Emergency Radio Format

[Nigel Graham 2Participant @nigelgraham2]

"It approaches its target at a depth of 1km at a speed of 200km/h. There's no way of stopping this underwater drone. The warhead on it has a yield of up to 100 megatonnes.

"The explosion of this thermonuclear torpedo by Britain's coastline will cause a gigantic tsunami wave up to 500m high…. "

So says Mr. Putin's mouthpiece, but I wonder how far out in the Atlantic it would really be detonated, since if 1000m depth is where it's meant to fire, that is beyond the Continental Shelf. Such a wave formed as a swell of 500m peak-to-peak amplitude would break a long way out at sea, because its root depth of 250m below sea-level is about twice Continental Shelf edge depth.

Yes, it would devastate coastal settlements as a mass of tumbling, fast-moving rolls of water; but not penetrate ever so far inland, depending on topography, forest cover, etc..

The radiation would be the greater danger..

It would need be delivered by a drone, too. Even the Kremlin night not want one of its submarines hoist by its own petard, and her compatriot boats would not want to be in the North Atlantic and Arctic Oceans at the time. For the shock-wave and its underwater echoes from a major explosion at 1km depth would spread spherically, losing amplitude by inverse-square law of distance but still very dangerous for a very long way, perhaps helped by natural wave-guide characteristics in the ocean.

Anyway, I wonder more how much truth there is in the claim; or if it's just Putin showing his contempt for the United Kingdom, the Republic of Ireland…. The Faeroes, Iceland, the Canary Islands, France, maybe Spain.

It might just be wildly exaggerated claims by Russian Federation military scientists seeking to impress their leader.

I don't know the comparative power in Mt, but the final blast of the Krakatau volcano in 1883 created a tsunami devastating coastal communities for a long way around SW Asia; and possibly detected by tide-gauges in Cornwall. That was underwater but at relatively shallow depth: a long series of eruptions appears to have so weakened the volcano that it collapsed and allowed cold sea-water to flood a huge volume of rock at over 1000ºC, creating a colossal flash-steam burst.

[Jon LawesParticipant @jonlawes51698]

So I guess the answer is, the general populace don't know…

I use the terms analog and analogue interchangeably as I can never remember which is which (despite being in avionics for years). I guess if I haven't learned by now I don't have much to gain by nailing it down!

[pgk pgkParticipant @pgkpgk17461]

I’m guessing that someone versed in the appropriate fields could give better answers. As I understand it submarine nuclear detonations would give different effects depending on depth. Deep enough and pressure contains the blast effect and damps it out dramatically. At a shallow depth you're going to get a massive vapourisation heavy laden radioactive water mist with the greatest danger being atmospheric spread. At an intermediate depth the upward thrust would cause the sort of wave front we're speculating about. Pick a point off the continental shelf and perhaps that would raise the wave height while allowing the spreading waves in other directions enough distance to become less threatening? How far away and at what depth a sub would have to be to avoid destruction is moot.
I recall reading something about the benefits of detonating a warhead above London rather than ground level to vapourise the Thames and reduce the area of fall-out while still creating a blast wave capable of levelling the place…

pgk

[Clive HartlandParticipant @clivehartland94829]

An airburst nuclear weapon firstly has the Flash, secondly the outgoing blast. Radiation levels affecting out to 5kms. Then, the incoming blast and this is the one that does more damage, you hide behind a wall, survive the first rwo and then from behind the incoming blast that throws everything back at you.

You could survive a nuclear blast if you had 18" of solid topsoil over you but you would have to stay there at least 3 days before you can get out. Then you do not know how much residual radiation you are walking through, or which way to go!

Decontamination would be essential, drink and eat nothing on the srface but it is stated that fallen animals if carefully opened, the meat can be eaten. Tinned food and bottled liquids fine. Decontamination again first.

Essentualy head upwind as fallout will go with the wind, That is only one blast but if they were in cascade you could walk into another zone! There would be very little chance of rescue! You are on your own.

If you have a warning then ensure all skin is covered against flash, put your back towards any detonation and good luck.

[CirclipParticipant @circlip]

Or, put your head between your knees and – – – – –

Regards Ian.

[John HaineParticipant @johnhaine32865]

200 kph underwater eh?

[KWILParticipant @kwil]

I fear that 100Mt delivered one at a time would be more effective.

I have Aldershot to the east and Aldermaston to the west, there is not much I can do about it, inspite of having been Civil Defence trained.

[JAParticipant @ja]

Posted by KWIL on 04/05/2022 10:30:48:

I fear that 100Mt delivered one at a time would be more effective.

It won't if they use Hermes.

This thread is getting a little bit too serious. Some joviality is needed

JA

Edited By JA on 04/05/2022 11:01:57

[KWILParticipant @kwil]

Hermes is now "called" EVRI. perhaps that means every mistake possible

[blowlampParticipant @blowlamp]

Posted by John Haine on 04/05/2022 09:12:00:

200 kph underwater eh?

Yes, it's possible. I recently watched an episode of Stingray and I think they mentioned travelling at a speed of 600 knots whilst submerged, so anything is possible.

Martin.

[Anthony KendallParticipant @anthonykendall53479]

Posted by SillyOldDuffer on 03/05/2022 16:33:22:

Britain's nuclear submarine commanders are allowed to launch their Trident missiles in the event they can't hear BBC Radio 4 on 198kHz. Low frequency radio not only has long distance ground wave, it penetrates underwater too. A submarine can detect BBC Radio 4 almost anywhere in the North Atlantic without surfacing and revealing it's position.

Unfortunately, the BBC has many enemies working hard to kill the institution. Be ironic if lefty comedians were stopped from pointing out political blunders and sleaze due to a "don't bother me with mere details" enthusiast not understanding what the Archers is really for!

Most of what you say is true about LF being received underwater.

Regret to distort a good story with facts but, communication with submarines is nothing to do with Droitwich Radio 4.

If there was no R4 LF, we would lose only the shipping forecast, Morning Service and cricket. All are available from other sources.

[pgk pgkParticipant @pgkpgk17461]

Posted by blowlamp on 04/05/2022 11:22:55:

Posted by John Haine on 04/05/2022 09:12:00:

200 kph underwater eh?

Yes, it's possible. I recently watched an episode of Stingray and I think they mentioned travelling at a speed of 600 knots whilst submerged, so anything is possible.

Martin.

A cording to Wikipedia the barracuda anti-torpedo missile can do 800kph 430knots. Stingray needs a turbo.

[duncan webster 1Participant @duncanwebster1]

Posted by pgk pgk on 04/05/2022 12:39:49:

Posted by blowlamp on 04/05/2022 11:22:55:

Posted by John Haine on 04/0……..

A cording to Wikipedia the barracuda anti-torpedo missile can do 800kph 430knots. Stingray needs a turbo.

Ah but according to Google it won't be in service until 3056, might still beat CrossRail

[blowlampParticipant @blowlamp]

Posted by pgk pgk on 04/05/2022 12:39:49:

Posted by blowlamp on 04/05/2022 11:22:55:

Posted by John Haine on 04/05/2022 09:12:00:

200 kph underwater eh?

Yes, it's possible. I recently watched an episode of Stingray and I think they mentioned travelling at a speed of 600 knots whilst submerged, so anything is possible.

Martin.

A cording to Wikipedia the barracuda anti-torpedo missile can do 800kph 430knots. Stingray needs a turbo.

Does Troy Tempest know about this?

[John Doe 2Participant @johndoe2]

Posted by Anthony Kendall on 04/05/2022 11:25:11:

Posted by SillyOldDuffer on 03/05/2022 16:33:22:

Britain's nuclear submarine commanders are allowed to launch their Trident missiles in the event they can't hear BBC Radio 4 on 198kHz. Low frequency radio not only has long distance ground wave, it penetrates underwater too. A submarine can detect BBC Radio 4 almost anywhere in the North Atlantic without surfacing and revealing it's position.

Unfortunately, the BBC has many enemies working hard to kill the institution. Be ironic if lefty comedians were stopped from pointing out political blunders and sleaze due to a "don't bother me with mere details" enthusiast not understanding what the Archers is really for!

Most of what you say is true about LF being received underwater.

Regret to distort a good story with facts but, communication with submarines is nothing to do with Droitwich Radio 4.

If there was no R4 LF, we would lose only the shipping forecast, Morning Service and cricket. All are available from other sources.

I think the point is that if the submarines do not hear the BBC and chimes of Big Ben etc., they will assume that London, at least has gone. But the military talk to the subs by other means. Or maybe 'The Archers' does in fact contain secret military instructions !!

Even Putin – mad as he has become – knows that if he sets off a nuclear device, then Moscow and half of Russia will also cease to exist. My Dad was on Quick Reaction Alert on the nuclear armed Vulcan bombers during the Cuban Missile crisis, and his primary target was a small city in Russia of between 500,000 and 1,000,000 people.

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