Page:Simple Sabotage Field Manual.djvu/29

 harder to navigate. Barges “accidentally” run aground are an efficient time waster too.

Attendants on swing, draw, or bascule bridges can delay traffic over the bridge or in the waterway underneath by being slow. Boat captains can leave unattended draw bridges open in order to hold up road traffic.

Add or subtract compensating magnets to the compass on cargo ships. Demagnetize the compass or maladjust it by concealing a large bar of steel or iron near to it.

(b) Cargo

While loading or unloading, handle cargo carelessly in order to cause damage. Arrange the cargo so that the weakest and lightest crates and boxes will be at the bottom of the hold, while the heaviest ones are on top of them. Put hatch covers and tarpaulins on sloppily, so that rain and deck wash will injure the cargo. Tie float valves open so that storage tanks will overflow on perishable goods.

(9) Communications

(a) Telephone

At office, hotel and exchange switch-boards delay putting enemy calls through, give them wrong numbers, cut them off “accidentally,” or forget to disconnect them so that the line cannot be used again.

Hamper official and especially military business by making at least one telephone call a day to an enemy headquarters; when you get them, tell them you have the wrong number. Call military or police offices and make anonymous false reports of fires, air raids, bombs.

In offices and buildings used by the enemy, unscrew the earphone of telephone receivers and remove the diaphragm. Electricians and telephone repair men can make poor connections and damage insulation so that