Could earlier arrival of No. 453 Squadron have saved Force Z?

[EwenS]

Two problems to overcome- aircraft availibility and aircrews to fly them.

Aircraft
150 Fulmar I built to end of 1940 when Mk II began coming off the production line. Then another roughly 340 Mk.II by the end of Sept 1941. Less of course losses to date from the Med operations, usual wear and tear etc.

Fulmars were being shipped overseas in late 1941 to both Egypt and Ceylon. There were enough on Ceylon by March 1942, to allow 273 squadron RAF to be equipped with 16, but I don't have arrival dates. What is clear is that Fulmars produced from July 1941 did end up in Ceylon by March 1942 273 squadron was manned jointly by RN & RAF personnel.

In summer 1941 the RN had a Naval Fighter Squadron (formed from 805, 803 from Formidable and 806 from Illustrious) in Egypt flying coastal convoy cover, latterly with RAF Hurricanes. These were scheduled to return to their parent carriers when those arrived back in the Eastern Med following their US repairs. Of course that all changed on 8th Dec 1941.

At the end of Feb 1942, 803 & 806 were withdrawn to re-equip each with 12 Fulmars which they then flew down to Ceylon arriving at the end of March.

Crews
The FAA was only just beginning to see the results of its expansion programme in the latter part of 1941 allowing more Fulmar squadrons to be formed, following the surviving squadrons of the initial batch in 1940.

The latter were located as follows in Aug / Sept 1941:-
800 - on Indomitable
803 - see above
804 - providing Fulmars & Sea Hurricane Ia to Fighter Catapult ships
806 - see above
807 - Ark Royal
808 - Ark Royal

Summer 1941 the new FAA fighter squadrons received Martlets and Sea Hurricanes and were destined to fly from Indomitable, Formidable & Illustrious and the first escort carriers as they came into service in 1942. The next batch of Fulmar squadrons were:-

884 - formed 1 Nov 1941 with 6 aircraft
886 - formed 15 March 1942 with 6 aircraft
889 - formed 16 March 1942 in Egypt with 12 aircraft. Formed from an RN Fighter Flight working with the RAF.
887 - formed 1 May 1942 with 6 aircraft

Ark cannot be released from Force H until a replacement arrives i.e. Indomitable. That wasn't even scheduled to happen until the end of Nov.

Then we come to the transport issue. If the decision is made on 28th Sept 1941 then it is going to be weeks before a ship is ready to sail. . A shipping movement like that has to be planned, a suitable ship(s) found (can't just be whistled up at the drop of a hat given the immense problems managing shipping movements at the time), allocated to a convoy, aircraft to be packed for the journey, transported to the dockside, loaded etc.

What "fast transport" are you thinking about? Even ships like the aircraft transports HMS Athens & Engadine were only capable of 17 knots. Also it wouldn't be an independent sailing if the cargo was that important. At best it would be sailing as part of one of the "fast" WS convoys. There were faster ships, but they were generally allocated as troopships without the necessary cargo space, hatch sizes etc to ship packaged aircraft.

The WS convoys were then:
WS11 - sailed 30 Aug 1941. Too early for your plan.
WS12 - sailed 30 Sept 1941. Again too early for your plan.
WS12Z - sailed 12 Nov 1941. This convoy took 7 RAF Hurricane squadrons some of which ended up on Malta via Gibraltar in Nov with other parts reaching Java, Burma and Singapore Jan / Feb 1942. It reached Durban on 18th Dec.

The alternative is one of the slow OS convoys to Freetown and then maybe an independent passage thereafter.
OS8 - sailed 3 Oct 1941 & reached Freetown on the 26th
OS9 - sailed 13 Oct & reached Freetown on 5th Nov
OS10 - sailed 25 Oct & reached Freetown on 18 Nov.

"Fast" is entirely relative. WS12 for example made just 13 knots when it left British waters, being slowed to 11 knots by wind and weather when it passed the Azores. Its average to Freetown was 11.73 knots. Individual troopships (ex cargo liners) might have been faster but you need a ship or ships with adequate cargo space for the large boxes these Fulmars are going to be packaged up in, and to cope with the numbers you envisage. WS12Z managed 14 knots leaving Britain, with a later split near Freetown allowing a fast section to proceed at 16 knots while the slow section advanced at 13 knots.

Incidentally WS12Z included the SS Sussex that delivered those 50+ Hurricanes to Singapore in mid-Jan 1942.

So in the overall scheme of things your latest plan seems to me like a no go.

 

[Admiral Beez]

If not Fulmars, what could the FAA send? Sea Gladiators don't seem up to the task. Sea Hurricanes must be short supply. Skuas and Rocs from mothballs?

 

[EwenS]

It is possible that such a force could have been useful. Assuming of course that such a force was actually available, and the trained crews (ground crew and air crew) were available.

However,
"By October 1941, the Fairey Aviation Company had built roughly 500–600 Fulmars, with production continuing at a healthy rate, so aircraft should be available."
maybe in error. Fairey built 600 Fulmars by the end of Dec 1942.
The First 250 planes were Fulmar Is with the 1080hp engines they were bog slow.

First order for Fulmar 127 Mk.I
Second order for Fulmar 123 aircraft built as 23 Mk.I & 100 Mk.II. Mk.II from serial N4017 delivered Dec 1940 to 778, the RN Service Trials Unit with 809 receiving them in Jan 1941.
Third order for 200 Fulmar II with first deliveries in April 1941
FAA Aircraft 1939 to 1945
Squadrons and Units of the FAA.

The first Production Fulmar IIs start to show up in March 1941 with the 1300hp Merlin 30s.

See above

Having 30 Mk IIs available in Sept 1941 is looking a bit dubious. FAA needs to replace the MK Is on existing carriers and forward land bases as fast as possible.

The whole Force Z plan was dubious at best and triumph of racism/wishful thinking/stupidity at worst.
Granted not a lot was known about Japanese capabilities in 1937-42 but what was known seems to have been ignored. The Idea of sending one new battleship and one old, crappy battlecruiser (with just about no back up/escorts) to "scare" the Japanese just seems incredibly stupid.
Japanese had 6 battleships and 4 battlecruisers (Yamato was unknown) Unknown is how many they were committing to use against the Americans and in what order.
Japanese had 12 Cruisers with 8in guns (Mogami gun swap was not known), British sent zero cruisers and were possible going to 'borrow" a few cruisers from the Indian Ocean convoy escort duty?
British knew that all/most of the Japanese capitol ships had refits or at least boiler swaps.above

They knew they had been remitted but not that for example the Kongos were longer and faster than the believed 26-27 knots in Jane's Fighting Ships 1938 & USNI books as late as 1942.

British knew that the Japanese carriers could carry a lot more planes than the British carriers could.

Until 1942 the Shokakus were still believed to be repeat Hiryu at the original 10,000 ton design.

How good the planes were is questionable but then the British were still using a lot of biplanes on their carriers.

British Intelligence had reasonably accurate information on Japanese aircraft, including the Zero, including range and weapon load. Seems no one read it. It was recirculated in mid-Dec 1941. Only aircraft missing was probably the Ki43 Oscar which was only reaching front line service in Aug / Sept 1941.

Japanese had been fighting in China for years.
How long would it take for the Americans to come across the Pacific if the Japanese attacked the Philippines?

Months if not years.

The IJN intended to attrite them as they moved across the Pacific. But the US knew from War Plan Orange planning that they lacked to support back to move the fleet rapidly west against opposition. As in WW2 it meant capturing Japanese occupied islands along the route, to remove things like their air bases. In Dec 1941 they had only something like 8 replenishment oilers in the Pacific, only half of which were fast enough to accompany the 4 carriers present by the end of the year.

The Philippines were just supposed to hang on as long as possible. In the end they lasted a lot shorter time than was ever envisaged in War Plan Orange.

The Japanese had several months to beat up on the British and Dutch before the great American battlefleet shows up if there is no Pearl Harbor, leaving the Japanese free to battle the Americans without worrying about the British token force in their rear. White man's superiority was only going to go so far.

The Fulmars offer a limited capability for limited missions.
Yes Fulmars were sent to Ceylon in March of 1942? but that is 5-6 months later. A lot changed in those 5-6 months.

Two Squadrons of Blenheim fighters could have done about as well as Fulmars. They might have been as useful (or more useful) as recon planes.

The whole Force Z thing was a fiasco waiting to happen. The "escort" of 4 destroyers was a bad joke. Even the 2nd best DD didn't have the range to high speed steam from Singapore to the gulf of Thailand and back to Singapore and the old S class boat really showed that when it left early due to low fuel.

 

[EwenS]

If not Fulmars, what could the FAA send? Sea Gladiators don't seem up to the task. Sea Hurricanes must be short supply. Skuas and Rocs from mothballs?

Simply put, Nothing.

Even if you can find the aircraft there is the question of the pilots to man them.

Fighter pilot training from the day an individual walked through the gate at the stone frigate HMS St Vincent at Gosport to reaching a front line squadron took over a year. For Mike Crosley (21 Course) it was from 11/12 November 1940, day of Taranto, to Jan 1942. For Hank Adlam (26 Course) it was from 3rd Jan 1941 to May 1942, but his was extended by a few months by a temporary posting to a second line squadron flying target tugs like Skuas. Both undertook their operational fighter training in 1941 on Hurricanes not Fulmars.

From 1938 the RN had begun increasing its intake of potential aircrew and ramped it up further after the outbreak of WW2. But most suitable candidates wanted to join the RAF. Crosley volunteered for the FAA after waiting some time for his call up for the RAF. Basically he got fed up and wanted into the war sooner or later.

 

[Shortround6]

Thank you for the corrections and additional information.

They knew they had been remitted but not that for example the Kongos were longer and faster than the believed 26-27 knots in Jane's Fighting Ships 1938 & USNI books as late as 1942.

That is true, Western knowledge of what the Japanese were doing was very sparce/error prone.
However they knew what the Japanese were allowed by treaty. They knew what they had done to their on ships in rebuilds and they knew that the Japanese cheated on the treaty limits.
Question is now by how much and cheated with how many ships.
You can do a lot with an additional 3000 tons for improvements; you can do a lot more if the new boilers are hundreds of tons (into four figures) lighter than the old boilers even if you keep the old turbines.
At some point the British were estimating the Nagato's at 25-26knots and not the original 23 knots. Speed estimates for the older 14 in ships may not have been increased enough?
Changes in elevation of main guns should have been a given, how much was the question.
AA guns were brought up to pretty much the 'standard' eight 4-5in heavy guns for old ships. Japanese did not do the Italian style rebuilds.
Repulse did not even get that. Six 4in AA guns (and not well sited) left her vulnerable although the three quad pom-poms were above average in 1941.
Repulse also did not get the change to 30 degree elevation for the main guns and does not seem to have gotten the 6 caliber shells or the modifications to the fire control system to use them. max range 24,500yds (?)
Hits at over 24,000yds were extremely rare for anybody but this was not known in the late 30s or early WW II. All of the Japanese 14in gun ships could easily out range the Repulse even before the later refits that increased elevation.

Until 1942 the Shokakus were still believed to be repeat Hiryu at the original 10,000 ton design.

This seems to have a real failure of intelligence as the Soryu/Hiryu were 16-17,000 tons standard. Four 16,500 ton ships are vastly different than four 10,000 ton ships.
The Soryu/Hiryu pair could carry as many planes as four Zuiho's.

British Intelligence had reasonably accurate information on Japanese aircraft, including the Zero, including range and weapon load. Seems no one read it. It was recirculated in mid-Dec 1941. Only aircraft missing was probably the Ki43 Oscar which was only reaching front line service in Aug / Sept 1941.

I was thinking more along the lines of the strike aircraft. While the Val and Kate had both shown up in China. The Val didn't show up until 1940 and it might not have been appreciated that they carrier aircraft and not land based. Could be wrong about that. The A5M4 was not a big enough jump to raise large flags. The A6M2 was but people did not notice.

The US "Battlefleet" got the least amount of improvements between WW I and WW II but the work was still substantial with increased elevation and new boilers and protection even if no change in speed. But the US Battlefleet was split with only 8 ships at Pearl and five or more in the Atlantic before the North Carolina's showed up. Odd ones were undergoing refit.
Collecting a 12-15 BB ship fleet at Pearl was going to take months even without trying to gather up the smaller ships and support ships.

 

[EwenS]

A lot to unpack in post 25 by Shortround 6.

Gun elevation
The USN went from 15° elevation to 30° with the 14" in the Tennessee class laid down in May 1917. It was the Nevada through New Mexico classes that had their elevation increased in the 1930s. That increase effectively leapfrogged the RN who had used 20° since before WW1 with the 13.5" ships, QE and R classes. The RN moved to 20° 30° with Hood.

As for the RN not increasing elevation before Warspite, the reason lies in a dispute between the RN and the USN regarding whether or not increasing the elevation increase was or was not a breach of the Washington Treaty provisions. In the end the RN dropped the issue as they were presented with a fait accompli. Unfortunately that was too late to be incorporated into the large repairs carried out on Malaya, Repulse & Royal Oak.

More to say on this tomorrow. Battery on tablet is about to expire!

 

[EwenS]

To continue.

From Navweaps site

"There is some question as to whether Repulse was modified to use 6crh APC projectiles and supercharges. "British Battleships 1919-1945" by Burt states that she was so altered in an entry dated "25.6.1941" (pg. 228) and says that she was under refit between June and August 1941 at Rosyth (pg. 237). These dates are incorrect as on 25 June 1941 she was at sea escorting a convoy and did not actually dock at Rosyth until 23 July 1941. There, she did a brief refit to prepare her for operations with the East Indies Command. She undocked on 10 August and then departed Rosyth for Scapa Flow on 15 August, meaning that this refit lasted about 3 weeks. As noted above, DNC had previously stated that it took about 6 to 8 weeks to make the modifications required to use 6crh projectiles. As an alternative explanation for the 25 June 1941 date, this may have been when the DNC entered a list of proposed modifications to the Ship's Cover and not the actual refit date. Burt also notes (pg. 234) that a later refit in the USA planned for September 1941 would have included alterations for using the longer HE 6crh projectiles, but this refit was cancelled and she was instead sent to Durban and then on to Singapore. In contrast to Burt, "Naval Weapons of World War Two" by Campbell states (pg. 25) that Repulse was not modified to use 6crh shells and "British Battleships 1906-1946" by Friedman states (pg. 282) that changes to her armaments during the war were limited to replacing the after 4"/45 (10.2 cm) triple mounting with an Octuple 2-pdr. mounting and the addition of eight single 20mm mountings."

And

"Super charges were only given to ships with a 20 degree maximum gun elevation and had been modified to use 6crh shells. Super charges were authorized for Malaya and the four surviving Royal Sovereign class in late 1941. However, as noted above, at least Ramillies and possibly Revenge were never modified to use 6crh shells and thus they would not have been given super charges. As described below in the Turret / Mounting section, the mountings on Vanguard were strengthened to withstand the stresses caused by firing super charges, but she never carried them during her career. Super charges were supplied at the rate of twenty per gun for all ships. As these super charges were larger than the standard ones, the passing scuttles were enlarged to accommodate them. Using these super charges was not problem free. As noted in "The British Battleship: 1906 - 1946" by Friedman (pg. 277-278):

"Ships would incur increased stresses on ring bulkheads when using the supercharges. DNC pointed out that the ships' structures were old and had probably deteriorated, Repulse being the most critical. Firing trials on board Malaya on 31 July 1941 showed deflections about 60 percent greater than normal, so DNC suggested that two-gun salvos not be fired, particularly from 'B' turret of Repulse. If that were impracticable, a limited number of two-gun salvos could be fired, but preferably not from 'B' turret of Repulse."

"
So It seems unlikely that Repulse was equipped with the 6crh shells and even less likely she received the supercharges to make maximum use of them.

 

[EwenS]

Links to online version of Jane's Fighting Ships 1938 edition Japan starts at p299

View: https://www.scribd.com/doc/84063027/Jane-s-Fighting-Ships-1938#page=280

USN ONI book on Japanese ship characteristics updated to Oct 1942

https://www.ibiblio.org/hyperwar/NHC/NewPDFs/USN/ONI%20Recognition%20Manuals%20and%20other%20material/ONI%2041-42.Japanese.Naval.Vessels.pdf

 

[Shortround6]

Thank you for the link.
I do have a Jane's from 1942 and they didn't change much on the Japanese pages. Although ships that were war losses are deleted.
I do note that Janes shortchanged the larger Japanese carriers in aircraft carried by quite a bit.

Basic point is that the Repulse was not that great a ship to use for Force Z and that Force Z was bluff in any case. The Japanese called the bluff.

We have gone through several threads discussing what the British could have to done to save Force Z but with hindsight we know where Force Z was attacked and can tailor our 'solution' to fit the circumstances. We also know what forces the Japanese had that area on Dec 8th which the British had no clue of when the ships were ordered to go there.

Was Force Z supposed to defend Singapore or was it supposed to deter Japanese aggression in the area and if so how big was the area?
Was Force Z supposed to help defend Borneo? With or without cooperating with the Dutch?
British were cooperating with the Americans in strategy but figuring out what the Japanese plans were is the question. Japanese attack on Peral was a real surprise. But the ships used at Pearl if sent to the Philippines and DEI instead would have wiped out the British, Dutch and American naval forces in very short order. Well before any American rescue/relief force could have arrived.

 

[Geoffrey Sinclair]

Fulmar I at 10,000 feet, with 131 gallons of fuel, with 50 minutes allowance, maximum speed 253 mph, 8 Browning with 500 RPG
range 508 miles, endurance 2.23 hours at 228 mph
range 660 miles, endurance 3.88 hours at 170 mph
The mark I used 87 octane, for 1,035 HP (1,080 with 100 octane), the mark II 100 octane for 1,300 HP, expect it to have less range and endurance, mark I force Z cover, 2 hours flight time, 30 minutes reserves, 1.38 hours patrol time.

RAF contract cards have contract 752200/38 requisition 1/38 for 250 Fulmar built as 150 mark I and 100 mark II (N serials, last mark I N4016, first mark II N4017) contract 101971/40 requisition 1/E1/40 for 250 Fulmar, (X and DR633 to 682 serials), another 100 added 5 July 1941 (DR700 to 749, BP serials in that order), Admiralty requisition 20/E1, RAF E1A.

150 Fulmar I built April to December 1940
Fulmar II production December 1940 to December 1941, monthly 9, 32, 30, 21, 19, 28, 28, 33, 27, 27, 32, 20, 18, total 324, another 121 January to November 1942, 5 more February/March 1943, total 450 mark II.

4 Merlin VIII built March/April 1939 then 180 built November 1939 to December 1940
660 Merlin 30 built November 1940 to July 1942

Lots of RN aircraft movements out of Britain were as part of units and so not counted as exports, official Fulmar exports were

month	Ceylon	Far East	India	Kenya	Mediterranean	Middle East	South Africa	Trinidad	Total
Oct-40​						11​			11​
Nov-40​						1​			1​
Dec-40​						9​			9​
Jan-41​						7​			7​
Feb-41​					4​	3​			7​
Mar-41​						26​			26​
Apr-41​						16​			16​
May-41​					6​	12​			18​
Jun-41​					6​	24​			30​
Jul-41​					6​	23​			29​
Aug-41​					4​	10​			14​
Sep-41​					7​	18​			25​
Oct-41​	2​	4​			4​	2​			12​
Nov-41​	3​				3​				6​
Dec-41​	7​	4​							11​
Jan-42​		4​			10​				14​
Feb-42​	7​				3​	1​			11​
Mar-42​	8​			3​	1​				12​
Apr-42​					2​		6​		8​
May-42​					2​	3​	3​		8​
Jun-42​							15​		15​
Jul-42​			2​	3​					5​
Aug-42​							1​		1​
Sep-42​			1​	1​					2​
Oct-42​				7​					7​
Dec-42​				1​					1​
Aug-43​								2​	2​
Sep-43​								3​	3​
Dec-43​								2​	2​
Feb-44​								2​	2​
Total	27​	12​	3​	15​	58​	166​	25​	9​	315​

Remembering these are departure dates from Britain.

Lots of British exports in 1940/41 were for setting up the training systems in Canada, Southern Africa, Australia and New Zealand, in terms of mostly combat types in 1941, 241 to Mediterranean, 2,061 to Middle east, 857 to USSR out of 6,206 exports for the year.

The idea of force Z as propounded by Churchill was a fast raider force able to threaten a large area, rather like Tirpitz. The Admiralty wanted a battle line, the 4 R class for a start. The Japanese struck while the RN was still moving forces into position. The US agreed if it was attacked it would send at least its destroyers present in the area to join the RN.

Martlet I at 15,000 feet with 136 gallons, 690 miles, 2.7 hours at 257 mph, 845 miles, 5 hours at 165-175 mph, 71 imports into UK August to December 1940 plus 9 mark II in May 1941, no further imports until January 1942, first arrivals at Mombasa May 1942.

 

[EwenS]

Thank you for the link.
I do have a Jane's from 1942 and they didn't change much on the Japanese pages. Although ships that were war losses are deleted.
I do note that Janes shortchanged the larger Japanese carriers in aircraft carried by quite a bit.

Basic point is that the Repulse was not that great a ship to use for Force Z and that Force Z was bluff in any case. The Japanese called the bluff.

We have gone through several threads discussing what the British could have to done to save Force Z but with hindsight we know where Force Z was attacked and can tailor our 'solution' to fit the circumstances. We also know what forces the Japanese had that area on Dec 8th which the British had no clue of when the ships were ordered to go there.

Was Force Z supposed to defend Singapore or was it supposed to deter Japanese aggression in the area and if so how big was the area?
Was Force Z supposed to help defend Borneo? With or without cooperating with the Dutch?
British were cooperating with the Americans in strategy but figuring out what the Japanese plans were is the question. Japanese attack on Peral was a real surprise. But the ships used at Pearl if sent to the Philippines and DEI instead would have wiped out the British, Dutch and American naval forces in very short order. Well before any American rescue/relief force could have arrived.

The point regularly missed and seemingly so again, is that Repulse was not dispatched from Britain as part of Force Z. She was the first step in an intended build up in the Indian Ocean that was intended to be complete by about April 1942. This was planned in Aug 1941. She was to be followed by the four R class as they completed their refits. On the way out they were intended as heavy escorts to WS convoys:-

Revenge - joined WS10 X at Freetown on 1 Sept (convoy left Britain in mid-Aug 1941)
Repulse - sailed with WS11 at end of Aug 1941
Royal Sovereign - sailed with WS12Z in mid-Nov 1941 (there was no WS13 for obvious resons!!!)
Ramilles - sailed with WS14 in Dec 1941
Resolution - sailed with WS15 in Jan 1942

Had she survived, Ark Royal was intended as part of the IO build up in 1942.

The decision to send PoW was taken at the end of Sept 1941 and she was dispatched with a destroyer escort as Force G. Initially PoW was to go to Cape Town before a decision was made about future movements. She was ordered on to Ceylon on 9th Nov after just 48 hours in that port. It was only on 11th Nov that Repulse was ordered to go to Colombo (after completing her IO escort duties and refuelling at Mombasa). It was 29th Nov before the two ships rendezvoused off Ceylon to sail to Singapore. Force G didn't become Force Z until after it arrived at Singapore on 2nd Dec.

So while Force Z is usually thought of as a single deployment it was two separate deployments driven by different thinking, until the two ships met up.

The object of sending PoW was deterrence. When she reached the IO, it was a question of pairing her with Repulse or Revenge, as the other Rs had still to arrive.

It is all laid out in Boyd "The Royal Navy in Eastern Waters. Linchpin of Victory 1935- 1942". Beyond that there was no plan as to how to use Force Z.

 

[Shortround6]

The idea of force Z as propounded by Churchill was a fast raider force able to threaten a large area, rather like Tirpitz. The Admiralty wanted a battle line, the 4 R class for a start. The Japanese struck while the RN was still moving forces into position.

The Renown, with new boilers and turbines (and larger fuel tanks) could travel over 50% further than the Repulse with her older machinery.
As EwenS has pointed out, this does not seem to a well thought out plan but rather a thrown together "force" with no real idea of how to operate or even where it was supposed to operate (what were it's limits).
The Idea of using 2-3 ships to 'deterring' an enemy that had 10 capitol ships is laughable if it wasn't so tragic.
Sacrificing several ships in the short term to inflict sizable losses on the enemy so you have an advantage in a later battle might be a good idea but you need a closer match than 4-5 to 1.

Using the 4 Rs as a battleline is not a good idea. Or is only good if you think the Japanese aren't very good. The Rs had very little work done to them between the wars and were slow. At least 2-3 knots slower than any Japanese battleship and perhaps 4-5 kts slower. How much was known to the British is subject to question.
Japanese 14 in guns were built with 25 degrees of elevation and were modified twice. Once to 33 degrees and later to 43 degrees. How useful the last was is subject to question but there is no doubt the Japanese 14in guns could out range the 15in guns on the Rs (getting hits is different) even without the 43 degree elevation.
The two Nagato's had 16 in guns that started at 30 degrees elevation, How much the British knew is subject to question but it seems they knew these ships at least had new boilers and they could guess at what that could mean in increase protection even if not higher speed.
4 Rs means 32 big guns while the 6 Japanese BBs carried 48 14in and 16 16in guns with the Kongos off somewhere else. Odds do not look good for the British.

The US agreed if it was attacked it would send at least its destroyers present in the area to join the RN.

And what did the Americans have for destroyers present in the area?
Sounds good but when the Japanese attacked the Americans had one heavy cruiser, one light cruiser and a whopping 12 destroyers in the Asiatic fleet. All ex WW I Clemson class 4 stackers. Good torpedo armament (used older torpedoes without the problems of the newer torpedoes) but crap gun armament and the AA armament was slightly better than waving their hats at attacking aircraft.

A decent plan for Force Z and whatever American ships could join should have been more than showing they could die gallantly.

 

[EwenS]

Regarding Soryu her design changed immensely over time. After a bit of juggling with carrier Treaty limits and using up the Hosho tonnage (experimental so replaceable any time), the IJN figured they had 20,100 tons to play with in 1933 enough for two ships. From that came design G8 with the folowing characteristics:-

Standard displacement - 10,050 tons
Speed 35 knots
Aircraft (+ reserves) - 24 fighters, 48 dive bombers. Total 72 (But probably some broken down in reserve).
Armament - mix of LA and HAA guns.

While most sources say that Soryu was laid down in Nov 1934, Katherin Milanovich in an article in Warship 22 noted that even before she was authorised work began in early 1934 on the "manufacture of the frames, hull plating and armour plates".

Under the 1922 Washington Treaty, navies were to advise other signatories "promptly" of authorisation dates, laying down dates and principal characteristics. (Part 3 Section 1 para a)

Then in March 1934 Japan suffered the Tomozuru incident and that caused suspension of work on Soryu and new stability margins to be computed and the whole design revised. The result was a shorter, narrower ship with a deeper draught and greater displacement. This was design G9 to which Soryu was built.

Standard displacement - 15,900 tons
Speed 34.5 knots
HAA / LAA guns only
Fighters 12(+4)
TB 9 (+3)
Recce 9 (+0)
Dive bombers 27 (+9)
Total 57 (+16)

Then by the end of Dec 1934, Japan gave the two years required notice that it would leave the Treaty system at the end of 1936.

So It seems that Japan reported something closer to the old G8 design. Whether this was a breach of the Treaty or not would depend on the timing of those disclosures viz a viz the G9 design becoming available. As Soryu didn't complete until after Japan left the Treaty system no further reporting of her size at that point was required.

Hiryu was a modified G9 design.

 

[EwenS]

With regard to Repulse's HAA armament, she missed out on the late 1930s upgrading, but was not alone amongst RN ships.

In 1933/34 The standard HAA armament on capital ships and cruisers was 4 x 4" in single mounts. The Abyssinian Crisis of 1935/36 revealed weaknesses in the Fleet's AA defences that led to a programme to improve them, mostly by replacing single 4" with twins.

Repulse went into her April 1933 to May 1936 large repair with 4 single 4" and came out with those plus two prototype between deck 4" twins. (These were part of a development programme towards the twin 4.5" fitted in later reconstructions and other ships). The latter were short lived and quickly replaced by 1937 or 1938/39 with a pair of single 4", to bring Her total to six. Her last pre-war refit was for 4 months to Jan 1939. After that dockyard periods were minimal. A month in Feb / Mar 1940 probably for weather related damage while supporting the Northern Patrol (winter 1939/40 was particularly harsh in the Atlantic and a lot of RN and merchant vessels suffered weather damage). Oct 1940 three weeks at Rosyth for a bottom scrape (She had lost a lot of speed). 17th Feb 1941 to 3rd March 1941 first refit for 23 months (But not much time to do anything significant). 19th July -15th Aug refit at Rosyth. Then off to the Far East at the end of the month. She put in a LOT of seatime in WW2.

Royal Oak completed a modernisation in Aug 1936 and Malaya in Dec followed by Warspite in June 1937. All received twin 4" in place of their earlier singles. This was still too early for the 4.5" gun which design only began in 1935 and began to be fitted from 1938, in time for the reconstruction of Valiant, Renown & QE.

Hood only saw her four single 4" upgraded to twins in a Feb - June 1939 refit. Those were augmented in a Mar-Jun 1940 by another three twins.

There were still cruisers running around to the mid-war period with single 4". Achilles didn't get the upgrade until her 1943/44 refit, Arethusa until early 1942, Australia until late 1940, Devonshire & Sussex until late 1942, Shropshire until late 1941, (although the last three had 8 singles before that).

The 4" twin Mk.XIX mounts were in extremely high demand as WW2 approached and throughout the war (in summer 1945 they were being recycled from ships being laid up to new construction). As well as rearming capital ships and cruisers it was the main armament of Hunt class destroyers (first completion March 1940) and Bittern / Black Swan class sloops as well as numerous AA ship conversions (cruiser and auxiliary) as well as Tribal class DD as replacement of one twin 4.7" mount.

So to improve Repulse's AA armament you need to find the time for a reasonable refit then find the gun mounts.

 

[SaparotRob]

The Renown, with new boilers and turbines (and larger fuel tanks) could travel over 50% further than the Repulse with her older machinery.
As EwenS has pointed out, this does not seem to a well thought out plan but rather a thrown together "force" with no real idea of how to operate or even where it was supposed to operate (what were it's limits).
The Idea of using 2-3 ships to 'deterring' an enemy that had 10 capitol ships is laughable if it wasn't so tragic.
Sacrificing several ships in the short term to inflict sizable losses on the enemy so you have an advantage in a later battle might be a good idea but you need a closer match than 4-5 to 1.

Using the 4 Rs as a battleline is not a good idea. Or is only good if you think the Japanese aren't very good. The Rs had very little work done to them between the wars and were slow. At least 2-3 knots slower than any Japanese battleship and perhaps 4-5 kts slower. How much was known to the British is subject to question.
Japanese 14 in guns were built with 25 degrees of elevation and were modified twice. Once to 33 degrees and later to 43 degrees. How useful the last was is subject to question but there is no doubt the Japanese 14in guns could out range the 15in guns on the Rs (getting hits is different) even without the 43 degree elevation.
The two Nagato's had 16 in guns that started at 30 degrees elevation, How much the British knew is subject to question but it seems they knew these ships at least had new boilers and they could guess at what that could mean in increase protection even if not higher speed.
4 Rs means 32 big guns while the 6 Japanese BBs carried 48 14in and 16 16in guns with the Kongos off somewhere else. Odds do not look good for the British.

And what did the Americans have for destroyers present in the area?
Sounds good but when the Japanese attacked the Americans had one heavy cruiser, one light cruiser and a whopping 12 destroyers in the Asiatic fleet. All ex WW I Clemson class 4 stackers. Good torpedo armament (used older torpedoes without the problems of the newer torpedoes) but crap gun armament and the AA armament was slightly better than waving their hats at attacking aircraft.

A decent plan for Force Z and whatever American ships could join should have been more than showing they could die gallantly.

What kind of hats?

 

[EwenS]

There seems to be an assumption the Japan would deploy its entire capital ship fleet against Britain in the South China Sea. Historically that is not what happened and for very good reasons. The actual dispositions on the outbreak of war were as follows:-

Pearl Harbor attack - 2 x Kongo fast battleships
Malaya / Thailand - 2 x Kongo fast battleships

BatDivs 1 (Nagato, Mutsu) & 2 (Ise, Hyuga, Yamashiro & Fuso) were sortied towards the Bonins (Iwo Jima area south of Japan) between 8th & 13th Dec 1941 to cover the return of the PH strike force in case the USN Pacific Fleet trailled it home. These ships then remained in Japanese waters until they were sailed ahead of Midway. The only exceptions were a couple of brief sorties by some of them to intercept US carrier strikes (Marcus Island raid in March & Doolittle raid in April).

The IJN was conscious that it had to protect its back door. If it simply attacked the DEI and sent everything in the direction of Malaya it was exposed to the US Pacific Fleet battleships and it couldn't guarantee the USA staying out. Remember the primary targets for the PH operation were the carriers which were absent (Utah, berthed at a carrier mooring was mistaken for one). Only after that the battleships. Had PH gone differently the IJN needed to retain something to protect the homeland.

And the damage inflicted on the USN battleships at PH was no where near as bad as usually portrayed. Of the 9 Pacific Fleet battleships, Colorado was on the West Coast refitting, repairs to Pennsylvania were complete by mid-Jan, Tennessee and Maryland by late Feb. And that before considering the transfer of the three New Mexicos to the Pacific in Dec 1941 / Jan 1942.

 

[Shortround6]

What you say is true but then we have the advantage of hindsight which the British did not have in the fall of 1941. On the other side we have the advantage of hindsight to know that the Americans, even if not hit by the Japanese at Pearl, cannot head for an undefended Japan starting Dec 7-10 due to supply issues.

There seems to be an assumption the Japan would deploy its entire capital ship fleet against Britain in the South China Sea. Historically that is not what happened and for very good reasons. The actual dispositions on the outbreak of war were as follows:-

Again, the British do not know (we think) of the Pearl Harbor plan when they come up with the Force Z 'plan'. If the Japanese do not do the Pearl harbor attack what sort of disposition could they have used against the British, Dutch and Americans in the attacks in Southeast Asia, Indonesia and the Philippines???
At least for the first week?

The IJN was conscious that it had to protect its back door. If it simply attacked the DEI and sent everything in the direction of Malaya it was exposed to the US Pacific Fleet battleships and it couldn't guarantee the USA staying out.

Japanese need to take the Philippines so the US is not going to stay out. Now the question becomes how soon they can get there. It is around 4400nm from Pearl to the eastern shores of the Philippines and how fast is the American fleet going to come? at 10 knots or 12 knots or at 20 knots? Or how many ships are they going to come with given the lack of tankers.
The American battleships are slow, they can go amazing distances at slow speeds but it is going to take 15 days to get them to where they can even see the Philippines or Bonin. Much faster and they will be running out of oil before they get there.

nd the damage inflicted on the USN battleships at PH was no where near as bad as usually portrayed. Of the 9 Pacific Fleet battleships, Colorado was on the West Coast refitting, repairs to Pennsylvania were complete by mid-Jan, Tennessee and Maryland by late Feb. And that before considering the transfer of the three New Mexicos to the Pacific in Dec 1941 / Jan 1942.

This is quite true. But will force Z (of any type, even four Rs) still be a viable force at the end of Jan 1942 when the reinforced American battle fleet gets to Philippines?

Basic point is that one modern battleship and one near relic Battle cruiser with no cruisers, no subs, and 4-6 destroyers (and several of them relics) are NOT a deterring force for a navy with 10 capital ships, 16, heavy cruisers and 6 carriers (known ?) if their allies are 3 weeks (or two months) away or more.

Substituting four Rs for the PoW and Repulse does not make things much better. The PoW and Repulse might be able to use speed to avoid action at times. The Rs cannot.

 

[Admiral Beez]

You raise a good point. The only way Force Z could remain a force in being and stand any chance of success is if it combined with the NEI's naval assets. If nothing else, that would have created a more balanced fleet. I still don't think it would have made much difference in the long run...but it might have given the Japanese forces a bloody nose or two.

The IJN would have had to adjust their forces deployed to Java Sea, since HMS Prince of Wales and Repulse (along with two additional destroyers HMS Encounter and HMS Jupiter, FWIW) would overwhelm their two heavy and two light cruisers and sizeable (14) destroyer force.