Tiger class cruisers opinions

[uk 75]

The three Tiger class cruisers arouse strong opinions.
As the only major non-carrier RN warships built after WW2 they mark the transition of the RN from a force built round its battleships' big guns to a missile dominated navy.
The 6" and 3" guns fitted to them were supposed to be a new approach to gunnery. As so often with Britain the promise failed to deliver.
Too small to receive Seaslug and too new to be scrapped as the County class GWDs entered service they became a quick fix to the RN's need to get big ASW helicopters to see.
HMS Blake became the first RN non carrier warship to operate the new Seaking helicopter. Described as a frigate towing a shed she lacked the subtlety of Italy's Terrier equipped helicopter cruisers. HMS Tiger took even longer to convert and HMS Lion was abandoned.
But in the harsh world of the 70s they were all the RN had.

 

[Dilandu]

Well, personally I like their design) It was compact and functional. The main problem was, that British - unlike France or Italy - was still under delusion of being the Great Power in league of USSR and USA, "just having temporary troubles". And therefore was unable to balance its military budget properly, and instead of using what they have, they chased for some kind of "ultimate solution".

P.S. I should point that Colbert small size did not prevent French from installing bulky Masurca SAM, and Italians fitted Terrier SAM into the 1930s Garibaldi. So I doubt that size was the real reason for not putting Seaslug on Tiger's.

 

[Rule of cool]

The only thing I object to was the cost and duration of their helicopter conversions, especially the 2nd one. That cost 20-25% of a new CVA01.

 

[Grey Havoc]

The absence of HMS Tiger and HMS Blake was keenly felt indeed during the Falklands War. Deactivating them, and then cancelling their reactivation was later widely admitted to be a serious mistake.

 

[Dilandu]

The absence of HMS Tiger and HMS Blake was keenly felt indeed during the Falklands War. Deactivating them, and then cancelling their reactivation was later widely admitted to be a serious mistake.

True. Both as helicopter carriers, fire support units and forward deployed radar pickets they would be quite valuable here. While they weren't invulnerable - Exocet shaped charge warheads could likely punch through their armored decks - they would likely be at least as durable as Counties-class destroyer.

 

[Grey Havoc]

On another note:

SHIPS OF THE ROYAL NAVY 1945-1989

Aerial view of Tiger-class light cruiser HMS Blake (C99) with Hawker Harrier overhead. 1969.

www.iwm.org.uk

 

[Dilandu]

The absence of HMS Tiger and HMS Blake was keenly felt indeed during the Falklands War. Deactivating them, and then cancelling their reactivation was later widely admitted to be a serious mistake.

I wonder, if they lagged in active service till 1982, and went to war - what would be done with them afterward? Materially, they were probably good for anotber decade of service (if repaired). Their 6-inch turrets, while troublesome, have a lot of spares - out of six build only two remained operational, after all.

Purely speculationary - the 3-inch may be removed and replaced with "Vulcan-Phalanx", a set of "Exocet" launchers could be installed.

 

[Dilandu]

On another note:

If I recall correctly, they could land & launch Harrier's, but nobody liked to do it - because deck was not big enough and placed low, and there weren't any way for Harrier to took off other than "hover off to the rear end"?

 

[Rule of cool]

Exocet shaped charge warheads

Did the Exocet have a shaped charged warhead? I don't doubt it, the Martel had a Misnay–Schardin plate for armour penetration, close enough to a shaped charge.

 

[Dilandu]

Did the Exocet have a shaped charged warhead? I don't doubt it, the Martel had a Misnay–Schardin plate for armour penetration, close enough to a shaped charge.

Hm, I always assumed it did. At least it looks quite like that:



I assumed that those cavities on the warhead casting are shaped charge (or, to be exact, explosively-formed penetrator) cavities.

 

[uk 75]

Exocet was planned but not fitted.

https://www.secretprojects.co.uk/threads/1969-plans-to-fit-exocet-details-of-ships.13805/

 

[Dilandu]

Exocet was planned but not fitted.

By the way, were there any proposals to fit Sea Dart on them? Visually, it looks like there is enough space below forward 3-inch turret for magazines.

 

[uk 75]

I think there were too few Seadart sets available even for newly built ships. I suspect one reason they were removed from the three Invincibles was to use them as spares for the T42s. No new T42s were built to replace the two lost in the Falklands.

 

[NOMISYRRUC]

The only thing I object to was the cost and duration of their helicopter conversions, especially the 2nd one. That cost 20-25% of a new CVA01.

FWIW the cost of Tiger's conversion included the cost of the Wessex helicopters. Blake's cost didn't. The cost of a new CVA.01 didn't include the cost of her aircraft.

 

[EwenS]

I think there were too few Seadart sets available even for newly built ships. I suspect one reason they were removed from the three Invincibles was to use them as spares for the T42s. No new T42s were built to replace the two lost in the Falklands.

At the end of the Falklands War the RN still had 6 Batch 2 & 3 Type 42 under construction (commissioned July 1982 to Dec 1985) plus of course Ark Royal V. So was there really any need for more Sea Dart ships?

AIUI the principal reason for the removal of Sea Dart from the Invincibles was to create space for the enlarged air group and the need for more aircraft weapons to be carried. That happened in the late 1990s. Any reuse as spares for other ships was merely a by-product of that need to repurpose that space.

By then Bristol was a stripped training ship and Birmingham decommissioned in 1999 and was stripped of useable equipment.

 

[Dilandu]

AIUI the principal reason for the removal of Sea Dart from the Invincibles was to create space for the enlarged air group and the need for more aircraft weapons to be carried. That happened in the late 1990s. Any reuse as spares for other ships was merely a by-product of that need to repurpose that space.

Agreed, during Cold War such removal would be too dangerous.

 

[Rule of cool]

FWIW the cost of Tiger's conversion included the cost of the Wessex helicopters. Blake's cost didn't. The cost of a new CVA.01 didn't include the cost of her aircraft.

What a bunch of scammers, any combination of things can be bundled into the price to to prove whatever point that person wants. The CVA01 was bundled with CVA02 and 8 Type 82s to provide a vast cost to justify cancellation, but nothing about what might be spent the Command Helicopter Cruiser and Type 42 classes instead.

 

[A Tentative Fleet Plan]

Tiger class helicopter conversions were fine, they were an interim capability until the Command Cruisers could be built.

 

[Rule of cool]

Tiger class helicopter conversions were fine, they were an interim capability until the Command Cruisers could be built.

Given the cost and duration of their conversions and subsequent length of service do you consider them value for money, a good capability investment?

 

[1Big Rich]

Years ago on the Warships1/NavWeaps boards (I think in the Boards2Go days), the subject of Tiger in the Falklands came up. A member named Peter Parkinson, a veteran of the class, has this to say:

My answer is that a Tiger class cruiser would not have useful it would have been an absolute asset.
And a Tiger as it was before they built the shed on the back of it.
Forget the unreliability tag I had two years on a Tiger and the guns worked perfectly apart from slowing down the 3 inch to 90 rounds per minute per barrel.
As far as I know they still are the only RN ships capable of shooting down multiple simultaneous AA targets.
At the Subic Bay practice area we were invited to do a surface shoot with a USN Baltimore cruiser against a disused monastry on a hill side.
The USN cruiser fired for nearly an hour with 8 inch shells. All the hillside was covered in explosions and smoke. When the smoke disappeared the monastry was still there.
We fired four sighting rounds from one barrel on A turret. The fourth round hit the target. We then fired 9 more rounds and destroyed the target.
THis was at over 20000 yds range at a speed of 16 knots using the optical sight in A system director and an AFCB 10 in A TS

-Peter Parkinson, 10-12-2000 17:15

Regards,

 

[NOMISYRRUC]

Slightly off topic.

As far as I know the plan was to rearm Belfast with a number of twin 6in Mk 26 turrets in the 1950s. They powers that be wanted some twin 3in Mk 6 turrets too, but it couldn't be done for structural reasons and/or the magazines for the existing 4in guns were in the wrong place. Are those statements true? And if they are . . . how many 6in Mk 26 turrets were to have been fitted?

FWIW her actual 1950s refit took 3 or 4 years (1956-59 or 1955-59 as sources differ) and cost £5.5 million (the average cost of a Tiger was £14 million).

With hindsight the refit wasn't worth the time and expense because she was paid off in 1963 and is she had been rearmed too the waste of money would have been greater or in common with Superb IOTL the refit might have been abandoned. IOTL she was in reserve until 1970 (relieving Sheffield as Reserve Fleet HQ Ship, Portsmouth in 1966) and became a museum ship in 1971. Which is the only positive thing about the refit because she'd have been scrapped in the late 1950s as part of the Sandys Defence Review and therefore wouldn't have survived for long enough to become a museum ship. OTOH Sheffield might have been retained until 1970 and become a museum ship in 1971 instead of being scrapped in 1967. She saw more war service than Belfast and her post-war career was just as eventful as Belfast's. So she might have been a better choice.

 

[CV12Hornet]

Slightly off topic.

As far as I know the plan was to rearm Belfast with a number of twin 6in Mk 26 turrets in the 1950s. They powers that be wanted some twin 3in Mk 6 turrets too, but it couldn't be done for structural reasons and/or the magazines for the existing 4in guns were in the wrong place. Are those statements true? And if they are . . . how many 6in Mk 26 turrets were to have been fitted?

Two twin 6", with the 4" guns retained due to a lack of space for the 3" magazines.

 

[Hood]

The helicruiser conversions at least gave them some viable use, expensive though that might have been.
Perhaps in hindsight, losing the two beam 3in/70s to Sea Cats might have been a big loss, the guns might have been more effective at close-range AA defence.
Certainly a barrage of 3in over San Carlos would have had a lot of moral impact on the Argentine pilots, nobody likes flying through accurate flak like that.

As unmodified cruisers they would have been awesome NGFS, but of course that rather limits them for being useful for anything else in peacetime to justify the manning and operating costs. At least the Sea Kings provided some useful rationale to keep them going or its likely they would have vanished much sooner - possibly during the 1966-70 culls.

 

[Dilandu]

Perhaps in hindsight, losing the two beam 3in/70s to Sea Cats might have been a big loss, the guns might have been more effective at close-range AA defence.

They have little choice: enlargement of hangar to carry larger Sea King helicopter blocked 3-inch guns fire arcs to rear. There were simply no points to retain them, with their arcs of fire so limited.

 

[1Big Rich]

The helicruiser conversions at least gave them some viable use, expensive though that might have been.
Perhaps in hindsight, losing the two beam 3in/70s to Sea Cats might have been a big loss, the guns might have been more effective at close-range AA defence.
Certainly a barrage of 3in over San Carlos would have had a lot of moral impact on the Argentine pilots, nobody likes flying through accurate flak like that.

As unmodified cruisers they would have been awesome NGFS, but of course that rather limits them for being useful for anything else in peacetime to justify the manning and operating costs. At least the Sea Kings provided some useful rationale to keep them going or its likely they would have vanished much sooner - possibly during the 1966-70 culls.

I think there's the rub, Hood. Peter Parkinson was of the opinion the 6in mount was fine and reliable as long as it was maintained. Un-modernized and kept in reserve as gunfire support ships, experience in maintaining the 6in twin mounts would be sparse. As ASW cruisers with the hangar and Sea Kings, there would be cadres of experienced ordinance men on top of the 6in and 3in mounts.

Maybe if one were kept in service un-modernized to preserve that kind of institutional knowledge with the other two in reserve. Perhaps even a training role would suffice. They could rotate in the in-service cruiser as well to extend their lives.

Two twin 6", with the 4" guns retained due to a lack of space for the 3" magazines.

Little wonder space was lacking, even slowed to 90 rounds per barrel per minute in the twin 3in, the potential ammo usage must have been incredible.

Regards all,

 

[NOMISYRRUC]

Two twin 6", with the 4" guns retained due to a lack of space for the 3" magazines.

In that case I don't understand why rearming her was seriously considered in the first place as the combined rate of fire of the 12 existing 6in guns was about the same as the combined rate of fire of two twin 6in turrets.

 

[Dilandu]

In that case I don't understand why rearming her was seriously considered in the first place as the combined rate of fire of the 12 existing 6in guns was about the same as the combined rate of fire of two twin 6in turrets.

Because her existing turrets weren't dual-purpose. Their max elevation was limited to 45 degrees, so they can't engage high-flying target - while new dual-purpose QF Mark 5 turrets could be elevated up to 80 degrees. Their train rate was also only 7 degrees per second - while QF Mark 5 turrets were able to turn at 40 degrees per second. Finally, the existing guns could only be loaded at -5 to +12.5 angles - while QF Mark 5 turrets could be loaded at any angle.

So to put it simply - two QF Mark 5 turrets were two orders of magnitude more efficient against air targets than four old turrets.

 

[EwenS]

While the 1948 Staff Requirement for cruisers included modernisation of Belfast, Glasgow & Liverpool with 2x6" Mk 26 turrets as well as the Fijis & Swiftsures, it didn't last very long. By the end of 1949 that had been reduced to modernisation of 3 Towns noted.

The other 3 Towns, Newfoundland, Swiftsure & Superb would receive "large repairs", keeping their original main armament.

Plans for Glasgow & Liverpool were cut back to "large repair" in early 1952 then cancelled altogether by the end of the year.

By July1953 plans for Belfast saw her keeping her original turrets.

 

[NOMISYRRUC]

Slightly off topic.

As far as I know the plan was to rearm Belfast with a number of twin 6in Mk 26 turrets in the 1950s. The powers that be wanted some twin 3in Mk 6 turrets too, but it couldn't be done for structural reasons and/or the magazines for the existing 4in guns were in the wrong place. Are those statements true? And if they are . . . how many 6in Mk 26 turrets were to have been fitted?

Two twin 6", with the 4" guns retained due to a lack of space for the 3" magazines.

FWIW (1)

From Conway's 1922-46 and 1947-95.

579ft pp, 613ft 6in oa x 63ft 4in Edinburgh class.​

Belfast's beam was increased to 66ft 4in when bulges were fitted in her 1939-42 refit.​

538ft pp, 555ft 6in oa x 62ft Colony class.​

538ft pp, 555ft 6in oa x 63ft Swiftsure class.​

538ft pp, 555ft 6in oa x 64ft Tiger class.​

Therefore, no space for the 3in magazines despite Belfast being 41 feet (7.5%) longer than a Tiger (between perpendiculars) and only having 8 inches (1.04%) less beam than a Tiger.

I presume that there was no space for the 3in magazines for the port and starboard turrets as the above suggests that there was plenty of space for a twin 6in turret & a twin 3in turret forward (à la the Tiger class) and possibly there was enough space for a twin 6in turret & twin 3in turret aft too (instead of one twin 6in turret aft à la the Tiger class). That includes space for the magazines feeding the turrets in A, B, X & Y positions and for the extra MRS.3 director.

FWIW (2)

I still can't get into the Naval Weapons website, but IIRC the combined rate of fire of Belfast's twelve 6in guns was 72 rounds per minute and the combined rate of fire in Tiger's four 6in guns was 80 rounds per minute. Therefore, the considerable cost of replacing the existing guns would only have bought another 8 rounds per minute and my guess is that's why the existing main armament wasn't replaced.

However, I'm surprised that the original plan was to fit two 6in Mk 26 turrets because I think there was space forward for one in B position (instead of the twin 3in turret on the Tiger class) and possibly space aft for two turrets aft (instead of one on the Tiger class) for a total of three or four 6in Mk 26 turrets. That includes space for the magazines feeding the extra 6in Mk 26 turrets and for the extra MRS.3 directors.

 

[NOMISYRRUC]

I think there's the rub, Hood. Peter Parkinson was of the opinion the 6in mount was fine and reliable as long as it was maintained. Un-modernized and kept in reserve as gunfire support ships, experience in maintaining the 6in twin mounts would be sparse. As ASW cruisers with the hangar and Sea Kings, there would be cadres of experienced ordinance men on top of the 6in and 3in mounts.

I'm not sure if this supports your argument, but here goes. IOTL there were no Tiger class cruisers in commission between the end of 1966 (when Tiger paid off) and the recommissioning of Blake in 1969. The Tiger class as built had a crew of 716 and when rebuilt had a crew of 885.

Maybe if one were kept in service un-modernized to preserve that kind of institutional knowledge with the other two in reserve. Perhaps even a training role would suffice. They could rotate in the in-service cruiser as well to extend their lives.

The Cavendish class cruiser Frobisher was the cadet training ship 1945-47. She was followed by the County class cruiser Devonshire (1947-53) and the Colossus class aircraft carrier Triumph (1953-55). The 17th Frigate Squadron trained the cadets from 1955 to early 1972 when it was relieved by the LPD Fearless. She was still the cadet training ship when Argentina invaded the Falkland Islands.

Lion was in reserve at Devonport 1964-72 when she was put on the Disposal List and was broken up at Inverkeithing in 1975. In your timeline she could have been recommissioned as the cadet training ship in 1972 instead of Fearless or even relieved the 17th Frigate Squadron in 1964 instead of paying off.

However, the problem with that is Intrepid was paid off in 1976 as part of the Mason Defence Review (although she returned to service a few times while Fearless was refitting). That means there would have been no LPD in service between 1976 and 1982 to retain the institutional knowledge of amphibious operations. Before anyone says there RN still had Hermes & the RFA's LSLs during those 6 years (plus Bulwark 1979-81) I've allowed for that.

 

[NOMISYRRUC]

The helicruiser conversions at least gave them some viable use, expensive though that might have been.

On the other hand their crew as helicruisers weren't much less than Centaur class aircraft carriers operating in the ASW helicopter and commando carrier roles. Plus you get several times more helicopters at the expense of two 6in & two 3in guns per ship.

Centaur could have been recommissioned in 1969 as a commando/ASW carrier and kept in service until December 1979 instead of recommissioning Blake and then remained in service until 1981 instead of recommissioning Bulwark. Albion could have been kept in service until April 1978 instead of paying off in 1973 (when Hermes recommissioned) by not rebuilding Tiger and recomissioning her in 1972.

Perhaps in hindsight, losing the two beam 3in/70s to Sea Cats might have been a big loss, the guns might have been more effective at close-range AA defence.

I agree.

Certainly a barrage of 3in over San Carlos would have had a lot of moral impact on the Argentine pilots, nobody likes flying through accurate flak like that.

As far as I know the 6in guns could be used as AA weapons too. Imagine having a VT fused 6in shell exploding near you every 3 seconds. It would have been every second-and-a-half if they'd kept the aft 6in turret.

As unmodified cruisers they would have been awesome NGFS, but of course that rather limits them for being useful for anything else in peacetime to justify the manning and operating costs. At least the Sea Kings provided some useful rationale to keep them going or its likely they would have vanished much sooner - possibly during the 1966-70 culls.

I think they'd be good for flag showing in peacetime (which according to Dr Clarke is what the Servdlov cruisers did) and as suggested in another post one of them could have been the cadet training ship. Although, I think keeping Albion and Centaur in service for longer would have been a better investment due to having several times more helicopters for 100 to 150 more crew.

 

[NOMISYRRUC]

Is it true that the original raison d'être for Tiger class helicopter cruiser conversions was that they'd be commando cruisers instead of ASW cruisers? If that's correct does anyone know how many Royal Marines they'd carry? At the time it was standard practice for RN capital ships and cruisers to have a detachment of Royal Marines anyway. Does anyone know how many Royal Marines were part of the complement of 716 men when they were gun cruisers and 885 after their conversions to helicopter cruisers?

IIRC the number of RM commandos was increased from 3 to 5 as a result of the Sandys Defence Review. That was because paying off most of the big ships allowed the formation of the 2 additional commandos. Which was in spite of the total number of Royal Marines being reduced by a few thousand.

 

[NOMISYRRUC]

Part of the Opening Post.

Too small to receive Seaslug and too new to be scrapped as the County class GWDs entered service they became a quick fix to the RN's need to get big ASW helicopters to see.

Part of Post 89 from the thread "Different thought process for Post WW2 British Navy".

The proposed guided missile conversion of a Fiji class cruiser produced a ship with dimensions of 550ft wl, 556ft oa x 62ft with a twin Seaslug launcher and 2 Type 901 guidance radars. However, the rest of the armament was reduced to one triple 6in Mk 23 gun turret (in A position) & 2 twin 40mm L60 Bofors Mk 3 with STD and only 24 Seaslug missiles were carried & there was no extra protection for the missiles. That was in November 1954 and is according to Page 130 of Norman Friedman's "Postwar Naval Revolution".

If they could have fitted Seaslug to a Fiji class cruiser, they could have done it to a Tiger class cruiser, which was the same length and 2 feet beamier.

Whether it would have been worth the time and effort is another matter. However, my guess is that converting them to guided missile cruisers would have taken no longer than it did to convert Tiger & Blake to helicopter cruisers. But, converting them to guided missile cruisers would have cost more than the helicopter cruiser conversions.

 

[starviking]

If they could have fitted Seaslug to a Fiji class cruiser, they could have done it to a Tiger class cruiser, which was the same length and 2 feet beamier.

Whether it would have been worth the time and effort is another matter. However, my guess is that converting them to guided missile cruisers would have taken no longer than it did to convert Tiger & Blake to helicopter cruisers. But, converting them to guided missile cruisers would have cost more than the helicopter cruiser conversions.

I wonder if it would have been seen as of use at the time. The Counties would carry 4 Seaslug 1s and 4 Seaslug 2s in the fleet, and no plans eventuated to update the earlier Counties to Seaslug 2. I have to wonder if Seaslug was seen as approaching obsolescence, especially with Sea Dart in development.

That said, the idea of a RN Guided missile cruiser with an automatic 6-inch turret up front and 3x3-inch turrets for close-in defense make me fell starry-eyed!

 

[NOMISYRRUC]

I wonder if it would have been seen as of use at the time. The Counties would carry 4 Seaslug 1s and 4 Seaslug 2s in the fleet, and no plans eventuated to update the earlier Counties to Seaslug 2. I have to wonder if Seaslug was seen as approaching obsolescence, especially with Sea Dart in development.

That said, the idea of a RN Guided missile cruiser with an automatic 6-inch turret up front and 3x3-inch turrets for close-in defense make me fell starry-eyed!

The Fiji class conversion had to sacrifice the Mk 23 gun turret in B position and the eight 4in guns as well as the aft triple 6in turret(s) which reduced the gun armament to one triple 6in Mk 23 gun turret (in A position) & 2 twin 40mm L60 Bofors Mk 3 with STD. Therefore, my guess is that a Tiger class rebuilt as a guided missile cruiser would loose the port & starboard 3in turrets as an absolute minimum and probably loose the 3in turret in B position too. That's after allowing for the Tiger class being slightly beamier.

For what it's worth when Tiger & Blake were converted to helicopter carriers (1965-72) overlaps when the last pair of Counties was built (1966-70). It's also coincides with when France converted Colbert their last gun cruiser to a guided missile cruiser (1970-72).

However, as the rebuild of Tiger began in 1968 it might have been possible to fit her with Sea Dart and ADAWS-3 instead of Seaslug and ADAWS-1.

 

[DWG]

FWIW (1)

From Conway's 1922-46 and 1947-95.

579ft pp, 613ft 6in oa x 63ft 4in Edinburgh class.​

Belfast's beam was increased to 66ft 4in when bulges were fitted in her 1939-42 refit.​

538ft pp, 555ft 6in oa x 62ft Colony class.​

538ft pp, 555ft 6in oa x 63ft Swiftsure class.​

538ft pp, 555ft 6in oa x 64ft Tiger class.​

Therefore, no space for the 3in magazines despite Belfast being 41 feet (7.5%) longer than a Tiger (between perpendiculars) and only having 8 inches (1.04%) less beam than a Tiger.

I presume that there was no space for the 3in magazines for the port and starboard turrets as the above suggests that there was plenty of space for a twin 6in turret & a twin 3in turret forward (à la the Tiger class) and possibly there was enough space for a twin 6in turret & twin 3in turret aft too (instead of one twin 6in turret aft à la the Tiger class). That includes space for the magazines feeding the turrets in A, B, X & Y positions and for the extra MRS.3 director.

The 4" Magazines on the Edinburghs were forward of the machinery. If I'm interpreting the drawing in Friedman correctly, then the hoists were near the centreline, emerging aft of the boat deck, just forward of the octuple pom-poms, so roughly parallel with the centre 4" mount on each side. The guns were fed from the hoist by a deck mounted rail system. As the 3" was fed from a magazine directly below it (IIRC), you'd need some significant re-arrangement to fit them - possibly doable for the forward and middle mountings, but not for the aft ones.

 

[NOMISYRRUC]

The 4" Magazines on the Edinburghs were forward of the machinery. If I'm interpreting the drawing in Friedman correctly, then the hoists were near the centreline, emerging aft of the boat deck, just forward of the octuple pom-poms, so roughly parallel with the centre 4" mount on each side. The guns were fed from the hoist by a deck mounted rail system.

I wrote in Post 21.

As far as I know the plan was to rearm Belfast with a number of twin 6in Mk 26 turrets in the 1950s. They powers that be wanted some twin 3in Mk 6 turrets too, but it couldn't be done for structural reasons and/or the magazines for the existing 4in guns were in the wrong place. Are those statements true? And if they are . . . how many 6in Mk 26 turrets were to have been fitted?

I don't know what you mean here.

As the 3" was fed from a magazine directly below it (IIRC), you'd need some significant re-arrangement to fit them - possibly doable for the forward and middle mountings, but not for the aft ones.

By forward mountings do you mean forward of the bridge, i.e. A & B positions? And by aft mountings do you mean aft of the rear superstructure, i.e. X and Y positions? Because that's what I meant by forward and aft. The 3in guns in B and X positions would take the place of the triple 6in turrets in those positions and would take their ammunition from the already existing magazines that were below them.

And if you meant the twin 3in mountings in P1 and S1 positions of the Tiger class by the middle mountings these are the ones that couldn't be fitted to Belfast because (as you wrote in more detail) the magazines for the existing 4in guns were in the wrong place.

 

[BlackBat242]

FWIW (2)

However, I'm surprised that the original plan was to fit two 6in Mk 26 turrets because I think there was space forward for one in B position (instead of the twin 3in turret on the Tiger class) and possibly space aft for two turrets aft (instead of one on the Tiger class) for a total of three or four 6in Mk 26 turrets. That includes space for the magazines feeding the extra 6in Mk 26 turrets and for the extra MRS.3 directors.

The Mk XXIII triple 6" turrets in the Colonies weighed 174 tons each (weight of turret and below-decks rotating mass).
The Mk XXVI twin 6" turrets of the Tigers weighed 171 tons each (rotating mass).

Space and weight are one consideration... cost is something completely different.

The Mk XXVI turrets and their loading equipment were complex and very expensive - you could easily buy 4 Colony triple 6" turrets for the cost of two Tiger 6" turrets.

 

[DWG]

I don't know what you mean here.

By forward mountings do you mean forward of the bridge, i.e. A & B positions? And by aft mountings do you mean aft of the rear superstructure, i.e. X and Y positions? Because that's what I meant by forward and aft. The 3in guns in B and X positions would take the place of the triple 6in turrets in those positions and would take their ammunition from the already existing magazines that were below them.

And if you meant the twin 3in mountings in P1 and S1 positions of the Tiger class by the middle mountings these are the ones that couldn't be fitted to Belfast because (as you wrote in more detail) the magazines for the existing 4in guns were in the wrong place.

Everything I said was in relation to Belfast. There were (originally) three 4" mountings per side P1, 2, 3 and Q1, 2, 3; from the drawing in Friedman the hoists appear to be inboard of P2 and Q2, just off the centreline with P1, P3, Q1, and Q3 fed by rails from the hoists. P3 and Q3 may have been over the machinery spaces, and in any case had been deleted when upgrading the AA for the Pacific campaign. So to replace the existing mountings with 3" you need to rearrange the magazine spaces to feed from beneath the P2 and Q2 turrets, while P1 and Q1 will need completely new hoists, and potentially entirely new magazine spaces, and if you wanted to reinstate P3 and Q3 they would need the same, but that might be in the machinery spaces.

 

[Arjen]

Scan from Anatomy of the Ship - The Cruiser Belfast by Ross Watton, Conway 1985.
Shell hoists marked SH, immediately abaft catapult.
PM for bigger scan.