7. SWITCHGEAR AND INSTRUMENTATION
Nothing works unless it is told to by its electrical or human
master. In modern warfare the first thing to be attacked are the
lines of communication. Likewise the most effective, quick, at
expensive way to disable equipment is to disable the control systems.
For example, how would you turn a computer on if someone removed
its 'on/off' switch?
A good way to disable any system is to disable/damage the control
systems. Especially on more modern systems, where specialist control
devices are made to order, this can be very expensive to fix.
Control systems essentially break down into three groups...
- Switches, levers and actuators: This is where a simple switch
operates something - for example the lights on a car;
- Switching systems/switchgear: This is where the control the
user operates a switch/pushes a button/pulls a lever and engages
other systems, which may be fully or partially automatic, and
which then switch themselves into different states according to
preset 'hardwired' timing or mechanical systems;
- Programmed systems: These are the most modern and involve
the use of computers or 'programmable logic controllers' to coordinate
the switching of different systems - for example in modern manufacturing
Note also that these switching systems need not be all electronic,
or all mechanical - there are still a number of systems in operation
using mechanical or electro-mechanical control systems.
How you tackle a system will depend mainly on its make-up. If
you have a wholly mechanical control system, for example on a
aggregate grading screen, you would either go for the levers that
control the system, or the linkages from these levers. But if
you were dealing with a more complex system, for example an electrical
generator, it would make more sense to go for the electrical output
controls (the switches, power meters, fuses, etc.) than to just
go for the switch that starts the engine.
7.2 Mechanical controls
Mechanical controls are either very flimsy affairs, such as brake
cables, or they are very tough, such as the levers on large earth
movers. Sometimes brute force, or endless tooling away, is not
the answer. Many hefty control systems, such as steering wheels,
actually come of very easily if you take them apart rather than
cut them apart.
As a very simple guide...
- Levers can be bent backwards and forwards till they weaken
and break. Stronger ones can be removed, or if that is not possible,
immobilised using resinous glue on their mounting pivots/hinges;
- Control cables can be cut - you will need side cutters/bolt
cutters (depending on size) for this as the high-tensile steel
does not cut very easily;
- Some levers are held in place with pegs or 'scotch' stops.
These can be removed, or glued/welded in place.
An issue to think of in all this is of course safety. You should
never cut the brakes of a mobile vehicle - it is extremely dangerous
to the operator and other people. Likewise never start cutting
a control cable or control rod unless you are pretty certain that
you can finish the job. Leaving cables and rods half cut is dangerous
as they can fly apart and injure those nearby when the machine
is operated. If you have any doubt about the effect of what you
are doing - don't do it!
Examples of electrical control panel components (figure 22)
7.3 Electronic controls
The illustration on the previous page shows a range of electrical
control components - switches, knobs, meters, relays and fuses.
How you tackle a control system is dependent upon how it is controlled,
and so it is important to know how to tackle each element of the
- Slide switches can be superglued very effectively, or you
can use a hammer and centre punch to push the switch slider through
- Rocker switches can be glued, although not so well. Most rocker
switch bodies are made from plastic, and are sometimes illuminated.
The simplest way to deal with them is to push/hammer a large insulated
electrical screwdriver through them. Unlike slide switches, rocker
switches can use mains voltages, so it is essential your hands
do not touch the bare metal of your tool. Rocker switches are
normally fitted from the front of the panel, so if you dig a screwdriver/chisel
under the edge and lever, you can pop the switch out of the panel.
Then you just clip the wires using insulated side cutters and
chuck the switch away (or stamp on it);
- Toggle switches can be easily damaged - you either use your
side cutters to cut off the toggle arm (making the switch harder
to use), superglue the pivot/ball at the base of the toggle, or
just hammer the arm of the toggle to break it;
- Push button switches are harder - you either glue them or
get an insulted screwdriver or punch and push the button in. Alternatively
you can get some 'mole' grips, adjust the screw so that the grips
tightly clamp onto the button, and then wrench it out;
- Key switches are most easily glued up;
- Micro switches are easily broken using a hammer, crowbar,
or they can be easily broken/prized away using a screwdriver or
chisel. But beware as they often operate at mains voltages.
- Knobs can either be broken off using a hammer/crowbar, or
if you have a small screwdriver you can just remove them. Some
knobs also just pull off. Those that have no obvious screw fixing,
and don't pull off are either permanently fixed on, or they have
a 'screw cap' - this can be popped off to gain access to the screw
- Most modern fuseholders are fixed into the panel, with only
their heads sticking out. You then unscrew or pop out the end
of the holder to remove the fuse. Another method is to pop out
the fuseholder and fill the space with resin/potting compound,
or to remove the fuse and just superglue the top back on again;
- Clip fuseholders can have their fuses removed, or more simply,
just bash them on top to bend the terminal spades beyond repair;
- Fuses should never be 'bridged' - that is replaced with bolts
or pieces of thick wire. There are there for a reason - to stop
things drawing too much current, overheating, and potentially
starting a fire. Just remove the fuse, or render it useless -
don't replace it with something that won't fuse when it is needed!;
- Circuit breakers (not illustrated - they are usually marked
'circuit breaker' or 'earth leakage trip') detect current leaking
to earth and break the circuit. They are essential to protect
people from being electrocuted, and should not be tampered with.
Either smash them beyond repair, remove them, or leave them alone.
Meters and displays:
- Panel meters use small coils to display a current or voltage
reading on a scale. The simplest way to disable them is to jam
a screwdriver through the dial - use an insulated electrical screwdriver
- Digital meters (not illustrated) use LED displays, arranged
as dots, bars or numbers, to give a digital reading. Again, these
are easily disabled using a screwdriver, or the spade end of a
- Cathode ray tubes (not illustrated - basically things like
TV screens, computer screens, etc.) are large glass bulbs with
no air inside. This means that when they are broken they implode
- and then shower the area and anyone stood nearby with shards
of glass. The simplest way to break them is to throw a brick/heavy
solid object at them from ten yards away, or cover the screen
with some think material such as canvas or carpet, and then hit
them with a hammer.
Relays and PLCs:
- Relays are magnetic switches - an electrical current creates
a magnetic force that switches the metal contacts. Many relays
can be removed from the sockets they are plugged into - this means
you can either remove and dispose of them, or remove them, cover
them in superglue, and quickly put them back. If you don't glue
them back remember to smash the socket housing. If you do glue
them back smash the relay so that it won't work. Alternately you
could leave the glued relay as it is and give someone a surprise
at a future date when it needs replacing;
- Programmable logic controllers (PLCs - not illustrated) are
becoming increasing popular means of controlling machinery - they
were discussed at the end of Volume I. The 'hardwired' kind are
often mass produced, and so smashing them doesn't achieve much.
But if you see a programmable version - which normally has a small
keyboard and LED display, smash the hell out of it with a hammer
or crowbar because they are very expensive to replace.
At the bottom of the electrical controls illustration is a small
control panel. This is a good example of what you might see -
it has controls (knobs/switches) and instruments (panel meters/LEDs)
- which need to be 'improved'. With any control box there are
- Glue it - just put glue over the switches - quick and easy,
and it doesn't make any noise;
- Disable it - this means pushing screwdrivers through the instruments,
and damaging the switches. This makes more noise, but is equally
- Dismantle it - this means taking switches and meters apart,
and if possible, removing the front panel and tackling the electrical
components behind the front panel;
- Smash it - the loudest but most devastating option. The control
box in the illustration is made of steel, making it very tough.
In these situations you really need to remove the screws holding
the front panel on to have a go at what's behind. If the control
box is plastic then a crowbar is the simplest option - either
use the round end as a hammer to break you way in, or the spade
ends to stab/lever the box apart. You can do a lot of damage very
quickly - but it is very noisy;
- Acid - where you are fairly sure that there is a lot of complicated
circuitry behind the front panel, you can make a small hole and
pour acid inside. But be very careful not to spill it everywhere
- and leave a note to tell the operators that there is acid inside.
The only thing to beware is that if electricity is still flowing
through the box then it may catch fire, or potentially explode.
The purpose of the control panel is also important. With large
earth movers it is sometimes easier to go for the controls than
for the extremely well-engineered workings of the engine. You
really have to apply the analysis explained at the beginning -
the source, control and use of energy. Damaging the energy control
systems is likely to immobilise the machinery, but is repairable.
Damaging the engine or power source is often a much more serious
matter to put right. You really have to make up you mind, as part
of your scoping exercise (see Volume I) as to what you want to
achieve from your work.
7.4 Computer systems
Computer systems were dealt with in general in Volume I, and there
is little to add.
In general you should always try to take on the main computer
unit - damaging computer screens or keyboards has little effect
as they are easily and cheaply replaced. But if you damage the
main unit, this gives a bigger "£ per hammer blow cost"
- some of the computer chips cost £300 to £800, and
a replacement hard disk can cost three times the cost of a keyboard.
A very annoying tactic is to get a floppy disk, cover it in glue,
and stick it into the disk drive. This not only means that the
computer is effectively disabled in a simple, quick and quiet
manner, but it is difficult to get the data stored on the hard
disk out of the system without paying a lot of money to a computer
engineer to remove the hard disk and read the data off it, or
replace the disk drive.
With larger computers, where the circuit boards inside are easily
accessible, the simplest option of to just open the cabinets,
pull out the boards and snap them in two - this can be difficult
by hand but if you prop them on a block or against the wall and
stamp in the middle this is easily achieved.
7.5 Basic sabotage of instrumentation and switchgear
As noted above, you have to make a judgement before you start
about what you want to achieve. Going for the control systems
can be quick, simple, and more importantly quieter, but you may
not have the permanent effect that damaging the sources or sinks
of energy might have. The exception to this general rule is the
more complicated systems controlled by PLCs - damaging the PLC
effective renders the whole unit useless until it can be replaced,
normally at great expense.
With mechanical systems, you have a option to cut or dismantle.
Dismantling is quieter, but takes longer. Also, by cutting or
smashing the controls you often creates "collateral damage"
which take more time and money to put right than dismantling would.
With electrical systems you need to make sure that the damage
you are doing will have some effect. Quite often the electrical
control boxes are mass produced, and they can just bring another
out and plug it in. In these cases it might be better to spend
your time on other parts of the system.
I generally apply the following hierarchy of options when tackling
- Go for the parts the operator actually must use as part of
the basic function of the system. For example, removing the steering
wheel of a car, and gluing the ignition, will be more effective
than smashing the speedometer;
- If there are essential display, such as temperature, speed,
or pressure, go for them next;
- Next go for the quick and easy controls - glue the switches,
screwdriver the displays, etc.
- If the control box is easily opened - that is if it is made
of plastic or the screws are located in easy reach, opening and
proceed to work inside. If not, move on to another part of the
- If time permits, think of some more creative sabotage - remove
and glue up the relays, or bend the levers into funny shapes;
- If time is critical, or you need to be as quiet as possible,
often 25 grams of superglue strategically squeezed can be as effective
as smashing the controls. In effect you defer the smashing and
dismantling to those who must repair your handiwork;
- Above all, do not do anything that endangers the operator
or the public - don't leave live wires dangling, don't bridge
fuses or only partially damage circuit breakers, and don't make
unsafe any control system that is essential for safety - for example
fire extinguishers, brakes, or safety valves.