Safe Studio Explosions – 2

Bombs that explode with considerable force and do a great deal of damage are not always easy to simulate in the studio. Nevertheless there are means of achieving very passable results if use is made of large weights to supply the energy.

Swinging weight

A weight tied to a rope and allowed to swing downward in an arc produces equally dramatic results on items that need to fly outward. A door of a room in which a bomb is supposed to have exploded can be fiercely ejected in this way. The weight, held by a solenoid catch, can, when released, sweep down and strike either the top or the bottom of the door. This time a switch fastened on the door itself operates a flash-pot inside the room. It is a good idea to squirt some smoke behind the door just before the action. This improves the effect.

The weight will, of course, enter into shot following the door, so it is necessary to disguise it to look like something that could have been blown from inside the room. If it strikes the bottom of the door its progress can be halted by fixing a second line tied to a dragging sand bag anchor. If it is at the top it can be released from its rope by having a nylon loop which is destroyed by a detonator fired simultaneously with the studio flash.

Falling weight

This arrangement consists simply of a heavy weight which, when released, falls upon the end of a lever. It works very well when applied to items of furniture or free-standing units on the studio floor.

The lever, which usually needs to be hidden, can be positioned either below ground level or inserted through a hole in the scenery.

One example might be a desk situated against a wall. If it were required to be blown to pieces with some force, the lever could be sited behind the scenery, passing through a hole in the set wall and its end locked into the back of the desk. It is easy to see that if the lever passes over a fulcrum then a heavy weight (such as a sandbag) dropped on the other end of the lever will cause the desk to jump up.

To create the explosion a flash-pot could be placed in the desk and fired via a switch fastened to the end of the lever where it would be triggered by the falling weight.

Parts of the desk could be made to fly off by using elastic and nylon lines released as the flashpot burned through the tethering point (see page 160).

SAFE STUDIO EXPLOSIONS

1. Swinging weight
a, Mock fuse and explosive, b, Switch, c. Flash pot. d, Battery. e, Weight, f, ‘Bomb’ release, g, Sandbag drag anchor.

2. Falling weight
a, ‘Bomb’ release, b. Weight, c, Lever, d, Fulcrum, e, Battery, f, Switch, g, Flash pots.