Chapter 12 - Clocks and Associated Devices - Arming Clock: Clock Starter PlateChapter 12 - Clocks and Associated Devices - Arming Clocks: UES II and UES IIa with Vorkontakt
GERMAN UNDERWATERS ORDNANCE MINES
Chapter 12 - CLOCKS AND ASSOCIATED DEVICES
ARMING CLOCKS
UES II AND UES IIa WITH LiS

The LiS is an anti-recovery switch used with the UES II and UES IIa. The preset time of the UES must run off for the LiS to operate. After normal operation of the clock, if the mine is removed to a depth of less than 17 feet, the mine will explode.

Operation (Figure 266). Before pressure has been applied to the clock contact arm 10, housing contact 11 is held off contact 14 by retaining screw 6. When the mine rea-ches a depth of 17 feet, hydrostatic pressure forces 6, which is attached to hydrostatic piston 4, upward, allowing spring-loaded lever 9 to move over and against the switching screw. Under normal operating conditions contacts 11 and 14 remain open. A reduction of water pressure of between eight inches and six feet causes screw 6 to force spring lever 9 downward, closing contacts 11 and 14 and firing the mine.

Figure 266 – The LiS

Chapter 12 - Clocks and Associated Devices - Arming Clock: Clock Starter PlateChapter 12 - Clocks and Associated Devices - Arming Clocks: UES II and UES IIa with Vorkontakt