Light cruisers like "Svetlana". Part of 4. Speed and armor
In the last article, we examined the capabilities of artillery armament of Svetlana-type cruisers in comparison with their foreign counterparts and came to the conclusion that, according to this parameter, Svetlana have a significant advantage over foreign cruisers. But any advantage is good only when it can be realized, and then the question arises to Svetlana. As a matter of fact, only one glance at the side view of the cruiser suggests that the bulk of its guns are located very low from the waterline, and did it not happen that in fresh weather it was flooded with water, making artillery fire ineffective or impossible?
In fact, of course, the filling of the upper deck with water in fresh weather depends on many factors, and not only on its height above sea level. So, for example, the convergence on a wave is very important. For a ship with acceptable flotation ability, it is enough to have a high forecastle: the upper deck behind it will not be poured especially. Probably that is why German shipbuilders, despite the rich experience of operating cruisers during the First World War and before him, did not hesitate to place low weapons even in their post-war projects.
Nevertheless, there is every reason to assert that with the seaworthiness of the Svetlan everything was not too good: in spite of the high forecastle side, the bows of the bow were such that the cruiser was trying not to ascend, but to cut through the wave. There are indications that two or even all four 130-mm guns could not be used at high speed due to heavy splashing, although it is not clear from the source whether this is documentary evidence or the opinion of the author. It should be noted that of all the foreign cruisers that we are considering, only Caroline had equally low-lying artillery, and the rest of the ships it was placed much higher.
But here's what is interesting: the seaworthiness of Caroline and Danai was considered by the British themselves very low. As for the German Koenigsbergs, the sources differ: the Germans themselves claim that the seaworthiness of their ships was beyond praise, but the British consider it completely unacceptable by the standards of the British fleet. In the absence of measurable evaluation criteria, one can only guess at the comparative seaworthiness of cruisers, but, most likely, the best among all the ships compared with the Svetlana was the English Chester. And, regardless of how high the Svetlan artillery was actually high, its low location does not color the project: according to the height of the artillery, the Svetlana and Caroline share the least significant last place. Although, we repeat, it is completely unclear how the distribution of places in this rating affected the capabilities of artillery in fresh weather.
Anti-aircraft and torpedo weapons
The anti-aircraft armament of cruisers does not make much sense to consider: it was on all the ships of World War I in a very rudimentary state and performed, rather, the task of driving away enemy aircraft, rather than destroying them. For this purpose, several small-caliber artillery guns were usually mounted on cruisers with an increased vertical pointing angle. In this regard, four 63,5-mm guns and four Maxim machine guns that were planned to be mounted on the Svetlana were quite adequate and approximately corresponded to (and even exceeded) the anti-aircraft armament of foreign cruisers: the German had two 88-mm anti-aircraft guns, Caroline - one 76-mm and four 47-m, etc. Much more interesting is the kind of anti-aircraft armament received by Svetlana after their completion in the 20s, but we will return to this issue.
In terms of the torpedo armament, the Svetlana were obvious outsiders. In the first versions of the project, it was intended to install torpedo tubes on a ship before 12 due to the fact that cruisers of this type were supposed to bring destroyers to the torpedo attack, and therefore, according to the admirals, they themselves could be at a distance of a torpedo shot from the enemy. But in the end, the case was limited to only two traverse torpedo tubes.
Similar weapons (two traverses TA) from all foreign cruisers had only Chester, but its torpedo weapon It was much more powerful. The fact is that the Russian imperial fleet was late with the transition to torpedoes 533-mm caliber. The British developed their first 533-mm torpedo as early as 1908 and put it into service in 1910. We even the newest Noviki continued to arm 450-mm torpedoes. In principle, they were quite reliable weapons, but in terms of their range and mass of explosives, they were much inferior to 533-mm “self-propelled mines” from the time of the First World War. Thus, the Russian torpedo could go 2 000 m with speed 43 knots, while the British 533-mm Mark II model 1914 r. - 4 000 m on 45 nodes, while the “Englishwoman” carried 234 kg of trotyl, while Russian - only 112 kg. Therefore, in terms of torpedo armament, Svetlana lost to both Chester and Caroline, which had four 533-mm torpedoes and, of course, Danae, carrying four three-tube 533-mm torpedo tubes.
The German G7 of the 1910 model, capable of passing 4 000 m on 37 nodes and carrying 195 kg of hexonite, were inferior in their combat capabilities to British ones, but alas, they were also superior to domestic torpedoes. At the same time, Koenigsberg carried two single-tube rotary and two underwater torpedo tubes.
Thus, we can say that the torpedo armament of domestic cruisers was completely inadequate and in its original form, in general, not necessary. The only thing that the traverse torpedo tubes were capable of - to sink the arrested and stopped transports. But actions on communications were not the priority task of Svetlan, and during the battle, at high speeds, there was always the danger of the torpedo not leaving the traverse apparatus (a strong oncoming flow of water). And the accuracy of shooting left much to be desired. Therefore, during the post-war completion, the Svetlan torpedo armament was replaced and drastically strengthened, but this happened later. And in the design form, the Svetlana was even inferior to the Austro-Hungarian Admiral Shpaun, carrying 4 torpedo tubes with a 450 caliber of mm.
Reservation
The Svetlan reservation system was simple and efficient.
The basis of the vertical booking was 75-mm armor belt with a height of 2,1 m, on the upper edge of which the lower deck rested. Under normal displacement, this armor on 0,9 m was under water. At the same time, as far as can be understood, their total length of the 154,8 m cruiser at the 75 waterline was protected by 150 m armor from the stem in the stern, where the armor ended with 50 mm by traversing - the 25 mm armor plate of the same height (2,1 m) protected the stern from it.
Thus, the Svetlan armor belt was solid and covered the entire waterline, but in the last approximately 5 meters its thickness decreased to 25 mm. It is also worth mentioning that his armor plates were placed on top of the 9-10 mm sheathing. Above the main armor belt, the space between the lower and upper deck was protected by 25 mm armor along the entire length of the ship. Interestingly, in this case, the armor plates did not fit over the skin, but they themselves were her and participated in ensuring the longitudinal strength of the hull. The height of this upper armored belt was 2,25 m.
The upper and lower decks of the ship along the entire length of the hull consisted of 20 mm armor plates. Thus, by and large, the protection of Svetlana-type cruisers consisted of an armored shell almost the entire length of a ship 75 mm thick, covered with 20-mm armor on top, over which a second armor with a vertical wall thickness 25 mm, also covered from above 20 -mm armor.
It is usually stated that all armor of Svetlana-type cruisers was produced by the Krupp method, with only 75-mm armor plates and armored shell being cemented, and the rest of the armor was homogeneous. However, this is highly doubtful, because, most likely, they could not produce cemented slabs 75 mm thick either in Russia or in the world. Most likely, cemented armored plates defended only felling.
In addition, the Svetlana reserved armored ammunition elevators (25 mm), chimneys between the lower and upper decks, and for the nose pipe - to the forecast deck (20 mm), conning tower (walls - 125 mm, roof - 75 mm, floor - 25 mm), as well as shields, protecting guns (according to various data - 20-25 mm. But the casemates of the cruiser were not protected by armor.
In general, it can be stated that the Svetlan armor practically perfectly protected against all calibers of the then artillery in 152 mm inclusive. Her 75-mm armor could be pierced with an 152-mm projectile from a distance of about 25, possibly an 30 cable. But at such a distance, of course, the enemy cruiser could come only at night, and during the day firing such projectiles at the Svetlana did not make sense. At the same time, the “top floor” of the body armor (20 mm deck and 25 mm board), of course, did not protect against six-inch high-explosive shells, but forced them to explode when it was overcome, and fragments of such shells could not penetrate the second 20 mm deck anymore. At the same time, the upper 25 mm belt, although it could not withstand a direct hit, was still quite capable of protecting it from fragments of shells that exploded in the water near the cruiser.
But there was another very interesting nuance. Still, the 20-mm armor is not too much, and the high-explosive 152-mm projectile exploded on it can easily break it, hitting the armor space with fragments of the projectile itself and fragments of armor. Wouldn't it be better, instead of two decks on 20 mm, to make one 40 mm, which almost guaranteed to protect against six-inch shells?
But what is interesting is that if, say, the same high-explosive 152-mm projectile hits the top, 25-mm armor, it detonates either during the process of breaking such armor, or immediately after its overcoming. In this case, the explosion will occur between the upper and lower decks - and you can be sure that the fragments of the projectile will not go down or up, as the explosion will occur in the armored box, above and below the closed 20-mm armor plates. Why protect the bottom, of course, because there are artillery cellars, machinery and boiler rooms, mechanisms. But there are numerous guns at the top, and if you make the upper deck out of the usual 8-10-mm structural steel, then the fragments of the projectile that exploded in the hull, punching the upper deck, can do things, mowing down artillery calculations. Two armored decks completely eliminate such troubles, and this is a very important advantage of the Russian ship project.
And what about other countries cruisers?
Let's start with the British scout "Caroline".
Its sides defended 76,2-mm armor, thinning to the nose, first to 57,2, and then to 38 mm. The stern belt became thinner to 50,8-63,5 mm, but did not reach the end of the stern. Caroline had no upper armor belt, but in the area of machine and boiler rooms of 76,2 mm the armor plates did not rise to the lower deck, as in Svetlan, but to the upper deck, i.e. the space between the lower and upper decks was protected by 76,2 mm, not 25 mm, as in the domestic cruiser. But only above the engine and boiler rooms, the rest of the board over the armor had no protection.
As for the booking of decks, everything here was not good, because it was not solid, but fragmentary: 25-mm armored plates were covered with engine rooms, boiler rooms and the steering compartment in the stern. The rest of the deck had no protection.
What can you say about the protection of cruisers like "Caroline"? It should be noted that it is very thorough for a ship with a normal displacement of 4 219 t (at the time of entry into service). No doubt, the British made a lot of effort to protect their scouts and achieved outstanding results: but, of course, it was impossible to provide a level of booking comparable to a Russian cruiser on a ship of this size.
The British were forced to abandon, in fact, armor, using instead steel NT (High Tensile Steel - steel of high resistance). The win was that this “armor” was at the same time the cruiser skin, by analogy with the 25 mm upper belt of Svetlana. So, for example, as you can see from the description, the 76,2 mm belt consisted of two layers of HTS - 25,4 mm, which, in fact, served as a skin and 50,8 mm over the first.
Thus, it should be taken into account that the 75 mm of the Svetlan armor belt cannot be directly compared to the British 76,2 belt, yet our cruiser had another 9-10 mm skin for armor, while the British cruiser did not have anything under the armor. . And besides, although it can be assumed that, by its protective qualities, HTS was close to Krupp's uncemented armor, but still it was not its equivalent. Unfortunately, the author of this article does not have accurate data on the composition and armor resistance of HTS, but according to his data, STS (Special Treatment Steel) was some kind of analogue of homogeneous armor in England, and HTS was only a slightly improved shipbuilding steel.
Most likely, the areas of Caroline beads that had 76,2 mm thickness were completely unkillable for high-explosive shells at almost any combat distance, but this cannot be said about the extremities, especially since according to some data, the waterline at the waterline had a non-38 mm closer to the stem , but only 25,4 mm thickness. The armor deck was generally little protected from what - since the upper deck was being booked, the high-explosive shell (or its fragments), which entered from sharp bow or stern angles, could easily have passed into the engine rooms or boiler rooms, bypassing the armor. Yes, and the same tip, without horizontal protection, could be pierced by shrapnel through, including the bottom of the ship.
As for the other defenses, it was quite impressive: the 152-mm conning tower and the 76-mm gun shields. It is very difficult to say how justified shields of similar thickness are, probably, it is not so easy to direct a weapon with such a mass of armor. But the most important thing - having paid much attention to the thickness of the defense, the British for some reason did not bother with its area at all, because of which there was a large gap between the shield and the deck, through which the fragments hit the gun calculations bypassing the “unkillable” shield.
Yet, despite all the flaws, the Caroline should be considered a very well-protected cruiser for its size.
The latest "towns", light cruisers "Chester" and "Birkenhead".
Unfortunately, their booking schemes could not be found, and the available descriptions may not be entirely correct. The fact is that the booking of “city” cruisers was gradually improved from one type to another, and confusion was possible here. According to the author's data, the protection of these cruisers looked like this: the extended armor belt, starting at the stem and ending, a little short of the stern had a thickness of 51 mm, and along the engine and boiler rooms - 76,2 mm (in the nose, perhaps, only 38 mm) . In the area of boiler rooms and machine rooms to the upper deck, but the cruiser had a very long forecastle, so that between the upper edge of the armor belt and the guns there was still one unarmored space between the decks.
According to some reports, the armored belt was a 25,4-51 mm armor plate on the 25,4 mm HTS “substrate”, i.e. 76,2-51 mm assigned to him "on the totality" of plating thickness and armor. On top of its upper edge, there was a rather original armored deck that had 19 mm above the engine and boiler rooms, 38 mm above the steering gear, and in other places only 10 mm of armor (or was it again HTS?). In any case, it can only be stated that for a ship with a normal displacement in 5 185, the booking does not strike the imagination at all and is obviously inferior to Svetlana, especially in terms of horizontal protection.
Nevertheless, the Chester was considered an excellent protected light cruiser and demonstrate its capabilities in real combat. In the Battle of Jutland, he "substituted" himself under the fire of the 2 reconnaissance group, including the cruisers Frankfurt, Wiesbaden, Pillau and Elbing, and the battle began at a distance of no more than 30 cables. In less than 20 minutes, the cruiser received an 17 150-mm high-explosive shells, however the defense did the trick. True, some 76,2 mm belt armor had to be changed after the German shells hit them, but in any case their main task - to prevent damage to boiler rooms and engine rooms and to prevent serious flooding - they carried out.
"Danae." Among all British cruisers this one is protected most rationally: a long belt almost the entire length, 38 mm in the nose, 57 mm against the artillery cellars, 76,2 mm against the engine and boiler rooms (and here the belt rose to the upper deck), and in the rest ground xnumx mm. But, alas, not from armor, but again from HTS. Armored form finally received the desired inch (50,8 mm) at least above the boiler rooms, machine rooms and artillery cellars, (and also, probably, above the steering devices), but ... it seems that the rest of the deck was not armored at all. In addition to the above, the “box-like” protection of the cellars - 25,4 mm vertical and 12,7 mm horizontal protection is of undoubted interest. As for the guns, their shields were significantly improved by increasing the area, but reducing the thickness to 25,4 mm.
Germanic "Koenigsberg". Here everything is more or less simple. The Germans found that the scheme they used on the Magdeburg was ideal for light cruisers and replicated it in all subsequent series, including the post-war Emden.
The armored belt 60 mm thick defended most of the waterline, followed by an armored formwork with bevels. Moreover, its horizontal part, which had 20 mm of thickness, was located at the level of the upper edge of the armor belt (lower deck level) and the bevels adjoined to the lower edge. At the same time, the horizontal part of the armored decks had only 20 mm (probably in the cellar area - 40 mm), but the bevels - 40 mm. In the stern, this protection ended with 80 mm by traversing from the lower edge of which, at the waterline level into the stern, a new armored formwork with bevels continued, having a uniform reservation in 40 mm. In the nose, the citadel ended before the end of the armored belt, 40 mm by means of a beam, and then 20 mm of the armor-formwork went through the nose (probably also with bevels). The wheelhouse had 100 mm walls and 20 mm roof, artillery - 50 mm shields.
The strengths of the German defense lay in a completely “unkillable” citadel — it is doubtful that the 152-mm projectile could overcome the 60 mm armor and the 40 mm bevel even at close range, so that the engine and boiler rooms were protected from the flooring fire perfectly. But only 20 mm of the horizontal part of the armored decks could still be pierced at a long distance. You can, of course, say that the Germans were preparing for a war in the North Sea, where, due to weather conditions, the distances of artillery combat are relatively low and you should first of all protect your ships from flattened, not from hanging fire. But there is one significant "but" - the British after all created dual-purpose cruisers, capable not only to serve in the squadron, but also to pirate on ocean communications - and here, in raids across the Indian or Pacific oceans, horizontal defense would be very useful .
And besides, the German reservation system had another flaw - ensuring the buoyancy of the ship with a long belt at the waterline and perfectly protecting what is below this very waterline, the Germans left the rest of the ship with only the most fragmentary protection provided by the gun shields and the armored armor. That is, almost any German cruiser could be crushed by high-explosive projectiles to a complete loss of combat capability, and its armor protection almost did not prevent this.
As for the Austro-Hungarian "Admiral Brown", his entire defense is 60-mm armor, covering the machine and boiler rooms and 20 mm armor-form above him: apparently, the extremities outside the citadel were not protected by armor. Regarding the felling of opinions, the sources differ - 50 or 20 mm. Of course, the guns were behind the shields, but the author of this article could not figure out their thickness. Of course, the “Admiral Brown” is the weakest-protected cruiser of all taken for comparison with the “Svetlana”, but we will be fair: it was very difficult to provide even such a level of armor protection for a high-speed ship only in 3 500 and normal displacement.
Of all doubts, among all the above cruisers, the best protection was given to domestic ships of the Svetlana type.
Speed and power plant
A very interesting look at the speed of cruisers has developed among the British. They believed that for “trade defenders” operating on communications, the speed of 25-25,5 knots would be sufficient, while for a destroyer to lead destroyer the speed of at least 30 knots is necessary.
At the same time, the "towns", that is, the Bristol, Weymouth, and, of course, the Chatyam cruisers, confirmed their planned characteristics in practice by providing full speed 25-25,5 units, while the power plants of these ships operated mainly on coal The last cruisers - the "towns", "Chester" and "Birkenhead", received oil heating and demonstrated a speed of a knot more.
"Scouts" were supposed to become more speedy, so "Caroline" got boilers with oil heating. Four turbines should have been developed without an afterburner on the 7 500 HP. each, while the speed should have been 28 knots, but the afterburner was envisaged, in which the cruiser should go up to eight hours. The power of each turbine in the afterburner should have been 10 000 HP but in practice, nothing happened - the maximum speed of the Caroline-type cruisers barely reached the 28,5 nodes. The “Danae” type cruisers turned out to be somewhat faster, developing from 28 to 29,184. The “Danae” itself was once able to develop even record-breaking 30,4 ties, with the power of the 40 machines 463 hp. but this result was not recorded, because the ship, subsequently, could not repeat it on the measuring mile.
As for the German "Königsberg", they, unlike the British "scouts" retained partially coal, partially oil heating. This may seem like a strange anachronism, but only if we forget about one of the most important functions of the German light cruisers - the war on communications. In those years, raiders often replenished coal reserves, overloading those from the captured vessels. This was not the best solution, because the quality of coal from ordinary transport steamships, of course, could not be compared with Cardiff for warships. Of course, the commanders of the raiders were much more preferable to use the services of special coal miners, providing their actions, but it was not always possible. But the raider could keep some inviolable stock of high-quality coal in case of pursuit of enemy warships and combat, and use stocks “expropriated” from captured ships on a daily basis.
Of course, the cruiser on a purely oil heating such an opportunity was denied. In those years, only coal was distributed everywhere, and it was almost impossible to replenish stocks of liquid fuel. Therefore, the Germans were forced to continue to use coal on their cruisers. Perhaps it was precisely because of the above that the German cruisers were not super-fast, but they still developed quite a decent speed for their time - 27,5-27,8 units. Austro-Hungarian cruisers developed a little more than 27 units, but their suspension was so unreliable that it imposed restrictions on their participation in combat operations.
Accordingly, light cruisers of the “Svetlana” type, capable of developing 29,5 units (and having confirmed their speed qualities after completion), turned out to be the fastest of all the ships we considered.
So, among the British, German and Austro-Hungarian cruisers, the domestic Svetlana carried the most formidable artillery weapons, were the most high-speed and the best armored. But what price did you have to pay for all these advantages?
To be continued ...
Previous articles of the cycle:
Light cruisers like "Svetlana"
Cruiser type "Svetlana". Part of 2. Artillery
Light cruisers like "Svetlana". Part of 3. Firepower versus peers
In fact, of course, the filling of the upper deck with water in fresh weather depends on many factors, and not only on its height above sea level. So, for example, the convergence on a wave is very important. For a ship with acceptable flotation ability, it is enough to have a high forecastle: the upper deck behind it will not be poured especially. Probably that is why German shipbuilders, despite the rich experience of operating cruisers during the First World War and before him, did not hesitate to place low weapons even in their post-war projects.
Nevertheless, there is every reason to assert that with the seaworthiness of the Svetlan everything was not too good: in spite of the high forecastle side, the bows of the bow were such that the cruiser was trying not to ascend, but to cut through the wave. There are indications that two or even all four 130-mm guns could not be used at high speed due to heavy splashing, although it is not clear from the source whether this is documentary evidence or the opinion of the author. It should be noted that of all the foreign cruisers that we are considering, only Caroline had equally low-lying artillery, and the rest of the ships it was placed much higher.
But here's what is interesting: the seaworthiness of Caroline and Danai was considered by the British themselves very low. As for the German Koenigsbergs, the sources differ: the Germans themselves claim that the seaworthiness of their ships was beyond praise, but the British consider it completely unacceptable by the standards of the British fleet. In the absence of measurable evaluation criteria, one can only guess at the comparative seaworthiness of cruisers, but, most likely, the best among all the ships compared with the Svetlana was the English Chester. And, regardless of how high the Svetlan artillery was actually high, its low location does not color the project: according to the height of the artillery, the Svetlana and Caroline share the least significant last place. Although, we repeat, it is completely unclear how the distribution of places in this rating affected the capabilities of artillery in fresh weather.
Anti-aircraft and torpedo weapons
The anti-aircraft armament of cruisers does not make much sense to consider: it was on all the ships of World War I in a very rudimentary state and performed, rather, the task of driving away enemy aircraft, rather than destroying them. For this purpose, several small-caliber artillery guns were usually mounted on cruisers with an increased vertical pointing angle. In this regard, four 63,5-mm guns and four Maxim machine guns that were planned to be mounted on the Svetlana were quite adequate and approximately corresponded to (and even exceeded) the anti-aircraft armament of foreign cruisers: the German had two 88-mm anti-aircraft guns, Caroline - one 76-mm and four 47-m, etc. Much more interesting is the kind of anti-aircraft armament received by Svetlana after their completion in the 20s, but we will return to this issue.
In terms of the torpedo armament, the Svetlana were obvious outsiders. In the first versions of the project, it was intended to install torpedo tubes on a ship before 12 due to the fact that cruisers of this type were supposed to bring destroyers to the torpedo attack, and therefore, according to the admirals, they themselves could be at a distance of a torpedo shot from the enemy. But in the end, the case was limited to only two traverse torpedo tubes.
Similar weapons (two traverses TA) from all foreign cruisers had only Chester, but its torpedo weapon It was much more powerful. The fact is that the Russian imperial fleet was late with the transition to torpedoes 533-mm caliber. The British developed their first 533-mm torpedo as early as 1908 and put it into service in 1910. We even the newest Noviki continued to arm 450-mm torpedoes. In principle, they were quite reliable weapons, but in terms of their range and mass of explosives, they were much inferior to 533-mm “self-propelled mines” from the time of the First World War. Thus, the Russian torpedo could go 2 000 m with speed 43 knots, while the British 533-mm Mark II model 1914 r. - 4 000 m on 45 nodes, while the “Englishwoman” carried 234 kg of trotyl, while Russian - only 112 kg. Therefore, in terms of torpedo armament, Svetlana lost to both Chester and Caroline, which had four 533-mm torpedoes and, of course, Danae, carrying four three-tube 533-mm torpedo tubes.
The German G7 of the 1910 model, capable of passing 4 000 m on 37 nodes and carrying 195 kg of hexonite, were inferior in their combat capabilities to British ones, but alas, they were also superior to domestic torpedoes. At the same time, Koenigsberg carried two single-tube rotary and two underwater torpedo tubes.
Thus, we can say that the torpedo armament of domestic cruisers was completely inadequate and in its original form, in general, not necessary. The only thing that the traverse torpedo tubes were capable of - to sink the arrested and stopped transports. But actions on communications were not the priority task of Svetlan, and during the battle, at high speeds, there was always the danger of the torpedo not leaving the traverse apparatus (a strong oncoming flow of water). And the accuracy of shooting left much to be desired. Therefore, during the post-war completion, the Svetlan torpedo armament was replaced and drastically strengthened, but this happened later. And in the design form, the Svetlana was even inferior to the Austro-Hungarian Admiral Shpaun, carrying 4 torpedo tubes with a 450 caliber of mm.
Reservation
The Svetlan reservation system was simple and efficient.
The basis of the vertical booking was 75-mm armor belt with a height of 2,1 m, on the upper edge of which the lower deck rested. Under normal displacement, this armor on 0,9 m was under water. At the same time, as far as can be understood, their total length of the 154,8 m cruiser at the 75 waterline was protected by 150 m armor from the stem in the stern, where the armor ended with 50 mm by traversing - the 25 mm armor plate of the same height (2,1 m) protected the stern from it.
Thus, the Svetlan armor belt was solid and covered the entire waterline, but in the last approximately 5 meters its thickness decreased to 25 mm. It is also worth mentioning that his armor plates were placed on top of the 9-10 mm sheathing. Above the main armor belt, the space between the lower and upper deck was protected by 25 mm armor along the entire length of the ship. Interestingly, in this case, the armor plates did not fit over the skin, but they themselves were her and participated in ensuring the longitudinal strength of the hull. The height of this upper armored belt was 2,25 m.
The upper and lower decks of the ship along the entire length of the hull consisted of 20 mm armor plates. Thus, by and large, the protection of Svetlana-type cruisers consisted of an armored shell almost the entire length of a ship 75 mm thick, covered with 20-mm armor on top, over which a second armor with a vertical wall thickness 25 mm, also covered from above 20 -mm armor.
It is usually stated that all armor of Svetlana-type cruisers was produced by the Krupp method, with only 75-mm armor plates and armored shell being cemented, and the rest of the armor was homogeneous. However, this is highly doubtful, because, most likely, they could not produce cemented slabs 75 mm thick either in Russia or in the world. Most likely, cemented armored plates defended only felling.
In addition, the Svetlana reserved armored ammunition elevators (25 mm), chimneys between the lower and upper decks, and for the nose pipe - to the forecast deck (20 mm), conning tower (walls - 125 mm, roof - 75 mm, floor - 25 mm), as well as shields, protecting guns (according to various data - 20-25 mm. But the casemates of the cruiser were not protected by armor.
In general, it can be stated that the Svetlan armor practically perfectly protected against all calibers of the then artillery in 152 mm inclusive. Her 75-mm armor could be pierced with an 152-mm projectile from a distance of about 25, possibly an 30 cable. But at such a distance, of course, the enemy cruiser could come only at night, and during the day firing such projectiles at the Svetlana did not make sense. At the same time, the “top floor” of the body armor (20 mm deck and 25 mm board), of course, did not protect against six-inch high-explosive shells, but forced them to explode when it was overcome, and fragments of such shells could not penetrate the second 20 mm deck anymore. At the same time, the upper 25 mm belt, although it could not withstand a direct hit, was still quite capable of protecting it from fragments of shells that exploded in the water near the cruiser.
But there was another very interesting nuance. Still, the 20-mm armor is not too much, and the high-explosive 152-mm projectile exploded on it can easily break it, hitting the armor space with fragments of the projectile itself and fragments of armor. Wouldn't it be better, instead of two decks on 20 mm, to make one 40 mm, which almost guaranteed to protect against six-inch shells?
But what is interesting is that if, say, the same high-explosive 152-mm projectile hits the top, 25-mm armor, it detonates either during the process of breaking such armor, or immediately after its overcoming. In this case, the explosion will occur between the upper and lower decks - and you can be sure that the fragments of the projectile will not go down or up, as the explosion will occur in the armored box, above and below the closed 20-mm armor plates. Why protect the bottom, of course, because there are artillery cellars, machinery and boiler rooms, mechanisms. But there are numerous guns at the top, and if you make the upper deck out of the usual 8-10-mm structural steel, then the fragments of the projectile that exploded in the hull, punching the upper deck, can do things, mowing down artillery calculations. Two armored decks completely eliminate such troubles, and this is a very important advantage of the Russian ship project.
And what about other countries cruisers?
Let's start with the British scout "Caroline".
Its sides defended 76,2-mm armor, thinning to the nose, first to 57,2, and then to 38 mm. The stern belt became thinner to 50,8-63,5 mm, but did not reach the end of the stern. Caroline had no upper armor belt, but in the area of machine and boiler rooms of 76,2 mm the armor plates did not rise to the lower deck, as in Svetlan, but to the upper deck, i.e. the space between the lower and upper decks was protected by 76,2 mm, not 25 mm, as in the domestic cruiser. But only above the engine and boiler rooms, the rest of the board over the armor had no protection.
As for the booking of decks, everything here was not good, because it was not solid, but fragmentary: 25-mm armored plates were covered with engine rooms, boiler rooms and the steering compartment in the stern. The rest of the deck had no protection.
What can you say about the protection of cruisers like "Caroline"? It should be noted that it is very thorough for a ship with a normal displacement of 4 219 t (at the time of entry into service). No doubt, the British made a lot of effort to protect their scouts and achieved outstanding results: but, of course, it was impossible to provide a level of booking comparable to a Russian cruiser on a ship of this size.
The British were forced to abandon, in fact, armor, using instead steel NT (High Tensile Steel - steel of high resistance). The win was that this “armor” was at the same time the cruiser skin, by analogy with the 25 mm upper belt of Svetlana. So, for example, as you can see from the description, the 76,2 mm belt consisted of two layers of HTS - 25,4 mm, which, in fact, served as a skin and 50,8 mm over the first.
Thus, it should be taken into account that the 75 mm of the Svetlan armor belt cannot be directly compared to the British 76,2 belt, yet our cruiser had another 9-10 mm skin for armor, while the British cruiser did not have anything under the armor. . And besides, although it can be assumed that, by its protective qualities, HTS was close to Krupp's uncemented armor, but still it was not its equivalent. Unfortunately, the author of this article does not have accurate data on the composition and armor resistance of HTS, but according to his data, STS (Special Treatment Steel) was some kind of analogue of homogeneous armor in England, and HTS was only a slightly improved shipbuilding steel.
Most likely, the areas of Caroline beads that had 76,2 mm thickness were completely unkillable for high-explosive shells at almost any combat distance, but this cannot be said about the extremities, especially since according to some data, the waterline at the waterline had a non-38 mm closer to the stem , but only 25,4 mm thickness. The armor deck was generally little protected from what - since the upper deck was being booked, the high-explosive shell (or its fragments), which entered from sharp bow or stern angles, could easily have passed into the engine rooms or boiler rooms, bypassing the armor. Yes, and the same tip, without horizontal protection, could be pierced by shrapnel through, including the bottom of the ship.
As for the other defenses, it was quite impressive: the 152-mm conning tower and the 76-mm gun shields. It is very difficult to say how justified shields of similar thickness are, probably, it is not so easy to direct a weapon with such a mass of armor. But the most important thing - having paid much attention to the thickness of the defense, the British for some reason did not bother with its area at all, because of which there was a large gap between the shield and the deck, through which the fragments hit the gun calculations bypassing the “unkillable” shield.
Yet, despite all the flaws, the Caroline should be considered a very well-protected cruiser for its size.
The latest "towns", light cruisers "Chester" and "Birkenhead".
HMS "Chester"
Unfortunately, their booking schemes could not be found, and the available descriptions may not be entirely correct. The fact is that the booking of “city” cruisers was gradually improved from one type to another, and confusion was possible here. According to the author's data, the protection of these cruisers looked like this: the extended armor belt, starting at the stem and ending, a little short of the stern had a thickness of 51 mm, and along the engine and boiler rooms - 76,2 mm (in the nose, perhaps, only 38 mm) . In the area of boiler rooms and machine rooms to the upper deck, but the cruiser had a very long forecastle, so that between the upper edge of the armor belt and the guns there was still one unarmored space between the decks.
According to some reports, the armored belt was a 25,4-51 mm armor plate on the 25,4 mm HTS “substrate”, i.e. 76,2-51 mm assigned to him "on the totality" of plating thickness and armor. On top of its upper edge, there was a rather original armored deck that had 19 mm above the engine and boiler rooms, 38 mm above the steering gear, and in other places only 10 mm of armor (or was it again HTS?). In any case, it can only be stated that for a ship with a normal displacement in 5 185, the booking does not strike the imagination at all and is obviously inferior to Svetlana, especially in terms of horizontal protection.
Nevertheless, the Chester was considered an excellent protected light cruiser and demonstrate its capabilities in real combat. In the Battle of Jutland, he "substituted" himself under the fire of the 2 reconnaissance group, including the cruisers Frankfurt, Wiesbaden, Pillau and Elbing, and the battle began at a distance of no more than 30 cables. In less than 20 minutes, the cruiser received an 17 150-mm high-explosive shells, however the defense did the trick. True, some 76,2 mm belt armor had to be changed after the German shells hit them, but in any case their main task - to prevent damage to boiler rooms and engine rooms and to prevent serious flooding - they carried out.
"Danae." Among all British cruisers this one is protected most rationally: a long belt almost the entire length, 38 mm in the nose, 57 mm against the artillery cellars, 76,2 mm against the engine and boiler rooms (and here the belt rose to the upper deck), and in the rest ground xnumx mm. But, alas, not from armor, but again from HTS. Armored form finally received the desired inch (50,8 mm) at least above the boiler rooms, machine rooms and artillery cellars, (and also, probably, above the steering devices), but ... it seems that the rest of the deck was not armored at all. In addition to the above, the “box-like” protection of the cellars - 25,4 mm vertical and 12,7 mm horizontal protection is of undoubted interest. As for the guns, their shields were significantly improved by increasing the area, but reducing the thickness to 25,4 mm.
Germanic "Koenigsberg". Here everything is more or less simple. The Germans found that the scheme they used on the Magdeburg was ideal for light cruisers and replicated it in all subsequent series, including the post-war Emden.
The armored belt 60 mm thick defended most of the waterline, followed by an armored formwork with bevels. Moreover, its horizontal part, which had 20 mm of thickness, was located at the level of the upper edge of the armor belt (lower deck level) and the bevels adjoined to the lower edge. At the same time, the horizontal part of the armored decks had only 20 mm (probably in the cellar area - 40 mm), but the bevels - 40 mm. In the stern, this protection ended with 80 mm by traversing from the lower edge of which, at the waterline level into the stern, a new armored formwork with bevels continued, having a uniform reservation in 40 mm. In the nose, the citadel ended before the end of the armored belt, 40 mm by means of a beam, and then 20 mm of the armor-formwork went through the nose (probably also with bevels). The wheelhouse had 100 mm walls and 20 mm roof, artillery - 50 mm shields.
The strengths of the German defense lay in a completely “unkillable” citadel — it is doubtful that the 152-mm projectile could overcome the 60 mm armor and the 40 mm bevel even at close range, so that the engine and boiler rooms were protected from the flooring fire perfectly. But only 20 mm of the horizontal part of the armored decks could still be pierced at a long distance. You can, of course, say that the Germans were preparing for a war in the North Sea, where, due to weather conditions, the distances of artillery combat are relatively low and you should first of all protect your ships from flattened, not from hanging fire. But there is one significant "but" - the British after all created dual-purpose cruisers, capable not only to serve in the squadron, but also to pirate on ocean communications - and here, in raids across the Indian or Pacific oceans, horizontal defense would be very useful .
And besides, the German reservation system had another flaw - ensuring the buoyancy of the ship with a long belt at the waterline and perfectly protecting what is below this very waterline, the Germans left the rest of the ship with only the most fragmentary protection provided by the gun shields and the armored armor. That is, almost any German cruiser could be crushed by high-explosive projectiles to a complete loss of combat capability, and its armor protection almost did not prevent this.
As for the Austro-Hungarian "Admiral Brown", his entire defense is 60-mm armor, covering the machine and boiler rooms and 20 mm armor-form above him: apparently, the extremities outside the citadel were not protected by armor. Regarding the felling of opinions, the sources differ - 50 or 20 mm. Of course, the guns were behind the shields, but the author of this article could not figure out their thickness. Of course, the “Admiral Brown” is the weakest-protected cruiser of all taken for comparison with the “Svetlana”, but we will be fair: it was very difficult to provide even such a level of armor protection for a high-speed ship only in 3 500 and normal displacement.
Of all doubts, among all the above cruisers, the best protection was given to domestic ships of the Svetlana type.
Speed and power plant
A very interesting look at the speed of cruisers has developed among the British. They believed that for “trade defenders” operating on communications, the speed of 25-25,5 knots would be sufficient, while for a destroyer to lead destroyer the speed of at least 30 knots is necessary.
At the same time, the "towns", that is, the Bristol, Weymouth, and, of course, the Chatyam cruisers, confirmed their planned characteristics in practice by providing full speed 25-25,5 units, while the power plants of these ships operated mainly on coal The last cruisers - the "towns", "Chester" and "Birkenhead", received oil heating and demonstrated a speed of a knot more.
"Scouts" were supposed to become more speedy, so "Caroline" got boilers with oil heating. Four turbines should have been developed without an afterburner on the 7 500 HP. each, while the speed should have been 28 knots, but the afterburner was envisaged, in which the cruiser should go up to eight hours. The power of each turbine in the afterburner should have been 10 000 HP but in practice, nothing happened - the maximum speed of the Caroline-type cruisers barely reached the 28,5 nodes. The “Danae” type cruisers turned out to be somewhat faster, developing from 28 to 29,184. The “Danae” itself was once able to develop even record-breaking 30,4 ties, with the power of the 40 machines 463 hp. but this result was not recorded, because the ship, subsequently, could not repeat it on the measuring mile.
As for the German "Königsberg", they, unlike the British "scouts" retained partially coal, partially oil heating. This may seem like a strange anachronism, but only if we forget about one of the most important functions of the German light cruisers - the war on communications. In those years, raiders often replenished coal reserves, overloading those from the captured vessels. This was not the best solution, because the quality of coal from ordinary transport steamships, of course, could not be compared with Cardiff for warships. Of course, the commanders of the raiders were much more preferable to use the services of special coal miners, providing their actions, but it was not always possible. But the raider could keep some inviolable stock of high-quality coal in case of pursuit of enemy warships and combat, and use stocks “expropriated” from captured ships on a daily basis.
Of course, the cruiser on a purely oil heating such an opportunity was denied. In those years, only coal was distributed everywhere, and it was almost impossible to replenish stocks of liquid fuel. Therefore, the Germans were forced to continue to use coal on their cruisers. Perhaps it was precisely because of the above that the German cruisers were not super-fast, but they still developed quite a decent speed for their time - 27,5-27,8 units. Austro-Hungarian cruisers developed a little more than 27 units, but their suspension was so unreliable that it imposed restrictions on their participation in combat operations.
Accordingly, light cruisers of the “Svetlana” type, capable of developing 29,5 units (and having confirmed their speed qualities after completion), turned out to be the fastest of all the ships we considered.
So, among the British, German and Austro-Hungarian cruisers, the domestic Svetlana carried the most formidable artillery weapons, were the most high-speed and the best armored. But what price did you have to pay for all these advantages?
To be continued ...
Previous articles of the cycle:
Light cruisers like "Svetlana"
Cruiser type "Svetlana". Part of 2. Artillery
Light cruisers like "Svetlana". Part of 3. Firepower versus peers
Information