Has D5 been determined?

Possible significance

1. DEFENSE SECRETARY KING ANNOUNCED SEPTEMBER 28 THAT

THE UK WOULD SCRAP

ITS SHORT-RANGE AND BATTLEFIELD NUCLEAR WEAPONS AND

CEASE TO CARRY NUCLEAR DEPTH BOMBS ON SHIPS. AT THE

SAME TIME, HE MADE CLEAR THAT BRITAIN WOULD GO AHEAD

WITH A TACTICAL AIR-LAUNCHED NUCLEAR MISSILE (TASM), AS

WELL AS CONTINUE THE TRIDENT D5 SSBN/SLBM PROGRAM.

Trident submarines scheduled to enter the military in 1978

Hunt for red October link?