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?

7.1 Controls/switchgear

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 equipment.

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 control panel.

Switches:

• Slide switches can be superglued very effectively, or you can use a hammer and centre punch to push the switch slider through the bottom;
• 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:

• 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 fixing.

Fuses:

• 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 for safety!;
• 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 crowbar;
• 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 five options...

• 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 as quick;
• 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 control systems...

• 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 system;
• 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.