Safe Studio Explosions – 1

Using the stored energy in compressed air or elastic rope, harmless and effective explosions can be achieved without resorting to the use of dangerous or impractical explosives.

Whoofer

This is a device consisting of a pressure vessel connected to a funnel-shaped hopper. The storage vessel has an inlet for compressed air and an exhaust valve which releases the air through a large diameter, heavy-walled flexible tube. The exhaust valve is a large capacity quick-release device capable of discharging all the air at once.

The hopper can be filled with powder and debris and it is usual to heap further piles of debris on top of the filled hopper.

A switch coupled to the lever of the valve can be wired to a flashpot positioned by the hopper. This dramatically supplements the effect.

Elasticated explosions

If a cupboard containing a bomb has to explode, simulation can be achieved by making the cupboard from separate components – doors, sides, top, etc. These are assembled on the set where the explosion is to take place.

Heavy-duty nylon threads are then passed through holes in the individual parts and knotted together on the inside. Strong elastic cords tied to the free ends of the nylon are strained back to fixing points. The position of the parts is checked for alignment and small conical wedges pressed into the holes from the inside, trapping the threads firmly in the woodwork. To prevent slip it is advisable to tie knots in the nylon at these junctions.

A flashpot is hung just below the main knot that joins all the threads on the inside and the firing lead is taken to a convenient operating position.

The exploding flash, burning through the nylon, releases all the parts which then fly outwards in a convincing manner.

To enhance the effect from such dummy explosions the nylon threads may be fastened to inanimate objects around the site of the bomb. For example, a suitcase or parcel bomb can be made to release threads which pull chairs, lamps, carpets, etc. from around the blasted area.

SAFE STUDIO EXPLOSIONS

1. The ‘whoofer’
a. Compressed air vessel, b, Input, c, Exhaust valve, d, Discharge pot. e, Switch. f, Flash puff, g, Flexible pipe.

2. Elasticated explosions
a, Elastic, b, Crate in separate parts, c, Lightweight table, d, Flash bomb, e, Nylon cord.