Acting on piston 1 from underneath is the hydrostatic pressure of the water and from above, the pressure of compressed air and spring 2. Piston 1 remains in its middle position as long as the torpedo maintains the preset depth. Linked to piston 1 through bell-crank lever 4, turning about fixed axis A, is pendulum 3 which is sensitive to the inclination (tilt) of the torpedo. When the torpedo tilts, pendulum 3 turns with respect to the body and is used, together with piston 1, to operate the depth rudder. When the depth at which the torpedo travels decreases, and its nose is raised, piston 1 and pendulum 3 shift shutter 8 to the right. This admits compressed air into cylinder 7 of the servomotor and moves piston 9 downward to lower depth rudder 6 which turns about fixed axis B. When the depth increases, cylinder 7 of the servomotor is connected to the outlet pipe and spring 5 raises depth rudder 6.
$3906$LHP,Rg$