Part 2 of this publication is concerned with the devices used to initiate British aircraft bombs and pyrotechnics. Included in this section are all British pistols and fuzes currently in service use. In addition, obsolescent pistols and fuzes, which are no longer in manu-facture, but stocks of which are still available for use, are also presented, as are certain pistols and fuzes which have been decleared obsolete, but are included because of their former importance, or as a matter of interest. More important obsolete items, such as the Fuze No. 845, are presented in the main body of this section. Other less important obsolete items are included in chart form.

A separate chapter summarizes the information on detonators.

Initiating devices for British bombs are divided into two distinct groups, pistols and fuzes. The term pistol is used to describe an initating device which contains no explosive components (primer, detonator, or booster) as it is normally shipped or issued. A pistol is purely a mechanical device, embodying certain arming and safety features for initiating explosive components which are inserted in the bomb as a separate entity. These sepa-rate explosive components used with pistols are termed detonator. Initiating device which do contain explosive components as integral parts, however, are termed fuzes. Generally, in addition to a primer-detonator combination, fuzes are also fitted with burs-ter charges, or boosters.

As a general rule, British pistols are used to initiate high-explosive bombs, while British fuzes are emloyed in miscellaneous types of missiles, such as smoke bombs, flares, etc. However, many exceptions will be found to this rule.

British fuzes and pistols are designated by a number and a mark. The number corres-ponds to the U.S. "Mark" designation, and the mark (always expressed in Roman numer-als) is equivalent to the U.S. "Modification". Sine some British pistols carry the same number and mark designations as a British fuze, the name "Pistol" or "Fuze" must always accompany the number and mark designation, as: Pistol No. 38 Mk I, Fuze No. 38 Mk I, etc. Minor changes in marks are indicated by asterisks, capital letters, or lower-case let-ters. Although the fuze or pistol designation is almost invariably stamped or stencilled on the external surface of the fuze or pistol, in many cases this designation is not visible when the fuze or pistol is inserted in the bomb. Besides the number and mark designa-tion, other information, such as the date of manufacture and the manufacturer's initials or symbol, are stamped or stencilled on the fuze or pistol.

Detonators are also designeted by number and mark, and have this designation, as well as the delay time and date of manufacture, printed on a paper washer, which is glued to the detonator head.

A novel type of device is employed by the British to secure their pistols and fuzes in bombs. This device consists of a spring clip or "tab locking device" fitting around the base of the pistol. The clip is attached to the pistol or fuze body by a series of dents which fit into cavities located around the body. A small tab, about ¼ in. long, projects below the clip. When the pistol or fuze is screwed into the bomb, the tab engages one of a series of small holes drilled around the top of the exploder container. This prevents the clip from moving around with the pistol and provides a ratchet effect on the pistol body. This device prevents the pistol or fuze from working loose while in the plane, and yet leaves it only hand-tight in the bomb, so that it may be easily removed.

A beveled spring washer and a solid locking ring are two other devices used to hold pistols and fuzes in place in the bomb.

Detonators are held in place in the bomb or detonator holder by the pistol, which fits over them.

Most British bombs are equipped for both nose and tail fuzing, and occasionally dual fuzing is used. However, it is the more common practice for British armorers to fuze the bombs in either the nose or the tail, using only one fuze. Generally, if a delay is desired, the bomb is fuzed in the tail, while nose pistols or fuzes will be used for instantaneous action.

In most instances, fuzes and pistols are designed so that they may be dropped safe by leaving some form of safety device (safety fork, safety pin, or safety clip) in place. Certain fuzes and pistols, however, may not be dropped safe, because of the absence of safety devices or the automatic removal of such devices when the bomb is released.

Tail fuzes normally have arming vanes as an integral part of the fuze mechanism. Tail pistols, on the other hand, generally are armed by an arming fork, which engages a simi-lar fork on the reach rod attached to the arming vanes. This arming assembly is incorpo-rated as an integral part of the standard British tail unit.

In most bombs of 500-lb. and under in weight, fuzes cannot be used. Pistols are scre-wed directly into an exploder container, which contains a detonator and booster pellets. In bombs weighing over 500-lb., the pistol is screwed into a detonator holder, which, in turn, is threaded into the exploder container of the bomb. In this size bomb, if a fuze is to be used, the detonator holder is omitted, and the fuze is screwed directly into the ex-ploder container.

A discussion of the detonators used with British pistols will be found in chapter 4. Re-latively insensitive anvil-type detonators are employed with pistols which have blunt stri-kers. Sensitive "capsule" detonators are used with pistols containing needle-pointed stri-kers.

Figure 119 shows the typical fuzing arrangement for a bomb of more than 500 lb. in weight.

Figure 119 – Typical fuzing arrangement for bombs over 500 lb.