charges for the 40-mm and the 3-inch guns are issued
completely assembled, with no replacement
In large guns (8-inch) using separate loading
ammunition, the propellant charge is made up of
sections of powder contained in cylindrical cloth bags
that approximate the inside diameter of the gun chamber
in which they are to be used. In most cases, more than
one section (bag) is required. For example, the 8-inch,
55-caliber gun uses a propellant charge consisting of
two sections; the 16-inch, 50-caliber gun uses a
propellant charge of six sections (fig. 6-4, view B). In
these guns the leaking of gases from the chamber is
checked by the mushroom and pads on the breech plug.
The breech plug also contains a lock, which receives the
separately loaded primer.
Fuzes are the components that set off the projectile
bursting charge. No matter how complicated or simple
the construction or function of the fuzes, they always
serve the same purpose.
All fuzes use the force of inertia for arming and, in
most cases, operation. Each type of fuze has a different
tactical use. The use and a detailed functional
description will not be covered in this text. For more
information on ammunition types and their fuzes, refer
to Navy Gun Ammunition, SW030-AA-MMO-010.
Fuzes can be generally classified by function, as
discussed in the following paragraphs.
TIME FUZES.Mechanical time fuzes (MTFs)
function a predetermined length of time after the
projectile is fired. The exact time is set before the
projectile is loaded into the chamber, by a mechanical
fuze setter on the mount, or you can set the fuze with a
special fuze wrench. The interval between the instant
the fuze is set and the instant the projectile is fired is
dead time. No matter when, how, or by what it is set, the
timing mechanism of a time fuze will not function until
the projectile is fired.
PROXIMITY FUZES.Proximity (variable time
(VT)) fuzes are energized after the projectile is fired and
function when the projectile nears the target.
PERCUSSION FUZES.Percussion (impact)
fuzes function as the projectile strikes the target or
(especially an armor-piercing projectile) after the
projectile penetrates. Some fuzes (nondelay type)
function immediately on contact with any thin material
(for example, the thin sheet metal skin of an aircraft).
Fuzes for armor-piercing projectiles, however, always
incorporate a slight delay to keep the burster from going
off until after penetration. These percussion fuzes can
be located either on the nose (PDF) or on the base (BDF)
of the projectile.
COMBINATION FUZES.Combination fuzes
incorporate both time and percussion features; that is,
the fuzes may go off either on impact or after the time
set, whichever occurs first.
AUXILIARY DETONATING FUZES.
Auxiliary detonating fuzes (ADF), as the name implies,
operate only with other fuzes. In gun projectiles, they
form part of the explosive train and pass on the
explosion initiated by another fuze (located in the
projectile nose) to the main bursting charge.
The term magazine applies to any compartment,
space, or locker that is used or is intended to be used for
the stowage of explosives or ammunition of any kind.
The term magazine area includes the compartment,
spaces, or passages on board ship that contain magazine
entrances and that are intended to be used for the
handling and passing of ammunition. The term is also
used to denote areas adjacent to, or surrounding,
explosive stowages, including loaded ammunition
lighters, trucks, and railroad cars, where applicable
safety measures are required.
Magazines are arranged with regard to ease of
supply, the best obtainable protection, and the most
favorable stowage conditions.
Many different types of magazines are provided on
ships. Each magazine is designed specifically for the
type of ammunition it is to contain. For our purpose,
however, we will be concerned with only three types:
primary magazine, ready-service magazine, and
PRIMARY MAGAZINES.Primary magazines
are designed as ammunition stowage spaces generally
located below the main deck and, if possible, below the
waterline. They are adequately equipped with
insulation, ventilation, and sprinkler systems. These
spaces must be provided with fittings so that they may
be securely locked. Primary magazines accommodate a