WW1 arms race: Germany vs. Great Britain

[BabelHuber]

I read through the threads regarding this topic, and this is the bottom line:

- The arms race was a stupid idea from Tirpitz because with only 2/3 of the British fleet strength, Germany would be inferiour in a war anyways due to the n-squared law.
- The relative strength of the German fleet forced GB to ally itself with Russia and France, because these fleets combined could pose a serious threat otherwise

So building the fleet was a bad idea, from a military point of view and from a political point of view. Please correct me if I am wrong.

But what would have happened if Germany had a different strategy, focusing on battlecruisers instead?

Let's say Germany would have done the following:

- Build the Nassau and Helgoland dreadnoughts
- Build all battlecruisers like in OTL (or similar, e.g. building another Moltke instead of Seydlitz)
- Stop all pre-dreadnought programs after 1906 or 1907 (e.g. stop building the Deutschland-class after Dreadnought was built)
- Using the ressources freed by building battlecruisers instead of the König- and Kaiser-class (the battlecruisers would be more expensive than the Dreadnoughts, but OTOH cancelling all pre-dreadnoughts would also free some ressources)

Then, in 1914, Germany would have had the following capital ships:

Dreadnoughts:
- 4 Nassaus
- 5 Helgolands

Battlecruisers:
- Von der Tann
- Moltke, Goeben, Seydlitz
- 3 Derfflingers
- 5 battlecruisers instead of Kaiser-class
- 4 battlecruisers instead of König-class

With this fleet the KM could still not hope to win a battle royale against the RN of course.

But I think this fleet could cause more troubles for the RN:
- The battlecruisers could escape all RN dreadnoughts, so they could choose when to fight
- Due to superiour numbers, the German battlecruisers could probably hunt down the RN battlecruisers
- The battlecruisers could act as commerce raiders if they could break through the RN's blockade (I assume that the RN would have a hard time catching battlecruisers due to their high speed, especially after suffering serious losses of own battlecruisers)

Would this approach lead to a more favorable outcome for the KM in WW1? Would they be able to disrupt British supplies? Or do you think that these battlecruisers would have been as useless as the German dreadnoughts were?

[Thanas]

I read through the threads regarding this topic, and this is the bottom line:

- The arms race was a stupid idea from Tirpitz because with only 2/3 of the British fleet strength, Germany would be inferiour in a war anyways due to the n-squared law.

That is the wrong way to go about it. The strategy was to be inferior from the start, it was to have just enough to make war a non-desirable idea for Britain. Tirpitz, who admired the British Navy and Britain in general, knew that a real challenge was not possible.

- The relative strength of the German fleet forced GB to ally itself with Russia and France, because these fleets combined could pose a serious threat otherwise

What? How? Germany would never ally with France and vice versa. They had a sort of alliance with Russia, but Wilhelm wrecked that one despite the Russians being eager to renew it.

Or do you think that these battlecruisers would have been as useless as the German dreadnoughts were?

All this does is allowing Fisher to do what he wanted to do anyway and built only BCs. Then we have the same situation in BCs as we would have with Dreadnoughts. The Germans would probably do a bit better in that situation considering their BCs seem to have been sturdier and BCs would be more useful than Dreadnoughts for commerce raiding, but the policy of the Kaiser was to never risk a capital ship so this in all likelihood would be for naught.

[Sea Skimmer]

Commerce raiding with large coal fired capital ships is pretty hopeless. Its just too hard to refuel, and far too much fuel is required. This is also why the large coal fired fast liners failed armed merchant cruisers in defensive and offense roles. You look at the odyssey of Von Spee, it was completely a quest for fuel even with use of neutral ports; his collection of cruisers was burning about as much coal as a single battlecruiser would. Basically if the raider is too big to refuel from captured ships, forgot about it.

The best surface raider was a inconspicuous merchantman; but its very arguable that after the radio became standard the whole idea was kind of hopeless as a long strategy anyway. Tactical success of surface raiders was generally linked to them being rare things and hard to bring to battle, which naturally limited how much damage they could actually inflict. SMS Emden was rabidly successful, but in large part only because the allies refused to rapidly establish convoys in the Indian ocean, and the British were still mobilizing and deploying the extensive reserve cruiser fleet they required as escorts. They also had lots of ships running off in this and that direction taking over all the German islands in the Pacific to deny raiders bases.

Tripitz kinda missed the point that deterring the British meant nothing unless Germany also won on land in the first place. If she did win on land, then a blockade of Germany would mean very little as it would be fairly implausible that the British would sustain a fifteen year war against them and vast additional shipbuilding resources would be on hand. I suppose though maybe it didn't sound so implausible at the time less then a century after Napoleon.

[Thanas]

Yeah, I think in some way the dreadnought did destroy Tirpitz strategy. While it allowed Germany to catch up in "meaningful" warships, it also meant that vast resources had to be expended again, resources that would have been better off on land. If there had been no dreadnought it would also meant no money spent on enlargement of the Kiel Kanal etc.

[Sea Skimmer]

His strategy was bunk to begin with. Maybe it had some merit if you thought Imperial power was completely based on math or something, in the real world designing to loose is designing to fail. I believe at the peak of disparity the German Navy had half the budget of the Army. Pretty nonsensical. Lucky for the west the Soviets then went and did the same thing.

[CaptHawkeye]

Would this approach lead to a more favorable outcome for the KM in WW1? Would they be able to disrupt British supplies? Or do you think that these battlecruisers would have been as useless as the German dreadnoughts were?

Considering battlecruisers did about 90% of the war's surface fighting I would hardly call them useless. In theory Fischer's ideas were 100% vindicated at the Falkland Islands. They were further proven at Jutland too though Armchair Admirals continue to believe otherwise.

I've often heard the idea of using BCs as commerce raiders, but I've never bought that. Considering BCs were designed to perform the precise opposite of commerce raiding (they were designed to hunt down potential commerce raiders) and secondarily to perform recon in force ahead the main fleet. I don't think anyone during the time thought that either, because radios meant you couldn't keep a big ship hidden for very long. Anything bigger than a destroyer simply draws too much attention to itself.

[Thanas]

His strategy was bunk to begin with. Maybe it had some merit if you thought Imperial power was completely based on math or something, in the real world designing to loose is designing to fail. I believe at the peak of disparity the German Navy had half the budget of the Army. Pretty nonsensical. Lucky for the west the Soviets then went and did the same thing.

Well, I think there is some merit to the strategy if you operate under the assumption that a) Britain will strike at the German merchant shipping and try to silence competition anyway soon. b) that you cannot match the British fully c) but that you can provide enough disincentive that a victory will be bloody and therefore Britain will not strike against Germany.

There was a real fear in German High Command that the British would "Copenhagen" them if the merchant marine grew too much for British liking. Of course, the reaction to the German fleet by the British sides was to call for such an action.

[BabelHuber]

What? How? Germany would never ally with France and vice versa. They had a sort of alliance with Russia, but Wilhelm wrecked that one despite the Russians being eager to renew it.

AFAIK GB and France were not natural allies. Their various interests tended to collide, especially in the colonies. If they had the same interest, they worked together, though, like in the crimean war.

But with Germany starting the arms race, GB and France started to more closely work together. I could be wrong, though, since I am no professional in this area.

All this does is allowing Fisher to do what he wanted to do anyway and built only BCs. Then we have the same situation in BCs as we would have with Dreadnoughts.

You are right - most probably the RN would have built battlecruisers instead of the Orions and their successors, too. Then we have the same situation again. I assumed in the OP that the RN does not change, but I see that this is unrealistic.

Commerce raiding with large coal fired capital ships is pretty hopeless. Its just too hard to refuel, and far too much fuel is required. This is also why the large coal fired fast liners failed armed merchant cruisers in defensive and offense roles. You look at the odyssey of Von Spee, it was completely a quest for fuel even with use of neutral ports; his collection of cruisers was burning about as much coal as a single battlecruiser would. Basically if the raider is too big to refuel from captured ships, forgot about it.

OK, but this would only leave light cruisers for this role, then. But additionally, these ships must be able to escape from battlecruisers, otherwise they are toast.

I'd envision a vessel with about 8000t and 6-8 15cm guns. To escape from an Invincible-class battlecruiser, 30+ kts would be a necessity. I'd estimate 70,000shp would be most probably enough power.

Would it have been possible to build such a light cruiser in 1910-1914? Or would such a ship be to expensive or consume too much coal?

Tactical success of surface raiders was generally linked to them being rare things and hard to bring to battle, which naturally limited how much damage they could actually inflict.

I don't know. Let's assume Germany would be able to use 15 light cruisers at one time for surface raiding. The RN would need ships to prevent them from leaving the North Sea, but also ships all around the world in its colonies to fight those which break through.

Do you think the RN could hunt down them all without them doing much damamge?

Considering battlecruisers did about 90% of the war's surface fighting I would hardly call them useless. In theory Fischer's ideas were 100% vindicated at the Falkland Islands. They were further proven at Jutland too though Armchair Admirals continue to believe otherwise.

A battlecruiser may be ideal for its intended role. But a Fisher-like design is not intended to fight ships with a similar calibre of guns. It is soleley intended to act as a fleet scout and to fight against smaller ships, preferably those which are slower and have a shorter gun range (e.g. armored cruisers). Against smaller cruiser it is a good weapon to keep control of the sea.

Once such a battlecruiser is put against a real battleship, it only has slim chances, though. On the other hand it is more expensive than a dreadnought.

Admirals tend to put battlecruisers in the line of battle because of their big guns and because they are available. Then they have to fulfill a role they are not intended for and this in turn means you have a ship in the battle line which combines the disadvantages of cruisers and battleships (high vulerability with high costs).

I don't know if you always can hold battlecruisers away from enemy battleships, but this is what you have to do when using them.

[CaptHawkeye]

A battlecruiser may be ideal for its intended role. But a Fisher-like design is not intended to fight ships with a similar calibre of guns.

The problem with Fisher's BCs during the war can be pinned on a single man, David Beatty.

It is soleley intended to act as a fleet scout and to fight against smaller ships, preferably those which are slower and have a shorter gun range (e.g. armored cruisers). Against smaller cruiser it is a good weapon to keep control of the sea.

This was Fisher's idea, the German idea for BCs was somewhat different and more successful. It was by accident the German BCs ended up standing in battle against the Grand Fleet at Jutland. They all got pummeled but only one had to be scuttled later.

Once such a battlecruiser is put against a real battleship, it only has slim chances, though. On the other hand it is more expensive than a dreadnought.

Yet Scheer's Scouting Force did just that at Jutland, and survived. Obviously a gigantic accident but still, the idea that a BC couldn't stand up to another capital ship wasn't as cut-and-dry as the concept's critics thought it was.

Admirals tend to put battlecruisers in the line of battle because of their big guns and because they are available. Then they have to fulfill a role they are not intended for and this in turn means you have a ship in the battle line which combines the disadvantages of cruisers and battleships (high vulerability with high costs).

The costs don't make sense if you just use them in that incredibly narrow role, sure. Except BCs were intended to perform many jobs, and they were 100% successful in most of them only giving in a "good" performance in one, fighting in a line of battle. Dreadnoughts are purely useful for standing in a battle line, not good considering that line battle was going extinct. Though no one could have known what Naval Aviation meant for the Dreadnought at the time sure. I just think it's telling that Fast Battleships dominated the construction scene after the war while the Super Dreadnought was pretty much an evolutionary dead end.

[Sea Skimmer]

Considering battlecruisers did about 90% of the war's surface fighting I would hardly call them useless. In theory Fischer's ideas were 100% vindicated at the Falkland Islands. They were further proven at Jutland too though Armchair Admirals continue to believe otherwise.

No they really were useless. The Falklands is the only time they ever did anything that could not have been done better by a cheaper dreadnought with more guns. They were so large that they just ended up fighting each other and the line of battlecruisers became worthy enemy objective in its own right, invalidating the use of them as scouts. At actions like Jutland all the scouting ended up being done by the light cruisers steaming ahead of the battlecruisers. Yet as big and expensive as they were, the battlecruisers could not engage enemy battleships on successful terms, which was the basis of Fishers idea. Fisher's desire for a speed advantage made sense, but it could only be exploited with an entire fleet, which was too expensive.

[CaptHawkeye]

I thought the basis of Fisher's idea was a cruiser killer, because the British were afraid of the threat posed by merchant raiding warships that were too fast for the Grand Fleet to chase. With a secondary job in scouting and maybe line battling when the chips were really down. Just that neither Navy really used the ships properly. (Grouping them into isolated squadrons.)

The British were obsessed with pursuing and annihilating any German squadron/fleet big or small. I mean if the Scouting Force had been a bunch of light cruisers and destroyers would it have merited any less attention? Anyway i'm not trying to argue here that BCs were a great idea, I just don't see history showing them as being totally pointless either. The basic idea seems to have been further refined into the Fast Battleship.

[Sea Skimmer]

OK, but this would only leave light cruisers for this role, then. But additionally, these ships must be able to escape from battlecruisers, otherwise they are toast.

I'd envision a vessel with about 8000t and 6-8 15cm guns. To escape from an Invincible-class battlecruiser, 30+ kts would be a necessity. I'd estimate 70,000shp would be most probably enough power.

Hawkins was somewhat larger and had 60,000shp for 30 knots, but she’d also completely trounce a ship with 6in guns. This is a problem, you start building large obvious raider cruisers, the British will reply with a similar but superior ships instead of battlecruisers. Also your large raider still won’t be able to touch a convoy defended by an obsolete predreadnought or armored cruiser, and while its big, its still not so big that it can destroy a smaller cruiser without fear of damage. A raider that takes damage that causes flooding or damages its uptakes will loose its speed and become very vulnerable. Full waterline armor belts are feasible on WW1 light cruisers, but extensively armored uptakes are not. Though you can repair them to some degree.

If you wanted a light cruiser raider, it should really be as small as possible so it can be numerous. Since the odds of a light cruiser raider defeating a serious opponent without taking crippling damage are low, why bother trying? An armament sufficient to overwhelm a defended merchant ship is all you need; four 15cm guns can do that. Size is going to be set mainly by how much endurance you want but nobody seems to have had much luck making cruisers that could steam over 6,000nm in the war period.

This then raises the question if the high speed and armor even make sense, or should the money not just be sent too subsidizing construction of large numbers of merchant ships suitable for conversion to raiders? Then you can fill the holds with coal and have high endurance with no problem. Of course then the British can counter them with armed merchant cruisers themselves, but the point being the up front investment is almost nothing, and the cost of keeping the concept ‘ready’ in peacetime is that of grease to pack the stored guns in. You can get all the extra men you need in wartime via conscription out of said merchant fleet and various reservist plans. This idea is more vulnerable to a tight blockade then dedicated warships raiders; though Germany slipped a lot of merchant raiders out historically in both world wars as it was.

The pocket battleship designs solved a lot of these issues, but it worked out only because they existed in a treaty environment which prevented the construction of countermeasures and saw all those old battlecruisers scrapped instead of laid up in reserve. They also simply weren’t numerous enough to be a really serious threat, allowing the RN and MM to simply group inferior ships against them. Germany had some pretty advanced diesel designs in WW1, diesel powered battleships were being proposed prewar, but actually putting it into service would be very difficult. A side problem is Germany has little to no oil, and in this era few oil supplies exist to be captured and few tankers to adapt to use as supply ships. Though building dedicated supply ships isn’t out of the question; many of the German ones in WW2 were purpose built; though also based heavily on WW1 experiences.

Oil though is really nice, it allows much longer ranges, faster starting boilers even if you don’t have diesels, and while underway refueling was never used by the Germans in the world wars it was still much faster, easier and less vulnerable to oil fuel at sea.

I don't know. Let's assume Germany would be able to use 15 light cruisers at one time for surface raiding. The RN would need ships to prevent them from leaving the North Sea, but also ships all around the world in its colonies to fight those which break through.

The thing is the odds of any given RN patrol ship encountering a raider inherently increase the more raiders you have in a given area. The RN is going to have far superior numbers of patrol units, and the raiders can’t expect to seriously reduce the number of said units in combat. That’s the problem with massed raiders. This also ultimately led to massive losses for the massed U-boat wolf packs of WW2 when they came up against massed escorts.

What you really needed was a nuclear submarine. Who knows, if detailed enough, adapted to the time plans were sent back in time, you could probably have built one back then too. It might melt down like the HEN Soviet types did but who cares.

Do you think the RN could hunt down them all without them doing much damamge?

I think they could end the threat in time, because they won’t be able to remain in the same area for long and are incredibly vulnerable when refueling. They’d be driven out of the North Atlantic fairly quickly. I mean really, look at the historical German raider operations in 1914. Spee’s squadron on the far side of the world was the only force to last a significant amount of time without being sunk, blowing itself up or driven into port.

[Sea Skimmer]

I thought the basis of Fisher's idea was a cruiser killer, because the British were afraid of the threat posed by merchant raiding warships that were too fast for the Grand Fleet to chase. With a secondary job in scouting and maybe line battling when the chips were really down. Just that neither Navy really used the ships properly. (Grouping them into isolated squadrons.)

Fishers core idea was to make the entire fleet faster to gain a major tactical advantage. For countering raiders that was to be exploiting radio communications to rapidly hunt down the enemy with a much smaller number of ships then previously required. For the battleline, it was to be as a fast scouting wing that could also engage the main enemy line. If he had his way the RN would have been nothing but battlecruisers, destroyers and submarines. Costs made this infeasible, so the RN ended up with a purpose split force.

Interestingly numbers were so limited at least as late as 1910 proposals were still being made for super armored cruisers, generally with 8 x 9.2in guns as dedicated commerce protectors. Meanwhile in the battlefleet role, its just hard to see what the ships were actually going to do. in The Russo-Japanese war ACs had stood in the line of battle and survived, but this was mainly because working APC shells didn’t exist and effective ranges were fairly short. Yet Fisher was the man working the hardest to increase battleranges in the Royal Navy.

The British were obsessed with pursuing and annihilating any German squadron/fleet big or small. I mean if the Scouting Force had been a bunch of light cruisers and destroyers would it have merited any less attention? Anyway i'm not trying to argue here that BCs were a great idea, I just don't see history showing them as being totally pointless either. The basic idea seems to have been further refined into the Fast Battleship.

Ask yourself this. If each side at Jutland had a big force of battleships, and a scouting force of light cruisers, would anything have been different that mattered? Not that I can see. The Germans still loose. Said battleship forces would have a lot more armor and a lot more firepower too. Invincible and Dreadnought cost almost the same amount, later battlecruisers opened up a progressively wider cost gap, and look at the disparity in fighting power. What good is superior speed if you cannot survive in range of the enemy?

The battlecruisers thus ended up fighting a sort of very expensive private war, and proved unable to stand up to engagements with even part of the enemy battleship force for long. If the German force did not have battlecruisers, then it might have been feasible for the British ones to blow past them and actually carry out the desired battlescout-outflanking role, though I am not sure what it would really have accomplished for precisely this reason. As it was bringing the enemy battlecruisers into action with battleships became the entire goal, because they were so worth destroying! It was a perversion of the idea of a scout.

Increasing the uniform fleet of the battlefleet did have merit, and was Fishers goal, but buying a small number of battlescruisers precisely takes away the surplus money that might be used to make all new dreadnoughts faster. It really took oil firing, and then small tube boilers to make a fast battleship feasible on a reasonable displacement.

The USN for its part decided uniform speed was the goal, even if it meant not increasing speed, and thus had the ‘Standards’, its plan was simply to outfight the enemy when he dared come within range and the hell with aggressive tactical manuvering scouting. I have a hard time seeing a flaw with this idea once battle ranges escalated so massively.

Of course the USN then designed the Lexington class, but they were designed for a rather different ‘strategic’ scouting role far detached from the main fleet and each other, in which the huge size was meant to support high speed and high endurance at high speed so they could find a dastardly enemy invasion fleet far out in the Atlantic. The USN idea of a tactical scout (not that it was a good one either) was a 35 knot four piper destroyer fielded in great expendable numbers.

[CaptHawkeye]

Ask yourself this. If each side at Jutland had a big force of battleships, and a scouting force of light cruisers, would anything have been different that mattered? Not that I can see. The Germans still loose.

The Germans lose but the real deal is whether they may have inadvertently validated the BC concept. Lutzow, Seydlitz, and Derfflinger all took immense punishment at Jutland and Lutzow had to be scuttled because the tide was too low to get her back into Wilhemshaven. The Germans sacrificed a lot of offensive punch in their ships but they took quite the beating. Maybe it's not that impressive, considering how much effort went into ensuring they were more durable than Superman and what they had to give up in order to be that tough. But it seems they did well considering the criticism of "BCs doomed in the line." Their performance is even more impressive if one realizes their was no German line yet, and for a little while they were the only relevant targets to soak up all the fire.

The battlecruisers thus ended up fighting a sort of very expensive private war, and proved unable to stand up to engagements with even part of the enemy battleship force for long. If the German force did not have battlecruisers, then it might have been feasible for the British ones to blow past them and actually carry out the desired battlescout-outflanking role, though I am not sure what it would really have accomplished for precisely this reason. As it was bringing the enemy battlecruisers into action with battleships became the entire goal, because they were so worth destroying! It was a perversion of the idea of a scout.

Agreeably so but BCs as a scouting arm always struck me as a job designers sort of knew they'd never be ideal for. For the Germans it makes a small degree of sense if you think about all the Armored Cruisers the British were using as forward scouts for the Grand Fleet. It's just that the way the Germans went about it was idiotic. The Scouting Forces were an independent squadron when they should have been attached to the HSF.

The USN for its part decided uniform speed was the goal, even if it meant not increasing speed, and thus had the ‘Standards’, its plan was simply to outfight the enemy when he dared come within range and the hell with aggressive tactical manuvering scouting. I have a hard time seeing a flaw with this idea once battle ranges escalated so massively.

I've been unable to spot one in the USN's concept of the Standard Type either. Almost every criticism i've ever seen leveled against the Standards was a result of naval aviation and you can't blame the USN for that. No one knew how much of a game changer airplanes would be in the future when they laid down Nevada or even Colorado.

Of course the USN then designed the Lexington class, but they were designed for a rather different ‘strategic’ scouting role far detached from the main fleet and each other, in which the huge size was meant to support high speed and high endurance at high speed so they could find a dastardly enemy invasion fleet far out in the Atlantic. The USN idea of a tactical scout (not that it was a good one either) was a 35 knot four piper destroyer fielded in great expendable numbers.

Those giant BC hulls ended up making a great carrier hulls at least. Silver lining.

[Thanas]

The German BCs had close to the same armor levels some British dreadnoughts had. So they really were more fast battleships than BCs in the Fisherian definition.

[Sea Skimmer]

The Germans lose but the real deal is whether they may have inadvertently validated the BC concept. Lutzow, Seydlitz, and Derfflinger all took immense punishment at Jutland and Lutzow had to be scuttled because the tide was too low to get her back into Wilhemshaven.

Lutzow was not lost to scuttling. When the order to scuttle was given her screws were coming out of the water, she was hopelessly sinking and becoming unstable to the point her captain feared she would capsize at any minute and ordered the men off. I love this mythical unsinkable German bullshit.

Seydlitz had to be beached several times to be saved and only made port with two salvage ships alongside her pumping out water. Even a slightly greater distance to port, or water that wasn't absurdly shallow, or lack of actual salvage ships would have doomed her.

This is meanwhile against British guns firing armor piercing shells that did not work properly, something the Germans had no right to expect. If they had worked, or heck even had the British simply not fired any APC at all and concentrated purely on the highly destructive CPC rounds all of them would have gone down and much earlier.

The Germans sacrificed a lot of offensive punch in their ships but they took quite the beating. Maybe it's not that impressive, considering how much effort went into ensuring they were more durable than Superman and what they had to give up in order to be that tough.

I'd say its not impressive. The broadside on a Derfflinger is about 400lb greater then that of HMS Dreadnought. She's close to 10,000 tons larger.

But it seems they did well considering the criticism of "BCs doomed in the line." Their performance is even more impressive if one realizes their was no German line yet, and for a little while they were the only relevant targets to soak up all the fire.

What are you going on about now? No German line? At what stage of the battle? In any case, British battlecruisers also faced down the German line alone at the end of the run to the south, and like the Germans they needed to turn away rapidly or face annihilation.

Agreeably so but BCs as a scouting arm always struck me as a job designers sort of knew they'd never be ideal for. For the Germans it makes a small degree of sense if you think about all the Armored Cruisers the British were using as forward scouts for the Grand Fleet.

Earlier German high seas fleet sorties also had armored cruisers attached.

The problem is, the light scouts on both sides still carried out the mutual missions anyway... which suggests both sides were short on screening cruisers. This is certainly the case for the Germans, they were much inferior in light forces. The battlecruisers basically ended up hindering one of the very missions they were intended for, via just consuming so many resources both in being constructed, and needing an extensive screen themselves. They were too big to risk freely.

It's just that the way the Germans went about it was idiotic. The Scouting Forces were an independent squadron when they should have been attached to the HSF.

Well, no, if the ships have any point at all they need to be detached, otherwise you've completely and finally eliminated any point in building them instead of more battleships. Ideally the battlecruiser force is supposed to eliminate all the enemy scouts, while preventing the friendly battleline from being scouted. But this was basically impossible unless you built ships with the speed of Lexingtons, and I dunno, twenty of them?

[Sea Skimmer]

The German BCs had close to the same armor levels some British dreadnoughts had. So they really were more fast battleships than BCs in the Fisherian definition.

Fisher had a firepower bias by nature. He didn't neglect armor, but wanted the minimal acceptable; 6in was actually reasonable for the I class at the expected battle range and angle against 1906 ammunition. I really cant see him seeing the German ships as battleships of any sort. Not when they were so outgunned and weight of shell was known to be an accuracy advantage at long ranges. I think they are in fact alien to any definition he would recognize.

[BabelHuber]

I think they could end the threat in time, because they won’t be able to remain in the same area for long and are incredibly vulnerable when refueling. They’d be driven out of the North Atlantic fairly quickly.

OK, I see. This leaves only submarines for commerce raiding, other ships don't seem to make sense in this role with WW1-level technology.

This means the only viable strategy would be control of the sea, and for this Germany was too weak anyways.

Fisher had a firepower bias by nature. He didn't neglect armor, but wanted the minimal acceptable; 6in was actually reasonable for the I class at the expected battle range and angle against 1906 ammunition. I really cant see him seeing the German ships as battleships of any sort. Not when they were so outgunned and weight of shell was known to be an accuracy advantage at long ranges. I think they are in fact alien to any definition he would recognize.

I think British and German battlecruisers are similar in name only. In reality they were different kind of ships:

The British battlecruisers were just cruisers with battleship-type armament. They still needed to be able to fulfill the role of a cruiser, needing a high range and versatility for being able to perform independent missions.

The German battlecruisers OTOH weren't cruisers at all. They were designed to counter the British battlecruisers in the North Sea.

So they did not need the range or the versatility of their Britisch counterparts. OTOH they needed to be able to take a few hits from battleship-type guns without being instantly mission killed.

Hence they were sturdier constructions with more armor, but saved weight by using smaller guns. The smaller guns could penetrate the RN battlecruisers' armor just fine while at the same time providing a higher rate of fire. Also they could take more hits.

At Jutland Beatty's battlecruisers had a numerical advantage of 6 to 5 and still lost 2 ships, while Hipper lost none in this first engagement.

Of course Beatty's stupid order to disregard safety masures compounded the problem, but I don't think this was the only reason for the losses. The British ships were more fragile by design, and this has to show.

The Goeben showed how tough a German battlecruiser was built. I don't think that a RN battlecruiser could withstand the same amount of damage without sinking.

[Sea Skimmer]

Hence they were sturdier constructions with more armor, but saved weight by using smaller guns. The smaller guns could penetrate the RN battlecruisers' armor just fine while at the same time providing a higher rate of fire. Also they could take more hits.

You really don't find many examples of armor over 7in thick, or even much of that, being pierced at Jutland, and the heaviest caliber penetration known was by a British gun, with crappy British shells, against German armor 250mm thick. German ships absorbed more hits, but they took a lot of damage in the process. Since no British ship was actually sunk by cumulative gunfire and torpedo damage, while one German one was and another would have vbeen if not beached you actually cannot conclude that the German ships were tougher on that basis. Every surviving RN battlecruiser Jutland was not just fit for action, but actively seeking action, while most of the German battlecruisers were in no state to fight and fleeing.

At Jutland Beatty's battlecruisers had a numerical advantage of 6 to 5 and still lost 2 ships, while Hipper lost none in this first engagement.

Result of explosions yes, but this are almost certainly to do with a decision to ignore good drill. End result is the KGV class interlocking system intended to make ignoring good drill physically impossible.

Of course Beatty's stupid order to disregard safety masures compounded the problem, but I don't think this was the only reason for the losses. The British ships were more fragile by design, and this has to show.

I don't think it really does show a really strong manner. None of the British ships which did not sink from explosions were in as bad of shape as several surviving German ships. For a while Von Der Tan had only one gun in action on local control in the run to the south for example because her wiring systems had been shot to pieces and several turrets hit. In general the much weaker firepower of German guns made most of the issues that should have existed with British armoring irrelevant. No doubt exists that the larger caliber British shells were more destructive when they did hit. The Germans would have been screwed had they not adapted better gunnery methods. That was what really counted for the Germans at Jutland, but it had nothing to do with specific ship designs.

Generally the Germans did think out things better, I don't think anything can justify just how crazy incremental the armoring on British ships was, but interestingly we see late war German designs only expanding incremental armor coverage. However when it came down to it, the British ships worked well, and the German advantage in drill, gunner and powder quality counted for far more then armor ever did. Seydlitz after all was seconds from exploding at Dogger Bank, and that was from a heavy British shell piercing her relatively thick barbette armor.

The Goeben showed how tough a German battlecruiser was built. I don't think that a RN battlecruiser could withstand the same amount of damage without sinking.

I think this is much exaggerated. Goeben never took serious gunfire damage, and only avoided sinking from being mined the last time by beaching, most of her mine strikes were very close to port and small shallow devices as they were laid to sink small Turkish collier traffic and not deeply moored to sink capital ships. She also had an awesome track record of running away from Russian predreadnoughts that could out shoot her. Kind of silly, the longest range moving ship to ship hit in the war is from a Russian predreadnought against her.

HMS Audacious infamously sank from one mine, but the mine exploded under her bottom, don't ask me how as I have no idea, and worse, under the engine rooms which would devastate any dreadnought of the era.

[BabelHuber]

You really don't find many examples of armor over 7in thick, or even much of that, being pierced at Jutland, and the heaviest caliber penetration known was by a British gun, with crappy British shells, against German armor 250mm thick.

OK.

Since no British ship was actually sunk by cumulative gunfire and torpedo damage, while one German one was and another would have vbeen if not beached you actually cannot conclude that the German ships were tougher on that basis. Every surviving RN battlecruiser Jutland was not just fit for action, but actively seeking action, while most of the German battlecruisers were in no state to fight and fleeing.

Some RN ships were also heavily hitted, like Tiger or Queen Elizabeth. It's just that the Germans ran away and the Britisch tried to pursue.

Invincible took only a single torpedo at the Dardanelles and had to be beached, too. Additionally, she had to be beached again after preliminary repairs on her way to the dry dock. This doesn't exactly show sturdiness, I think.

Sedlitz was hit by 21 heavy heavy shells and one torpedo or so. I doubt than any RN battlecruiser would have made it home after taking such a beating and it is no wonder that Sedlitz needed some luck for her way back to port.

Lützow was also hit by 20 or so big caliber shells. This was compounded by hits to the forward torpedo room. There lots of water poured in which sealed her fate. I read that this torpedo room was a rather stupid design decision, because torpedos did more harm than good to capital ships. After Jutland the foward torpedo was removed from the other Derfflingers, so more bulkheads could be added.

Also note that she was sunk by own ships. If more time would have been available, she probably also could have been saved.

Result of explosions yes, but this are almost certainly to do with a decision to ignore good drill.

Three battlecruisers exploded at Jutland alone. Also the Hood exploded when battling Bismarck in WW2, albeit being hit by a shells more advanced.

So I think this shows that RN WW1 battlecruisers had the tendency to explode under heavy fire. Perhaps this has something to do with the internal design of the ships, so when a shell pierced through the outside armour it could do more damage on the inside.

Also none of the Britisch dreadnoughts exploded at Jutland. IIRC the Warspite was hit by 14 shells or and barely made it home, but didn't explode.

I don't think it really does show a really strong manner. None of the British ships which did not sink from explosions were in as bad of shape as several surviving German ships. For a while Von Der Tan had only one gun in action on local control in the run to the south for example because her wiring systems had been shot to pieces and several turrets hit. In general the much weaker firepower of German guns made most of the issues that should have existed with British armoring irrelevant. No doubt exists that the larger caliber British shells were more destructive when they did hit. The Germans would have been screwed had they not adapted better gunnery methods. That was what really counted for the Germans at Jutland, but it had nothing to do with specific ship designs.

True, some German ships were badly beaten, but after the initial battlecruiser engagement basically the German fleet just tried to escape home. They had to avoid being sunk by the numerically vastly superiour RN fleet after all.

Generally the Germans did think out things better, I don't think anything can justify just how crazy incremental the armoring on British ships was, but interestingly we see late war German designs only expanding incremental armor coverage. However when it came down to it, the British ships worked well, and the German advantage in drill, gunner and powder quality counted for far more then armor ever did. Seydlitz after all was seconds from exploding at Dogger Bank, and that was from a heavy British shell piercing her relatively thick barbette armor.

Seydlitz had a design issue at that time: When a turret was hit, the resulting explosion could flash-ignite the magazine. This was fixed after Dogger Bank , so at Jutland this wasn't a factor anymore.

I think this is much exaggerated.

From what I have read, considering that Goeben didn't have access to dry docks she took a huge amount of beating. But perhaps this _was_ exaggerated, I don't know.

HMS Audacious infamously sank from one mine, but the mine exploded under her bottom, don't ask me how as I have no idea, and worse, under the engine rooms which would devastate any dreadnought of the era.

I thought that in this case, the ship could have even been saved if the ship's complement had acted more professional. But they did not, so the ship sunk. But again I could be wrong.

As bottom line I'd say RN WW1 battlecruisers tended to explode while German ones tended to need dozens of hits before going down. SO I'd give the German design a clear advantage.

[Sea Skimmer]

Some RN ships were also heavily hitted, like Tiger or Queen Elizabeth. It's just that the Germans ran away and the Britisch tried to pursue.

Yeah and the British could pursue with a ship like Tiger because her damage, while extensive was not actually that serious in terms of her ability to fight. Many of the fleeing German ships were burning wrecks. QE BTW was not hit in the battle. Barham, Warspite and Malay were.

Invincible took only a single torpedo at the Dardanelles and had to be beached, too. Additionally, she had to be beached again after preliminary repairs on her way to the dry dock. This doesn't exactly show sturdiness, I think.

You mean Inflexible and she struck a mine not a torpedo. Reported flooding was 1,600 tons which should not have endangered her, the beaching seems to have been precautionary. Maybe not surprising when a bunch of ships had just sunk in minutes from minutes. The repair was an external coffer dam which came loose steaming in the open sea at Malta, nothing to do with the ship design really.

Sedlitz was hit by 21 heavy heavy shells and one torpedo or so. I doubt than any RN battlecruiser would have made it home after taking such a beating and it is no wonder that Sedlitz needed some luck for her way back to port.

Considering that HMS Lion took thirteen or fourteen hits, still had 75% of her main armament in action, speed unimpaired, no flooding of note, and HMS Tiger was hit fifteen times with damage to one turret, no serious impairment to speed, no serious flooding, I’d say you really never thought about this much. That includes a barbette hit on Tiger rejected by her armor. Seydlitz had 200 men killed at Dogger bank by precisely such a hit penetrating.

While no battlecruiser, HMS Warspite was also hit 15 times, had only 30 casualties, and no loss of speed or main armament.

Lützow was also hit by 20 or so big caliber shells. This was compounded by hits to the forward torpedo room. There lots of water poured in which sealed her fate. I read that this torpedo room was a rather stupid design decision, because torpedos did more harm than good to capital ships. After Jutland the foward torpedo was removed from the other Derfflingers, so more bulkheads could be added.

Yes the torpedo flats were stupid because they could allow 800 or so tonnes of flooding from the smallest leak. They were present on all German capital ship designs in WW1, even post Jutland stuff shows them. not exactly an endorsement of superior German design. The decision to subdivide torpedo flats did not come until late 1917 when Bayern hit a mine in the Baltic, and while not really in danger of sinking as far as I am aware, took so much flooding in her bow that it took several weeks to nurse her back to a dry dock.

Most RN designs also had such compartments too. It’s a detail design issue, but so what? Most British problems are also detail design issues, not gross disparities in design standards/priorities. The Germans on the other hand had a serious detail design issue with wiring, running electrical power cables high in the ship above most of the armor. Splinters would then break the cables and left many turrets without electrical power. They could still be handworked, but only very slowly. British turrets were generally hydraulically run and had the power enter lower down. Reports of turrets disabled by power failure seem to be very rare for the RN.

Also note that she was sunk by own ships. If more time would have been available, she probably also could have been saved.

No she would not have. She would have capsized. That is precisely why she was abandon and ordered torpedoed. I love you idiot German fanwhores who think scuttling a sinking wreck proves a ship so flooded she could no longer move would have survived. The thing was done for, period.

Three battlecruisers exploded at Jutland alone. Also the Hood exploded when battling Bismarck in WW2, albeit being hit by a shells more advanced.

SMS Pommern exploded at Jutland too because of stupid wing passages for her secondary magazines ran along the edge of the hull; Hood exploded from main armor penetration against a ship 20 years newer, no warship even today is immune from exploding warheads in proximity to its own magazines. But hey Tirpitz also blew up in WW2, and Blucher in WW1, Sharnhorst in the second, several German cruisers spontaneously blew up before the war ever started, and what was the point of this?

So I think this shows that RN WW1 battlecruisers had the tendency to explode under heavy fire. Perhaps this has something to do with the internal design of the ships, so when a shell pierced through the outside armour it could do more damage on the inside.

Ah, so you are admitting that you are in fact wholly and completely ignorant of the why and rather then learn anything about it, you’re wasting my time with your own speculation. Great.

Also none of the Britisch dreadnoughts exploded at Jutland. IIRC the Warspite was hit by 14 shells or and barely made it home, but didn't explode.

If by barely made it home you mean was steaming under her own power with all main battery weapons fit for action, then yes. Three British battlecruisers blew up, and two armored cruisers engaged by battleships blew up, the latter being no surprise what so ever. One German predreadnought, one light cruiser blewup, the former from a torpedo and the latter from shellfire. Numerous German ships barely avoided explosions from ammunition fires by flooding magazines.

That was a real German advantage, the gunpowder used was more resistant to explosions and bought time to flood magazines. But that doesn’t say much about the superior armor that it had to be done so often. Most likely because most of the superiority in armoring was in the lower belts, and yet lower belt armor was unlikely to be hit, simply because its only a small part of the ships profile as a target. Upper barbette and turret armor disparities were not so great.

Seydlitz had a design issue at that time: When a turret was hit, the resulting explosion could flash-ignite the magazine. This was fixed after Dogger Bank , so at Jutland this wasn't a factor anymore.

ALL SHIPS had this issue in 1915. The Germans just barely survived in ordered to learn. However in fact many German ships still did not have improved flash doors at Jutland. Nor were such doors fully effective. The British had no such experience, and so did not improve the ships they had until after Jutland. However that is almost certainly not the actual cause of the battlecruiser explosions at Jutland. Rather an order from the top to ignore drill with ammunition handling is the most likely cause, leading to excessive numbers of charges being stocked at all working positions. This made it possible for an ammo fire to get out of hand much more quickly then should have been the case, and before magazine flooding could be ordered.

Preventing flashover though, actually just prevents an immiedate explosion. Pressure and heat from the ammunition fires still presented an immense risk of explsion, and forced magazine flooding, as was required numerous times for German ships at Jutland, and more then a few times on RN vessels. All of this is a small detail design issue, entirely devoiced from the ships armoring or gunnery design.

Plus, Seydlitz only took that damage in the first place precisely because her superior barbette armor could not in fact keep out superior sized British shells, even with the British shells being essential defective in design.

From what I have read, considering that Goeben didn't have access to dry docks she took a huge amount of beating. But perhaps this _was_ exaggerated, I don't know.

What she really took, was immense amounts of time to repair after each incident. Since no dry dock was on hand they had to build huge cofferdams around the hull and then repair the work within the dry area. This kept her out of action for very long periods of time, during which the Russian fleet would raid up and down the Turkish black sea coast opposed only by a few submarines and mines. The damage from her final mining and beaching wasn’t fixed until after the war was over. I believe the hull wasn’t full restored to order until her 1930 refit. Her career was no doubt impressive, it just tends to get exaggerated.

I thought that in this case, the ship could have even been saved if the ship's complement had acted more professional. But they did not, so the ship sunk. But again I could be wrong.

The problem was progressive flooding through numerous small leaks opened up by an underbody explosion. Even with better crew drill it would have near impossible to stop them all out. Underbody explosions tend to bend the entire frame of a ship. These leaks allowed water to flood all the ships sources of power, and with no power you had no pumps... ship is doomed. Nobody in WW1 had emergency generators or portable pumps spread around the ships to guard against this. Nor did anyone have dispersal of the main machinery plant.

[Eternal_Freedom]

QE wasn't at Jutland. Warspite and the rest of the 5th Battle Squadron took a lot of hits but certainly proved the concept of the fast super-dreadnought. Warspite only took so many hits because her rudder jammed and she circled for a while under the guns of a large portion of the German fleet.

As for RN battlecruisers exploding under heavy fire, no shit, any ship is going to go boom if the magazine explodes. Even battleships will explode if the magazine is hit so it's hardly a design failure.

[Captain Seafort]

As for RN battlecruisers exploding under heavy fire, no shit, any ship is going to go boom if the magazine explodes. Even battleships will explode if the magazine is hit so it's hardly a design failure.

IIRC Malaya was bloody lucky not to go the same way as the battlecruisers after she was hit in her secondary battery.

[BabelHuber]

Yeah and the British could pursue with a ship like Tiger because her damage, while extensive was not actually that serious in terms of her ability to fight. Many of the fleeing German ships were burning wrecks. QE BTW was not hit in the battle. Barham, Warspite and Malay were.

I meant Warspite, not QE, sorry.

From what I understood, the German ships took more hits due to their numerical inferiourity, so I think that it is no wonder a lot of them were in bad shape.

Also the RN pursuided the KM, so of course the German ships ran away and the Britisch ones tried to catch them.

AFAIK Scheer did order the battlecruisers to attack at Jutland later in the battle to cover the retreat of the fleet, so both Scheer and Jellicoe were seemingly still ordering damaged ships to fight.

But of course I have to concede that Tiger was hit over a dozen times without being taken out of the battle. The same is probably true for other RN battlecruisers like Lion, so they were not _so_ weakly armored.

You mean Inflexible and she struck a mine not a torpedo. Reported flooding was 1,600 tons which should not have endangered her, the beaching seems to have been precautionary. Maybe not surprising when a bunch of ships had just sunk in minutes from minutes. The repair was an external coffer dam which came loose steaming in the open sea at Malta, nothing to do with the ship design really.

OK, Inflexible and mine then, sorry.

According to my sources, she needed to be beached to prevent her from sinking. But I just noticed that the mine caused the flooding of the forward torpedo flat, so she had the same design issue that Lützow plagued. Since this weakness is shared by German and British designs, I have to concede that this incident proves nothing.

Considering that HMS Lion took thirteen or fourteen hits, still had 75% of her main armament in action, speed unimpaired, no flooding of note, and HMS Tiger was hit fifteen times with damage to one turret, no serious impairment to speed, no serious flooding, I’d say you really never thought about this much. That includes a barbette hit on Tiger rejected by her armor. Seydlitz had 200 men killed at Dogger bank by precisely such a hit penetrating.

While no battlecruiser, HMS Warspite was also hit 15 times, had only 30 casualties, and no loss of speed or main armament.

I think I see your point here: Since a hit from Moltke was unable to penetrate a barbette of Tiger (but not vice versa), the German ships were comparatively under-armed.

AFAIK Tiger was hit by Moltke with 28cm guns. Could the 30.5cm guns of the Derfflinger-class have penetrated the barbette?

Moltke was a 1st Generation battlecruiser, while Tiger was a 2nd Generation battlecruiser (derived from Orion instead of Dreadnought).

So where the Derfflingers's 30.5 guns a good choice, or do you think they were under-armed, too?

Yes the torpedo flats were stupid because they could allow 800 or so tonnes of flooding from the smallest leak. They were present on all German capital ship designs in WW1, even post Jutland stuff shows them. not exactly an endorsement of superior German design. The decision to subdivide torpedo flats did not come until late 1917 when Bayern hit a mine in the Baltic, and while not really in danger of sinking as far as I am aware, took so much flooding in her bow that it took several weeks to nurse her back to a dry dock.

Most RN designs also had such compartments too. It’s a detail design issue, but so what? Most British problems are also detail design issues, not gross disparities in design standards/priorities. The Germans on the other hand had a serious detail design issue with wiring, running electrical power cables high in the ship above most of the armor. Splinters would then break the cables and left many turrets without electrical power. They could still be handworked, but only very slowly. British turrets were generally hydraulically run and had the power enter lower down. Reports of turrets disabled by power failure seem to be very rare for the RN.

Didn't know about the cable issue, but this seems to be a rather big design blunder in deed.

No she would not have. She would have capsized. That is precisely why she was abandon and ordered torpedoed. I love you idiot German fanwhores who think scuttling a sinking wreck proves a ship so flooded she could no longer move would have survived. The thing was done for, period.

Don't act like an ass, German fanwhores show a different behaviour.

I got this from the German Wikipedia (http://de.wikipedia.org/wiki/SMS_L%C3%BCtzow, translation by me):

During the nightly retreat at last she had to be driven backwards to releave the bulkeads in the front. Meanwhile 7,500t of water had flown in, so the Lützow couldn't be maneuvred anymore. Heck and rudder where outside of the water, and also the ship's propellers spinned outside the water. The ship had to be abandonded finally after it was already prepared to be hauled back to Wilhelmshaven, because the British fleet came closer and it was impossible to stay out of firing range.

So you were right, she couldn't have made it back home on her own. On the other hand, if Wikipedia is correct, it was also not impossible to get her home with some help. They just ran out of time.

SMS Pommern exploded at Jutland too because of stupid wing passages for her secondary magazines ran along the edge of the hull; Hood exploded from main armor penetration against a ship 20 years newer, no warship even today is immune from exploding warheads in proximity to its own magazines. But hey Tirpitz also blew up in WW2, and Blucher in WW1, Sharnhorst in the second, several German cruisers spontaneously blew up before the war ever started, and what was the point of this?

This discussion is about WW1 battlecruisers. Bluecher was an armored cruiser, exactly the type the Invincible-class was designed to obsolete.

German light cruisers were mostly inferiour to their Britisch counterparts anyways (due to their sub-15cm guns).

WW2 German battleships, well, we don't need to discuss this. They were less competitive than the WW1 German ships, I'd say.

Ah, so you are admitting that you are in fact wholly and completely ignorant of the why and rather then learn anything about it, you’re wasting my time with your own speculation. Great.

No, I simply made an assumption which could be wrong.

If by barely made it home you mean was steaming under her own power with all main battery weapons fit for action, then yes. Three British battlecruisers blew up, and two armored cruisers engaged by battleships blew up, the latter being no surprise what so ever. One German predreadnought, one light cruiser blewup, the former from a torpedo and the latter from shellfire. Numerous German ships barely avoided explosions from ammunition fires by flooding magazines.

But this is exactly the point: This ship barely avoided explosion, that ship barely avoided explosion, but the only ships which actually exploded where the Britisch battlecruisers.

Lots of ships tended to explode when they were already outdated and hit by gunfire they were never intended to handle. But the British battlecruisers were modern designs at that time.

That was a real German advantage, the gunpowder used was more resistant to explosions and bought time to flood magazines. But that doesn’t say much about the superior armor that it had to be done so often. Most likely because most of the superiority in armoring was in the lower belts, and yet lower belt armor was unlikely to be hit, simply because its only a small part of the ships profile as a target. Upper barbette and turret armor disparities were not so great.

So in addition to their weak guns, the heavily armored belt was no real advantage for KM battlecruisers?

This would mean that the German battlecruisers would have been more effective with bigger guns, but less armored belt?

This in turn would mean that Tiger-like designs were the best battecruiser designs back then.

And the Renown-class would have been a step in the wrong direction?

To sum it up: The fact that Moltke couldn't penetrate the Tiger's barbette proves me wrong on the one hand. I must admit this clearly.

But on the other hand: ´Why did then only RN battlecruisers blow up so spectaculary? Why did all other ships with similar hits escape such an explosion?

When various German and Britisch dreadnoughts and battlecruisers suffered critical hits by other capital ships, but only British battlecruisers exploded (2 under Beatty's command, 1 under Hood's command and HMS Hood in WW2), can this be only bad luck (Hood) and disregarding of safety measures? (all RN WW1 battlecruiser losses)?

Or did they have some other issue in common which is not related to armor strength?

[Simon_Jester]

By the way, BabelHuber, you wouldn't happen to be from a German-speaking country, would you? I caught you spelling "British" as "Britisch" once. And you sometimes at the end of the sentence your verb put.

[This is not a criticism, just wondering; to me your English reads like I'd expect from a German with a reasonably good education in the English language, but without the fine polish of long practice and experience.]

To sum it up: The fact that Moltke couldn't penetrate the Tiger's barbette proves me wrong on the one hand. I must admit this clearly.

But on the other hand: ´Why did then only RN battlecruisers blow up so spectaculary? Why did all other ships with similar hits escape such an explosion?

When various German and Britisch dreadnoughts and battlecruisers suffered critical hits by other capital ships, but only British battlecruisers exploded (2 under Beatty's command, 1 under Hood's command and HMS Hood in WW2), can this be only bad luck (Hood) and disregarding of safety measures? (all RN WW1 battlecruiser losses)?

In a word, yes.

So I think this shows that RN WW1 battlecruisers had the tendency to explode under heavy fire. Perhaps this has something to do with the internal design of the ships, so when a shell pierced through the outside armour it could do more damage on the inside.

More like (and Skimmer already mentioned this) poor British powder handling procedure. Basically, a hit that penetrated to anywhere within the magazine-turret-barbette area would automatically ignite loose powder the British had kicking around because they were in too much of a hurry to handle explosives responsibly. Therefore it would cause a flash fire that would go through open blast doors (kept open because the British were being morons, see above) and ignite the magazine, blowing the ship to bits.

This didn't have anything to do with what the Germans did right. It had to do with what the British did wrong.

Seydlitz had a design issue at that time: When a turret was hit, the resulting explosion could flash-ignite the magazine. This was fixed after Dogger Bank , so at Jutland this wasn't a factor anymore.

See? Same problem. The British didn't fix it (though it happened to Lion at Dogger Bank).

As bottom line I'd say RN WW1 battlecruisers tended to explode while German ones tended to need dozens of hits before going down. SO I'd give the German design a clear advantage.

The catch is that the advantage boils down to one thing: better explosives handling, which had little or nothing to do with the designs. If the Royal Navy had been given the Kriegsmarine's ships and vice versa, not much would have changed in that respect.

If you want a measure of design quality, compare British ships which did NOT explode from a lucky shot to the 'critical hit' areas of the ship, and see how many hits they took and how well they handled them. Also make sure to factor in that, as an inherent weakness in the German design scheme, the ships had smaller-caliber guns, and so their hits would predictably penetrate less armor and do less damage.

Comparing Derfflinger (a 26000-ton battlecruiser launched in 1913) to Tiger (a 28500-ton battlecruiser launched in 1913), the German ship mounts eight 30.5 cm guns, with a combined broadside weight of roughly 3280 kg, while the British ship mounts eight 13.5" (34.3 cm) guns, with a combined broadside weight of 5080 kg.

Firing shells that weighed 50% more would give Tiger a very large advantage, in terms of being able to do decisive, ship-wrecking damage to an opponent. To find a competitive weapon you'd have to look at the Mackensen design, which increased weight to 31000 tons (as much larger than Tiger as Tiger is compared to Derfflinger!).

And around the time the first Mackensen was finished (i.e. considerably later than the historical launch date), it would have been competing with the Admiral-class battlecruisers, i.e. Hood. Which in turn eight 15" guns for a broadside of 6960 kg, opening the gap all over again, and also being a faster, bigger and heavier ship in general.