Which warship reconstruction was the most expensive? Which one the best?

Mutsu blew up without being hit once. Kirishima didn't last long once the hits started landing although those were 16" superheavies. Yamashiro was apparently still firing and under at least some control for a significant period of time after the first shell landed. Hiei on the other hand was suffering from a single 8" hit although numerous other light hits didn't make things easy for her.

I've yet to see anything that suggest that the IJN considered those reconstructed ships obsolete after Midway it's just that they needed carriers. Indeed up to that point what battleship had been sunk at sea by opposing aircraft while it had a CAP and a reasonable escort? Indeed which ones were even hit under those circumstances (I can think of at least one but it didn't take serious damage)?

 

The point, Triton, is that the Fuso and Yamashiro were extensively upgraded in 1930...12 years before Midway. The Hyuga and Ise underwent their major modernizations in 1934 and 1935 respectively...8 and 7 years before Midway.

Now unless the Japanese had invented the Mark I Crystal Ball, they would have no way of foretelling the future of naval warfare.

Then you have to consider how much the US Navy wasted rebuilding their battleships in the late 20's and early 30's, before they ran out of money. The modernizations were started up again, just before Pearl Harbor, but was held up, because of the need for the Battleships to be available for duty.

The Royal Navy did not run out of money.

The R-Class battleships were going to be replaced by the anticipated Lion class battleships. As such, the British saw little need to extensively modernize them, given that the R's were going to be sent to the scrapyard soon there after. However, World War II changed British plans.

The first three QEs, Queen Elizabeth, Warspite, and Valiant, were extensively modernized between the wars. The Barham was modified, but to a somewhat lesser degree than the previous three, and the Malaya, was modernized even less than the Barham.

 

For me, the modernization of the Kongo-Class was one of the best if not the best reconstruction during the interwar period.
These were the only battleships to escort Kido Butai and therefore useful.
They still remained a british battlecruiser design, so designed to fight cruisers or destroyers at longe range, sending them into close-combat-nightfights wasn't a swift move...

The RN should have kept and modernized HMS Tiger, in the early 30ies the german pocket battleships showed, that speed was becoming more and more important in warfare against commerce raiders.

 

Well they were upgraded at least in designation to battleships with the recontruction. The other battleships were IMO useful as well they just weren't used much. I consider that a fairly important distinction.

As for sending them into the waters around Gaudalcanal I don't really see how you can fault that if they were as you say "designed to fight cruisers or destroyers" . That's what they expected to find there although it's worth noteing it was cruiser gunfire that doomed the Hiei. Kirishima on the other hand had no idea that SoDak and Washington were in the area and indeed ID the former as an older US battleship.

 

The RN in the 1930s was facing what would later be called "block obsolescence" - twelve of their fifteen capital ships had been commissioned in 1915-17 (and Hood in 1920) and would all come due for replacement or modernization at about the same time. They could give them all a modernization that would extend their service lives for say ten years, but then they would have the same problem down the road. So they evolved a policy of modernizing the ships that had the most potential - the QEs and battle cruisers - and phasing out the Rs as new ships, KGVs and Lions, came into service. I say "evolved" because as far as I know the program was not planned from the outset like say the USN's FRAM 1 and FRAM 2.

The Rs, although slightly younger than the QEs, had less potential for modernization. They were slower, and apparently they were not in the best material condition, possibly due to their completion being hastened in wartime. Since they had smaller engineering plants, there was about twenty feet less length between the forward and after turrets and could not accommodate the mid-30s aircraft installation featuring hangars and a cross-deck catapult. It may not be coincidence that the Rs dropped out of the modernization program about the same time that the midships aircraft scheme was adopted.

Royal Oak had one of the early modernizations, including deck armor over magazines, removal of underwater torpedo tubes, improved antiaircraft armament, and a catapult on X turret. Ironically of course she was the one of the class to be lost, in the second month of the war.

Barham had a modernization similar to Royal Oak's, and Malaya a slightly more extensive one including catapult and hangars and deck armor over engines as well as magazines. Repulse's modernization was similar to Malaya's, and the last four were major reconstructions.

Hood was the youngest of the WWI generation and little major work was done in the interwar period. A full reconstruction was planned after Valiant and QE were finished, which would have remedied all the potential causes of her loss, but the RN was understandably reluctant to take her out of service for 2-3 years once war was underway.

 

Do you know, for how long the QEs were planned to be kept in service?

 

Raven and Roberts, British Battleships of World War II, quote a memo about the proposed reconstruction of Hood which says that she was expected to remain in service another 10-15 years, so I would guess about the same for the reconstructed QEs. That would take them into the early 1950s. Thoroughly reconstructed ships were not drastically inferior to new ones, except in speed for battleships. If large numbers of capital ships had still been an important part of navies in 1950, Valiant, QE, Renown, and Hood could have played their part.

 

Underwater protection was the main difference. The old battleships, even with torpedo-bulges, were often disabled after one hit, sunk after 2.

 

In terms of WW 2 the three major rebuilds that Tennessee, California, and W. Virginia underwent were easily the most extensive and "best" reconstructions of earlier ships performed during that conflict. These ships were brought up to "modern" (eg., equivalent to a Washington or S. Dakota class BB) standards. Their deck armor was nearly doubled and amounted to 4 to 5" for the main protection. The additional bulging out of them gave them a nearly unprecedented torpedo defense system much deeper than even newer classes of BB got.
They had a fully modern 5"/38 secondary battery, the latest fire controls and radar aboard.

Their only deficit was speed.

The Italian Conte De Cavour class, likewise, were excellent rebuilds making what were average WW 1 dreadnought type battleships into modern fast BB's.

The best British rebuilds, the QE and Renown, both were good designs except for placing the hangers and cross deck catapult amidships like they did. I can understand the need to do this given the pathetic state of the FAA before the war, but it was a design flaw in that it took up considerable amidships deck space that was far more valuable real estate for secondary battery or AA guns than marginally useful aircraft.
The hangers and aircraft also represented a considerable fire hazard in a bad place. This was something every navy recognized during the war. The RN fixed that by eliminating the aircraft and their fuel, using the hangers for other purposes and the previous catapult area as a boat deck in most cases.

For smaller classes of ship, the US "Four piper" DD's underwent a bewildering number of conversions with mixed, but usually useful, results. These included becoming small seaplane tenders, ASW vessels, APD's, destroyer minesweepers, minelayers, coast guard cutters, among others.

As for carriers, I think Japan proved you could turn just about any hull into an aircraft carrier, with mixed results...

 

Was the french Navy the only one which did not really modernize their capital ships?
Why was that? No money? Unlikely, they built innovative ships like the Surcouf or the Mogador-Class in the interwar period.
Hopeless to modernize the Béarn or the Bretagne-class?
Did they modernize smaller warships?

 

The Bretagne class were all modernized pre-war, only the extent of these modernizations varied.

There simply was not much to do to the aircraft carrier Bearn tom improve her, which is why the French were planning to build the Joffre class carriers.

The Surcouf was hardly innovative, although it may have been imaginative, but I believe that the British were there first with the X-1 & M-class submarines.

 

What did they change? I can't see a major difference.

Surcouf maybe wasn't innovative but special at least. She had a hangar, a motorboat and enough room for 40 prisoners.

You are an expert in these things: Do you think that the torpedo bulges added to the british QEs and Revenges were effective?

 

You won't, except for the superstructure added in the 1920's. Most of the changes were internal - better rangefinders, better fire control, oil-fired boilers, increasing the maximum angle of the main guns, removed armor here, added armor there, etc.

A major reconstruction - like the Italians did to the Conte Di Cavour & Andrea Doria classes - was just not in the cards for the French Courbet & Bretagne classes.

Had a hangar, yes, but no catapult.

From a stability and seakeeping standpoint alone, the torpedo bulges were effective.

 

Killing two birds with one stone then.
HMS Resolution had the nick-name Rolling Reso, i acually don't know if given before or after her refit. She survived a torpedo hit from a french submarine too. I seams that the QEs and Revenges could survive a hit by one torpedo, 3 were fatal.

 

as did the British MAC carrier fleet based on working merchant ships.

 

And the Americans with their LST "aircraft carriers."

 

Only the Axis navys converted passenger liners in carriers. Jun'yo reached Japan after being hit by three torpedoes. Remarkable. Ark Royal was sunk by a single torpedo.

 

In part you are comparing 'apples to oranges'. Much depends on where the torpedo hits, what internal damage it inflicts and the state of damage control on the ship (poor, adequate, good).

 

...and the type of torpedo, which was used. The Royal Navy was known for good damage control and excellent crews, the IJN wasn't.

 

The types of torpedoes were relatively the same concerning explosive power. The notable exception would be the Japanese Long Lance torpedo.

However, the design of the HMS Ark Royal had several defects that would lead to her loss from only one torpedo hit.