General

Rocket fuzes are mechanical devices which initiate the explosive system of the roc-kets in which they are used. Rocket fuzes, as well as bomb fuzes, contain the more sen-sitive initiating explosives of the explosive system, such as detonators, boosters, etc. No counterpart of the bomb pistol is used in rockets.

Nose fuzing of rockets is more common than base fuzing, as is shown by the compa-rative number of nose and base fuzes. This tendency can be explained to some extent by again noting the British emphasis on antiaircraft rockets, which use impact, or aerial-burst, nose fuzes, and by the fact that the inherent delay in base fuzes, acting on an in-ertia principle, makes them most practical for employment in the less widely used S.A.P. rockets.

Designation

Rocket fuzes are designated in the same manner as bomb fuzes and pistols. A "Num-ber", corresponding to the U.S. "Mark", and a "Mark", corresponding to the  U.S. "Modifi-cation" and always expressed in Roman numerals, are used to designate a particular fuze. These numerical symbols are, of course, accompanied by the word "Fuze". Minor changes in marks are indicated by asterisks, capital letters, or low-case letters.

Types of Fuzes

Rocket nose fuze employ various types of action and arming. Instantaneous impact, instantaneous impact-self destroying, pyrotechnic-delay aerial burst, and mechanical-delay aerial burst are the common types of action. The Fuze No. 731 Mk I, also known as the Kealy fuze, is an interesting development of the use of electrical time setting in an attempt to eliminate "dead time".

Gas pressure arming and impact firing are the main features of the rocket base fuzes discussed in this section.