Armored cruiser Bayan. Selection of performance characteristics and design
Thus, on April 27, 1897, at a meeting of the MTC's shipbuilding department, designs submitted by the French firm Forge et Chantier were reviewed. However, none of them were deemed satisfactory as a prototype for the newest Russian cruiser. The meeting then turned to foreign cruisers whose performance characteristics were known, but a suitable prototype was not found among them. Nevertheless, from the wide variety of types and designs, the meeting singled out the armored cruiser Esmeralda, built by the Armstrong shipyard for Chile, not as a prototype, but rather as a benchmark to be considered when designing the ship.
The next meeting on the new cruiser took place on May 7 of the same year. It was much more representative: present were Admiral K.P. Pilkin, Vice-Admirals N.I. Kaznakov, I.M. Dikov, S.P. Tyrtov, S.O. Makarov, F.K. Avelan, Rear Admirals N.I. Skrydlov, N.N. Lomen, and MTC inspectors for artillery Major General A.S. Krotkov, Mechanical Engineering Director N.G. Nozikov, and Shipbuilding Director N.E. Kuteinikov. The meeting was chaired by P.P. Tyrtov, Administrator of the Ministry of the Navy. Naturally, he was familiar with the minutes of the April 27, 1897, meeting of the MTC's Shipbuilding Department. And it was he who, at the very beginning of the meeting, made two fundamental statements.
First, he informed the meeting that the Naval Ministry had the funds to order one or two ships of approximately 6000 tons displacement, but since there were no available slipways in Russia, the ship (or two) would be built abroad. Second, P.P. Tyrtov pointed out that, in accordance with...
...approved in July 1895 by the plan of shipbuilding works for the coming seven years (1896-1902) and taking into account the urgent need for our fleet In cruisers, it is proposed to order ships of this very type, and these cruisers will have to carry out reconnaissance service with the squadron, without ceasing to be combat ships at the same time.
The esteemed assembly has reconsidered all the points I have described in previous article Projects and cruisers: a citadel cruiser with a speed of 22 and 24 knots, versions of the enlarged Svetlana of 1,000 and 2,000 tons, the French armored cruisers Dupuy de Lôme and Potuo, the German Victoria Louise, the British armored deck Arrogant and the armored Esmeralda. Additionally, the following were taken into account:
1. The British armored deck cruiser Edgar (7,350 tons, 18,5 knots with natural draft and 20 knots with artificial draft, deck 25-76 mm, slopes 127 mm, casemates 152 mm, conning tower 305 mm, armament: 2 * 9,2-inch (234-mm), 10 * 6-inch, 12 * 57-mm, 5 * 47-mm, 4 * 457-mm torpedo tubes);
2. Italian armored cruiser Carlo Alberto - 6,500 tons, 18,6-19,1 knots, 150 mm side, 37 mm deck, 50 mm gun shields, 150 mm conning tower, armament: 12*6-inch, 4-6*120-mm, 14*57-mm, 8*37-mm guns, 4*450-mm torpedo tubes.
In addition to these, some projects for cruisers with a displacement of 5225 and 5700 tons were also considered, the characteristics of which, unfortunately, are unknown to me.
All of the above-mentioned cruiser class representatives were compared with the Diana-class cruisers currently under construction in Russia. What do they have to do with it?
The fact is that, when determining the performance characteristics of the Pallada and Diana, our admirals desired a reconnaissance cruiser for the squadron that would also be capable of disrupting enemy trade along oceanic routes. This versatility, of course, led to a certain increase in the cruiser's size, as a pure reconnaissance cruiser could have been built with a smaller displacement.
Now, however, the admirals had something else in mind: they wanted a ship roughly equal in size to the Pallada, whose "excess" displacement beyond that needed for a scout would be used not for endurance and range, but for increased combat effectiveness. Of course, such a cruiser was in no way designed for line combat; it could not be placed in battleship formations.
But it was expected that such a cruiser, operating outside the line of battleships, would still be capable of participating in a squadron battle, although it remained unclear to me in what capacity. One might assume that this meant fire support, in which the cruiser, while outside the line, would fire at engaged enemy battleships, or combat with enemy cruisers attempting to do the same to our squadron battleships.
The Diana-class cruisers were obviously not ideal for this, but among all the other cruisers considered, no ship met the admirals' requirements. The cruiser had to be armored, which immediately ruled out all armored deck options. Of the remaining options, the citadel cruiser was deemed too unconventional—the attempt to replace the armored deck with intricately shaped casemates failed to resonate with our admirals. They rightly noted that horizontal armor on a ship cannot be replaced by vertical protection, even if that protection is angled. The French Dupuy-de-Lôme was "overwhelmed by armor," sacrificing speed and range; the Esmeralda lacked a double bottom and artillery protection, etc. Accordingly, all the presented "candidates" for the Russian cruiser prototype:
The main combat elements of the ship: artillery, the ship's movement, the protection of the hull and artillery, and, finally, the coal supply, are not coordinated with each other as much as is desirable for our cruiser, which will have to cruise in more limited areas, depending on the location of the main combat forces, and at the same time will have to act in combat, in connection with squadron battleships.
But now, having carefully studied the designs proposed by Forge et Chantier and the performance characteristics of other cruisers from other countries, and thus having received a starting point and an understanding of what could be demanded from the foreign shipbuilding industry, the meeting could determine the main performance characteristics and design features of the future Bayan.
The armored cruiser Esmeralda is, in a sense, the forerunner of the Bayan
Design assignment
1. Displacement no more than 7,000 tons. At the same time, the meeting initially limited the displacement to 6,700 tons, but many admirals opposed this, believing that 6,700 tons would not be enough;
2. The normal coal load was set at 10-12% of the displacement. The speed was to be 21 knots without forcing the boilers, and this was to be confirmed as an average during 24-hour continuous trials. The full coal load was to be no more than 1,5 times the normal load and ensure a range of 7000-8000 miles at a speed of 10 knots.
The oddity of this last requirement is striking. If we take the minimum and maximum coal capacity of a new cruiser with a displacement of 6,700 tons, the result would be 1,005–1,206 tons. But let's recall that the armored cruiser Diana, which had a similar displacement (6,731 tons) and was designed as a scout-raider, had a full coal capacity of only 972 tons. So, it turns out that the newly designed scout-combatant, which was to operate "in more limited areas," was allowed to have a coal capacity 1,24 times greater than that of a scout-raider designed, among other things, for ocean communications? This in itself is odd, but what's more interesting is that the Diana's range at 10 knots was determined to be only 4,000 miles. It turns out that the new cruiser, with the same displacement, was allowed to carry 1,24 times more coal than the Diana, but its cruising range was expected to be 1,75–2 times greater!
I haven't found any explanation for this phenomenon in the sources. However, I can surmise that the admirals didn't consider the Diana-class cruisers' lines optimal and thought the French could design them much better, which would lead to an increase in range. I also suspect that this was a "high-stakes" assignment, meaning the Naval Ministry's leadership was attempting to squeeze the maximum out of the foreign contractors. Although they were certainly aware, to put it mildly, that their required specifications were somewhat overstated.
3. The hull must have a standard design (double bottom), with the underwater section sheathed in wood and copper. Copper sheathing was later abandoned, which was certainly appropriate, but it was included in the original specifications.
4. Power plant - twin-screw.
5. Boilers are permitted exclusively of the Belleville system, with economizers. The fresh water supply must be determined proportionally to the indicated power of the machines, at a rate of 1 ton of water per 100 indicated power. This water supply must be sufficient for the maximum distance covered by the coal reserves.
6. The armor was to be based on vertical armor, protecting the side at a height above the load waterline of at least 16% of the ship's width, and a carapace (i.e., sloped) deck. The requirement for the side armor seems odd, but the intended purpose was for its upper edge to be level with the deck "first above the carapace." It's noteworthy that the armor belt thickness was not specified—only the armor height.
It should be noted that there was some friction among the admirals regarding armor, which is all the more difficult to resolve given the uncertainty about the exact thickness of side armor they considered sufficient. Based on some indirect evidence, I can surmise that they were discussing 60 mm—the same thickness of armor plates used on the French "Potu." To support this hypothesis, I will cite two facts.
First, the initial meeting required the future cruiser's side to be armored all the way to the upper deck. Recall that the Dupuy-de-Lôme, which met this requirement but carried 100mm of armor, was considered "overwhelmed by armor at the expense of speed and range." In this light, the Potou's armor belt, reduced to 60mm, would have seemed quite adequate. Second, S.O. Makarov expressed a dissenting opinion at the meeting, declaring that 60mm armor was useless as an armor belt. He argued that such armor would be easily penetrated by shells with armor-piercing tips, even from medium-caliber artillery, and was therefore unnecessary. He proposed eliminating it altogether in order to conserve displacement.
There were other proposals, too. Rear Admiral N. N. Lomen proposed an armor belt along the entire waterline, 127 mm thick in the middle section and at least 2 meters high, with the armor height at the bow extending at least to the middle deck. However, the initial requirement for armoring the sides below the upper deck was ultimately amended at the insistence of N. E. Kuteinikov. He also advocated the need for double protection, that is, an armor belt and sloped carapace decks—this option became the final one in the design specifications.
7. The armament was to consist of 2 x 8-inch, 8 x 10 x 6-inch, and 20 x 75-mm guns, as well as three torpedo tubes—one in the bow and two submerged on the sides. The 8-inch guns were to be located in turrets, all 6-inch guns and some 75-mm guns in casemates. The artillery was to be positioned so that five 6-inch guns each could fire at the bow and stern.
Initially, the meeting considered it acceptable to place 8-inch guns in deck mounts behind the shields, and the general arrangement of the guns was to ensure that only three 6-8 inch caliber guns could fire into the bow and stern.
8-inch/45 gun of the armored cruiser Rossiya
But Rear Admiral N.N. Lomen opposed this, insisting on a turret-mounted main battery. He also emphasized the need to increase chase and retreat fire.
The point was that, initially, since they had decided to turn the future cruiser into a "combat vessel," the admirals believed that chase and retreat fire would be of little use, since the battle would, after all, be conducted broadside. This explains the initial sufficiency of three guns, firing bow and stern. But N.N. Lomen pointed out that enemy cruisers could develop more powerful fire, "and it would be unwise for us not to have what and how our adversaries are armed." Furthermore, the rear admiral quite rightly pointed out the importance of chase and retreat fire for a reconnaissance cruiser, which would both attack enemy "second-rank" cruisers if they attempted to approach the squadron and engage in combat while retreating. He proposed turrets for 8-inch guns for the same reason, since in a battle at sharp course angles, the failure of a bow or stern eight-inch gun would critically weaken the power of artillery fire.
N. N. Lomen also had another sensible proposal. He recommended placing half of the 6-inch guns on the upper deck, with the artillery of this caliber housed in two-story casemates. He explained his proposal by arguing that in fresh weather, half the 6-inch guns would have a significant advantage. Unfortunately, this proposal was not accepted, possibly due to the excessive increase in upper weight and the corresponding decrease in the future ship's stability.
8. The cruiser was to have one or two combat tops for the placement of small-caliber artillery and a ram “of the type accepted in our fleet.”
In this form, the design brief for the cruiser was approved by the Admiral General and sent to A.M. Abaza in France on June 11, 1897. In October-November 1897, the Naval Ministry received three designs for "armored scouts," which I will briefly review below in order of their compliance with the requirements of the specifications.
Cruiser project from Atelier et Chantiers de la Loire
Displacement 6,741 tons, normal coal capacity - 8% (539 tons), armament: 2 x 8-inch, 8 x 6-inch, 20 x 75-mm, 10 x 47-mm, 8 x 37-mm, number of torpedo tubes unknown. Range - 7,500 miles with "emergency" coal reserves.
Advantages. The designers managed to fit the cruiser into the specified displacement specifications, and in addition, almost all of the cruiser's artillery, with the exception of the 4 x 75 mm guns, was located on the upper deck, which significantly improved the conditions for conducting fire combat in fresh weather.
Disadvantages. The placement of the guns on the upper deck was also a design flaw, as the 6-inch guns were mounted not in casemates, but in an unarmored superstructure and were equipped only with shields. This design grossly violated the technical specifications and was unacceptable. Furthermore, MTK specialists noted numerous irregularities in the shipbuilding calculations.
Unlike other designs submitted by the French, the cruiser featured a highly developed superstructure on the upper deck, effectively an additional deck in the form of a spar deck (forming the roof of this superstructure). This design obviously meant increasing the hull's weight, but the hull's contribution to the load in the Atelier et Chantiers de la Loire design was the same as in cruisers of other designs that did not feature such a superstructure. Furthermore, the cruiser's width-to-depth ratio was 2,48, while in other designs it reached 2,66. This was not a problem, but with such a ratio one would expect the cruiser's metacentric height to be lower than in other designs. However, it miraculously turned out to be higher—1,19 m versus 0,91–0,99 m for its competitors.
All of the above led the MTC to the conclusion that the cruiser's hull was overly lightweight, and the metacentric height was likely miscalculated. Moreover, I would add, given the significant upper weights associated with the extensive superstructure and the placement of artillery on the upper deck and spar deck, this error could have been quite significant. However, the MTC had no intention of "correcting the errors" and simply shelved the project as completely unusable.
Cruiser project of the Le Havre branch of the Forges et Chantiers company
Displacement 6,950/7,550 tons, normal coal capacity - 10% (695-755 tons), armament 2 x 8-inch, 10 x 6-inch, 20 x 75-mm, 8 x 47-mm, number of torpedo tubes unknown. Range - 8,035 miles with "emergency" coal capacity.
The cruiser was presented in two variants. The first, as required by the specifications, had Belleville boilers and a displacement of 7,550 tons. The second had Norman-Sigody boilers, which reduced the normal displacement to 6,950 tons. The "small" MTK variant wasn't even considered; Norman-Sigody boilers were of no interest to the Navy, which was a shame! In defense of the MTK, it must be said that Norman-Sigody boilers were unknown to our navy, while Belleville boilers had proven themselves to be highly reliable.
Advantages. The most powerful artillery armament—the number of 6-inch guns—was 10, while all other projects had 8. Unfortunately, this project had no other noticeable advantages.
Disadvantages. The cruiser was inadequately protected. The side armor was only 75 mm thick, and that's only if you include the side armor, which was made of ordinary steel. Furthermore, it only extended halfway along the cruiser's length, leaving the ends exposed. Perhaps this protection alone could have ruined the project, but the list of shortcomings was only beginning.
Since only half the waterline was protected by armor, it would have been logical to design a carapace deck with powerful slopes at the ends to at least provide some protection. But no—at the bow, the carapace deck ended 16 meters from the stem. True, the designers included a "double cofferdam with a double patented self-acting patch designed by engineer Coville," but MTK didn't believe in its miraculous properties. This cofferdam was already present on the armored cruiser Svetlana, which was under construction, and MTK specialists had no objection to it in principle, but from a protection standpoint, it was better than nothing, and that was all.
Contrary to the specifications, only 6-inch artillery was housed in casemates; all 75mm guns were mounted in the open. Even so, the casemates were very cramped and lacked internal bulkheads, meaning a shell penetrating the armor could wreak havoc. Overall, the cruiser's protection was deemed completely unsatisfactory, due to the small proportion of the load allocated to it—14,88% of the normal displacement, compared to 18,25% for the Loire design.
There were other shortcomings, too. For example, the middle casemate, located amidships, lacked its own magazines, making ammunition supply difficult, to say the least. The double bottom extended only as far as the hull, so the coal in the side coal pits was "adjacent" to the outer side plating. The engine rooms lacked longitudinal bulkheads, which, from a survivability standpoint, was completely unacceptable. The problem wasn't that there wasn't enough weight for these bulkheads, but that the compartments were so crowded together that they simply wouldn't fit.
The project was rejected due to the unacceptable crowding of 6-inch artillery and completely unsatisfactory protection of the extremities.
Cruiser project by the Toulon branch of the Forges et Chantiers company
Displacement 7,800 tons, normal coal capacity - 9,6% (749 tons), armament: 2 x 8-inch, 8 x 6-inch, 20 x 75-mm, 7 x 47-mm, number of torpedo tubes unknown. Range - 7,800 miles with "emergency" coal reserves.
This project made such a lasting impression on MTC that the latter did not even reprimand the developer, A. Lagan, for exceeding the displacement by 800 tons.
Advantages. The ship's protection was excellent. While the Le Havre design provided 1,059 tons of armor, the Toulon design provided almost 40% more—1,478 tons. Accordingly, the artillery protection was much better: as in the Le Havre design, the ship had three casemates, but these housed not only the 6-inch guns, as the Le Havre designers had, but also some of the 75 mm guns, as required by the specifications. Moreover, the casemates were properly designed—each gun was shielded from its neighbors by armored bulkheads.
However, in terms of side protection, A. Lagan violated the requirements of the technical specifications. Instead of double protection with an armor belt and deck slopes, he left only a single armor belt—the armor deck was horizontal. However, this belt was very long, and the thickness of its armor plates along most of the ship's length reached a record 200 mm.
A. Lagan's explanation for violating the specifications in this regard was based on the fact that eliminating the slopes allowed for an increase in the thickness of the armor belt—which he, in fact, demonstrated in his design. The Le Havre design by Forges et Chantiers complied with the specifications in terms of armor layout, but its belt armor was only 75 mm thick with the side armor, and probably 60-63 mm without it. Moreover, to understand how much the armor protection of such a belt was inferior to the 200 mm of A. Lagan's design, it would be completely insufficient to divide 200 mm by 60 mm and conclude that the vertical side armor of the Le Havre design was more than three times as thick. It should also be taken into account that armor of 60 mm plus was too thin at the time to be cemented. Consequently, A. Lagan's armor belt was cemented, while his opponent's was homogeneous, which further reduced the armor's durability. Therefore, and beyond any doubt, the thinner armor belt was relatively easy to penetrate, while only large-caliber shells from squadron battleships could defeat the 200 mm of armor used by A. Lagan. In light of the above, it is necessary to consider A. Lagan's arguments, as he presented them.
Firstly, a shell penetrating a relatively weak armor belt can either hit the bevel or, "reflected" by the latter, simply break off the penetrated armor plate, throwing it overboard. This would open a wide path for water to enter the hull, potentially leading to the destruction of the ship.
Secondly, even if the penetrated plate remained in place, and the bevel held up and did not let through either the shell or its fragments, the triangular space formed by the armor belt and the bevel adjacent to its lower edge will still be flooded.
Thirdly, the absence of bevels increases the useful volume of the armored space of the hull, which, in turn, greatly facilitates the rational placement of mechanisms and other cargo.
These arguments, when applied to armor systems in general, did not demonstrate that the "double" protection of an armor belt and a sloped hull was weaker than that of an armor belt alone. Of course, the argument about better placement of machinery and cargo was undeniable, and other arguments undoubtedly had some bearing. The fact that a sloped hull, even with a penetrated side, was incapable of preventing water from entering the hull was the main reason the Naval Ministry rejected the construction of an armored cruiser with an armored deck in favor of an armored cruiser.
However, this "single" protection had one significant drawback. If the armor was penetrated, the vehicles, machinery, and other vital components and cargo were completely unprotected from the blast and shrapnel of an exploding shell. This is why, despite all the reasons cited by A. Lagan, the Russian Imperial Navy generally preferred double protection—an armor belt and a sloped armor plate.
But in this particular case, it was deemed that a 200mm armor belt, three longitudinal bulkheads behind it, the space between which could, if desired, be filled with some kind of "water-excluding substance," would provide sufficient protection. Accordingly, the armor scheme proposed by A. Lagane was accepted without objection.
Disadvantages. Of course, A. Lagan's design wasn't all about advantages, but I'll discuss the shortcomings of the armored cruiser Bayan later, when analyzing its performance characteristics. I'll note here that, according to the specifications, the only significant drawback was the 800-ton excess displacement. However, the Ministry of Transport and Communications deemed this increase an acceptable tradeoff for the design's other qualities.
It's quite clear that A. Lagan's design was the clear winner in this small competition, leaving its competitors far behind. It's therefore no surprise that the Naval Ministry chose it. For my part, I can only express regret that shipbuilders from countries other than France were not allowed to participate in the competition for the armored cruiser "Bayan"—it would have been quite interesting to see how they would have solved the problem posed by our Naval Ministry.
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