WesWorld

Heya there .

I'll try to answer the best I can. Let's see.


"You do know that the Germans were limited to 10kts due to the VT? It was not the concept nor that the Germans tried to much on a smaller hull that left the original Panzerschiffe smaller than 19kts. In fact, they already used 4+kts more than allowed."


I do know it, and I'm amused that the german engineers and designers were able to create such a capable ship in such small displacements at the time they did.

However ,the fact that they had to pack so many features on so little space made the design to fall short of what they intended to do. At least IMHO .


"Further more the DEs were build to replace the old predreads in first place. And then there were the political reasons to use the 28cm guns."


Of course I know that the two "old" Deutschlands were to be replaced. And as you have seen, I'm well aware of the political side of the design in putting 11' guns to make the rest of the world believe that Germany, Versalles or not, still had a navy to be reckoned.

however ,sticking to the Panzerschiffe debate, the question "what is better, 5 heavy cruisers or 3 Panzerschiffen?", answered just by military reasons is 5 heavy cruisers. Just in my opinion.



"Beg your pardon but could you explain what you mean? With a bad luck hit a 6" shell could even jam YAMATOs turrets so what´s your point?"

I'm talking just by memory here but IIRC the sides, roof and back of the turrets on the Graf Spee were vulnerable to 6' fire. That might not be a problem when they're facing the light cruiser firing at your ship, however ,it indeed is a problem if you're firing at anyone else (as it happened in the battle of River Plate)



"I also think when browsing through your technical readouts again and if you examine some shemes and (re-)read some sources about the Battle at the River Plate you´ll find out that SPEE came out with small damage. The armor layout the Germans used offered a little bit more protection than one would expect from the amount of metal only and especially the turrets weren´t that thinly armored. I quote from Richard "Tiournu" Worth´ book "Fleets of WW2" here: "None of the eighteen 6-inch hits defeated her [SPEEs] armor (three of them bounced off turrets), and she emerged from the duel without serious damage.""


Indeed, Tiornu is a real monster in the world of naval warfare, however...

See, the Graf Spee was the third Deutschland completed, was by far the heavier and the better, as it had the most armor of the trio. The Deutschland-Lutzow, however, was way worse in that department and so was the Scheer (even while the Scheer was also way over the original ship of the class).

Why was that?...the Graf Spee was the last one, we see that from the first up to the last ship there's a sustained upgrade on the armor. It's clear that, from the very first moment, the designers saw what I'm saying in this thread: To fullfit the Panzerschiffe concept, the Deutschland needed more armor because it was vulnerable to cruiser fire: the very same kind of ship she theoretically had to "outfight". And that's just my point.

Speed at the moment wasn't such a problem (there was no capital ship at the moment able to reach those speeds except Hood, Renown and Repulse) ,well, 28 knots sounds quite well, but then in the real deal, the Graf Spee wasn't able to steam at more than 26.



"8" shells packed enough power to overcome SPEEs armor on the other off course but as pointed out earlier a 7" plate doesn´t offer perfect imunity as well."

no, perfect not. But much improved, yes,and that was exactly what it was needed. Rememeber that I tried to keep the ship under 15000 tons standard on purpose, so I also set my own limits, not as draconian as Versalles' but still limits.

It might not be perfect, but is enough. Mixed with 2 more knots of top speed and 305mm shells you have a ship able to make any heavy cruiser tremble upside down.

(they did tremble when faced against the Spee, of course -the exeter trembled in fear so much she almost sank...well, those 11' shells she received also had something to do with it -, but it's not the same to be in front of a ship with more speed, heavier weapons and more armor, than to be in front of a ship worse in the three departments)



"The concept for the german units asked for a heavy gun because they were meant to replace predreads and should offer some punch against units used by other baltic nations. The Germans also calculated variants with guns up to 35cm but the 28cm guns offered the best compromise."


then the concept of panzerschiffe as "able to outrun anything it can't outfight" is false?. I've read and heard that statement too many times to be convinced now, but I know what propaganda and the media can put in the collective mind of the people, so I really want to know it .


"Could you please quote the data you have at hand? Why do you think they were thinnly armored (especially SPEE) - especially when comparing them to cruisers (most likely opponent) of the same era. In fact, I think the opposite is true."


because they WERE thinly armoured for the task they had to do, the first of the class much worse than the other two, of course, however even the Graf Spee wasn't armored enough for the task. It was a very good improvement, of course, however still wasn't enough.



"Further more I´d like to point out that a one vs. three never is a good idea but SPEE proofed to be able to held her position - despite her main guns being mounted in only two turrets. The latter is maybe a real drawback in such a situation but your alternate design would have the same problem."


it's the only way to keep 6 guns in two turrets, and two turrets are the ony way to keep weight down. I see no problem at all with the Deutschland's weapon deployed the way it was .

and yes, the Graf Spee held it's own quite well, never said the opposite .


"Again, I have to ask for your sources. Is the above your (educated) opinion (guess) or based on technical evidence?"


here I didn't write it well. It was the ammunition, not the gun itself.

If I understand it correctly, the 11' german shell had a defective fuse or however it's said (sorry ,english is not my first language and sometimes I have real trouble to write what I want), so the shell didn't detonate properly sometimes. I'd say that this qualifies as the shell (and the gun that fires it as a collateral effect) as a dismal failure.

Regarding on what do I base that affirmation, well I've read and seen this affirmation in quite many sources, however none of them monographic on naval topics. There's a limit on my time and my money (the real trouble lies in lack of the second ) and as I'm heavily interested in almost all and every matter regarding WW2 I have to watch very carefully what I buy...and 90% of the time is about the Air War (my true field of expertice when it comes down to WW2).





"The same is true for a 11" shell so why waste money and weight if one only needs a gun that outclasses a CAs main armament? Why not use a 10" or 9" gun allowing to get more barrels and a much more balanced design?"

because one hit of a 12' shell is felt much deeper than one of 11'. More so than one of a 10' shell or a 9' one.

In the other side, mounting more guns would cause your ship to have more guns, and so you would have to add more turrets (unless you want to go with quadruples, and I tend to dislike them), and there you go another heavy piece of equipment boosting your weight. No deal for me, I'd rather take 6 barrels, but of the heavier calibre so they can disable fast what they touch.


"What about ALGERIÉ or ZARA? Both were planned and build long before 1940 and both should be rated as very dangerous for a Panzerschiff - both the original as well as your version. Don´t focus on WICHITA alone..."


with the increased speed, armor and weapons in my version I really don't see so extreme danger from an Algerie. It's a dangerous foe?. yeppers...but if someone in an Algerie wants to exchange some shots with the ship avobe posted he's in MUCH deeper trouble than I am.

About the italian ships...well, don't take me wrong ,but given the performance of the italian Royal navy in WW2, I really fear no italian cruisers .



"Well, if you ask for a CA with oversized guns I again question the balance of the design and why you think the DEs were more off balance than your own design."


because the increased armor and speed reduces the unbalance.

Don't take me wrong, I don't say my ship ain't unbalanced...it is. However, it's not BY FAR as unbalanced as the Deutchland was. It's the same reason why I say that the Graf Spee was more balanced than the Deutchland...increasing armor you equalize a bit the design.


" Compared to the CAs of her era the DEs featured relatively thick armor - maybe just because her most likely opponents (british and french vessels) featured no armor at all that was thicker than a sheet of paper. :o)"


worse, those were REAL tinclads



"Why CAs at all? If you aim for a vessel that should be used as a raider a 9-12 guns CL should be enough by far. A really long-legged (18000nm at 15kn is what the DEs achieved - more than your design offers, btw) TOWN-class, that´s what I would have used. One doesn´t need 8" shells to sink a merchantmen..."


hummm, could be ,but you still want to have those guns to fight against faster ships. A light cruiser might be fast but there are FASTER ships (Destroyers, or other ,faster, light cruisers). Then you want to wipe them out the faster you can. It's a simple rule of thumb: you are going to get opposition, you might not always run...so have some guns in the reserve to defend yourself .




"Of course the DEs weren´t perfect but I wasn´t aware of the fact that they were seen as badly flawed."


if you knew the discussions I've had to stand in spanish forums you'd be surprised. That's exactly how they are seen, if not worse. It's curious ,in those discussions I was the one defending the Deutchlands!




"I´m not sure if I should agree. First of all I think the DEs fullfilled their requirements quite good - especially when build. That ships laid down years later will render the concept obsolete can not and should not be used to blame the DEs. New technical developments are meant to have this effect."


Agreed to some extent.

Even for 1928 it was clear that Deutchland's armor wasn't enough to stand safely a light cruiser's fire. I'm sure that if the german designers had some more field to play in (some 5000 tons more) that's exactly what they'd have added, not more weapons or more machinery.

But yes, for the time they were built they could've done their job much better than what they were able to during WW2. They were not a failure (in fact they were a miracle and a great achievement, IIRC was the first ship in the world to feature an all-welded hull to save weight!), and for the moment were a resounding success...but in the war they didn't exactly shine.




"What do you mean by "economical"? I think you´ll need more money, man, material, time, slips, yards etc. to build and maintain 5 cruisers instead of 3."




in this I admit I have no idea on the monetary costs of the Panzerschiffen compared with heavy cruisers. I assumed up to this same moment that they were more expensive, but I can be perfectly wrong

I haven´t forgotten to answer your latest post. I just think it is necessary to go into detail and I´m away from my sources once again.

Cheers,

HoOmAn

Hi there,

I´ve been able to look through some of my sources even though I didn´t had the time to browse them all or do extensive calculations. However, I´d like to raise my voice on some points again (others will be discussed in a later post most likely).

1) Costs

A PB and a HIPPER cost nearly the same (~85 mio. RM) and PRINZ EUGEN topped them all with more than 100 mio. RM.

Thus from an economical point of view you simply can´t trade three PBs for 5 HIPPERs. In addition you have to keep an eye on crews. The late-war HIPPERs had about 1600 men on board while the PGs carried "only" 1000-1200.

2) Hull Armor

You raise the point that the PBs were not well enough armored against cruiser fire.

As a basis for my calculations I used a 150mm L/50 gun with a 54kg AP shell and a muzzle velocity of 814m/s. Such a gun is comparable to what was around in Europe during the late 20s and 30s.

Accourding to my sources DEUTSCHLAND had a 60mm belt, a 45mm torpedo bulkhead (both angled) and a 40mm deck (above engineering spaces). In addition there is a nother 20mm longitudal bulkhead on each side above the main AD. SCHEER was armored similar but traded five mm of its TB (now 40mm) for a 45mm AD. Finally there is SPEE with a 80mm belt, a 40mm bulkhead and a 45mm deck (which extended over full beam).

My problem now is that I can´t tell you exactly at what angle the belt and bulkhead was installed but accourding to the drawings I have at hand I assume 15 degree.

I further assume a standard cap for the shell and armor quality that resembles that of american Class A because claculations are easier that way. Please keep in mind that german Wh material has to be rated 10-20% more effective than Class A.

2a) DEUTSCHLAND

Having the above in mind one gets the following imune zone against the discribed 150mm gun and its shell:

Belt outside ~160hm. Deck inside ~180hm.

So outside 180hm (20200 yards) a 150mm AP shell is able to defeat DEs AD while DEs belt is valnurable to penetration inside 160hm. That said a shell penetrating the outer belt hasn´t reached the ships vitals yet and it will not have enough power to penetrate the 45mm TB as well. Thus damage is kept outside machinery spaces. It is somewhat difficult to calculate the degree of protection the TB adds to the belt because two layers do not behave like a single plate. Their combined thickness of 105mm would offer less protection than a single 105mm plate accournding to Nathan Okun but on the other hand the first layer decaps the shell, sets its fuze and deflects it somehow so the difference will not be too much and we can assume the vitals to be save outside 110hm.

2b) SCHEER

SCHEER is imune to that gun between ~160hm (belt only) and ~190hm (deck). Her TB is slightly thinner but overall vertical protection will be quite similar to DEs.

2c) SPEE

SPEE has to be rated as imune against 150mm fire within 135hm (belt only) and 190hm. With the TB taken into consideration imunity is achieved even at ~90hm.

Please note that I did not add the mentioned 20mm longitudal bulkhead to the equation for all three ships. It would have made deck penetration even more difficult depending on the angle of fall of an incoming shell and the location it hits.

3) Turret/Barbet Armor

Accourding to my sources (Gröner, Breyer...) the PBs barbets featured 100mm armor (above deck level) while the turret faces reached 140mm. The turret roofs featured 85mm of armor as did the sides. The floor of each turret was made of 105mm of armor.

The turrets can be assumed save between 80hm and 235hm (please note the guns maximum range is 232hm).

4) Conclusion

The PBs vitals and turrets/barbets were protected against light cruiser fire at all ranges a daylight fight would take place most likely. I´d call that good protection and it explains why AJAX and ACHILLES achieved so little against SPEE and why all telling blows came from EXETER.

Against 8" fire (125kg AP shell from a 20,3cm L/4 the hull armor on the PBs offers protection between ~170hm (belt) and 165hm (deck) - a narrow window for sure but still much better than the armor on most CAs. The turrets would be save between 130hm and 240hm.

I guess it is not necessary to run any calculations to show how effective a 11,1" shell can be against cruiser armor...

Hope that helps,

HoOmAn

huhmmm interesting...seems the GS wasn't as vulnerable as I originally thought.

thanks for your data, Hooman, gives me a whole new perspective to the panzerschiffe concept in real life

I have messed around with the whole idea a bit more and came up with this - notice the absence of torpedo bulheads because they no make sense without expansion spaces of >= 4 m eitehr side, not doabl in a ship this size.

Bernhard's cruiser killer, Germany Panzerschiff laid down 1926

Displacement:
11,702 t light; 12,341 t standard; 14,387 t normal; 15,966 t full load
Loading submergence 795 tons/feet

Dimensions:
656.17 ft x 68.90 ft x 22.97 ft (normal load)
200.00 m x 21.00 m x 7.00 m

Armament:
6 - 10.43" / 265 mm guns (3 Main turrets x 2 guns, 1 superfiring turret)
6 - 5.91" / 150 mm guns (3 2nd turrets x 2 guns)
8 - 3.46" / 88 mm AA guns
16 - 1.46" / 37 mm guns
Weight of broadside 4,216 lbs / 1,912 kg
10 - 21.0" / 533.4 mm above water torpedoes

Armour:
Belt 4.92" / 125 mm, ends unarmoured
Belts cover 87 % of normal area
Main turrets 5.91" / 150 mm, 2nd turrets 1.97" / 50 mm
AA gun shields 1.18" / 30 mm
Armour deck 1.97" / 50 mm, Conning tower 5.91" / 150 mm

Machinery:
Oil fired boilers, steam turbines plus diesel motors,
Geared drive, 3 shafts, 78,562 shp / 58,607 Kw = 30.00 kts
Range 12,000nm at 15.00 kts

Complement:
656 - 853

Cost:
£4.160 million / $16.641 million

Distribution of weights at normal displacement:
Armament: 527 tons, 3.7 %
Armour: 2,655 tons, 18.5 %
Belts: 749 tons, 5.2 %, Armament: 816 tons, 5.7 %, Armour Deck: 1,014 tons, 7.0 %
Conning Tower: 75 tons, 0.5 %, Torpedo bulkhead: 0 tons, 0.0 %
Machinery: 2,515 tons, 17.5 %
Hull, fittings & equipment: 5,806 tons, 40.4 %
Fuel, ammunition & stores: 2,685 tons, 18.7 %
Miscellaneous weights: 200 tons, 1.4 %

Metacentric height 3.3

Remarks:
Hull space for machinery, storage & compartmentation is adequate
Room for accommodation & workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.08
Shellfire needed to sink: 17,123 lbs / 7,767 Kg = 30.2 x 10.4 " / 265 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 2.1
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 70 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0.64
Relative quality as seaboat: 1.14

Hull form characteristics:
Block coefficient: 0.485
Sharpness coefficient: 0.33
Hull speed coefficient 'M': 8.25
'Natural speed' for length: 25.62 kts
Power going to wave formation at top speed: 50 %
Trim: 61
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 86.9 %
Relative accommodation and working space: 123.6 %
(Average = 100%)
Displacement factor: 119 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0.98
(Structure weight / hull surface area: 131 lbs / square foot or 641 Kg / square metre)
Relative longitudinal hull strength: 1.13
(for 18.04 ft / 5.50 m average freeboard, freeboard adjustment 1.76 ft)
Relative composite hull strength: 1.00

range prolly closer to 18000 nm due to diesels.
aft 150 mm gun superimposed over aft main gun.

mixed weight: 2 floatplanes = 75 t
crusising diesels 6.600 hp = 9% of overall install hp on central screw. assume diesels are 50% beavier than turbines, add 125 t.

Quoted

Originally posted by RAM
huhmmm interesting...seems the GS wasn't as vulnerable as I originally thought.

thanks for your data, Hooman, gives me a whole new perspective to the panzerschiffe concept in real life

A late note: Take into consideration that armor plates of up to 80mm generally were made of homogenous, not face-hardened armor.

The lesson to be learned from this is that you don´t need thick armor (100+mm) on (light) cruiser most of the time because even 80mm (inclined or 100mm vertical) offer a very decent protection against the vast majority of naval guns (everything up to 6" that is) at most reasonable ranges. There always will be a chance for a lucky hit at looong ranges or a knife-fight at night, sure, but how likely is that in a naval environment that relies on optical sighting and FC?

Don´t get me wrong: I still question the value of those early french, british or american tin-clads that had close to no armor at all or those japanese cruisers with no turret protection but every cruiser with at least a 60mm belt and a 20mm backing plate or TB has decent hull protection against 6" gunfire at reasonable ranges. Same for the turrets.

So when you look at many peoples ss-design you can see they tend to waste a lot of weight on armor (to achieve imunity against 8" gunfire maybe?!) where it is not necessary. Just my opinion of course.

Cheers,

HoOmAn