for Roads

• Change sign posts at intersections and forks; the enemy will go the wrong way and it may be miles before he discovers his mistakes. In areas where traffic is composed primarily of enemy autos, trucks, and motor convoys of various kinds, remove danger signals from curves and intersections.
• When the enemy asks for directions, give him wrong information. Especially when enemy convoys are in the neighborhood, truck drivers can spread rumors and give false information about bridges being out, ferries closed, and detours lying ahead.
• Distribute broken glass, nails, and sharp rocks on roads to puncture tires.
• The following type of road damage can be slow, making it impractical prior to, or for military offensives. If you can start damage to a heavily traveled road, passing traffic and the elements will do the rest. Construction gangs can see that too much sand or water is put in concrete or that the road foundation has soft spots. Anyone can scoop ruts in asphalt and macadam roads which turn soft in hot weather; passing trucks will accentuate the ruts to a point where substantial repair will be needed. Dirt roads also can be scooped out. If you are a road laborer, it will be only a few minutes work to divert a small stream from a sluice so that it runs over and eats away the road.

for Passengers

• Bus-driver can go past the stop where the enemy wants to get off. Taxi drivers can waste the enemy’s time and make extra money by driving the longest possible route to his destination.

for Oil and Lubrication

Oil and lubrication systems are not only vulnerable to easy sabotage, but are critical in every machine with moving parts. Sabotage of oil and lubrication will slow production or stop work entirely at strategic points in industrial processes.

• Disconnect the oil pump; this will burn out the main bearings in less than 50 miles of normal driving.
• Put metal dust or filings, fine sand, ground glass, emery dust (get it by pounding up an emery knife sharpener) and similar hard, gritty substances directly into lubrication systems. They will scour smooth surfaces, ruining pistons, cylinder walls, shafts, and bearings. They will overheat and stop motors which will need overhauling, new parts, and extensive repairs. Such materials, if they are used, should be introduced into lubrication systems past any filters which otherwise would strain them out.
• You can cause wear on any machine by uncovering a filter system, poking a pencil or any other sharp object through the filter mesh, then covering it up again. Or, if you can dispose of it quickly, simply remove the filter.
• If you cannot get at the lubrication system or filter directly, you may be able to lessen the effectiveness of oil by diluting it in storage. In this case, almost any liquid will do which will thin the oil, A small amount of sulphuric acid, varnish, water-glass, or linseed oil will be especially effective.
• Using a thin oil where a heavy oil is prescribed will break down a machine or heat up a moving shaft so that it will “freeze” and stop.
• Put any clogging substance into lubrication systems or, if it will float, into stored oil. Twisted combings of human hair, pieces of string, dead insects, and many other common objects will be effective in stopping or hindering the flow of oil through feed lines and filters.
• Under some circumstances, you may be able to destroy oil outright rather than interfere with its effectiveness, by removing stop-plugs from lubricating systems or by puncturing the drums and cans in which it is stored.

for Radiators

• A water cooling system can be put out of commission in a fairly short time, with considerable damage to an engine or motor, if you put into it several pinches of hard grain, such as rice or wheat. They will swell up and choke the circulation of water, and the cooling system will have to be torn down to remove the obstruction. Sawdust or hair may also be used to clog a water cooling system.
• If very cold water is quickly introduced into the cooling system of an overheated motor, contraction and considerable strain on the engine housing will result. If you can repeat the treatment a few times, cracking and serious damage will result.
• You can ruin the effectiveness of an air cooling system by plugging dirt and waste into intake or exhaust valves. If a belt-run fan is used in the system, make a jagged cut at least halfway through the belt; it will slip and finally part under strain and the motor will overheat.

for Fuel

Tanks and fueling engines usually are accessible and easy to open. They afford a very vulnerable target for simple sabotage activities.

• Put several pinches of sawdust or hard grain, such as rice or wheat, into the fuel tank of a gasoline engine. The particles will choke a feed line so that the engine will stop. Some time will be required to discover the source of the trouble. Although they will be hard to get, crumbs of natural rubber, such as you might find in old rubber bands and pencil erasers, are also effective.
• If you can accumulate sugar, put it in the fuel tank of a gasoline engine. As it burns together with the gasoline, it will turn into a sticky mess which will completely mire the engine and necessitate extensive cleaning and repair. Honey and molasses are as good as sugar. Try to use about 75-100 grams for each 10 gallons of gasoline.
• Other impurities which you can introduce into gasoline will cause rapid engine wear and eventual breakdown. Fine particles of pumice, sand, ground glass and metal dust can easily be introduced into a gasoline tank. Be sure that the particles are very fine so that they will be able to pass through the carburetor jet.
• Water, urine, wine, or any other simple liquid you can get in reasonably large quantities will dilute gasoline fuel to a point where no combustion will occur in the cylinder and the engine will not move. One pint to 20 gallons of gasoline is sufficient. If saltwater is used, it will cause corrosion and permanent motor damage.
• In the case of Diesel engines, put low flashpoint oil into the fuel tank; the engine will not move. If there already is proper oil in the tank when the wrong kind is added, the engine will only limp and sputter along.
• Fuel lines to gasoline and oil engines frequently pass over the exhaust pipe. When the machine is at rest, you can stab a small hole in the fuel line and plug the hole with wax. As the engine runs and the exhaust tube becomes hot, the wax will be melted; fuel will drip onto the exhaust and a blaze will start.
• If you have access to a room where gasoline is stored, remember that gas vapor accumulating in a closed room will explode after a time if you leave a candle burning in the room. A good deal of evaporation, however, must occur from the gasoline tins into the air of the room. If removal of the tops of the tins does not expose enough gasoline to the air to ensure copious evaporation, you can open lightly constructed tins further with a knife, ice pick or sharpened nail file. Or puncture a tiny hole in the tank which will permit gasoline to leak out on the floor. This will greatly increase the rate of evaporation. Before you light your candle, be sure that windows are closed and the room is as air-tight as you can make it. If you can see that windows in a neighboring room are opened wide, you have a chance of setting a large fire which will not only destroy the gasoline but anything else nearby; when the gasoline explodes, the doors of the storage room will be blown open, a draft to the neighboring windows will be created which will whip up a fine conflagration,

for Batteries and Ignitions

• Jam bits of wood into the ignition lock; loosen or exchange connections behind the switchboard; put dirt in spark plugs; damage distributor points.
• Turn on the lights in parked cars so that the battery will run down.
• Mechanics can ruin batteries in a number of undetectable ways: Take the valve cap off a cell, and drive a screw driver slantwise into the exposed water vent, shattering the plates of the cell; no damage will show when you put the cap back on. Iron or copper filings put into the cells i.e., dropped into the acid, will greatly shorten its life. Copper coins or a few pieces of iron will accomplish the same and more slowly. One hundred to 150 cubic centimeters of vinegar in each cell greatly reduces the life of the battery, but the odor of the vinegar may reveal what has happened.

for Gears

• Remove the lubricant from or put too light a lubricant in the transmission and other gears.
• In trucks, tractors, and other machines with heavy gears, fix the gear case insecurely, putting bolts in only half the bolt holes. The gears will be badly jolted in use and will soon need repairs.

for Tires

• Slash or puncture tires of unguarded vehicles. Put a nail inside a match box or other small box, and set it vertically in front of the back tire of a stationary car; when the car starts off, the nail will go neatly through the tire.
• It is easy to damage a tire in a tire repair shop: In fixing flats, spill glass, benzine, caustic soda, or other material inside the casing which will puncture or corrode the tube. If you put a gummy substance inside the tube, the next flat will stick the tube to the casing and make it unusable. Or, when you fix a flat tire, you can simply leave between the tube and the casing the object which caused the flat in the first place.
• In assembling a tire after repair, pump the tube up as fast as you can. Instead of filling out smoothly, it may crease, in which case it will wear out quickly. Or, as you put a tire together, see if you can pinch the tube between the rim of the tire and the rim of the wheel, so that a blow-out will result.
• In putting air into tires, see that they are kept below normal pressure, so that more than an ordinary amount of wear will result. In filling tires on double wheels, inflate the inner tire to a much higher pressure than the outer one; both will wear out more quickly this way. Badly aligned wheels also wear tires out quickly; you can leave wheels out of alignment when they come in for adjustment, or you can spring them out of true with a strong kick, or by driving the car slowly and diagonally into a curb.
• If you have access to stocks of tires, you can rot them by spilling oil, gasoline, caustic acid, or benzine on them. Synthetic rubber, however, is less susceptible to these chemicals.

Next: Sabotage for Water Transportation