Here’s a question for you: if you’re the commander of a submarine full of nuclear missiles, how can you be sure what not receiving a launch order really means? If could — and probably does — mean that everything is hunky dory on land, and there’s no need to pull the trigger. Or, could radio silence mean that the party already kicked off, and there’s nobody left to give the order to retaliate? What do you do then?
One popular rumor — or “rumour,” given the context — in the UK holds that BBC Radio 4, or the lack thereof, is sort of a “deadman’s switch” for the Royal Navy’s ballistic missile subs. [Lewis (M3HHY)], aka Ringway Manchester on YouTube, addresses this in the video below, and spoiler alert: it’s probably not true.
The theory goes that if all other means of communication fail — an unlikely eventuality given the level of redundancy and the sheer number of sensors a ballistic missile sub has at its disposal — monitoring the airwaves for the BBC Radio 4 Today program should give a sub commander a clear indication of how things are going on the beach, as it were. Today has been running continuously since October 1957 — the same month Sputnik was launched; coincidence? The absence of the show from the airwaves would be a clear indication that things had gone terribly wrong, and that the submarine commander would be free to use his judgment regarding the disposition of the weapons under his control.
On the surface, it sounds like a good plan, but a moment’s thought puts the lie to it. How would a commander distinguish between the end of the world as we know it and a more mundane event, like a storm or a power failure? Or even the failure of some of the boat’s radio gear, or just poor propagation (the specific Radio 4 signal was supposed to emanate from Droitwich on 198 kHz in the longwave band). Kicking off World War III under those circumstances, which is basically the equivalent of a US sub coming to periscope depth to visually assess the Waffle House Index, would probably be considered bad form, at the least.
Still, we’d imagine that monitoring civilian broadcasts is just one of the many tools at a boomer skipper’s disposal, and contributes mightily to the overall situational awareness picture. There are also a lot of other interesting tidbits in the video, especially the “letters of last resort.”