Barrier - any
physical factor which reduces the ability of vehicles or personnel to
enter into our protected areas. Berms, Ditches, Steel or Concrete
Structures for examples.
Blast Wall - Many
weapons produce a blast, a wave of high pressure. This can break
windows, providing lethal slivers of glass. It can destroy the cladding
on a wall, and the cladding can fly around lethally. It can demolish
whole walls, which can fall on occupants. It can knock over whole
buildings and cause collapse of multi storey concrete and masonry
buildings. The best protection is to keep the source of the blast as
far away from our assets as possible, preferably in another continent.
This is not always possible. Using bigger perimeters, with cover from view and barriers and gates help keep away some blast
weapons. Having a sterile area inside the boundaries can help. Defence
structure steel buildings, strongly framed in steel with filmed glass
in strong frames, frangible cladding and so on can mitigate the effects
of blast. But there are times when there is no option but to try to
reduce the blast with Blast
Walls. These are walls made from steel framed concrete
panels, with an anti spall skin behind the concrete. The panels are
angled up onto steel frames. These will resist Blast, and direct it
upwards, reducing lethality. Read more about our blast walls here.
Building Robustness -
the ability of a building to be subject to considerable overload but
not to fail catastophically (say with progressive collapse as in
Oklahoma City). Read more about our robust
Bunker - A safe place
for troops to live in and work from. It will have Mortar Roof with Det
Screen, Rocket Screens
or Rocket Walls, Doors, perhaps Embrasures. Read more our about bunkers here.
Counter Terrorism -
the action of security forces and any other citizens to prevent
terrorism and apprehend terrorists, preferably before any atrocity
Cover from View (CFV)
- An arrangement of fences at the perimeter or in other locations used
to prevent observation of our security forces' personnel or vehicles or
fixed assets or routines in our bases or posts. Read more our about cover from view here.
- Civil or Military facilities and their surroundings important for the
continuity of normal life as we choose to live it. Read How to Make Buildings Robust.
Defence Structures -
Buildings of other structures designed and constructed to protect our
personnel and assets from attack. The type of structure depends on the
threat, which may be from a variety of weapons, or from optical or
Such structures may also provide all types of administrative or storage or workshop or command and
Defense Structures -
US spelling of Defence Structures (see above)
- See Defence Structures above.
Teeth - Linked surface mounted steel and
concrete devices able to be placed rapidly across roads or other areas,
and able to stop and destroy Vehicle Borne Improvised explosive devices.
Embrasure - This is
the hole in the wall through which an observer looks. It should enable
the man to see his arc without moving his head much, in other words,
the V shape taking up the thickness of the wall should be on the outer
face, not inside. Where the wall is thinner, it should be reinforced
with a steel backing plate. It may have Macrolon or steel shutters. It
may have a shelf for binoculars. From the outside, the dark shadow in
the hole is clearly visible and this should be camouflaged with
disruptive pattern dark paint. If it is possible to see another
embrasure through the OP
or Sangar from outside, the
observer will be strongly silhouetted and so a curtain must be placed
stopping people from seeing straight through.
Explosion - A rapid
chemical reaction creating large amounts of heat in a short time, thus
expanding rapidly at high pressure, producing a shock wave, blast and
Explosive - The
chemical or mix of chemicals that can cause an explosion. High
explosive has extremely fast action propagating by a shockwave
travelling through it. Low explosive is slower, in effect burning very
quickly. Explosives can be solids; or plastic; or a mixture of liquids.
Explosive Device - A
construction containing explosive with an initiation system. The
container may be intended to fragment on detonation; or maybe just a
drum to contain the chemicals. Home-made explosive devices are
'improvised explosive devices', IED.
Force protection (FP)
- Any measure or combination of measures used to reduce the risk of
injury to our security forces, or damage to their assets.
Forward Operating Base (FOB)
- A forward operating base is a secured position away from a main base,
which is able to provide protection for our forces, and enable them to
opearte effectively. The FOB will provide appropriate level of logistic
support and may have: Fences and Cover
From View Screens; Bunds; Barriers; Road Barriers and
Check Points. Gates.
Facilities with Mortar Roofs
and Rocket Screens
or Rocket Walls; Sangars.
Read more our about forward
operating base here.
Fragmentation - The
bits of material shot about at high velocity following an explosion.
These may be a part of the weapon casing, deliberately intended to
fragment, called primary fragments; or they may be material at the
target, building components or rubble, scattered by the explosion,
called secondary fragments. Secondary fragments may stay attached
(constrained), or fly freely, (unconstrained).
Gates - Gates vary: lifting barriers;
normal soft skinned gates, which can be clad as an extension to the cover-from-view screen,
strengthened gates which can resist small arms or projectiles; blast
and vehicle bomb resisting gates. Gates are designed for the specific
location and threat. They are most effective if used in pairs as lock
gates; or in a labyrinth. They are best if covered by Sangars. They may
be used in combination with blast walls or dead stop barriers or both.
Read more our about gates
- Chain Hedgehogs: these are light weight road barriers consisting
of two tripods of steel members, with light chains stretched between
them. The chains can be readily lowered to allow vehicles to pass, but
if a vehicle hits the chain when taut, the two tripods are dragged into
the sides of the vehicle making further progress difficult. Since all
the bits can be carried in a Land Rover, they make it easy to establish
a vehicle checkpoint
quickly, effectively and safely. They reduce the risk of accidentally
shooting joy riders or revellers. Read more our about hedgehogs here.
- a vehicle being used for an attack on our security.
Hostile Vehicle Mitigation
- Implementation of methods to reduce the threat from Hostile Vehicles.
IED - stands for
Improvised Explosive Device. This refers to home made explosives
frequently utilised by terrorists.
Impulse - The
pressure from a blast multiplied by the duration of the pressure, (or
the area under a pressure/time graph).
Membrane Bunds or Membrane Walls
- These are cellular membrane formers which can be filled with sand or
stone or earth, for a variety of purposes: they can be used to form
cost effective bunds able to stop all vehicles; and rocket walls for
Mortar Roof - A
mortar round is a projectile which is fired with a very high trajectory
and drops almost vertically onto its target before exploding. It has a
fuse which is usually detonated on impact, sometimes with a time delay.
If it lands on the ground it provides blast pressure and shoots off
shrapnel all round to a lethal radius of about 40 metres. If it lands
on a soft building, the effect can be worse: the roofing material is
splintered and adds to the shrapnel, and the enclosure in the building
can make the effect more lethal; or the structure itself can collapse,
killing the occupants. A Mortar Roof has a steel skin at a standoff,
which detonates the round. The shrapnel still shoots on downwards, and
this is stopped by a concrete skin underneath. Under the concrete skin
is a metal anti spall skin, which largely contains any pulverised
concrete fragments from shooting downwards. The assembly is carried on
steel frames, which will not be destroyed by the blast pressure.
Underneath this Mortar Roof is the normal soft-skinned building, which
will probably stop any remaining fragments as well as provide the
climatic enclosure. Read more our about mortar
Observation Post (OP)
- A room with a view. This room can be within a building; or on top of
a building; or free standing, on the ground or on a tower. The
essential point of the OP is that it provides good observation over the
area to be observed. To cover the perimeter of an installation, the
edge of the installation needs to be in a series of straight lines with
an OP at each corner; and perhaps more between. It may seem obvious
that these are better if higher, but height adds blind spots
underneath. OPs should have interlocking arcs. Read more our about observation post
Penetration - The
distance inside a barrier that the payload of a vehicle can travel into
the protected area before being immobilised by the barrier. Penetration
can also mean the distance a fragment can travel into a target if it
does not go right through it.
Protective Design -
Design taking into account the need to protect facilities and their
Resilience - the
ability of our facilities and our organisations and systems to survive
attacks and accidents with the minimum of disruption and the maximum of
continuity. Read How to
Make Buildings Robust.
Road Barriers - Dead
Stop Barriers: A popular means of attack is to use a vehicle as a bomb.
This is driven at speed towards our security enclosure. Normal bollards
may damage the truck, but it will still penetrate into our sterile
area. A barrier stops a truck dead in 2 metres or so, demolishing it
and its driver and effectively preventing penetration. Read more our
about road barriers
Road Barriers -
Surface Mounted Road Barriers: As implied by the name, these barriers
are simply placed on the ground, and linked together. They will stop
any vehicle, and, as they have no foundation, will move under impact.
They should be quick and easy to move, place, and repair after any
impact. The best of these are Defence-Structures Dragon's Teeth. Read
more our about road barriers
Rockets used as Artillery or Mortars
- Millions of Anti Tank Rockets are strewn around the world. They are
designed to be aimed or guided to their targets. They can be launched
from fairly light, mobile tubes. They come in a variety of sizes from
60 mm to 127 mm. They are usually of the HESH (High Explosive Squash
Head) variety and make a big bang. Because of the range and ease of
launch and availability, they can be used as artillery or mortars: that
is they are shot off into the air in the vague direction of Security
Forces, with little aim or guidance. It is sad that Civilians from
quite far away are the most frequent casualties.
screens and mortar
roofs can provide substantial force protection against such
weapons, though nothing can provide 100% safety. Mortar Roofs may need
some extra bracing against the horizontal component of low trajectory
large calibre rockets.
Rocket Screen - A
rocket or rocket propelled grenade (RPG) is a projectile which travel
in a low trajectory and which explodes on impact, producing shrapnel
and blast. If a rocket hits a soft skinned building the effect can be
worse: the wall itself is splintered and adds to the shrapnel, the
blast blows in windows which become lethal, and the blast can blow down
the wall or the entire structure killing the occupants. A rocket screen has a
steel skin at a standoff, detonating the round before it hits the
building. The shrapnel usually carries on towards the structure and is
stopped by a concrete wall. Behind the concrete wall is an anti spall
skin which prevents or reduces penetration by chunks of concrete
pulverised by the shrapnel. This whole assembly is supported on a steel
frame which resists the blast. Behind this is the normal soft skinned
building which should stop any remaining fragments and provide the
climatic enclosure. Read more our about rocket screens here.
Rocket Walls - Sand
or Earth or Stone filled Membrane walls which are strong enough in
themselves to protect from rocket attack.
- During the Afghan wars of the 'Great Game' tribesmen would hide in
the crevices of the rocky mountainsides to observe and to shoot at the
British soldiers. These would shoot back, so the positions would be
fortified with slabs of rock, embrasures, roofs, camouflage. The Afghan
word for these tiny little forts is Sangar. Things have not changed
much, and a Sangar is an OP
which is protected against incoming ordnance and the weather, and from
which weapons as well as binoculars could be used. A Sangar is a
fortified OP. Often a Sangar will be equipped with a Mortar Roof, a Rocket Screen and Cover From View.
Security - the state
of well being and safety for our people and our assets.
Security by Design -
Ensuring that all aspects of security are considered during the
planning and design and excecution of all our facilities and systems.
Read How to Make
Buildings Robust/Structures Resilient.
Shrapnel - High
energy fragments flying around after an explosion, usually the
deliberately designed casing of the explosive device.
Spall Skin - When
concrete is hit by a high speed fragment, it shatters locally, and
often a scab is detached on the far side of the slab which itself
becomes a projectile. A steel skin, even relatively thin, can slow or
stop this scab. This is a spall skin (or anti-spall skin, or
Terrorism - Acts of
individuals or groups prepared to use violence against anything or
anyone they consider a 'target', civil or military, human or material,
in the pursuance of ideological or religious or politcal or commercial
Terrorist - anyone
who takes any part in terrorism; usually weak sad people who have been
brainwashed by other individuals (who manage to be a long way away when
the bomb goes off).
VBIED - Vehicle borne
improvised explosive design (IED) (Car Bomb or Truck Bomb for examples).
Vehicle Check Point (VCP)
- It is often necessary to stop vehicles, for identification or search.
These give outstanding opportunities to catch villains and prevent
crimes, but also to annoy the normal and law abiding populace, to shoot
innocents, to cause traffic jams, and to expose the security personnel
to risk. A proper VCP starts to resemble an efficient customs post,
with many lanes, clear diversions into separate bays, cover from view
for the search process, all covered by OPs or Sangars. They will have crew rooms,
a rapid response Guard Room, climatic enclosure, Mortar Roofs and Rocket Screens. Read
more our about vehicle
check points here.