Drachinifel - naval history

[stevep]

Dec 20, 2021 5:51:21 GMT miletus12 said:

Nov 24, 2021 14:47:22 GMT lordroel said:

King George V class - Design, Service and Myths r - naval history - 177

I watched until 1.05.50 and then looked at the function rate % for shells out for PoW, KGV and DoY in the3irw engagements against Bismarck, Bismarck and Scharnhorst respectively. I was surprised at the fail to function % rates for shots out.  This here from Anthony Williams  had other hard numbers for me to match

The design of this gun was based upon the 12"/50 (30.5 cm) Mark XIV, which was an experimental weapon completed in August 1933 to test "all steel" construction techniques. These new 14" (35.6 cm) guns were to a no-wire, radial-expansion construction, which resulted in a stronger, lighter gun that was less likely to suffer from barrel droop. This improved design gave the British a weapon that was more accurate and had a longer barrel life than the larger 16"/45 (40.6 cm) Mark I. Unfortunately, the mountings for these weapons were prone to mechanical failures during the early part of the war, with both HMS Prince of Wales and HMS King George V having numerous problems during their engagements against Bismarck.



Many, if not most, of these problems had been corrected by 1943. During the early part of her action against Scharnhorst at the Battle of the North Cape on 26 December 1943, HMS Duke of York made 31 straddles out of 52 broadsides fired and during the latter part she made 21 straddles out of 25 broadsides, a very creditable gunnery performance. In total, Duke of York fired 450 shells in 77 broadsides. However,

Interesting. The 30% shots out failure for Duke of York in 1943 was considered an improvement over KGV and the PoW performances in 1941? Can anyone explain this conclusion for me? 

I mean the North Cape battle should be compared to Komandorski Islands. USS Salt lake City, a Pensacola class cruiser, when introduced into service had problems with her guns, feed systems and hoists, when introduced. Famously in Manila Bay pre-war (1937?)_, this problem which affected all of the US Pensacola and Northampton cruisers had been encountered and were unacceptable. Live fire function checks were executed and the mechanicals were sorted out. This cruiser, USS Salt Lake City, shot a 90 minute gun action. We can make a fair comparison. .     
   
PoW's loss was a design flaw in her shaft alleys' pass throughs. One torpedo with a 150 kg warhead sank her. One protects the ship with multiple beam bulkheads. RMS Vittorio Veneto survived because her compartmentation was superior. No excuses here. Bad engineering is the forensic conclusion.  

  Factually inaccurate.  One hit at a key junction caused problems.  The real damage was done by restarting the shaft without checking for damage.  That's what ripped a good section of the ship open.  She would have gone down from other hits under such an attack but its inaccurate to say that a single torpedo sank her.

[miletus12]

Dec 20, 2021 10:37:48 GMT stevep said:

Dec 20, 2021 5:51:21 GMT miletus12 said:

I watched until 1.05.50 and then looked at the function rate % for shells out for PoW, KGV and DoY in the3irw engagements against Bismarck, Bismarck and Scharnhorst respectively. I was surprised at the fail to function % rates for shots out.  This here from Anthony Williams  had other hard numbers for me to match

Interesting. The 30% shots out failure for Duke of York in 1943 was considered an improvement over KGV and the PoW performances in 1941? Can anyone explain this conclusion for me? 

I mean the North Cape battle should be compared to Komandorski Islands. USS Salt lake City, a Pensacola class cruiser, when introduced into service had problems with her guns, feed systems and hoists, when introduced. Famously in Manila Bay pre-war (1937?)_, this problem which affected all of the US Pensacola and Northampton cruisers had been encountered and were unacceptable. Live fire function checks were executed and the mechanicals were sorted out. This cruiser, USS Salt Lake City, shot a 90 minute gun action. We can make a fair comparison. .     
   
PoW's loss was a design flaw in her shaft alleys' pass throughs. One torpedo with a 150 kg warhead sank her. One protects the ship with multiple beam bulkheads. RMS Vittorio Veneto survived because her compartmentation was superior. No excuses here. Bad engineering is the forensic conclusion.  

  Factually inaccurate.  One hit at a key junction caused problems.  The real damage was done by restarting the shaft without checking for damage.  That's what ripped a good section of the ship open.  She would have gone down from other hits under such an attack but its inaccurate to say that a single torpedo sank her.

The report states that the screw and attached shaft backed out of the aft bushing seal and that there was no intermediate bladder seal at the bulkhead  (as in American and Italian designs) between the drive block and flex joint and tunnel bearings, (See diagram for a typical representation.)



The claim is that the continued powered rotation of the shaft wallowed out the hole at the snapped shaft joint and made repair or seal off impossible. This is ridiculous. The crew should have noticed something immediately because a PTO, not under load that is free spinning with an unsupported wild end would have vibrated and set up a harmonic detectable by noise and hammer effect at the shaft block.

Now one has two unfortunate choices, either the runaway spinning shaft was so dangerous that the crew abandoned post without shutting down the turbine driving the shaft which makes no sense, because someone did decouple the turbine input, or the poor engineering crew saw the condition and were people who did not understand what an unloaded shaft condition looked like at all, and resumed power to that shaft, and that makes no sense either, given what a runaway PTO with vibration effects and overheated bearings is as a noise and heat condition. Yet, the engineer of the section did exactly that action.  Either way, the hole was there after the ship's motion dragged the section of shaft attached to the damaged screw out of the aft bushing and peak bulkhead and allowed water intrusion into the shaft alley which was not sealed by bladder seals past the aft peak bulkhead. This information is contained in the PDF, is illustrated in drawings and description and is a design flaw in the KGV that made damage control and intrusion path seal-off impossible when one understands that progressive flooding from the one torpedo hit and only that one puny torpedo hit that was needed to sink the HMS Prince of Wales.   

When one combines the intrusion event with the decision to compartmentize flood control with longitudinal bulkheads as opposed to transverse beam bulkheads, then one sees the other design flaw that doomed Prince of Wales. Her bulkhead scheme made her settle with a progressive list. 

You can read this conclusion in detail in that section that starts at page 15 through page 20 inclusive in the PDF. The description of the event chain is remarkable for the confluence of events and wrong decisions made by those who designed her, built her and failed to damage control her because they did not know that this combination of faults and events would occur. 

To be fair, USS Pennsylvania's better response was the result of Pearl Harbor and Ostfreisland lessons learned, shallow water, and her stopped condition after the torpedo strike and as with the Vittorio Veneto, prompt recognition of the situation and slow down and immediate containment of the shaft alley water intrusion event at a bulkhead frame shaft pass through seal afore of the snapped shaft joint so one can understand that the shipwrights who built Prince of Wales never expected this event chain or this condition to confront her crew. It was never encountered or tested for. The Americans and the Italians did encounter and test for it. 

Nevertheless... the PoW crew really have no excuses. The noise and heat they must have encountered from the shaft condition (burning bearings) should have indicated that shut down was needed. They did, Why was the shaft restarted and turned? The ship's generator that supplied power to the AAA guns and other auxiliary systems was attached to that shaft which drove it. The PoW needed that generator. So, the engineer of the section restarted the shaft under orders. The decision ... was made necessary by that third unacceptable design flaw built into the KGVs. When one watches the commentary in the video as to lessons learned or suspected in the PoW loss, one sees that this event chain was understood, even back in 1941 after the fact, because the DoY, Anson and Howe were modified and delayed to correct the discovered shaft and power system mistakes. 

As to the compartmentation and torpedo defense system and that vulnerable knuckle between the three void torpedo defense and belt armor aft, this was a design choice that had some curious results. The Japanese aerial torpedoes used against Prince of Wales were set to run a bit deep. Comment (video) is made that the torpedo which exploded at the shaft hit was a hull strike that exploded under the shaft. Incorrect. Damage to the shaft indicates a direct shaft strike. The force transmitted to the shaft was longitudinal as well as transverse. This had to be a direct kinetic event and not a water hammer effect.   

What the knuckle did was contain the water hammer itself and direct it, so that it deformed that aft peak bulkhead bushing and open a void hole oval in shape. No wallowing was necessary to doom PoW. Interesting. If the scallop had been of a different shape, the intrusion might have been containable? Speculation that is.

As for the rest of the POW torpedo defense system, this should raise eyebrows. 



It appears the Special Attack Unit aircraft, either by accident or intent, attacked the PoW's outer propellor shafts' mounts. And those shafts were mechanically defeated.    
      
   

[lordroel]

Dreadnought Modernisation - A tri-wire balancing act - naval history - 186

[miletus12]

Dec 22, 2021 15:19:05 GMT lordroel said:

Dreadnought Modernisation - A tri-wire balancing act - naval history - 186

Strictly speaking from an engineering structures point of view, this subject Drachinifel covers well, at least from a theoretical point of view. As usual there are things omitted that one must be in mind when one listens to his treatment.

First, the refits, and these are refits, depend on the naval doctrine and practical resources, including financial resources, which the navy referenced, has available to it. This will change the way the refit will be carried out from navy to navy. 

Using the Americans as the example (Since I know them best.) and comparing them to the British and the Japanese;

British and Japanese guns ballistically were less homogenous than their American counterparts.  Thus when the British and the Japanese went for an elevation refit, the main armaments' slides and trunnions had to be redesigned ship by ship, instead of class by class. The Americans still had to take ship idiosyncrasies into account, but the decision to make the guns conform to a medium velocity ballistic profile made a more general engineering solution for the Standards to raise gun elevations through the expedient of moving the counter-mass system and deepening the pits in the slides more general.  The British with a mix of high velocity-low shell mass NelRods, medium velocity QE's and the R's and the Renowns and the Hood should have been in much better shape than the Americans as to the gun elevation, but then their barbetter systems were split between single car and hoist, and two lift separate shell and propellant presented to the back of the gun in some older WWI ships and not universal side feed as the Americans used.  The Japanese followed the British and KEPT the single car system for most of their refit and new construction. This caused considerable expense and trouble for the Americans to deepen the pits, and even more trouble and expense for the British who modernized their shell handling machinery in those cases where they raised gun elevation in the QEs and the Japanese? They just shortened the slides and raised the trunnion mounts to allow more elevation. This added topweight instability in their barbettes.

When it came to armor plate and upgraded passive defense on a gunship, one notes the armor schemes of several modern battleships as presented at 36.00. This has absolutely nothing to do with the WWI ships' refits under discussion as these armor schemes reflect 1935 ish thinking by the various navies.

The Standards' protection scheme was actually kind of unexpectedly good against torpedoes and rather awful against gunfire and bombs.

At least for the Americans, this was more representative of the armor package after the mid 1930s refits.



There is a problem with American face-hardened armor. Around WWI when the Standards were being built, the Americans experimented with carburization which is part of the tempering treatment to set the depth of face hardening as a ratio of the plate cross sectional. With Krupp Cemented Armor and Vickers Cemented Armor, the face hardening depths for their plate varied from 25-35% of the cross sectional depending on whose formula was followed in the casting of the plate. There was little to choose between the two best plate armors made in Europe. The Japanese, as was period evident, used Vickers Cemented Armor for their own plate. They would continue to tweak this armor to produce their own variant which was superior to VCA in their WWII construction.

So what was the problem with US Class A armor plate of the era?  The Americans carburized deeply to 40-45%, that is to say they created plate up to 12 inches or (40.6 cm) thick that could stop enemy and their own shells of 12 inches bore size and below from defeating the face hardening. Those shells shattered at most battle ranges. Incredibly, the US armor plate worked quite well in the 5-12 inch plate thickness range against those shells that were 12 inches or less in bore diameter. The problem comes at 13 inches bore diameter or larger. The Class A shattered like glass.  There was insufficient elasticity in the plate. 

So; post Pearl Harbor, the repaired Standard battleships had their belts and deck armor either replaced with Class B nonface hardened plate backed by special treatment steel, or they were not to be used in gun actions against their equivalent Japanese counterparts unless absolutely necessary. As for the newer American battleships, the armor plate had to be replaced with a newer generation of Class A plate (Bethlehem plate; not Midvale.), which was an enormously expensive in war fix for ships building.                          

When it comes to AAA, the Americans will lag with the Standard refits behind the British and even the Italians. They will have better directors and fire control. The Japanese in their refits neglect this vital add on which can be described as "scrape-offs". 

The Americans never increased speed when they refitted armor decks with a bomb decapper and fuse initiator, elevated guns, and bulged hulls in the mid 1930s. They did rebuild their engine plants to try keep the Standards' speed, but the USS West Virginias actually lost a knot. In practical terms, that applies also to the QEs which also lost a knot (Down to 23 knots, not 25 knots Drachinifel claims.). The Kongos did earn a knot; but was not able to fight against their American opposites anyway. Refer, however, to the American reluctance to commit Standards to fight the Japanese battleline? The one time the Standards did fight their Japanese opposites at Surigao Strait, Oldendorf used his destroyers to neutralize Yamashiro and Fuso, then committed his cruisers. He held his battleships back for good reasons, partly because of limited armor piercing ammunition and lack of tactical speed, but he was reluctant to risk some of the Standards due to their armor acute vulnerabilities to Japanese 14 inch armor piercing shells.             
 

[lordroel]

SMS Sankt Georg - naval history - 187

[miletus12]

Dec 25, 2021 12:02:54 GMT lordroel said:

SMS Sankt Georg - naval history - 187

They only built three rather small armored cruisers, did the Austro Hungarians. Just what did they think they were doing? The only overseas interest outside the Mediterranean or even the Adriatic was the China coast station.  

[lordroel]

The USN Pacific Submarine Campaign - The Dark Year (Dec'41 - Dec'42) - naval history - 188

[miletus12]

Dec 29, 2021 15:22:08 GMT lordroel said:

The USN Pacific Submarine Campaign - The Dark Year (Dec'41 - Dec'42) - naval history - 188

I covered the torpedo crisis here.

1. Withers had nothing to do with the development of the Mark 6 exploder or the Mark 14 and 15 torpedoes. That was Ralph Christie. Withers was the Comsubpac responsible for bungling the Coral Sea and East China Sea USN submarine deployments and Nimitz fired him. That was how awful he was.  

2. The diesel engine crisis was political, not technological.  The USAAC had their hyper-engine program which they mismanaged. The USN had a diesel engine program folded into the Hoover Administration budgets as a part of national recovery from the depression. It was BRILLIANT.  Of the three lines developed, the Fairbanks Morse, the Winton/GMs were of the 2 stroke solid injection types that resulted in almost never fail diesels. The one line which failed was the 2 stroke clown copy of the MAN diesel made by Hooven-Owen-Rentschler as a double-acting type engine (Original model was prototyped off of the diesel engines on the KMS Leipzig, which was licensed / copied... er the design stolen.). These pieces of garbage were installed in 25% of USN submarines at the beginning of WWII. These were known to make a lot of noise and shake themselves to bits. Sort of like the German diesels from which they originated. How did the HORs (whores) wind up in US submarines?

Ohio's congressional delegation did for HOR what New York's did for Curtiss and Connecticut's did for the Navy Torpedo Factory. It has always been a part of American military procurement that pork barrel politics interferes with best products at best prices. 

3. One of the interwar tactics teachers responsible for the faulty submarine tactics used in the Fleet Problems was Thomas Withers. War Plan Orange 1935 included "unrestricted submarine and air warfare" against Orange. Yet, when this boob authored the submarine "fighting instructions" he did not allow for /or include the lessons learned in sea denial from the First Battle of the Atlantic. USN captains were (as per the video) penalized for attacking fleet trains or ambushing convoys during the Fleet Problems. They knew how, they were just punished by beaching for doing it.  

4. The TDC or torpedo data computer was notorious early war for being geared (literally) for using the wrong speed inputs for the torpedoes in use. This was a WAG factor that interfered with solutions.    

5. The description for how gyro steer operated is wrong. The gyro was supposed to gate a vector base angle and an input governance device was supposed to "curve" the torpedo's path continuously to meet a target track. if the IGD failed the torpedo straightened out. It was when the gyro tumbled or leaned in precession of spin that the torpedo circled.   

6. The depth controller input was a hydrostatic valve attached to a pendulum. The pendulum was mis-plumbed and the seal around the hydrostatic valve leaked in addition to the faulty placement of the intake on the pressure plate. Plus; there was the stated movement of the valve to the tail cone on the torpedo body and the unexpected pressure drops from the location shift from the Mark 10 to the Mark 14s and Mark 15. It required movement of the valve back to the midbody, a new weight adjustment on the pendulum bob, a new live fire range built to test the torpedo (not a flow tank with a maladjusted non-correctable depth gauge), a new type of gasket (Rubber not cork.)  and several courts martial and civil prosecutions for the idiots responsible to fix that "minor" problem.  In the meantime, the submariners used their set screwdrivers and turned the adjustment screw to read "zero".  

[lordroel]

HMS St Lawrence - naval history - 189

[miletus12]

Jan 1, 2022 12:19:33 GMT lordroel said:

HMS St Lawrence - naval history - 189

It was weird. The British lost the battles; but won the war on the lakes.  

[lordroel]

Basic Fleet Tactics - 1,000 years of holding the line - naval history - 190

[lordroel]

USS Bunker Hill - naval history - 191

[miletus12]

Posting here.



WWI operations against the U-boats.



One will be surprised how the WWII U-boats failed to match their dad's achievements.

[lordroel]

Jan 11, 2022 9:39:45 GMT miletus12 said:

Posting here.



WWI operations against the U-boats.



One will be surprised how the WWII U-boats failed to match their dad's achievements.

Think these have been posted in the past here.

[lordroel]

HMS New Zealand - The Lucky Kiwi Capital Ship - naval history - 192