(1) The interlock slide, which is moved fore-and aft by threads on the muzzle door operating shaft in the manually-operated mechanism, is driven by gears, sprockets and a chain from the operating shaft of the power-operated gear.

(2) In the manually-operated mechanism the breech and muzzle door interlock lever (A in

(3) In general, the interlocking bolts operate with the interlock slide in the same manner, regardless of whether the muzzle door operating mechanism is of the manual- or power-operated type. However, in order to properly control the operation of the control valve in the power-operated type, the interlock bolts engage the thrust rod or attached parts as well as the interlock sleeve. Also, in the power operated type, these bolts do not prevent the operation of the emergency hand drive, so additional

In this chapter, Figures 68 to 73, 77, 79, 80 to

The interlocking mechanism consists of three sections: The Breech and Muzzle Door Interlock; the Tube Drain Valve and Muzzle Door Interlock; and the Firing Mechanism Interlock. The levers and indicators for these interlocks are shown in Figure 68.

In general, the interlocking mechanism is mechanical throughout and centers about the muzzle door operating shaft, which extends (in the manual

The interlocking mechanism actually is protection against improper operation of the tube. It prevents (a) opening the breech door when the muzzle door is open, and opening the muzzle door when the breech door is open; also, it prevents (b) opening the drain valve when the muzzle door is open, and opening the muzzle door when the drain valve is open. It prevents (c) firing of the tube except when (1) the muzzle door is locked open, (2) the breech door is locked closed, (3) the

Figure 73 Cylindrical slide disassembled, showing (A) Muzzle door indicator; (B) Ring with pointer and tooth in (C) Helical groove in cylindrical slide; (D) Slot for head of drain valve interlock rod; (E) Slot for breech and muzzle door interlock bolt; (F) Acme thread on (G) Breech end of muzzle door operating shaft.

The Breech and Muzzle Door Interlock controls the opening and closing of the breech and muzzle doors. It is so arranged that when one door is open the other door is closed and locked tight.

In the "manually operated" type of muzzle door operating mechanism, a cylindrical slide engages an acme thread on the breech door end of the muzzle door operating shaft (Figure 69) and slides in the breech bracket (Figure 70). This cylindrical slide moves away from the operator when closing the muzzle door, and toward the operator when opening the muzzle door. The distance this slide travels between the extreme positions is 4.858 inches. By means of slots, this cylindrical slide engages bolts in the breech and muzzle door interlocking system (see Figures 69 and 71), also in the drain valve and the firing interlocking systems.

The breech and muzzle door interlocking bolt (Figures 69 and 71) is actuated by a breech and muzzle door interlock lever (Figures 70 and 72). When the muzzle door is fully closed, the slot in the slide is in line with the interlocking bolt (Figure 69) and the interlock lever can be moved to "Breech Door Unlocked" position (Figure 72). In this position, the interlock bolt is raised into the slot of the slide (Figure 71), clearing the lug on the breech door locking ring, and allowing the locking ring to be rotated so the breech door can be opened. The lug on the locking ring prevents the bolt from being lowered while the breech door is unlocked. When the breech door is closed and locked, the interlock lever can be moved to "Muzzle Door Unlocked" position, as in Figure 70, and the bolt goes to its lower position where it is clear of the slot in the slide, as in Figure 69.

As the muzzle door opens or closes, its movement

With the power-operated mechanism, the shaft for opening and closing the muzzle door is operated by a hydraulic cylinder which, in turn, is

Rods extend down from the breech and muzzle door interlock lever and from the drain valve and muzzle door interlock lever, and connect with gearing which locks or unlocks the emergency hand operating shaft (H in Figure 45, page 32). The interlock slide is moved backward or forward by an interlock chain.

The tube drain valve, located just under the breech end of the tube, is operated by a lever attached to a shaft, at one end of which is a collar (B in Figure 76). This collar is locked or unlocked by moving the drain valve and muzzle door interlock lever (A in Figure 77). The interlock lever has a pinion gear which engages a rack gear (B in Figure 77) attached to a rod (A in Figure 76) which extends down to a lever which operates an interlock bolt which operates on the collar on the drain valve stem (B in Figure 76). This rod also extends up to the cylindrical slide, as shown at C in Figure 77.

The collar on the drain valve shaft is locked, as shown at B in Figure 78, when the interlock lever is moved to "Drain Valve Locked" position, thus preventing movement of the drain valve lever, and the head of the rod disengages the cylindrical slide, as shown in Figure 79, permitting movement of the muzzle door operating shaft so as to open the muzzle door.

This interlock acts in the same manner on tubes which have power-operated muzzle door mechanism.

Figure 78 Drain valve shaft, showing (A) Rod in lower position, engaging (B) Collar on drain valve shaft and locking valve.

The firing interlock lever rotates the interlock sleeve (Figure 80). When the lever is at "Muzzle Door Unlocked" (Figure 81) the interlocks on the depth and speed setting mechanisms are released so the spindles can be moved in to engage the mechanisms in the torpedo. When the depth and speed setting mechanisms are engaged with the torpedo, hubs on the interlock sleeve prevent rotation of the interlock sleeve head by the firing interlock lever.

When the firing interlock lever is moved to "Tube Ready to Fire" (Figures 82 and 83), after

Raising the firing interlock lever from "Muzzle Door Unlocked" to "Tube Ready to Fire" also rotates the sleeve head which moves the shutter bar so the opening in the shutter bar is lined up to allow the piston of the torpedo stop cylinder to pass through it and set the firing mechanism in

At the same time, the firing interlock bolt has been rotated downward, engaging the muzzle door end of the interlock slide (Figure 83), thereby locking the muzzle door in its open position.

To make this test, the lock on the interlock disconnect (see Figure 84) is unlocked and removed,