follows is a risk assessment that I made on behalf of a demining
NGO for a research group. The research group were not staffed
by experienced deminers and so wanted all risks outlined as
clearly as possible, with strategies for risk reduction as detailed
as possible. It was not appropriate to make "requirements" over
the manner in which the research was to be conducted, so changes
to the group's actual operating procedure were limited to suggestions
rather than requirements.
April 2003, AVS
Assessment for APOPO/MgM live-area tests
is co-operating with APOPO in its assessment of the ability
of trained pouched-rats to detect buried explosive items. To
facilitate this, MgM previously prepared extensive Safe-test
areas for the rats in an area near to the mine-belts but where
there were no live devices. The vegetation in the area was cut
and the area checked, then test-boxes were marked out and safe
devices with an explosive content were concealed in November
have now used the safe-test areas extensively and recorded their
required performance data.
also asked MgM for the opportunity to assess the explosive detection
abilities of its trained pouched-rats in as realistic a setting
as possible. The purpose of the tests is for APOPO to assess
the efficiency of the rats and the practicality of their deployment
method in a live area.
facilitate this, MgM have prepared test lanes that cut through
the known mine-belts in the live mined-area. These are called
Hazardous-test areas because they are known to contain live
and functional mines.
purpose of this document is to indicate to APOPO the level of
hazard that is perceived in their testing so that APOPO staff
are fully informed of any risks they may run. MgM will do everything
they can to ensure that the risk is minimised, but cannot accept
liability for any residual risk, whether predicted or otherwise.
known mines in the Hazard-test areas are the GYATA-64 and the
POMZ-2 and POMZ-2M. The PP-Mi-Sr is another possible threat.
There is no significant recorded ordnance threat, with small
arms ammunition being the only UXO located to date. If other
explosive devices are found the threat assessment may need to
The GYATA-64 is a large AP blast mine with an
explosive content of 300g TNT. It is 106mm in diameter and 60mm
high. If detonated by stepping on the pressure plate, the GYATA-64
will remove the foot and damage the lower leg extensively. Past
demining accidents in Mozambique have involved three "lower-leg"
and one "through-knee" amputations. No deminer deaths from stepping
on a GYATA-64 are recorded. If the mine is detonated in or beside
a hand, amputation should be expected. Eye damage may occur
if within 15 meters of a detonation without using a protective
visor. All eye damage can be permanent and severe. Ear damage
could occur if within a similar distance, but is unlikely if
more than 10 meters away. Ear-damage from blasts of this size
at more than five meters is usually temporary and results in
a very small permanent hearing loss.
picture Below shows the metal content from a GYATA-64 alongside
an example of that mine. The leaf-spring that holds up the firing-pin
is on the left.
slightly elevated risk
Hundreds of these mines have been found in MgM's clearance task,
and almost all are believed to have been functional. There is
occasional evidence that the exposed rubber tops of the mines
have been degraded by sunlight, weather and/or bushfires. There
is also evidence of internal corrosion to the thin steel leaf-spring
and coil-spring that hold the firing-pin in place. Weight on
the mine compresses the springs and allows the firing pin to
line up with a hole and fire into the detonator. Corrosion of
the leaf-spring and the coil-spring above it could reduce resistance
and so make the mine more sensitive to pressure applied from
above. MgM have successfully exposed and either disarmed or
destroyed many hundreds of these mines and so my current judgement
is that the condition of the mines does not significantly increase
deminer risk during normal manual operations, but that disarming
should not be attempted without good reason.
POMZ-2 and POMZ-2M are stake mounted fragmentation mines with
an explosive content of 75g TNT. The difference between them
is in the way the fuze attaches, with the 2M model having a
threaded hole for the fuze to screw into. In the POMZ-2 the
fuze pushes into place and is more likely to be found separate
from the mine body. Sometimes locally sand-cast, the cast-iron
bodies vary in quality and they fragment into rice-sized grains
or larger chunks.
picture shows a POMZ-2M fresh from the store.
detonated by removing the pin, a POMZ will spread fragments
all around. The density of fragments being greater at the sides
of the mine. Fragment speeds have been estimated at up to 600
metres a second, with very few fragments actually achieving
that speed. Lacking direction and being an irregular shape,
almost all fragments slow down quickly after leaving the mine.
At 600 meters a second, a fragment could penetrate the standard
body armours (offering protection from STANAG fragments moving
at 450 meters a second) and kill. But there is no record of
this having happened with POMZ anywhere in the world. There
are records where light armour and a 5mm polycarbonate visor
have stopped 95% of POMZ fragments at a one metre distance in
people have been seriously injured and killed by POMZ. There
is evidence of this in the mine-belts where MgM works in Mozambique,
with a partial human skeleton having already been located (and
buried according to local custom) and another reported to be
ahead of the clearance group.
a POMZ detonates within five metres of a person, severe penetrating
injuries to unprotected parts of their body may be expected.
Armour penetration could occur and fatal injuries result. The
visor is the weakest part of conventional body armour (providing
protection from STANAG fragments moving at around 280 metres
a second) and may fail, resulting in severe eye or head injury.
Ear damage could occur at up to 15 metres distance but is unlikely
if more than 5 meters away. Ear-damage from blasts of this size
is usually temporary and results in a very small permanent hearing
Hundreds of POMZ mines have been found in MgM's
clearance task, and almost all are believed to have been non-functional
due to fuze corrosion. None have had more than a few centimetres
of heavily rusted intact tripwire attached. None have been found
with an intact wooden stake. Some are found with the roll of
TNT having fallen out of the cast casing. Some have been found
partly buried by silt or leaf-litter, others are lying on the
surface. All the POMZ fuzes have been members of the MUV family,
with a very few having a stainless steel casing, the rest an
aluminium alloy that is heavily corroded. The extent of the
common corrosion has meant that the pin has fused into the shaft
of the striker and the striker and spring are corroded to the
fuze casing. Except when the fuzes have stainless steel casings,
these mines are considered safe to move cautiously for later
destruction. Only the Chief of Demining and the Chief of Operations
are normally permitted to move them.
picture shows an old POMZ-2, dug up some twenty years after
it was placed.
PP-MI-SR mines have been found recently in the mine-belts. None
had been found in the belts up to and including the area where
APOPO Hazard-Test lanes have been prepared. The PP-MI-SR mines
were found lying on their side on the surface. They have either
MUV or bakelite RO-1 style fuzes. One of the mines found had
been fitted with two fuzes, apparently in error.
PP-MI-SR mines are of the bounding fragmentation type. Usually
placed with the lower half in the ground and the top of the
mine protruding, those found in Mozambique usually have RO-1
style fuzes. RO-8 pressure fuzes can be used with the mine,
but none have been reported in Mozambique. With an RO-1 fuze,
initiation is by pulling a tripwire, which pulls the pin from
the fuze, allowing the spring loaded striker to fire into the
detonator. When the mine is initiated, a small charge in its
base throws the body of the mine into the air. The body of the
mine is secured to the base with a wire cable. When the wire
cable is pulled tight (usually at 60-100 cms) the main charge
of approximately 310g TNT in the body of the mine detonates.
The thick steel of the mine body shatters, spreading hundreds
of metal fragments in a 360º radius around the mine. The speed
of the PP-MI-SR fragments has been estimated at up to 1200 metres
a second, with very few fragments actually achieving that speed.
Lacking direction and being irregular shapes, most fragments
slow down quickly after leaving the mine. At 1200 metres a second,
a fragment will penetrate the standard body armours (offering
protection from STANAG fragments moving at 450 meters a second)
and kill. This has occurred with many similar mines elsewhere
in the world.
demining in Mozambique, there have been five recorded accidents
with bounding fragmentation mines (but none with the PP-MI-SR
model) and four have resulted in fatalities. In the fifth it
seems that the mine did not bound properly. Four other people
were injured in these accidents, despite being some distance
away. One deminer was killed by a single fragment that struck
him in the neck at 31 metres from the detonation.
any bounding fragmentation mine detonates within five meters
of a person, that person will be at very high risk of suffering
multiple penetrating injuries to head and body regardless of
the protective equipment worn. At up to 50 metres, severe damage
could be inflicted on unprotected areas. Ear damage could occur
at up to 25 metres distance but is unlikely if more than 15
picture shows a PP-MI-SR with an MUV type fuze.
The undergrowth in the APOPO Hazard-test lanes
was mechanically cut when the lanes were made and any PP-MI-SR
mines on the surface would have been easily identified. None
were found. The fresh undergrowth will be cut again before the
tests are conducted, and a second visual search conducted. If
any PP-MI-SR is visibly present, the test lane will not be used
by APOPO and a new Risk Assessment may be made. Any PP-MI-SR
present that is entirely concealed underground is unlikely to
be initiated by the shallow scratching of a rat, so is considered
to be a very low risk.
Hazard-test lanes comprise part of a known mined-area alongside
a railway line in the Limpopo river valley. MgM has been active
in the area for two years and has cleared large sections of
the defensive mine-belts present. Clearance is being done by
manual deminers using metal-detectors, assisted when appropriate
by a range of Mine Protected area-preparation machines and explosive
detecting dogs (EDDs).
date the mines located have been in two or three belts (varied)
and have been GYATA-64 AP blast mines and POMZ-2 and 2M fragmentation
mines. At the start of April 2003, two PP-MI-SR bounding fragmentation
mines were found. They were several hundred metres from the
area prepared for use in the APOPO trials. Defensive mine-belts
are sometimes "maintained" by the defending forces, and may
be "patched" with other available mines - which seems to have
cutting lanes through the mine-belts and leaving uncleared strips,
MgM has prepared live Hazard-test lanes where they have a high
degree of confidence that there are mines. The test lanes are
approximately five meter wide strips, with safe areas all around.
The uncleared areas are clearly marked with pickets and marking
Hazard-test lanes are clearly marked. There is resurgent undergrowth
and the stumps of previously cut undergrowth in the lanes. Access
is via cleared and QA checked safe areas. The area undulates
slightly but is largely level. No further significant rainfall
is expected this season.
the testing is conducted, the undergrowth will be cut again
(using mechanical assets).
1) Should an employee or associate of APOPO suffer an accident
anywhere within MgM's working area, MgM cannot and does not
take any responsibility for the injuries, medical costs and
suffering that may result. At all times, APOPO staff and associates
operate at their own risk and on the understanding that they
carry their own appropriate insurance.
When the undergrowth in the Hazard-test lanes is cut, the perimeter
marking will be made good and a further set of pickets and tape
shall be established outside all four sides of the test lane
and at least 40cm from it. No APOPO personnel shall be allowed
inside the outer marking. This is because the rat-handlers stand
on both sides of the lane to control the movements of a rat
across the hazardous area. While doing this they watch the progress
of the rat intently. With their attention on the rat, they may
place their feet under the perimeter tape (as has been observed
in the Safe-test area). By placing a second perimeter marking
40cm back, any accidental movement across that marking should
not be catastrophic.
The third APOPO staff member (who records the rats signals)
must stand as far as possible from the rat, and at least five
metres from either handler, moving as they move.
All APOPO staff in the mined-area must wear protective equipment
and a visor that does not allow the wearer to see the ground
without looking through the visor. Short, "dog-handler" visors
may be sourced as an alternative to those currently used by
APOPO. If this is done, APOPO should recognise the slightly
increased risk to the lower face that this may represent.
No APOPO personnel shall approach the Hazard-test area without
the express permission of the Chief of Operations or the Chief
of Demining, and shall always be accompanied, obeying all safety
conditions in force.
No APOPO personnel should approach the Hazard-test area without
the presence of an MgM paramedic and ambulance at the site.
Any observers invited by APOPO (and approved by MgM) shall obey
all safety rules and maintain safety distances as directed.
APOPO should ensure that they are adequately insured. The method
under trial requires three people to be inside what is usually
considered to be the minimum safety distance for a blast-mine
threat. Their risk is minimised by the wearing of body armour
and visors. All others must be at a distance not less than 25
metres from the working area.
At all times during any activity in the MgM-Task area that includes
the Hazard-test lanes, MgM must remain in control and retain
the right to halt all activity and withdraw persons from the
field. If a person behaves in an unsafe manner and ignores safety
directions, MgM reserves the right to permanently exclude that
person from the Hazard-test area, the MgM-Task area, and the
safety cordon around it.
The indications of the pouched-rats will be recorded but will
not be made available to the deminers who will clear the area
manually in the normal manner after the APOPO tests are completed.
The way that they record their finds of fragments and "innocent"
items may be changed to reflect APOPO's needs.
POMZ mines that are on the surface or have visible fuzes that
appear to have stainless-steel sleeves should be removed before
the APOPO tests begin, or the lane where they are should be
removed from the APOPO test area. When a mine is removed from
a test-lane, its original position will be recorded in the manner
required by APOPO.
APOPO shall draft operating procedures, including basic safety
features and procedures in the event of an accident, and present
them for MgM and IND's approval or adjustment prior to the testing.
Accident procedures must be practised before work begins in
the Hazard-test area.
conditions outlined in the previous section represent an attempt
(agreed with MgM) to reduce risk to the bare minimum during
the APOPO tests. However, there remains a small identified risk
that results from the method under test. The residual risk results
from the weight of the pouched-rats and the way that the rats
indicate a "signal". They commonly scratch the ground close
to the concealed explosive. The force that a rat applies to
the ground when doing this has not been measured and recorded.
It is possible that a heavily corroded GYATA-64 could become
very sensitive so that the pressure exerted by the rat detonated
it. It is even possible that a rat's weight alone could be enough
to initiate the mine (the rats are large and fat).
cannot prevent this occurring.
it does occurs, I anticipate that the rat would be killed and
the three APOPO staff in close proximity may suffer some slight
hearing loss (temporary). They may also suffer light injuries
to their legs where they are unprotected by the armour apron.
They would also be in a state of shock.
further slight risk arises if a rat digs the pin from the fuze
of a POMZ or were to roll an exposed POMZ around. While most
of the fuzes are inoperative, if the POMZ were to detonate there
is a significant risk of injury to the APOPO staff and a small
risk of severe or life-threatening injury. By removing exposed
POMZ, MgM will do all it can to reduce this risk.
MgM's agreement, I recommend that the APOPO handlers seek to
minimise any scratching that a rat may make in any one area,
if at all possible.
MgM's agreement, I recommend that APOPO consider supplying their
handlers and the data recorder with frontal leg protection to
be worn as additional protection during the tests.