Introduction

Pyrotechnis rockets are relatively small pyrotechnic items, similar in principle to the familiar sky-rocket, which are used mainly for signaling, line-carrying, and illumination. In most cases they are fired from a hand projector.

These items generally use a type of construction in which the head and rocket tube are integral. The rocket tube is filled with a propellant composition having a tapered, conical vent hole in its center to facilitate burning. The after end of the tube is constric-ted, or contains a plug of narrower diameter than the rest of the tube in order to con-centrate the expanding propellant gases. The choke and a short length of the vent tube interior are coated with gunpowder to assist in ignition of the propellant.