UK Thermonuclear Warheads.

[bri21]

So yes as far as the records go we see no signs. But, all sorts of things get said in private that never make it to record and that sort of thng did happen, though less and less overtime.

Which is precisely why there is no point in pursuing this line further, because there is no evidence. Unless we consider speculation that there might, ... just possibly ... have been private conversations ... unrecorded ... at the back of the bike sheds on a wet afternoon.

There is no evidence ... only speculation. Speculation that might or might not contain a grain of truth. But we'll never know that. Period.

 

[Zoo Tycoon]

Considering Canada was fairly closely involved in the UK atomic bomb development project i.e. I understand the Hurricane device used a significant amount of Canadian plutonium, was Canada ever considered as a offering a suitable test location?

What was the decision making process which lead to Monte Bello Island & Maralinga?

I'm sure it's in B Cathcart "A Test of Greatness" but never been able to get my hands on a copy (just seen there are copies on Amazon).....even when this was published there may have been details which were still considered classified.

 

[bri21]

Considering Canada was fairly closely involved in the UK atomic bomb development project i.e. I understand the Hurricane device used a significant amount of Canadian plutonium, was Canada ever considered as a offering a suitable test location?

Not so. Canada had no weapons grade plutonium. It could then only be made artificially in a thermal reactor, and in 1952 Canada had no suitable thermal reactors. UK weapons grade Pu came from Calder Hall, specially built for that purpose.

I've seen no reference to a Canadian test site. In the early planning it was suggested that the US might co-operate and permit use of one of their sites, but the US proved less than co-operative, and there were political issues for both the US and UK.

What was the decision making process which lead to Monte Bello Island & Maralinga?

One objective of Hurricane was to assess the effects on a harbour or port city. Monte Bello was chosen as the most suitable available geographic location for that reason.

Maralinga? I don't know. Possibly for economic and logistic reasons, given that the logistics apparatus was set up and working for Hurricane.

 

[Zoo Tycoon]

Considering Canada was fairly closely involved in the UK atomic bomb development project i.e. I understand the Hurricane device used a significant amount of Canadian plutonium, was Canada ever considered as a offering a suitable test location?

Not so. Canada had no weapons grade plutonium. It could then only be made artificially in a thermal reactor, and in 1952 Canada had no suitable thermal reactors. UK weapons grade Pu came from Calder Hall, specially built for that purpose.

I believe the Canadian NRX reactor came into operation in 1947 at a design power rating of 10 MW (thermal), increasing to 42 MW by 1954. A small Pu separation faclity also came into operation shortly after its commision. Its been reported in several places that this Pu supplimented Uk produced Pu in the Hurricane device.

Details of NRX can be found on wiki-
http://en.wikipedia.org/wiki/NRX

Also reports of Canadian Pu to Uk -
http://en.wikipedia.org/wiki/Canada_and_weapons_of_mass_destruction
Section 1 Line 14

Please feel free to correct.

 

[zen]

My point was we cannot say for certain, only for certain in the records we have, which we could say about almost anything, but it pays to bear this in mind.

Now I seem to reccal reading once there was early thoughts to a Canadian test site, where I read that I cannot remember.

 

[fredgell]

Zens point about records is quite valid - who knows what might be lurking in some out of the way document - carefully filed but under some misleading heading?
To quote Douglas Adams -

"`...You hadn't exactly gone out of your way to call attention to them had you? I mean like actually telling anyone or anything.'
`But the plans were on display...'
`On display? I eventually had to go down to the cellar to find them.'
`That's the display department.'
`With a torch.'
`Ah, well the lights had probably gone.'
`So had the stairs.'
`But look you found the notice didn't you?'
`Yes,' said Arthur, `yes I did. It was on display in the bottom of a locked filing cabinet stuck in a disused lavatory with a sign on the door saying "Beware of The Leopard".'"

One day, when all records have been scanned, run through OCR software and fully cross linked it may be possible to say something doesn't exist. (actually it is never possible to say something like this doesn't exist, just that it hasn't been found yet).

I seem to recall that there was a strong line of public antipathy to nuclear weapons in Australia in the 60s and 70s. The fuss that was made when it was uncovered that the UK was testing new weapons in the 70/80s was quite notable (even though not the actual atomics).

Plus the mid 50s was a strange period when looked at in modern terms. British/Commonwealth interests in the Far East were still very strong - particularly in connection with Malaya, and this ran on into the 60s.

Yes, without hard evidence to hand, it is speculation. But that's also the area where defence planning is also most apt to tread. It is almost imposible to believe that the issue wasn't studied, at least in theory.

If nothing else look at the spread of relevant resources, missile testing in Australia, atomics testing in Pacific, widespread deployments of RAF V Bombers. A lot of infrastructure was in place and up until the late 60s UK defence planning was still global in reach and context.

Great thread this...

Regards

Fred

 

[bri21]

Also reports of Canadian Pu to Uk -
http://en.wikipedia.org/wiki/Canada_and_weapons_of_mass_destruction
Section 1 Line 14

Please feel free to correct.

Please tell me that you are not seriously suggesting that this unattributed source should be taken seriously.

So an unidentified contributor to Wikipedia, possibly a spotty teenager, alleges on 25 June 2005 that Canadian plutonium was incorporated into the UK bomb programme. He produces no evidence in support of that assertion, although having had five years to do that, AND YOU BELIEVE HIM?

Ye Gods! Save us! Save us from people who believe that what they read on Wikipedia is the Gospel Truth Brought Down From The Mountain!

Why is it Zootycoon that reputable academic researchers are not contributing to Wikipedia in large numbers?

Could it be that after they have sweated blood over a carefully researched and well-referenced piece of research, that within ten minutes of having posted it onto Wikipedia, some spotty high-school mischief-maker can (and does) edit it to draw completely different conclusions?

These forums have their problems, but at least the contributors here expect and require posters to provide some evidence. Because without evidence a posting means diddly-squat.

 

[bri21]

Now I seem to reccal reading once there was early thoughts to a Canadian test site, where I read that I cannot remember.

Lots of sites were considered so I'd be surprised if Canadian ones were not on the list. But I can't remember either.

A difficulty with Canadian sites would be finding an unpopulated ice-free location, given that a prime objective was to measure the effects of a shallow underwater burst close to a port or harbour. Not a lot of those sites in Canada.

 

[alertken]

(A.J.Pierre was a State Dept officer, then academic: his Nuclear Politics,OUP,1972 pre-dates opening of archives at Kew, which have been so thoroughly trawled into brian's site.
P.123: "The first plutonium-producing pile went critical at Windscale in July,1950...The 1952 date (for) a quantity of Pu to be available for the testing of a (UK) Bomb became an immutable deadline....based on...technological estimate (of) the time it would take (Hinton/ICI) to construct the plants" (Risley).
P.54: The Anglo-Canadian Project: (2 pp on reactors ZEEP and GLEEP, and): "The post-war Pu separation plant at Windscale had its origins in the Montreal chemical laboratories" (sourced to C.Hinton,Br. Devts. in A.E, Nucleonics,XII (1/54), pp.6-8).
So: the Art, not the Article: Canadian brainpower, not Pupower.

May I suggest we have taken the Oz/Can. angle as far as is pertinent to this thread? No one nation "owned" nuclear brainwork. After Korea, and Red human waves, seen as rehearsal for a thrust on N.Germany, UK judged nukes to be the cheapest/sole means of repelling, by deterring. UK spent great resources to try to do its own thing, platforms + fission + fusion, until Sputnik and was then so glad to embrace Ike's bosom. PRC became a separate, solo Threat, esp. to Oz, after ejecting the Sovs. in 1960 and firing its fission device. From 1954 reliance on US Pacific Forces (later, such as 6 SSBNs on Guam) was central to Oz policy: credibility of US' commitment would have been negated in Sov/PRC eyes by a few (undeliverable) OzBombs - if US' mates don't believe them, why should we? That point did not apply to US' unsinkable aircraft/missile carrier in the N.Sea: UK would be H-Hour target; warheads launched on Moscow from UK might be US-solo, US/UK-dual key, UK independent...Sovs would not trouble themselves with that sublety.

 

[bri21]

(A.J.Pierre was a State Dept officer, then academic: his Nuclear Politics,OUP,1972 pre-dates opening of archives at Kew, which have been so thoroughly trawled into brian's site
P.123: "The first plutonium-producing pile went critical at Windscale in July,1950...The 1952 date (for) a quantity of Pu to be available for the testing of a (UK) Bomb became an immutable deadline....based on...technological estimate (of) the time it would take (Hinton/ICI) to construct the plants" (Risley).

Agreed!
And Lorna Arnold's first book on this covered this ground also.
Lorna Arnold. A Very Special Relationship: British Atomic Weapon Trials in Australia. Published by HMSO, London, 1987. ISBN 0-11-772412-2

May I suggest we have taken the Oz/Can. angle as far as is pertinent to this thread? No one nation "owned" nuclear brainwork. After Korea, and Red human waves, seen as rehearsal for a thrust on N.Germany, UK judged nukes to be the cheapest/sole means of repelling, by deterring. UK spent great resources to try to do its own thing, platforms + fission + fusion, until Sputnik and was then so glad to embrace Ike's bosom. PRC became a separate, solo Threat, esp. to Oz, after ejecting the Sovs. in 1960 and firing its fission device. From 1954 reliance on US Pacific Forces (later, such as 6 SSBNs on Guam) was central to Oz policy: credibility of US' commitment would have been negated in Sov/PRC eyes by a few (undeliverable) OzBombs - if US' mates don't believe them, why should we? That point did not apply to US' unsinkable aircraft/missile carrier in the N.Sea: UK would be H-Hour target; warheads launched on Moscow from UK might be US-solo, US/UK-dual key, UK independent...Sovs would not trouble themselves with that sublety.

Agreed again. It's been well covered.

 

[zen]

UK would be H-Hour target; warheads launched on Moscow from UK might be US-solo, US/UK-dual key, UK independent...Sovs would not trouble themselves with that sublety.

No 'subtlety' and 'trouble themselves with' are not correct. They could not run the risk of it being anything but some pattern of a more general missile bombardment as part of WWIII.

Or to put in the language of the targeting planners "when one flies, they all fly".

 

[alertken]

WE177C

this for brian: your site has WE177C as comprising Cirene variant of the standard UK-solo Primary (itself as Cleo/WE177A and Jenny for Polaris A3), plus a c.200kT variant of Reggie Secondary (itself a variant of RN's Polaris A3 warhead). You have it as built from the 3rd. warhead displaced from each SSBN by the Chevaline programme, and thus WE177C production was constrained to (16x4=) 64 rounds. But the timing is wrong. Chevaline at sea from Oct.,'82: WE177C deployed 1975.

Healey-Schroder Report, NATO’s Nuclear Planning Group: NPG was formed in April,’67 as the means, preferable to an ANF/MLF, of putting a local finger near triggers affecting irradiation of Germany. UK/FRG Ministers’ report was adopted 11/69 as “Provisional Political Guidelines for the Initial Defensive Tactical Use of Nuclear Weapons by NATO” (Bulletin of the Atomic Scientists 4/85,P.47: Who Controls NATO’s Nuclear Weapons? 200kT limit on "Tactical" nukes bouncing around FRG. B-61 so constrained from initial NATO deployment, 1969. UK agreed to constrain UK warheads in FRG <200kT, and to replace (36x2) 72 RAFG F-4M B-43 with 60 Jaguar/WE177C from 1975.

Ministers imposed the logic of crewing only 2 RN SSBNs concurrently and took advantage of production disruption at AWRE, 1968-70 caused by contamination, to accept 3, not 4, x16x3 A3 warheads. (1x16x3: ) 48, too late for Revenge, at sea 9/70, were available to be deployed in RAFG Jaguars between 11/75 and 3/77 as WE177C. 24 SEATO F-111K could not have been dispersed with Project 'E' stores so (24x2) 48 WE177A had been authorised in 1965, orphaned, 1/67. 24 went to RAFG Buccaneer, 1971/72; 12 became Cirene in WE177C for RAFG Jaguar; the remaining 12 were abandoned; 12 new Reggies were built.

Howzat? If it might well be so, then the issue is Sqdn U/E. You have Coltishall Sqdns. and the Lossie OCU with WE177C. No Colt. SSA; I do doubt issue of nukes to OCUs and sustaining their a/c to NATO Operational standard. So: did RAFG Jaguar comprise 4 Sqdnsx15 U/E?

 

[yellowaster]

Regarding Canadian plutonium:

The Canadians appear to have been producing some plutonium at Chalk River by early 1951.
see <http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB7/ae1-1.htm>

 

[bri21]

Regarding Canadian plutonium:

The Canadians appear to have been producing some plutonium at Chalk River by early 1951.
see <http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB7/ae1-1.htm>

I don't doubt your source. But the point you are making is I suspect, that this Canadian Pu was used for the British bomb. So .... where is your source for that?

 

[yellowaster]

Nope, certainly not making any assertion that Canadian Pu was used anywhere. Merely providing some evidence that the Canadians did indeed make some Pu.

 

[bri21]

Re: WE177C

this for brian: your site has WE177C as comprising Cirene variant of the standard UK-solo Primary (itself as Cleo/WE177A and Jenny for Polaris A3), plus a c.200kT variant of Reggie Secondary (itself a variant of RN's Polaris A3 warhead). You have it as built from the 3rd. warhead displaced from each SSBN by the Chevaline programme, and thus WE177C production was constrained to (16x4 64 rounds. But the timing is wrong. Chevaline at sea from Oct.,'82: WE177C deployed 1975.

On the face of it that appears logical. However, it's more complex than that. The RN originally planned enough warheads and missiles for 5 boatloads, at a time when a 5th sub might, just might, have been approved. Eventually only four subs were built, but there were more warheads/missiles built than were ever deployed at sea. The Navy maintained enough for 4 tactical outloads for four subs, because they forsaw a situation where (if rising tension had given them some months warning) three subs could be got to sea; and ... if the fourth boat were not actually in pieces in the dockyard .... it might be ... was ... possible to get it to sea with a scratch crew. In that situation they'd require four tactical outloads plus the usual spares margin, plus the usual margin for warheads in the servicing and supply chain. I don't have a figure for Polaris A3T, however the figures released recently by the 2010 coalition govt for Trident are a pretty good illustration. 165 warheads operationally available (73%) and under naval control, plus a further 60 (27%) for warheads operationally available as spares and those warheads in the servicing and supply chain. 225 in total. It's unlikely that (proportionally) Polaris numbers were very different.

That 4-boat + spares policy continued largely un-noticed by others for some years until serious planning started for Chevaline, when it was discovered that there was to be a serious shortage of fissile material. The Navy then commissioned a staff study that concluded that the 4-boat policy was no longer realistic in the light of actual operating history. The study recommended that the Navy should adopt a 3-boat policy that was then approved.

The tactical outload spares (under naval control) and the warheads in the (civilian controlled) servicing and supply chain were also reassessed. The result was that 60 warheads could be released by the Navy for breaking and recovery of fissile material. Of that 60 there were 60 Jennie primaries that were dismantled, and 60 Reggie secondaries that were reused, two-thirds as the secondaries in Chevaline, married to a new-build, new primary design. Some were transferred to use as the secondary in WE.177C.

There is no hard evidence anywhere as yet, although it is thought that these recycled secondaries were then known as Circene. There were also further quantities of new-build WE.177C, both secondaries and primaries.

We do know with certainty, that some existing WE.177A warheads were refurbished and reused as the primaries in WE.177C. Others working in this area of WE.177 history are convinced that existing and undelivered RAF orders for WE.177A were converted into orders for WE.177C. I'd again recommend the recent book by Richard Moore referred to in an earlier post. ISBN 978-0-230-23067-5. There is also a forthcoming book British Nuclear Weapons and the Test Ban 1954-1973: by John R.Walker. Don't know publication date yet or ISBN.

Back to Chevaline again. The fissile material shortage was acute. So serious that when Margaret Thatcher took office, declassified files show that she did a deal with US Pres Jimmy Carter to 'borrow' plutonium from US stocks in order to complete Chevaline on schedule. Presumably because UK Pu production was too slow, and because recycling more Polaris warheads would degrade operational numbers further. It seems that although sales of fissile material were prohibited by the Non-Proliferation Treaty, LOANS were not. Presumably the loan was repaid as UK production rose again.

I'll try to find some time to dig out the archives refs for the 4-boat to 3-boat study and others from my own files.

I hope that answers your question. You've lost me on the rest.

BTW. Final approval to go the distance with Chevaline was given by Roy Mason in 1975. It wasn't ready to deploy until '82.

 

[bri21]

However in the late 70 early 80 advanced modeling and testing proved the majority of the required fusion pressure is in fact generated by ablation compression when the surface of the secondary sublimes.

I stand corrected! Up to a point!

The big question though is: what comes first, the chicken or the egg?

While it's true that ablation is the mechanism that generates significant compression of the fusion fuel, the big question here is what causes or triggers ablation of the secondary containment. The clue is in the word 'trigger' as in fission trigger, or fission primary.

For it is X-ray emission from the fission primary that triggers all else. Without it there could be no ablation of the secondary containment, and no compression of the fusion fuel.

So not wishing to be labelled as pedantic, (and this is a site read mainly by laypeople) I took a shortcut and carelessly said X-ray emissions create the compression. As indeed they do in a roundabout sorta way.

Would that argument stand up in a criminal court? Possibly not.

And it's worth remembering here that X-ray emission from a fission primary has other uses than as a means of compressing and igniting thermonuclear fuel, whether by ablation or some other mechanism.

Lorna Arnold - Britain & the H-Bomb p181 says to describe Grapple Z BURGEE. <i>"This other round, [<i>BURGEE</i>] <i>to be tried if PENDANT failed, was a novel concept - a triple, or three-stage bomb which would, in effect, have two small, immune primaries with a combined yield sufficient to ignite thermonuclear fuel in the third component."</i>

In other words, a small primary (<i>small enough to be almost immune from neutrons from a nearby ABM burst</i>) that could via X-ray emissions, compress a second small almost immune primary to a greater degree than could ever be possible by chemical HE. Resulting in a very efficient and powerful primary that would then ignite thermonuclear fuel. Because the power of a primary is not merely an expression of the amount of fissile material in its fissile core, but the degree to which the core can be compressed prior to the initiation of fission.

I may be wrong, and I may have misunderstood Arnold's sometimes impenetrable style, but what Arnold appears to be describing here is a two-stage fission-fission device, where X-rays ignite the second fission stage. Although Arnold made no mention of an ablation process, that may be an author's shortcut, and it should not be assumed that there was not one in play.

No wonder that the Americans were so interested! No wonder that to keep the Americans happy, the British continued to test devices right up to the cut-off date before the Atmospheric Test Ban Treaty took effect, when they had already reached their goal with Grapple Z Flagpole.

 

[zen]

Sorry Bri, but I'm lost on that one! Surely he's talking about a Fission-Fission-Fusion weapon?

Hmmmm....
Flagpole, Burgee....a certain nautical flag flavour of naming system?

One might speculate on follow on efforts named Duster and Jack.

 

[alertken]

You've lost me. Sorry. I try hard (my wife says I'm very trying). I share L.Arnold's impenetrability. Off, now to read Moore. I'm trying to be coherent with the thought that your and others' WE177 quantities and deployed Units are over-stated.

After 1958 the only purpose in UK building warheads out-of-US-custody was to disperse them. BAOR's SSMs, RAFG/TBF on Main Base, and RAF MR v. boomers could take 'E' stores for just as long as US cared to issue them free-of-charge, thank you. MBF's dispersal mode needed "UK's" Red Snow in Yellow Sun Mk.2/Blue Steel, briefly until c.1965 when 144 Skybolt, ordered 20/6/60, would arrive, armed with ZA297/W-49.

UK-solo Improved Kiloton Bomb, OR.1177/RN GDA.10, was initiated c.1960 as 10kT WE177A for RN-carrier/NDB roles, and for TSR.2 in NEAF/FEAF: and so at recurring unit cost only, for RAFG in that short-field notion (odd undercarriage). So, AWRE's programme on 17/12/62 was for WE177A for TSR.2 to replace 32 NEAF Red Beard/Canberra and 64 RAFG 'E'/Canberra (?2 for 1, dual carriage), and 48 WE177A(N) plus NDBs for 3 Strike Task Forces; plus 144 ZA297.

On 18/12/62 no ZA297; on 6/4/63 the Polaris Sales Agreement introduced (your 15/8 5x16x3 "UK" warheads for A3T for 1968 deployment. RAF slipped in as MBF bridge intended 1965-1968, 2 Vulcan Wings, 48, of laydown Weapon X, WE.177B, utilising ZA297 resources. WE177A was set back. RAF tried to rollover its WE177B onto (24x2) TSR.2 in NEAF/FEAF, but instead kept the WE177B Vulcans as TBF to replace 7/12/64 grounded Valiant. So these 48 were the sole WE177B; from 1/8/82 36, from 1/10/86, 24 were on Marham Tornado.

From 2/66: F-111K in NEAF/FEAF with (24x2) WE177A released from CVA-01; RAFG would have 'E'/(36x2) F-4M until c.1971, then WE177A/AFVG-UKVG. In July,1968 that became 24 WE177A/Buccaneer S.2B (deployed from early-1971) and Jaguar GR.1, later MRCA (to be Tornado). I think these 24 were RAF's sole land-target WE177A, and the other 24 became firstly RN WE177A(N), then takenover for RAF Bucc/Tornado maritime role.

RAFG 'E'/F-4M rolled over for WE177C/Jaguar in 4 Sqdns from 11/75; you additionally have WE177C at Coltishall 6 and 54 Sqdns and at Lossie 226 OCU. (online) 2005 Defence Estates Baseline Report (which led to Colt. becoming HMP Bure) has the sim. as the only 1970s' building: every bicycle shed is listed: no SSA. I doubt the allocation of nukes to sit on Reserve stations. Maybe the attrition point was that UK-based a/c and crews would deploy to Bruggen. I suggest 60 RAFG Jaguar WE177C, rising in 1985-ish to 84. Sources for the extra 24 are either ex-Vulcan WE177B, and/or ex No.3 warheads displaced by Chevaline. Source for the 60 is, I suggest, the 5-shipset A3 pool inherited by Minister Healey and seen as excessive and free (sunk!) just as he chose to replace RAFG 'E'/runway-hugging F-4M with Jaguar dispersed to autobahns.

So, for me: 24 RAF WE177A; 24 WE177A(N), RN then RAF; 48 WE177B of which 24 in 1985-ish became WE177C; and 60 WE177C. I think RN had 28 WE177A(NDB) on helos/SHAR: so, in all, 184 deployed (add spares).

 

[bri21]

I'm trying to be coherent with the thought that your and others' WE177 quantities and deployed Units are over-stated.

Believe that if you want to Ken. However, as I know only too well, most historians working in this field reach slightly different conclusions. None agree on precise numbers. So join the club! It already has numerous members.

After 1958 the only purpose in UK building warheads out-of-US-custody was to disperse them. BAOR's SSMs, RAFG/TBF on Main Base, and RAF MR v. boomers could take 'E' stores for just as long as US cared to issue them free-of-charge, thank you. MBF's dispersal mode needed "UK's" Red Snow in Yellow Sun Mk.2/Blue Steel, briefly until c.1965 when 144 Skybolt, ordered 20/6/60, would arrive, armed with ZA297/W-49.

Where did that W-49 come from Ken? Presumably a typo should read W-59. No more than 90 warheads ordered for Skybolt, and not all were based on W-59 with a UK primary. Some were to be existing Red Snow transferred intacto from Yellow Sun.

UK-solo Improved Kiloton Bomb, OR.1177/RN GDA.10, was initiated c.1960 as 10kT WE177A for RN-carrier/NDB roles, and for TSR.2 in NEAF/FEAF: and so at recurring unit cost only, for RAFG in that short-field notion (odd undercarriage). So, AWRE's programme on 17/12/62 was for WE177A for TSR.2 to replace 32 NEAF Red Beard/Canberra and 64 RAFG 'E'/Canberra (?2 for 1, dual carriage), and 48 WE177A(N) plus NDBs for 3 Strike Task Forces; plus 144 ZA297.

"Improved Kiloton Bomb, OR.1177/RN GDA.10, was initiated c.1960" --- 1958 actually. And much of this is misconceived IMO. The RAF never wanted WE.177A. Their original requirement stated several much higher yields up to and including 300 kt. When denied those yields and having to make do with WE.177A the RAF began serious planning for stick-bombing with up to four WE.177As. That's why so much effort was expended trying to fit two WE.177 into TSR2 bomb bay. That's also why, after a change of government, the RAF succeeded in reinstating a larger yield tactical bomb into the programme. That became the Type C.

ZA297 was to OR.1195, and was the warhead for WE.177B, the stop-gap warhead for Vulcans until relieved by Polaris. 53 were built, not 48. The Type B was intended to be handed-down to TSR2 on Vulcan demise, but it soldiered on for much longer. Nor was it ever planned for Skybolt, and certainly not in those numbers (144).

On 18/12/62 no ZA297; on 6/4/63 the Polaris Sales Agreement introduced (your 15/8 5x16x3 "UK" warheads for A3T for 1968 deployment.

Is there a purpose in using quote marks here "UK"? Is it intending to suggest that these were not UK warheads of UK design?

So these 48 were the sole WE177B;

53 built. First deployed Sept '66, minus airburst radar fitments in nose not needed in laydown role.

From 2/66: F-111K in NEAF/FEAF with (24x2) WE177A released from CVA-01;

No WE.177B were deployed before Sep '66.

No WE.177A were deployed before 1969 when the first 40 began to be issued to RN frigates for the NDB role.

So, for me: 24 RAF WE177A; 24 WE177A(N), RN then RAF; 48 WE177B of which 24 in 1985-ish became WE177C; and 60 WE177C.

Most other historians I'm acquainted with put much higher figure on WE.177C. Furthermore, RAF Plan R specified numbers required 273 WE.177 in total that included the 53 Type B. The remainder were WE.177A. Of these, few were then delivered to the RAF and orders for WE.177A were subsequently converted to WE.177C. Of the 273 weapons, none were for the Navy which had ordered 63. 20 were for strike, 43 were for NDB use, altho' could be used in the strike role also. See AIR 2/18210 here:http://nuclear-weapons.info/images/tna-air-2-18210-e62.jpg

So .... 273 + 63 = 336

I think RN had 28 WE177A(NDB) on helos/SHAR: so, in all, 184 deployed (add spares).

No researcher but Ken, to my knowledge disputes the RN orders at 20 strike = 43 NDB = 63 total. It's debatable whether the 20 transferred to the RAF with the Buccs were the only ones transferred. Some historians believe there were others. Or if the 20 transferred weapons were deducted from the planned RAF stock of 273. No one knows the answer to that, and to date there is no declassified source.

After 1958 the only purpose in UK building warheads out-of-US-custody was to disperse them.

And finally, that's not true either Ken.

There are numerous references in numerous archived files about numerous nuclear warhead proposals to other motives for wanting British-owned, British-made warheads. The most common reason being that UK-owned warheads were not subject to the political control of the Americans. An obvious example being the current Trident warheads. A less well-known example (and sticking with WE.177) were the plans seen in the link to AIR 2/18210 above. That shows that there were plans to replace the US B-57 NDB carried by RAF Nimrods with a British-owned WE.177A. The reason being that a British weapon could be carried by ships and aircraft outside the NATO area. Project E weapons were limited in that respect. The UK wanted the freedom to deploy NDBs in the Far East, during the Indonesian affair, to give but one example. And just imagine the furore if the frigates hurriedly sent to the South Atlantic had aboard US Project E NDBs. There are numerous references to the freedom of action offered BAOR by UK-owned weapons, free of US custodian's time-consuming control mechanisms in the heat of a Continental land battle. That these warheads never materialised had little to do with your assertion Ken, and everything to do with the shortage of money, fissile material, engineering and scientific resources.

However, this, and the earlier number-crunching, is straying rather a long way from the thread topic.

 

[bri21]

Sorry Bri, but I'm lost on that one! Surely he's talking about a Fission-Fission-Fusion weapon?

Hmmmm....
Flagpole, Burgee....a certain nautical flag flavour of naming system?

One might speculate on follow on efforts named Duster and Jack.

It gets worse!
The as planned Grapple Z sequence was Flagpole, Pendant, Pennant, Burgee.

 

[JFC Fuller]

It is interesting to speculate what the physical size of WE.177 would have been had the 300kt requirement been pursued from the outset, would it have resulted in a larger weapon or weapon or would dual carriage have still been plausible in the Buccaneer and TSR-2?

 

[bri21]

Sorry Bri, but I'm lost on that one! Surely he's talking about a Fission-Fission-Fusion weapon?

My interpretation of a somewhat obscure piece of writing was that it was a fission-fission bomb. Of course it's always possible to add a further fusion stage.

 

[zen]

It gets worse!
The as planned Grapple Z sequence was Flagpole, Pendant, Pennant, Burgee.

I grasped (oh dear -grapple) that I think, rather just a little speculation on that score as to what might follow on after.

I was going to ask again but I see your answered while I typed....Which begs a few questions about what efforts might have continued on this three stage weapon?

Another question and unrelated is the matter of Orion and whether such concepts ever where worked on this side of the Atlantic. While I have suspicions the term 'shaped charge' is not achievable with a nuclear weapon, I do have some suspicions over turning a propulsive fuel coating to some other purpose. Such as digging out bunkers perhaps.
------------------------------------
As for historians, of course there are may colours to the lenses one might view past events with and while some put on the rose-tinted type to see all in a panglossian way, others put on the brown tint and see.....that all was excremental in colour. It certainly is a common theme to hear some talk down the UK and all its efforts (which is often to be found comming from one notable source on these forums). That serves not just to taint the perspective of the past, but to engineer certain perceptions of the present. For our perception of the past informs and colours our perception of the present.
It serves a poltical purpose, and when it is detrimental to your own country it is invariably the case it serves some other country instead. Even if it is by accident rather than design, the road to hell paved with good intentions.

So when discussing defence, one must expect some to push hard a perspective that says "all your efforts are worthless", which serves to sap your will (if you believe them) to the benefit of others who do not have your interests at heart.
And where would one expect this to be at its most extreme.....?
In a topic like this one of course.

 

[bri21]

It is interesting to speculate what the physical size of WE.177 would have been had the 300kt requirement been pursued from the outset, would it have resulted in a larger weapon or weapon or would dual carriage have still been plausible in the Buccaneer and TSR-2?

The original RAF spec called for several factory-set yields beginning at 40 kt and rising to 300 kt. Then the Navy added their three yields of ½ kt, 2 kt and 10 kt (later dropping the 2 kt). The original RAF requirement specified a dia not greater than Red Beard at 28 inch, but early studies settled on a dia of approx 18 in, before reducing to 16½ in.

However, yield wasn't the most crucial factor in determining diameter. WE.177A dia was 16½ in. Ditto for the 450 kt WE.177B. So a 300 kt weapon shouldn't have presented any difficulty at the same size.

However, WE.177C at 190 kt might possibly have been shorter and lighter. It used a casing identical to the Type B with some ballast added to bring weight (and ballistic characteristics) into line with WE.177B. That expedient avoided further lengthy delays and development expense.

The RAF wanted the larger yields because operational research at AirMin showed that they were needed to deal with the types of tactical targets assigned to the RAF by SACEUR. 10 kt simply wasn't enough. The Navy on the other hand were not assigned such difficult targets. Their surface strike targets were mainly shipping and coastal and NDB use for which 10 kt was sufficient.

I know that Lawrence has an aversion to politics. However it cannot always be avoided. The RAF were caught in a difficult situation, and through no fault of their own. The Cabinet had discussed tactical nuclear weapons and were divided. PM Harold Macmillan was opposed to tactical nuclear weapons of a yield greater than 10 kt, and that was the dictat handed down to the RAF. A dictat determined by politics, and not on the technical facts. So while the Navy were content with 10 kt, the RAF hopes for 10 - 300 kt weapons were dashed.

Many years later the RAF got a larger yield re-inserted into their programme as WE.177C at 190 kt. But for that they had to wait for two changes of government, and WE.177C didn't arrive until the mid-1970's.

 

[bri21]

It gets worse!
The as planned Grapple Z sequence was Flagpole, Pendant, Pennant, Burgee.

I grasped (oh dear -grapple) that I think, rather just a little speculation on that score as to what might follow on after.

I was going to ask again but I see your answered while I typed....Which begs a few questions about what efforts might have continued on this three stage weapon?

Another question and unrelated is the matter of Orion and whether such concepts ever where worked on this side of the Atlantic. While I have suspicions the term 'shaped charge' is not achievable with a nuclear weapon, I do have some suspicions over turning a propulsive fuel coating to some other purpose. Such as digging out bunkers perhaps.
------------------------------------
As for historians, of course there are may colours to the lenses one might view past events with and while some put on the rose-tinted type to see all in a panglossian way, others put on the brown tint and see.....that all was excremental in colour. It certainly is a common theme to hear some talk down the UK and all its efforts (which is often to be found comming from one notable source on these forums). That serves not just to taint the perspective of the past, but to engineer certain perceptions of the present. For our perception of the past informs and colours our perception of the present.
It serves a poltical purpose, and when it is detrimental to your own country it is invariably the case it serves some other country instead. Even if it is by accident rather than design, the road to hell paved with good intentions.

So when discussing defence, one must expect some to push hard a perspective that says "all your efforts are worthless", which serves to sap your will (if you believe them) to the benefit of others who do not have your interests at heart.
And where would one expect this to be at its most extreme.....?
In a topic like this one of course.

Precisely! Couldn't have writ it better meself!

 

[zen]

Is it to cross a line to ask, what where these targets SACEUR had in mind for the RAF?

Its just I'm reminded of a certain chap I've contact with online who worked for the US in targetting scenarios and he wrote of who some targets are rather more difficult to deal with than others.

Precisely! Couldn't have writ it better meself!

You are too kind.

 

[alertken]

zen: targets:
After US' 6/10/48 Mutual Defense Assistance Act, US/UK made a Target Intelligence Treaty. R.J.Aldrich,The Hidden Hand, Murray,01,P215. Presumably RAF talked to USAFE when tasking Lincoln/Washington/Canberra. Nuclear target co-operation contact began 9/55 G/C C.Finn/L/C P.D.Berg,Anglo-Am. Strategic Air Power Co-operation in the Cold War and Beyond,Air &Space Power Journal,W/04. 21 May,57: US/UK MoU: co-ordinated targeting, plus supply of Project 'E' weapons: UK Tactical Bomber Force Canberra B.6 (w.e.f 2/7/59 48 Mk.7 at Coningsby) and RAFG Canberra B(I)6/8 (64 from 5/58), plus BAOR SSMs, assigned to Saceur (I know no target list; might it be tactically flexible?)

MBF:SAC targeting was in harmony from May,57, “highly satisfactory” Wynn,P275, and was wholly integrated by MoU 3/7/58: 106 V-Craft were to address 69 Counter-Value/20 Air Defence and 17 bomber Counter-Force targets I.Clark, Nuclear Diplomacy & the Special Relationship,OUP,94,P132.

8/60, UK was in Joint Strategic Target Planning Staff, Omaha "where Br. officers participated in targeting decisions" AJ Pierre, Nuclear Politics,OUP,1972,P.269 . SIOP-62, USAF/USN/RAF, effective 1/4/61: total deployment was 3,240 weapons/7,847MT, 1,060 targets. (from now defunct www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB130). In the Cuban Crisis MBF+RAF IRBM Force (? inc. NEAF) had 98 targets:16 cities, 44 offensive airfields, 10 Air Defence Control Centres, 28 IRBM sites Clark,P393.

The sole Chevaline target appears to have been Moscow: “‘Govts. did not want (USSR’s capital to be) a sanctuary’ (nature) of the concept is (to rain) warheads and decoys (to) swamp the target (Its) effect does not come from the contents of (1 FBM but) probably the (32 warhead) complement of 1 SSBN (Difficult) to disentangle the system to take on a number of targets at once”. L.Freedman,The Evolution of Nuclear Strategy, Macmillan,1981, P148. D.Healey, The Time of My Life,Penguin,90, P455.

To be at the top planning table was the purpose of all UK's nuclear weapons investment: 25/7/58 CAS “indicated (MBF’s) advantages in relation to USAF/SAC’s alert force (what) had to be measured in terms of deterrence was speed and effectiveness of attack”. Clark,P131; RAF was “allocated (some) breaching targets (arriving) high(er) up and faster (i.e: sooner) than” SAC. Waypavers. Wynn,P278. Our Bomb would earn “influence in world affairs (our) right to have a voice in the final issue of peace or war (so) attention is given to certain (Sov) targets (of) greater importance to us than (US)” P.Hennessey,The Prime Minister,Penguin,2001,Pp.184/112, all in an Alliance context: in 1961 Macmillan was told it was “doubtful our deterrent (could be used) independently (we had no) serious operational plans (to) do so.” R.Lamb:The Macmillan Years, J.Murray, 1995, P303. PM Wilson retained SSBNs, 1965, but: “there was to be no nuclear pretence or suggestion of a go-it-alone Br.nuclear war (UK Force was a Saceur-assigned) fully committed part of NATO” HW,Labour Govt,Weidenfeld,1971,P40. So it had been since 23/5/63 when all UK-based Strike Forces were Saceur-targeted, bar “where (supreme) national interests are at stake”: now: “in grave National Emergency”.Wynn,P.550. An, ah, Symbol of a new Combined Bomber Offensive. Hang out together, or surely be hanged alone. Behavioural Science PhDs are earned on the case of UK (trying to) let them fly while US sits on its isolationist hands.

 

[bri21]

Is it to cross a line to ask, what where these targets SACEUR had in mind for the RAF?

Its just I'm reminded of a certain chap I've contact with online who worked for the US in targetting scenarios and he wrote of who some targets are rather more difficult to deal with than others.

That's a subject the RAF and MoD are remarkably tight-lipped about. All the stuff on that topic that I'm aware of in the archives is still classified. For those who are less familiar with the National Archives:
a) there are files that are fully declassified.
b) there are files that are declassified, while individual pages or words are redacted by the censor.
c) there are files where only the title is declassified.
d) there are files that we do not know exist.

Targeting matters are usually in group c) and possibly in group d), however, we have no means of knowing of the latter group.

The old 40-city targeting plans for Bomber Command - the national, as opposed to NATO's strike plan are not so difficult to find. Two colleagues did some work on this recently and came up with most of the 40-city list combined with a map of the Galosh ABM footprint that I'd located. I'll inquire if it's OK to upload the list here. I still have the Galosh footprint, although I see that it's since been removed from the archives. Censored after the horse has bolted with a copy.

 

[bri21]

Presumably RAF talked to USAFE when tasking ...

Presumably ..? So where is the evidence Ken?

US/UK MoU: co-ordinated targeting, plus supply of Project 'E' weaponsI know no target list; might it be

Presumably .... now ....might it be .... so where is the evidence Ken?
Oh how I wish I had £1 for every piece of speculation found on these forums. I'd be a very rich man!

The sole Chevaline target appears to have been Moscow:

Evidence Ken?
And there is no evidence because your assertion is not true. Chevaline was fully integrated into the NATO strike plan. In accordance with the UK's treaty obligations to NATO and WEU, just as Polaris A3T and Bomber Command's V-force before it had been; and just as Trident is now. Lots of evidence for that.

However, there was also a National Retaliatory Strike Plan, for use in the unlikely event (IMO) that the UK believed it had to engage in nuclear war with the USSR alone, without it's NATO allies, and specifically without the USA. That's precisely why Bomber Command, then Polaris, then Chevaline, and now Trident are described as our Nuclear Deterrent. Some argue (and you'll find some of those in Churchill's 1954 Cabinet as it took the decision to build a UK H-bomb) that a British deterrent wasn't only useful in deterring the Soviets, but served also to deter the more gung-ho elements in Washington who appeared to believe that a nuclear war could be confined to Europe. A sentiment that has recurred in every decade since.

It goes without saying that a National Strike Plan based on possibly only one sub at sea when the time comes, is inherently more limited than the combined strength of its US and French allies, all singing from the same hymn book. So the UK had to make difficult choices based on the weapons available, AND the likely effectiveness of Soviet ABM defences. A swamping of the Soviet defences (as in the US and NATO strike plans) was never an option, given the small numbers available to the UK, and given that the ABM Treaty allowed the Soviets up to 100 ABMs around Moscow, while British incoming RVs numbered only 32 maximum from one sub, all fired in a 15 minute window. Added to that, the Galosh footprint didn't only protect Moscow within the Inner Ring Road. It's coverage extended to much of the Leningrad-Moscow corridor and a wide area around Moscow. However, the British targeting policy based on the Moscow Criterion that was essentially a decapitation strategy, was limited to an unlikely war situation where the UK was alone, and the good-old-US-of-A had chickened out. As the [facts] show they did in 1914 and 1939.

To be at the top planning table was the purpose of all UK's nuclear weapons investment

Not true Ken, and you know it's not true.
Yet you persist with anti-British propaganda, that isn't supported by any evidence. You know perfectly well that a British nuclear deterrent, rightly or wrongly, is an essential prerequisite for national security and national survival. That is why successive generations of Britons (and polls suggest up to two-thirds of Britons) have continued to bear the considerable cost of British nuclear weapons. No British government of whatever colour could maintain itself in office without that support from a majority of the British people. The very same British people who have unconditionally supported the US in its efforts since 9/11.

Any other additional perceived benefits of British nuclear weapons (such as being at the top table whatever that means) are just that. Additional, perceived, and supplementary to our nuclear deterrent's main purpose as an essential tool for national survival.

 

[zen]

My understanding is three warheads on Polaris is to ensure the highest probability the target is hit and destroyed. CEP figures for SLBMs are rather less good than for landbased ICBMs.

IF we assumed a Moscow Criterion, that is to take out Moscow was the sole aim of the Deterrent, then the 32 figure does not give us directly the number of targets but rather the number to ensure those targets are hit. That also has to factor in potential failure of the missile or warhead.

But tactical weapons delivered by aircraft over Germany and Poland is a different issue. Objective of the nukes would either be to take down advancing masses of Soviet forces (who's doctorine focuses of mass), or to strike behhind them to deprive them of the continuence of supply (including personnel), starving them of the logistical supprt necessary to continue to advance.

Knocking down people is airburst territory, relatively small bombs can do that and throw advancing forces out of shape. But hardend fixed targets are ground burst territory, where the weapon has to dig out the target or crush them with shockwaves.
If the RAF wanted a higher yield for their bombs it might suggest their target list includes a number of such hardend sites.
Bad news about ground burst is how limited the weapon is, it must be delivered with quite some accuracy.

RN's job in takingout surface forces can be done with quite small bombs, if the wave generated overturns the ships, thats a kill, regardless of whether it actualy destroys stuff on the ship.
EoS use, is likely against softer landbased targets.
SO I can see why the RN is less interested in big bombs, leave that to the SSBNs.

Finaly theres something like 50,000 targets in the USSR, though a lot are close together and can be effectively a much smaller number in terms of bombs required.

 

[Sea Skimmer]

Yes, Polaris was armed with multiple warheads that fell around a single aim point in a triangle. You cannot aim them at three different targets, but you might catch several different targets under that large but inaccurate pattern of bursts. A city like Moscow is absolutely filled with targets, government, military and lots of rail yards and industrial facilities all together. I’d imagine the idea ultimately came down to ensuring a range of targets were struck across Moscow including many overlapping hits on the Kremlin area. The cumulative effect of the many would utterly destroy its functionality and population.

The Soviet ABM systems may very easily have been able to take out a Polaris missile before it releases warheads so only the missile count really matters. 16 isn’t very many to go scattering around. S-200 also had at least a very limited ability to serve as ABM against an IRBM like Polaris, and around 200 Soviet batteries were deployed. So even if Polaris did not concentrate on Moscow the ABM problem remains over virtually any major Soviet city.

Plus Polaris reliability and accuracy is also just not that good on average in tests, so if you don’t concentrate on killing one target you can only target a few additional ones. Double and triple targeting will be required to ensure a hit. Otherwise you don’t assure destroying anything, and the nuclear planning process is now a crapshoot.

You can't really expect a Polaris sub to knock off a whole swarm of targets like the warhead count suggests. Its way too limited a technology. That's why the US jumped to Poseidon and Trident C-4 before the cost limited RN was able to come back for new subs and missiles.

 

[zen]

The darkside of ABM based on nukes is the tendancy to blind the sensors used to target the incomming missiles, even if its for just a few moments it can be a telling matter. ABM is not 100% effective.

Rather like the limitations of command and control break down with disturbing rapidity once a major exchange begins.

ABM works best on buying time to decide what is happening, a chance for the politicians to somehow avert WWWIII.

As for Moscow, I would'nt be surprised if we're talking say something in the order of a 60% success rate for the missiles and several per target, the actual number of aimpoints might be as low as 6 or 7. One of the more disturbing aspects of the use of a nuclear arsenal is how quickly you expend it to guarentee dealing with so few targets.

Which is why some have always felt the need for bombers instead of missiles, if you can deliver the weapon with sufficient accuracy and get through to the target, the actual number of bombs need be less.

 

[bri21]

A city like Moscow is absolutely filled with targets, government, military and lots of rail yards and industrial facilities all together. .....The cumulative effect of the many would utterly destroy its functionality and population.

Agreed! And the USSR was a highly centralised state. Almost everything required for control of the state apparatus was concentrated in Moscow. Hence the decapitation strategy that the UK adopted.

and around 200 Soviet batteries were deployed.

The ABM Treaty limited the USSR to 64 launchers on two sites, one to protect the capital city, the other to protect a missile field. The Soviets never deployed ABMs other than the Moscow area, and there's no evidence that they broke their treaty obligations by deploying more than the 64 permitted; and it wouldn't be in their best interests to do that and re-ignite an arms race they were doomed always to lose. Missiles were another matter. The ABM Treaty permitted them up to 100 ABMs. However, in the short time available after missiles first flew, many doubted their ability to reload launchers with their spare ABMs.

 

[bri21]

The darkside of ABM based on nukes is the tendancy to blind the sensors used to target the incomming missiles, even if its for just a few moments it can be a telling matter.

ABM is not 100% effective.

Exactly why the British believed Chevaline's pitifully low numbers would be effective in a decapitation strike.

 

[zen]

Presumably the loss of an RV per Bus was accepted for the decoys if they bought enough time delay in attempts at interception.
The closer the RVs got the city and the ABM system sensors the worse the blinding effect of their own nuclear warheads?

 

[bri21]

The old 40-city targeting plans for Bomber Command - the national, as opposed to NATO's strike plan are not so difficult to find. Two colleagues did some work on this recently and came up with most of the 40-city list combined with a map of the Galosh ABM footprint that I'd located. I'll inquire if it's OK to upload the list here. I still have the Galosh footprint, although I see that it's since been removed from the archives. Censored after the horse has bolted with a copy.

Found the Galosh footprint along with another from the same file. Both have since been censored and removed from the National Archives copy in DEFE 25/335 a file concerned only with Chevaline. However no one asked me to return my copy. So here they are, if they upload.

Both were originally black and white only. They've been 'painted' with colour only to make them more suitable for viewing on my own website, and the originals in b+w are still available.

Sincerely hope that intelligence on Iraqi WMDs was better than this.

 

[alertken]

The bunker map is Secret, which meant: "shield from the Sovs", UK Eyes A(tomic), which meant: "shield from the dodgy French...and the cousins", with whom we had Target and other Intelligence Treaties. Odd.

 

[bri21]

The bunker map is Secret, which meant: "shield from the Sovs", UK Eyes A(tomic), which meant: "shield from the dodgy French...and the cousins", with whom we had Target and other Intelligence Treaties. Odd.

And the evidence for these assertions is where Ken?

Since the two maps relate only to a National Retaliatory Strike Plan, it's not really any business of the French (dodgy or not) or of the 'cousins', since the 'cousins' and the 'dodgy' French (track record here in Bosnia) may well leak it to the Soviets, who in turn could then adapt to better survive a UK-only strike.

And the cousins and the French may have a perfecky reasonable motive in leaking if a leak were to curry favour with the Soviets, and avoid or minimise a nuclear attack on France or the good-ol-US-of-A. That's possibly why it's marked UK Eyes A [Only].

Simple really!

And since none here has seen the alleged 'Target and Intelligence Treaties' who can know the degree of 'oddness'. Again it boils down to mere speculation, or lack of supporting evidence.

 

[alertken]

"Independent" UK design work. Moore threads through most complex records in the 1960-64 period, addressing Skybolt, Polaris and WE177B.

UK Skybolt was schemed successively with: Steven/Polaris A1 W-47 (12/59, P.119); with Thor W-49 derived from Mk.28 (P.119); with "ideas evidently based on original (UK) work (inc.) Acorn" P.120. US, 1/61 chose new Mk.59, which "is comparable with the general ideas we have in mind for our own development" (P.121) which Moore suggests as "not simply an anglicised copy". By 8/61 that was coded RE179 (P.125), 850kt (p.211).

UK Polaris: Chief Scientific Adviser Zuckerman to PM 16/5/64 (p.237): we "had a choice of either copying (Mk.58) as closely as possible or of modifying it by substitution of a UK-designed primary to be in closer accord with UK practice. The secondary will be the same in both cases."

WE177B (p.196: ZA297, initiated to 1963 OR.1195, and derived from the OR.1176 warhead funded as PT176 mid-1961 and to be WE177A) settled 1965 at 450kt (P.220): Moore does not address its secondary's pedigree.

P.280: re.Feb.1961) "whether there was independent work on secondaries is very difficult to say"; (UK was) "making an independent contribution in warhead design and not simply copying US drawings (the) primaries were Br.designs" (pp.238/9).
(Re UK assistance to any Australian project: P.95 after UK/US 1958 Agreement UK was) "hampered by the fact that its nuclear secrets were no longer necessarily all its own to give away".

It's intermingled. I settle for brian's point of 2-Way Street: inspiration, components/materials. Subsequent to YS Mk.1 our weapons drew upon/were influenced by US data: neither copies nor conceived immaculately. Here, as with much avionics kit, as with Westland's anglicisation of choppers, we re-engineered to improve and render suitable for our distinctive operation. Moore quotes (P.18) V/A Sir Peter Gretton, 1965 (I will): "not get involved in (whether UK's deterrent) is independent or not (this) is mainly a political question...it does not affect...the main issues" (which, to speculate, were: does it work, does it deter? Which, manifestly, it did/does.)