Two Survey by Detonation" is with the
implied generalization that machines will always reduce costs.
Unfortunately, this is not necessarily the case. At least one machine
tried in Asia recently consumed more dollars per day in diesel fuel (let
alone maintenance and transport) than it cost to fund the deminers it
was claimed that it could replace. Now, while it may be easier to make
the case for machines in the Balkans (where deminers are comparatively
expensive), the fact that we can’t trust them to clear all of the
mines means that (a) while the Level Two Survey finds mines in an area
that we need to clear for the project involved, we still need to use the
deminers (i.e., the total cost is machine + deminers, NOT machine
instead of deminers), and (b) even if we could use the machine to
determine the boundary of the mine field, what happens if the first mine
found is only one meter from the start line?
What does this mean?
While I agree with the general thrust of David and
Steven’s support for ‘Level Two Survey’ and that machines can have
a part to play, I feel that this deserves to be predicated on the basis
of several caveats, including something along the lines of:
• Where a machine is used to determine the actual
perimeter of contamination within a suspected mined area, the use of the
technique involved must adequately demonstrate how the boundary of the
contamination is determined given the limitations of the machine
involved. Where this is not possible, a second method, such as dogs or
manual clearance, must be used.
• Planning the use of machines in Level Two Survey can
have valuable benefits in terms of improvements in speed. The cost of
the machines must be offset by the benefits in demonstrated reduction in
This can be done. For example, a machine that
is used to clear vegetation and prepare ground ahead of manual deminer
teams can speed up a project (though not always—think of trying to
clear up mines when you’re working behind a mine plough that’s just
buried mines in heavy clay!). That’s why we talk about
"mechanical ground preparation" (and I believe Hendrik talks
about mechanically assisted demining). It comes down to that old slogan:
"Are we making it faster, cheaper or safer?"
Am I being picky? Perhaps. I certainly don’t want
to detract from the overall thrust of the article and its illumination
of the cost-benefit analysis approach to demining. However, I hope my
comments will be taken in the light of helping us all reach the goal of
good Level Two techniques and so improving our productivity.
*All figures courtesy of the author.
1. See The Journal of Mine Action, Issue 5.2, Summer 2001
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