The guns aboard modern naval vessels, though complex in detail, are made up of basic components that vary little from one gun to the next. In this chapter we describe these common components and how they function. The remainder of the chapter is dedicated to describing the operation of the gun systems in the fleet today, including misfire procedures.

GUN COMPONENTS

LEARNING OBJECTIVES: Describe common gun system components and discuss the purpose of each component.

Every gun system includes equipment used for gun positioning, loading, and firing. Although loading equipment varies in design from gun to gun, its purpose remains the same-to load a complete round in the gun chamber for firing. The greatest similarities between the guns are the positioning and firing components. We will describe these components first, followed by a discussion of the various gun systems in use today. As we discuss each gun system, we will describe the major components and how they work together to load and shoot a complete round of ammunition.

Before we begin, let's examine three terms that are very basic to this subject-ordnance, gun, and gun mount. As terminology is basic to a thorough understanding of gunnery, other terms have been highlighted throughout this discussion to attract your attention.

ORDNANCE-Ordnance is the term covering all weapons, weapons system components, and support equipment (guns, ammunition, missiles, launchers, bombs, rockets, mines, torpedoes, fire control, and so forth).

GUN-A gun is a tube, closed at one end, from which a projectile is ejected at high speed by the gases produced from rapidly burning propellants.

GUN MOUNT-A gun mount consists of all the machinery used to position, load, and fire a gun.

POSITIONING EQUIPMENT

Positioning equipment includes all the machinery used to support and move the gun tube to the desired train (horizontal) and elevation (vertical) angle. This includes the stand, the base ring, the trunnion, the gun carriage, and the slide, as shown in figure 6-1. It also includes the gun train and elevation power drives.

Stand-The stand is a steel ring bolted to the deck that serves as a foundation and rotating surface for movement in train. The stand contains both the train bearings and the training circle. The training circle is a stationary internal gear that the train drive pinion "walks around' to move the gun in train.

Base Ring-The base ring is also called the lower carriage. It is the rotating platform, supported by the stand, that supports the upper carriage.

Figure 6-1.-Gun-positioning equipment.

Gun Carriage-The gun carriage is also called the upper carriage. It is a massive pair of brackets that holds the trunnion bearings. The trunnion bearings support the trunnions, which are part of the slide, together forming the elevation pivot point.

Slide-The slide is a rectangular weldment that supports all the elevating parts of the gun.