Sea Slug

Comparison between Sea Slug and Terrier yes.
Between Terrier and Sea Dart no.
As that would best be done in a thread about Terrier or Sea Dart. Not in a thread about Sea Slug.

In terms of why continue with Sea Slug. Never underestimate institutional inertia. Having piled such effort into the system, which is the result of delay and reevaluation post WWII. Continuation was the simplest way forward.

Dollars mattered and other things held a higher priority. Including things like transistors when they came about.

Size matters and Terrier also imposed demands on a ship's design.
So at the time Sea Slug seemed a reasonable first system.

By the time we get to the late 50's, NIGS and Typhon are on the horizon and pulling a hard jive ho towards Terrier seemed like hampering the future arrival of the wonder weapons.
 
Prior to RIM-2E, Terrier was a 3,000lb beam riding weapon with a 218lb warhead and a range of 30-40,000 yards. Sea Slug was a 4,000lb beam riding weapon with a 200lb warhead and a range of 30-40,000 yards.

The overall Terrrer solution may have been more elegant but it was a 27ft long missile, compared to the 20ft of Sea Slug, and the handling systems used in most of the installations were hardly simple. The most elegant Terrier configuration was the Mk.4 Missile Launching System, used in the Boston and Canberra Heavy cruiser conversions, that stowed the missiles vertically and loaded them vertically through hatches onto twin arm launchers. However, even that system still required the missile wings and fins to be manually attached just prior to the missile being loaded onto the rail. Such was the length of the missile the conversions still required a deck house built above the existing main deck to house them. Whilst RIM-2E and F offered significantly superior performance to Sea Slug they probably would have offered only marginal, if any, improvements in ship fitting considerations. By the time those missiles appeared the RN was looking at Blue Envoy and then NIGs.
 
Last edited:
Seriously? DL-6 Farragut, two-ring Mk-9 GMLS, 40 RIM-2, two guidance channels on 5700 t; Counties 24 Sea Slug, one guidance channel on 6200 t. And this would be a "marginal impact in ship fitting considerations"? Taking into account the large difference of performance already with RIM-2E in 1963, and even more latter on with RIM-67 Standard ER, the ship-impact / performance ratio of Sea Slug was really miserable from start and only got worse during the 60s. Interestingly as part of the GW series, GW 51 Talos achieves 46 RIM-8 Talos (not Terrier, I did not mention Terrier in my initial post) and two AN/SPG-49 - /SPW-2 guidance channels, on a lesser displacement and shorter hull than the other designs in the same series with 48 Sea Slug and only one guidance channel!
 
Sea Slug is the outcome decisions in 1945-1947. As part of the first generation of SAM SAM systems to enter service.
It's slow entry to service is part and parcel of the general delay in UK systems which among other issues is due to financial constraints.
It is not comparable with a system conceived in the 1960's and entering service in the late 60's or early 70's.

It was argued to switch to Green Flax, a.k.a Thunderbird MkII. Bigger, heavier and more demanding on ship design.

It's planned successor was NIGS, which is comparable with Typhon.
 
CNH said:
Not originally. A much later proposition.
Click to expand...

The first proposed atomic warhead for what would become Sea Slug was Winkle (at that time the nuclear option was primarily intended for use against high altitude atomic armed bombers), which was quickly supplanted by the even more compact & further along in development Pixie. A number of other designs were subsequently mooted, some of which were purely British designs and others which were British versions of American designs. Each design proposed was incrementally more powerful than the last, in part due to the increasing importance of the just added surface to surface role (the Sverdlov-class cruisers were becoming a particular concern). The warhead that was soon ultimately nailed down for the Sea Slug was Tony, which was an anglicized version of the W44/Tsetse. However, Tony suffered due to a well intentioned decision by the British to use what they considered less sensitive and therefore safer conventional explosive components in their version of the design; this led to a drop in actual yield in live fire tests (down to around 8kt). I believe they eventually had to go with more powerful explosives to get the proper yield, but the self-inflicted delay had totally disrupted production plans, which together with what can be best described as Treasury idiocy is why the Sea Slug never received it's planned atomic warheads.

Maiwand1880, it's arguable whether or not Britain should have stuck to it's guns, so to speak, on many of those programs you mention. For example, the F-111K and Sea Mauler were expensive disasters (putting it mildly), Skybolt through no fault of it's own was a equally expensive dead end, Polaris ultimately was so-so at best, the Spey Phantom proved to be far more expensive, with a more modest capability, than the P.1154 would have been even in a worse case scenario, which greatly limited procurement at a time which the RAF and RN needed more aircraft than ever (and weren't getting them). And the less said about the Little John & Sargent procurements the better (Lance was only able to partly make up for that and even it proved to be more expensive than a Blue Water follow on would have likely been).
 
Talos is even worse, and really Bloodhound is the closest UK system. But in time Blue Envoy was considered....and swiftly rejected as too big, unwieldy and as bad as, and comparable with the then mixed powerplant fighter.
 
I suggest the following is the point:
Seaslug 1 is unavoidable on the first 4 Countys as they were designed around the weapon. Terrier and Tartar in their early versions would have been no better and possibly worse.
My quibble is with Seaslug 2. Australia showed with its three Adams class w Ikara what we could have had instead.
Seadart CF299 is relevant because it takes 15 years to get into service properly. It and Seaslug2 were dead ends which could like other over ambitious UKweapons been replaced by Tartar/Standard. A well designed UK Adams style destroyer/frigate for us, theDutch and RAN would have been better thanthe 4 Countys, T82 and 42
 
Were they actually overly ambitious or just underfunded, dragged out and just nibbled to death?
 
Maiwand1880 said:
Seriously? DL-6 Farragut, two-ring Mk-9 GMLS, 40 RIM-2, two guidance channels on 5700 t; Counties 24 Sea Slug, one guidance channel on 6200 t. And this would be a "marginal impact in ship fitting considerations"? Taking into account the large difference of performance already with RIM-2E in 1963, and even more latter on with RIM-67 Standard ER, the ship-impact / performance ratio of Sea Slug was really miserable from start and only got worse during the 60s. Interestingly as part of the GW series, GW 51 Talos achieves 46 RIM-8 Talos (not Terrier, I did not mention Terrier in my initial post) and two AN/SPG-49 - /SPW-2 guidance channels, on a lesser displacement and shorter hull than the other designs in the same series with 48 Sea Slug and only one guidance channel!
Click to expand...

The Counties actually had a Sea Slug magazine capacity of 39. They could have had a second channel of fire if they sacrificed the helicopter hangar, thus giving them the same aviation facilities as the DLG-6 class. Equally, one can speculate that they could have sacrificed one of the 4.5 inch turrets for an ASROC launcher. The County class and the DLG-6 class were very close.

You are of course correct that the US was able to push forward with improvement and development of three classes of naval SAM simultaneously, during a period of very rapid technological advancement. The British could only really manage one such development programme at any one time. That is why Sea Slug development ends, NIGs is postponed never to be seen again and SIGS is pursued. SIGS results in a weapon that exceeds the Sea Slug Mk.2 engagement envelope against supersonic targets in a much more compact missile that weighed just 1,200lbs.

As for GW.51 with Talos, it was actually the same hull as the original GW.51 with 48 Sea Slugs. The difference was that the Talos ship sacrificed both twin 6" guns leaving its secondary armament as just 4 twin bofors. Talos was a much larger weapon than either Sea Slug or Terrier and thus had a much greater impact on a hull of the same given size.
 
Last edited:
In fairness to the RN, it does deploy 4plus4 Countys by 1971. This compares with
FRG: 3 Adams FR 6 (Suffren Dupetit) IT 3(Doria and Veneto), NL 1 De Zeven
 
Because Pride and Prestige I presume. Great Britain together with it's colonies and the Commonwealth ruled the largest part of the Planet prior to the 1950's and as Battleships represented the naval power of a nation in WW1 which shifted to Carriers by WW2 these vessels presented enormous Prestige to the country having them. In the 50's with the new technological advances and the tech race with the Soviets and Americans the British did not wanted to get far behind hence the large amount of missile programs in this era, but sadly their economy could not cope with that many programs- Instead of going to a few ones at a time to get full founding, the numerous programs eaten up the limited budget the Nation could allocate for such research.
Eventually the government and the parties seen it would be best to buy the equipment from the USA rather to research themselves and thus arriving to the current day when Great Britain was seen as a lapdog to USA rather a true separate Great Power.
I do not know how close were USA and Great Britain regarding missile tech and nuclear tech wise, because I do not see British licence produced / improved Terriers, Tartars, Taloses, Polarises or Tridents. I'm not familiar with missiles to that degree so I don't know if the RN SSBN'S have own produced missiles or bought ones.

This: Based on US tech but improved by ourselves would had both saved money for the RN and also allowed to show Prestige on the world stage for Great Britain in my opinion.
 
More like not wanting to rely totally on the US.
More like fear of being left high and dry, alone against the USSR.
After all a senior Democrat said something along the lines of "well China civilised the Mongols, so let Europe civilise the Soviets".

After all VJ brought immediate war loans end and demand for repayment before the UK could return it's economy back to civilian production.
Humiliated by another loan with some terrible clauses in it.

After being shut out post Trinity from Manhattan and having to (re)start a domestic nuclear weapons program.
Driven by humiliation and fear of betrayal.

Buying US was done in precious Dollars and that was kept for higher priority matters....including fuel and transistors.

Besides RN standards were different to USN standards.

Just as things seemed to ease, along comes Suez.

Just as things ease and we're lured into Skybolt and Mauler, both are cut. The former done with a statement we'd not get Polaris.
Nassau confrontation shifted that stance.
 
Maiwand1880 said:
, but Sea Slug was a complete engineering disaster. Those monstrous missile, magazine, launcher, director had a tremendous ship-impact while having a limited performance.
Click to expand...

They worked, aren't they? And actually worked fine. For 1950s, it was essentially either that, or nothing.

Maiwand1880 said:
Makes really one wonder why the English did not give it up and move to RIM-8 Talos,
Click to expand...

Because "Talos" with its enormous power consumption may be impossible to fit on "County"-class ships. Also because "Talos" was even less ergonomically effective than "Seaslug". And because liquid fuel - even the usual aviation one - is generally much more dangerous to handle on warship, than solid fuel.

Essentially, it was "Terrier" versus "Seaslug". And from late 1950s point of view, frankly, there weren't much difference. The existing models of "Terrier" missiles were all beam-riders - exactly as "Seaslug" - more compact, but less accurate.
 
And I must remind, that the early "Terrier" missile launch systems - like Mk-9, which was installed on "Providence"-class and "Garibaldi" - weren't exactly that much better than "Seaslug". They also relied on long hangar-type magazines, with only a small number of missiles constantly finned and prepared for launch; most of supply required pre-launch manual checkout & fin installation.
 
On a slightly different track;-
1- where was the Sea Slug development centre located? I’m sure I remember reading it moved a few times.
2- where were the missiles built? I think the last ones came out of Lostock, but not sure? Was there an assembly line at Bagington ? Any pictures of the missile production?
3 - anyone know the numbers built?

A very long time ago I remember seeing a Sea Slug guidance electronics section, probably a mk1. It consisted of multi conducting rods running lengthways with components soldered between the rods, all solder connections were neatly wire wrapped, amazing component density, coated in thick red wax and a throughly horrid prospect for mass production. The Bloodhound electrical pizza slice cans looked so much nicer. Sea Dart guidance section looked other worldly compared to these two.
 
I stick to my point somewhere above. The first 4 Countys with Seaslug 1 were not a bad deal as they gave the RN capacity which Terrier would have needed dollars and possible more space for (Garibaldi and De Zeven were bigger than the Countys).
The real issue is the evolution of systems in the period after 1962. Seaslug 2 failed to deliver. Seadart does not enter service until the first T42 in the 70s. The last 4 Countys should have had Tartar/Standard and then a new Standard/Seadart design
 
No they could have replaced the guidance with Sea Dart Polyrod system and thus a MkIII with SARH.
Adopting components from Blue Envoy they could add in Command Guidance.
A change in warhead might increase lethality and may reduce weight.

They could also leverage Blue Water two position rocket nozzle technology and eliminate the boosters or at least reduce them significantly.
 
Last edited:
Maiwand1880 said:
Anyway comparaison is in order here. Counties were nice ships, aesthetically speaking, but Sea Slug was a complete engineering disaster. Those monstrous missile, magazine, launcher, director had a tremendous ship-impact while having a limited performance. Makes really one wonder why the English did not give it up and move to RIM-8 Talos, like they did in many other areas at that time: C-130 instead of AW.681, F-111 instead of TSR.2, F-4 instead of P.1154, S-55, S-58 and S-61 instead of local helicopters, Little John / Lance instead of Blue Water, Skybolt then Polaris instead of Blue Streak and Blue Steel, Sea Mauler instead of what-ever, US nuclear weapon designs instead of theirs, W33 and M110, W48 and M109, instead of Tony for their own artillery, etc. Perhaps was it because under the naval version of Project E, RIM-8 D Talos with W30 nuclear warhead, the most desirable combination, would have necessitated a Marines detachment and a senior USN officer on board their ships in order to implement the safeguarding and double-key provisions, something a little bit difficult to swallow for them?
Click to expand...

They didn't because the US usaully wanted top dollar for those systems/weapons and the UK was basically broke. Home produced kept British Pounds in British pockets, rather than in US pockets. Further, most UK systems were comparable in performance to US systems. After WWII, Britain led the world (and the US) in most technical fields. They had developed and fielded jet fighters, they had developed and fielded SAMs and so on. The US quickly surpassed them but it was still hard to suggest that a US system was better than a UK one. So, they decided to develop and build UK systems instead.
 
France developed Masurca, which was similar to Terrier. Only three ships carried the system. But unlike Seaslug they served into the 21st.
France also procured 4 Tartar launchers. 2 of these were transfered to new ships to fire Standard and are still in service. They were joined by two ASTER carrying destroyers.
Although France deployed far fewer air defence ships than the RN, their taxpayers seemed to get a better deal.
 
MW quite right to suggest US-off-the-shelf, for what would be a short-order run. So the thought recurred, 1948-62:
* SAM-N-7 Terrier declined 7/51 due to “bad effect (on UK nascent ) GW industry” S.R.Twigge, Early Devt of GW in UK,’40-60,H’wood,93,P.164, plus uncertainty US “would supply” Grove,Vanguard to Trident,P121.

* 1956: Talos offered at fixed price; declined at Nassau, 3/57 as unsuited for RN ships, and “given the desire not to be dependent on foreign supplies” Grove,P121. Rejected again 1958 in hope UK's mollusc would get a grip. G.Hartcup,The Silent Revolution,Br’ssey,93,P252.

Those thoughts applied to the HE versions. Your point re USMC custodians only dawned on UK Marshals, Admirals and Ministers around 1957, causing UK-domestic sourcing for RN and for out-of-NATO-Area RAF.
 
Further to my comments re US T systems. UK was the only non US nation to deploy more than 4 to 6 area air defence ships. The RN had more than ten by the 80s. For these numbers the Dollar burden becomes significant.
The failure of Seaslug 2 and the longer and more complex than planned CF299 to Seadart evolution could not be predicted. After all our technology was comparable with the US.
Even today the RN is only NATO European navy with 6 area defence ships. Only the Japanese have a similar force. Again the implementation has not lived up to hopes.
Given the numbers we have deployed, US systems would have been too costly. Joint production might have helped both US and UK: Seawolf and its successor are better than their US counterparts.
 
Has anyone been able to confirm or deny the speculation that the Sea Slug Mk.2 was never actually certified and cleared for use?
 
Zootycoon said:
On a slightly different track;-
1- where was the Sea Slug development centre located? I’m sure I remember reading it moved a few times.
2- where were the missiles built? I think the last ones came out of Lostock, but not sure? Was there an assembly line at Bagington ? Any pictures of the missile production?
3 - anyone know the numbers built?

A very long time ago I remember seeing a Sea Slug guidance electronics section, probably a mk1. It consisted of multi conducting rods running lengthways with components soldered between the rods, all solder connections were neatly wire wrapped, amazing component density, coated in thick red wax and a throughly horrid prospect for mass production. The Bloodhound electrical pizza slice cans looked so much nicer. Sea Dart guidance section looked other worldly compared to these two.
Click to expand...

2: The missiles were assembled in RN Armament Depots from components from various suppliers*, RNAD Ernesettle was the main one and there was a second at Singapore; when the latter closed the set up was transferred to RNAD Gosport.

3: The missiles took their serial numbers from the Aft Body with a prefix depending on the type, SE for a MK1 or S2E for a Mk2; I remember S2Es getting into the 300s but I don't know what number they started with, and I don't think they did the WW2 trick of scrambling numbers to confuse the Russians potential enemy.


The Mk1 missile used valve (thermionic tube) technology but Mk2 used discrete solid state components but I never got to see inside the Guidance Receiver. I did have an opened-up Seaslug gyro on my desk and frequently spun the innards, even with a finger flick it spun for a long time.

*To reduce costs and speed up delivery the empty containers were sent back to the suppliers for the next delivery; this caused real problems when we were taking the missile out of service as there weren't anywhere near enough -even for things like warheads!
 
I know it may be slightly 'off topic', but the comparisons between Seaslug and Terrier/Talos/Tartar do seem to be neglecting one important point.
Yes, Seaslug (Mk1 especially) was not an ideal/perfect weapon, Mk2 seemed 'better'. However, the U.S. had to invest heavily in a "3-T get well" programme to fix many issues they were experiencing with their first generation ship-board SAM's.
There is an age old expression - "the grass is always greener on the other side of the fence", but in the case of the first generation Naval SAM's this was patently not the case.
Not everything British was terrible, and not everything American was wonderful.
 
pf matthews said:
Not everything British was terrible, and not everything American was wonderful.
Click to expand...

Also should be noted that Terrier was essentially the accidental byproduct of "Bumblebee" program) It could pretty easy never been born, and gun-launched Zeus/Arrow guided shell would took its place)
 
Hood said:
I can't remember specific file now and I will have to dig out the reference, but the Sea Slug was offered to West Germany around 1962 (if my memory is correct).
Click to expand...

Related to the need for AD which eventually resulted in the Lütjens destroyers? Were Counties offered?
 
Hood
The West Germans had a progamme to purchase the Adams class from the US. I think 6 were planned, but three entered service. They also received Fletcher class destroyers.
There were some corvettes transfered from UK and aircraft (Seahawks, Gannets) so the Germans, like the Aussies, may have looked at buying Countys before going with the Adams.
Like the Dutch the Germans then designed a Tartar carrying ship called a Korvette but similar to the Tromps. It was cancelled and later the Germans bought Koertenar frigates from NL instead.
So 1962 Seaslug purchase pretty unlikely
 
I wrote too soon. Germany began negotiations about their spec for the Adams class in 1963 and ordered them in 1964. So a 1962 Seaslug offer works. I assume like Australia it involved the Countys.
 
A photo here shows a model of the tilted bucket loading mechanism for Sea Slug envisioned for some of the GW cruisers:
wkdrXC3.png
 
Generally about the Counties from 23:00:
But there are rare Seacat launch and interception as well as Sealsug loading and firing!
 
Tzoli said:
Generally about the Counties from 23:00:
But there are rare Seacat launch and interception as well as Sealsug loading and firing!
Click to expand...
Gods that's a marvelous piece of history!
And weirdly I suspect I've seen it as a boy umpteen decades ago.....
 
I have found the reference in my Kew notes (my memory was 2 years out). The minute mentioned a possibility of selling the Sea Slug Mk.2 to the West German Navy.

AVIA 65/949 Joint Admiralty/Ministry of Aviation New Naval Guided Weapon Working Party (NIGS)
Minute from J. E. Serby DMARD to Rear Admiral R. E. Washburton Director General Weapons, 11/11/1960
 
Maiwand1880 - 'What an unwieldy system'

Perhaps you could put yourself in the place of the engineers and designers who, from 1943 (earliest mention I've seen of a naval SAM system that would lead to Sea Slug) were trying to fit a completely novel weapon system on a ship. A system that was not even tried and tested on land.


Chris
 
Last edited:
Talos
7,800lb weight, 32ft long, 28" diameter
Sea Slug
4585lb weight, 19ft long, 16.5" diameter?
Sea Dart
1,210lb weight, 14ft long 17" diameter ?
 
Out of interest, in 1949 how many SAM/SAGW projects were underway in the USA and how many in the UK?
How many in 1960?

Chris
 

Similar threads

Please donate to support the forum.

Back
Top Bottom