Shipbucket

Very briefly about the alternative.
It is based on two messages. First, that since second half of XIX century the development of a worldwide weapons system has ceased to keep up with technical progress, became scholastic, and its path became similar to Brownian movement. The proposed alternative is an attempt to optimize the overall weapons system. One of the conclusions of this optimization is the recognition of artillery as the main type of weapons.
Second, the alternate United States is used as an illustration of this optimization, because exactly the evolution of the American weapons system contained many elements that were closest to the proposed optimum. If we make only one assumption that in the development of their armed forces the Americans were more likely to rely not on classical European knowledge, but on their own practical experience, then we can assume that the American weapons system would have taken a more optimal path.
The timeline of this alternative differs little from the real history up to 1939. Unless, the United States is more isolationist and more committed to the Monroe Doctrine. However, this has little effect at first. Maybe only, Cuba is annexed instead of Philippines, and the Philippines is granted independence under United States patronage, with a US base in the Manila Gulf. But by 1939 the isolationist policy giving a result, oddly enough, somewhat opposite to indifferent neutrality.
However, the isolation gives significant deviations in part of the weapon development, combat engagement, and military organization. The starting point for alternative changes was an experience of the Civil War. For the Navy, this was the moment the New Navy creating. Herewith, the greater importance was of all the previous experience in the development of the US naval forces from the very moment the obtaining of independence. So let's start with a real-historical preamble to understand what the New Fleet could be if the Americans were based on their own experience.

Some images based on the work of Craig Hoefer, for which many thanks to him. I refer to some of his drawings in their entirety to show the full line of development.

Old Navy
In the initial, most difficult period for the young American state, 1775-1815 - the War of Independence, the Quasi-War with France and the War of 1812 - the US Navy had no ships of the line and did not know linear or any other squadron tactics. There were three reasons for this. The first was financial: the scarcity of the federal budget, which made building and maintenance of such large ships extremely difficult. Another reason is operational-tactical: the ships-of-line's characteristics assumed low speed and, to a certain extent, a limited range, which did not meet the needs of the united American states, given their fleet quantitative backlog and huge coastline. Finally, the third reason was strictly conceptual: it is impossible to resist a numerically superior enemy with his own tactics. Moreover, even at then age, the shipbuilder of the American navy, Joshua Humphreys, aimed not only at parity with the former metropolis, but also at superiority. As an experienced shipbuilder, he knew how inert his professional environment was. The shipbuilder bears a huge responsibility for the fate of an expensive ship, for the lives of the crew, and, ultimately, for the sea power of the country. Therefore, the builders of warships shied away from experimentation, using reliable time-tested solutions. The ships of the late 18th century differed little from those of the 17th century. In order to bypass rivals when numerical parity was impossible, the Americans needed to get out from the plane of established views into a new quality. At the same time, the inert mass of the former fleets could only follow the revolutionary outlook, and the Americans would have a chance to come out ahead in matters of fleet building.

Humphreys have proposed a large frigates that carried ships-of-line's long-range 24-pound guns on the main gun deck instead of the usual for frigates 18-pounders (in a smaller number, of course), but surpassed ships-of-line in mobility. They carried 32-pound carronades on the forecastle and quarterdeck. Ranked as 44-gun (but actually carrying a lot more barrels), the large frigates would certainly outperform any normal, as maximum 38-gun frigate, and under certain conditions had a chance against a ships-of-line. Similar frigates have existed before too, but in the hands of American sailors, thanks for their high qualifications, and the Humphreys design's superior characteristics, the large frigates demonstrated its worth during the War of 1812. Of no small importance was the very strong and durable material of the hulls of large Humphreys' frigates, a special type of American oak - live oak. Although the Americans had too few large frigates to do everything that entrusted to them, nevertheless, Humphreys' calculation was justified - to neutralize only three large frigates, the British had to attract significant forces.

The effect produced by large frigates gave rise to consequences that were important for the US Navy: this type was highly appreciated there, and it further developed, including with the transition to a sail-steam drive. If the "oak frigates" created under the Humphreys' sole influence, the steam ships were building by different shipbuilders, while the consolidator and guarantor of the sequence of development during this period became the Chief of the Bureau of Steam Engineering, Benjamin Franklin Isherwood. He was the designer of most of the ship propulsion systems of then time, gradually improving them from model to model and developing a reliable and effective design. His views led to the transformation of the steam engine from an auxiliary propulsion unit into the main one, and then into the only one.

And the last pre-war sailing-steam 1st class frigate of the US Navy - laid down in 1855, USS Niagara - marked a new turn in the large frigates' development. Designed by George Steers, the creator of the very yacht America, after which the main sailing trophy named, Niagara was the first warship with clipper lines and the first warship with the wider hull behind the mid-frame. In fact, become a corvette (in the American classification of that time - a sloop-of-war), that is, a ship with a single continuous open gun deck from bow to stern, the frigate in the person of Niagara, naturally, lost exactly the battery of close battle carronades, remaining only with a battery of long-range cannons. An equally important factor was that, unlike classmates, this Niagara's battery was a homogeneous of 12 new 11-inch Dahlgren guns, capable of firing both solid balls and bombs. In addition, at Niagara, not only stern and bow guns were installed on the rotary mounts, but also onboard ones, although the latter - with small sectors of fire.

One of the problems of the emerged ship's screw movers was the need to pass the propeller shaft through the sternpost, which weakened or complicated. In addition, the location of the propeller made difficult the rudder installation. These problems tried to solve by passing the shaft to side of the sternpost. In order to reduce the thrust misalignment tried to pass the shaft as close to the stem as possible. However, this led to the fact that the propeller and the rudder interfered with each other. Therefore, the screw was carrying out behind the rudder blade. However, too long a free shaft end meant excessive vibration.
In 1860, the Navy replenished with one more iconic ship. Built by the renowned clipper builder John Willis Griffiths, the 67-meter 1500-ton sloop (II class frigate) Pawnee was first in the US Navy which received two screws installed symmetrically relative to diametral plane without complicating the sternpost and rudder joint, with a large deflection, and, therefore, with short shafts. They rotated by a single engine through a gear transmission in opposite directions.


Other notable feature of the Pawnee was the reduced rig and the absence of a bowsprit - the sail on it became auxiliary propulsion.
Initially its battery consisted of four 11-inch Dahlgrens on slewing rails, similar to those of Niagara, with 12-foot ports. Its structural strength was such that in 1863 it was addition armed with one 50- and one 100-pound rifled cannons.
The new quality of the artillery component forced a change the signs of the US Navy ships' classification. Previously, neither due to the absence of a closed gun deck nor to the rig, the Pawnee would cannot have been considered a frigate. However, now it was similar to the latest generation large frigates not only by these features. The ability to put his artillery on the large frigates line distinguished namely him from an ordinary sloop.

It was that exactly with 11-inch Dahlgren was soon armed the American ship of type unseen before. Born in the Civil War and differed of many features from everything that existed before, this new type could get name by any of these features. Moreover, not only could. In Europe, which copied the form, but was not familiar with background of the birth of this class, it called a monitor, an ironclad, or a battleship. However, this class was born under a name that accurately reveals its essence, its artillery nature - a battery. Thus refuting the opinion once again that the first capital ship carrying only main battery guns was Dreadnought. After all, a battery is an artillery organizational unit performing a single mission, and therefore homogeneous.
Another point is also no less important. If in the sailing fleet were mattered whether you approached the enemy from the leeward side or from the windward, now only artillery decided everything. The warship became artillery not only by the gun was its main weapon; now its tactics, and its operativeness, and its strategy became exclusively artillery too.
The Secretary's Annual Report for 1861 stated that "No sailing vessels have been ordered to be built, for steam as well as heavy ordnance, has become an indispensable element of the most efficient naval power."
The 1865 Secretary's Annual Report stated: " ...The skillful disposition of the sails ... is no longer necessary ... To confine himself to seamanship, without the ability to manage the steam engine, will result in his [the naval officer's] taking a secondary position..."
The title of the founder of a new type received not by casemate battery but by Monitor because in comparison just with casemate the Monitor represented a new word only in artillery alone. Although Virginia carried 12, well, let without howitzers - 10 barrels, and Monitor only 2, the casemate battery could shoot in direction of the target only a smaller part of them. In addition, to lock the target into a narrow sector of fire of the casemate installation, it was necessary to orient the ship to a certain position. The Monitor, on the other hand, with its rotating turret and slopping funnels, has an almost circular sector of both its barrels. It did not carry a dead mass of unnecessary guns, it used them effectively, and the saved weight could used to increase the power of artillery or the thickness of armor. With two artillery schemes in front of them, progress took the best.
So, Britain cherished the colonies and therefore began to armor the cruisers. Unionist America needed a means for operations near the coast of the rebellious states, so there not very naval designers built not very sea ships - without boards, without masts, without sails - and gave them under the command of not very sea captains-artillerymen. In their warships the Americans saw not armed vessel, but, on the contrary, floating guns.

My old batteries illustrations. 1 px - 170 mm approx scale.

Coastal batteries


Seagoing batteries



Link to fullscale

However, when the tasks of the internal war received this satisfactory remedy, the admirals of the Navy decided to attend to the threat of foreign intervention. During the Civil War, speed tactics were confirmed by the experience of South raiders in the eyes of the Americans. Therefore, when Britain began to build armored frigates, the Americans resorted to a proven means and responded with large frigates again. Niagara's characteristics were in line with the Navy's focus on ocean-going warships, and it proved to be an obvious candidate for replication. Thus, his influence on the development of the design of the large frigate was more important to the Navy than his own career.
In March 1962, the rebuilding of the large frigate Roanoke into a screw seagoing battery began. It was proposed cut to a corvette, to deprive the mast, to strengthen the structure for accommodate the side armor and 4 armored turrets, similar to those of the Passaic battery class. However, it soon became clear that the load would be too great for the ship's hull.
At the same time, the question was being decided, whether to support conceptually the construction of both types of ships, batteries and large frigates, or either one of them, or choose something mean between of them. The first option threatened by the fact that with limited funding both batteries and large frigates were too few for each to satisfactorily fulfill its task. The variant with armored frigates, combining the properties of these types, was already adopted by the British, and, as before, to resist the large British fleet with its tactics was impossible. If you build the Navy from any one type, then it is obvious that battery is completely incapable of ocean operations, while a large frigate with coastal ones, at the very least, would cope. This had to rely on speed again. It was clear that the armor would not allow the British ship to be as fast as possible, in which case the armored ship would not be able to destroy the high-speed frigate. However, conversely, a large frigate could not destroy an armored one too, if its protection consists only of a distance beyond the control of the enemy artillery. To get out of this situation, the Americans needed to artillery that would outrange the enemy one. To do this, they were going to use 8-inch rifled Parrott (7300 m/35°, 7.5 t, 86-91 kg) or Dahlgren on large frigates.

So, the admirals needed a ship for naval operations, for which the Roanoke conversion project originally established was not capable. Therefore, from reducing the load due to the abandonment of some of the turrets, they came to a more radical one: to the abandonment of all armor - both onboard and turret. So far there were not enough rifles, only one of mount get their. All the same standard smoothbore 11-inch Dahlgren's of similar weigh (3300 m/15°, 7.1 t, 75 kg) was putted temporarily on the rest mounts. However, the planned installation of an additional cylinder of the main engine, as well as an auxiliary cylinder and machines for turning the turrets (albeit weaker than the design ones), was completed. The dismantling of the masts that had already been made was considered a mistake, but there was no way back. If single-gun rotary mounts had a design that allowed them to be brought into the ports of both port and starboard, where the rigging did not interfere with a significant sector of fire, then the steam-driven mount was fixed in the diametral plane, and multiple rigging seriously limited their sector of fire. However, now a third fewer guns than Niagara, gave of one barrel larger side salvo. With the Roanoke conversion, Isherwood's goal of only the mechanical propulsion for a large frigate was achieved. After the war, all the frigates remaining in the ranks underwent a similar modernization.

_________________
"I have thousand advisers who know how build a pyramid, but have not one who can tell me whether to build it or not." - John Kennedy.

Raider forays of CSS Alabama and CSS Florida, which built in English shipyards, peaked in 1863, and peaceful relations between United States and Great Britain became under serious threat. Congress has responded by authorizing the construction of a new class of large frigates as part of this year's naval procurement bill. The 108 meter class Wampanoag was designed by clipper architect Benjamin Franklin Delano as the fastest in the world and was intended for raiding operations against British ports and commerce. It contained many features unseen in American military shipbuilding. The hull had an unusually high aspect ratio - 6.32 instead of 5.78 for Niagara. Prior to this, hulls were formed by shipbuilders based on their idea of the most streamlined forms, and then the engineers somehow installed their machines there. Now Isherwood called Delano to cooperation so that lead the hull contours around the large compound (double expansion) Wampanoag machines with an unexampled 8 main water tube boilers and two auxiliary boilers for steam superheating. The machines designed by Isherwood had a gearbox, reduced a frequency that was optimal for power plants, to a frequency that was optimal for screw. The controversy about this design has delayed building, don't allow to complete the Wampanoag timely for it to take part in the Civil War. At full speed, the ship reached an unprecedented 17.75 knots.

Previously, the rudder blade was suspended to the sternpost along its entire edge; at Wampanoag it was fixed only at two points of the axis: at the top on the rudder shaft and at the bottom on a massive cast console-extension of the keel. In this case, the axis of the blade did not coincide with the edge, and thus the rudder prove to be compensated.

_________________
"I have thousand advisers who know how build a pyramid, but have not one who can tell me whether to build it or not." - John Kennedy.

_________________
"I have thousand advisers who know how build a pyramid, but have not one who can tell me whether to build it or not." - John Kennedy.

New Navy Concept
So, in the means of war on the sea US admirals saw not armed vessels, but vice versa - floating guns. Therefore, it is natural that when, at the end of the 19th century, the Navy admirals were concerned about gaining superiority in outer waters, they began to look for it primarily in artillery. In laying down the principles for the future New Navy, they thought as follows.
What is the superiority of a ship in artillery? Usually, this is primarily understood as the superior power of the cannon, equal proportional scaling of all its characteristics, in short, superiority in caliber. But does the endless growth of all the characteristics of the gun make sense? If the energy of the projectile is already enough to penetrate the enemy's armor, then with an increase in this energy twice, will the overall superiority of the Fleet increase by the same two times? Obviously, increasing the projectile energy above the level of guaranteed penetration of enemy armor will not add anything to the fleet's abilities. Moreover, an increase in the power of the projectile above sufficient will pull at himself the blanket of the balance of characteristics, harming other properties of the ship. This means that the destructive ability of the projectile should not exceed sufficient.
Well. Let us say that the ability of cannons to hit a modern battleship are provided for you. However, this does not give superiority yet - the enemy's cannons will can penetrate your armor probably too. What should be the superiority of artillery? The two shoot each other. Who will win? Who will hit first. And what guarantees a hit first? As long as you are on an equal footing with your opponent, nothing guarantees victory. The conditions should be so unequal in your favor as not to leave the enemy a single chance. To be guaranteed to hit first, you need to be able to start firing from such range on which the enemy will not be able firing to you at all. Then he can surpass you in the power of the projectile, in the rate of fire, in the number of barrels - yes in anything, and as many times as he like. As long as you can fire at him while remaining out of reach, all this his superiority will not matter. The superiority of artillery lies in its most important property - in range. This is the key to naval superiority. For superiority of artillery, neither a caliber higher than sufficient, nor a greater number of barrels, nor a high rate of fire is required - only the ability to hit from a distance with which enemy cannot hit you.
Of course, in order to achieve a range that exceeds the total currently available level, you need to work a lot. However, the superiority of the ship does decide the issue not of that your Navy be slightly worse or slightly better. The superiority of the ship decide the issue, is it worth invest any funds to the huge oceanic fleet, or it is better to let them go to the land army, which, having received significantly increasing the budget, will certainly allow you to surpass any enemy on land. The issue of ship superiority decides whether you will be able to conduct politics outside of your part of the land. It makes no sense to build a fleet, knowingly doomed to death in battle. The Americans had to either find an opportunity for superiority in the range of ship artillery fire, or abandon the ocean-going fleet and the expansion beyond America.
In addition to artillery, there are two more important components of a ship: protection and speed. How does reliance on the range of artillery fire affect the overall balance of characteristics?
The next point is important here. The balance rule states that one component can be achieved only by weakening the other. However in our case, the bet on the range of fire redistributes the priorities within the artillery component only, without limiting in any way the possibilities of either armor or speed data. Moreover: thanks to the focus on the range, that artillery component pressure, which it render on the two other in tendency to keep within rigidly defined limits of displacement, even decreases. After all, keeping the caliber at the minimum sufficient level and the absence of a race for the quantity of the barrels, from a trivial point of view is the weakening of artillery. That allows strengthening armor and/or increasing speed. How use this opportunity to achieve the most beneficial balance of the two remaining components?
If your artillery is superior in range and you are out of reach for enemy, then you do not need armor. The absence of the need to spend displacement on armor, coupled with "weakened" artillery, will very conveniently give an increase in speed. After all, superiority in an artillery duel is only tactical superiority. However, to maintain a distance that is advantageous for your artillery is possible having superiority in speed only. Speed is operational superiority when you are ahead of your opponent by action and dictate your terms. The pursuit of speed can reduce the range. However, the displacement reserve due to the lack of armor and lighter weapons allows you to increase the fuel supply. It turns out that an unarmored and less armed ship is more versatile. Taking more fuel, it surpasses by range of sailing, and having used up part of it - by speed. Netto displacement, the difference between standard and full displacement, is an extremely important characteristic of a ship's capabilities.

Italy at all times was far from the position of the leading maritime power. However, there was a moment in history when even the Mistress of the Seas followed the trend of Italian shipbuilding. These were the 1870s-80s - the time of works of the great Italian shipbuilder Benedetto Brin. To his heavily armed, high-speed, and protected by a powerful, but small citadel, the Caio Duilio-class battleships, laid down in 1873, the British responded the following year with Inflexible and with the Ajax and Colossus classes in 1876 and 1879. However, back in 1871 at the meeting of committee investigated wrecking of HMS Captain, famous gunsmiths Armstrong and Whitworth said they were ready to provide guns that make meaningless any armor at all. Brin, developing his maximum artillery power concept, also came to a consideration that since even the thickest armor does not make the ship invulnerable, means that you can completely abandon it for big guns and powerful machines. His next class of battleships - laid down in 1876 Italia - relied only on the power of artillery and speed. In Britain, Nathaniel Barnaby also presented a project for an "improved Italy," but the British Admiralty, as the point of view of Amstrong and Whitworth, ignored it too.
Therefore, it is not surprising that the Americans following the British, starting the construction of the New Navy, also turned their eyes to the creations of the Italian genius. The ideas of American naval commanders have long been close to the latest ideas of Brin. Therefore, they did not follow the lords of the British Admiralty, on a specific issue seemed as retrogrades to them, and did not reject authoritatively substantiated arguments. However, the Americans considered a possible battle of Italia and to find out, that it is able to keep away from the usual battleship but is not able to destroy it. To fire enemy, Italia was required come to it, and for an Italian ship, it was dangerous. Although its guns had a long range, it was still insufficient to conduct a battle out of the reach of enemy shells for sure. And during the life time of Italia, rivals could well have received similar guns. Thus, the Americans found that they needed not so much super-heavy guns as super-long-range ones, which would provide superior range for long time. If this succeeded, then there would be no need for the huge weight of the projectile. The Italians needed it in order to inflict as much damage as possible on the enemy in the short time that Italy could approach to it. However, if you can to shell the enemy without entering the range of its artillery absolutely, you have theoretically infinite time at your disposal - the main thing is that your projectiles would can penetrate armor. The same factor, despite the significant distance, made unnecessary some special superiority in accuracy too. After all, sooner or later, but you will covered the target.

As with any weapon, one could not forget about the concept of operational density, that is, that the number of weapons should correspond to the length of the line of contact with the enemy. Some relaxation could given by superiority in operational mobility, but it has a certain limit too. If the enemy has enough resources to deploy actions in three directions and your number of resources is enough to cover only two directions then, of course, there can be no talk of any superiority. Therefore, large quantities of cheap ships are preferable: this gives flexibility and discretion; this reduces the total damage from the loss of one ship. At the tactical level, at the level of an individual battle, as shown by the comparison of a big frigate with a conventional battleship, ability to hit of enemy, while remaining unattainable for it, allows a numerical lag. After all, is it all the same, the projectiles of one ship do not reach you or hundred of ships? Just in order to take turns to shoot all your opponents, you need large ammunition and a sufficient lifetime of barrels.
However, taking care of the lower costs per unit of weapons, the Americans were in no case going to sacrifice by separate taken unit. They believed that the task of any type of weapon should be reduced to the necessary minimum, practically to a single task. However, they demanded from the type the ideal performance of this single task. If this type cannot perform even a single task, no amount of quantitative superiority would help. It would seem that the requirement of perfect fit to a single task leads to a highly specialized design. However, limited funding does not would allow Navy to keep a whole set of fleets, each of which would be adapted for a purely separate task. America needed a capital ship that would ideally perform the task that required the greatest stress - the general battle - but the properties of which at the same time, although in the second place, but as much as possible would correspond to the rest of the tasks of the fleet. That is, they needed an universal frigate again.
Another innovation in the tactics of American capital ships was the rejection of "cutting off the head" of the enemy column, or in other words - "setting the bar over the T." This maneuver led to approaching to the enemy column, which contradicted the principle of maintaining an advantageous distance. In the opinion of the Americans, a long-distance artillery battle was more consistent with the parallel following of the enemy's column.

So, the new big frigates were intended for squadron battles with capital ships. And the nature of their actions had to be exclusively offensive - fire from a superior distance. This style of action was simultaneously supposed to serve as a defense against an opponent of equal rank. This is about tactics and efficiency.
In terms of strategy, Mahan's doctrine insisted on a preliminary gaining of dominance at sea by victory in a general engagement. However, let us say we have achieved this goal and are ready to move on to the next phase - to destroy enemy communications or to strike at his forward bases. Does this mean that a large fleet of capital ships, which has absorbed the lion's share of the naval budget, becomes redundant at the end of a short-term general battle, and some other fleet is required for further actions?
When the capital fleet for a squadrons battle consists of heavily armored slow-moving ships, so it happens. But a high-speed ship will be able to cope with raider tasks, and therefore it will not be superfluous either after a squadron battle, or in the case when the enemy has no squadron fleet at all.
However, expensive big frigates were too few in number for raider missions. They needed to be supplemented with a larger number of smaller, lighter-armed ships. Such ships were needed in the squadron too. The fact is that the maneuvering of capital ships had to obey the logic of battle with the enemy's capital ships. Therefore, their maneuvering could not be ideal from the point of view of protection against torpedo attacks. That is, if the defeat of enemy torpedo-boats is assigned to special secondary artillery on board the capital ships themselves, then their maneuvering cannot guarantee the correct positioning of this artillery relative to the attacking torpedo-boats, and, therefore, cannot ensure the maximum effectiveness of this protection. The carriers for that artillery should be special ships, fast and armed enough to cope with torpedo-boats. For this, small frigates were intended. The discretion made anti-torpedo-boat artillery more effective not only because of the possibility of occupying more advantageous positions. Since capital ships could not distracted from their main mission, their actions against torpedo-boats could only be defensive. Small frigates, having torpedo-boats as their main target, could use more effective attacking tactics against them. This consideration gave rise to the idea that tactics optimized for the use of the main weapon precludes arming the ship with any other weapon. In particular, this deprived the perspective arming of artillery ships with torpedoes too. According to the calculations of the simulation of actions in Naval War College, 2 small frigates were required for each big frigate.
In this way, the Americans "calculated" their type of the main warship.

However, for this ship, as we can see, were needed completely unusual guns. Let us find out further how the Americans got them.

_________________
"I have thousand advisers who know how build a pyramid, but have not one who can tell me whether to build it or not." - John Kennedy.

How did the American cannon gain range superiority?

Hooped Civil War Rifled Artillery
The production of artillery in the United States from the very beginning had the peculiarity that the country practically had no resources for gun bronze - copper and tin. But there was a lot of iron. Therefore, American gunsmiths tried to cast weapons from iron. But cast iron was fragile, and guns from it often burst while fire.
At the same time, on the eve of the American Civil War, the transition to rifled artillery began in Europe. In Britain, a number of manufacturers offered their designs to the government, but Armstrong, who was not only an applicant, but also "accidentally" had the position of Engineer for Rifled Artillery of the War Cabinet, received contract. This completely ruled out the rest of the British manufacturers. They had to look for contracts abroad. One of them - Theophilus Alexander Blakely - offered his guns to the Americans. Blakely's guns came handy to them. The Americans had just started the Civil War, and they needed many guns. Moreover, Blakely's cannons were just iron, and the problem of strength was solved by reinforcing them with wrought iron hoops. For true, Blakely got little from this. Enterprising Americans immediately began to produce these guns themselves - Brooke from the Confederates, Parrott, and Delafield in the Union.

A feature of the Blakely-Brooke-Parrott cannons was presence of only few but large grooves. All other American Civil War guns used a similar rifling system. However, its main difference from the European rifling system was the way it interacted with the projectile. To consider this, you should be acquainted with the construction of these guns projectiles.

_________________
"I have thousand advisers who know how build a pyramid, but have not one who can tell me whether to build it or not." - John Kennedy.

Projectiles for Civil War Rifled Artillery
The shells of the first rifled guns interacted with rifling help of projections on the body that entered the grooves. This method was unsatisfactory in terms of gas checking. Another method of projectile interaction with the rifling was taken from small arms - a lead jacket, which was supposed to compressing into the rifling by gas pressure and, due this, acquire a shape that facilitates both guiding along the rifling and gas checking. However, the thin lead skin did not adhere well to the iron projectile and was coming off while fire.
When the first Blakely cannons, still with rectangular grooves, came to America, they were supplied with the best design Britten's projectiles, having a more stable expanding lead sabot. Lead remained lead, however, and unlike rifle bullets, higher strains in cannon meant that Britten's projectiles were only slightly better than the previous ones. American inventor Read began to make thin sabots of harder metals - copper or wrought iron. After him, many others began to produce similar projectiles, including Parrott himself. However, these soft metal sabots were again often crushed and coming off while fire.
In addition to these problems, there was also the problem of the clearance between the projectile body and the bore surface. The clearance was required to allow projectile easy moving through the entire barrel when muzzle-loading. However, its presence led to projectile irregular direction within the bore while fire. To solve this problem, Blakely adopted Commander Scott's "slant hook" or "centrical" rifling system, which had the property of self-centering along the bore axis. Since the guiding elements of this system were projections of the hard body metal, the issue of reliable projectile guiding along the grooves was solved.
There was still the question of gas checking. The American Sawyer covered his cannon's hard-ribbed projectile with lead for sealing, but the thin layer was still frequently damaged. Commander (future admiral) Dahlgren solved the issue simply by combining the projections with a lead sabot in one design. Now the hard projections took the mechanical strains, and the lead sabot served only to gas check, did not carry any strains, and therefore was not damaged.
The culmination of American own design during the Civil War can be called the projectiles of Superintendent of the US Military Academy at West Point, Lieutenant Colonel Delafield. These projectiles were cast from malleable iron in one piece with thin sabot that had ready-made projections for rifling. Thus, the Delafield projectile skirt combined the role of a guiding element and an obturator.

So, as we can see, American ordnance was quite original and satisfactory. However, there was little interest to it in Europe, and the Americans themselves were delighted with European achievements. They especially revered one European cannon, several decades ahead of its time.

_________________
"I have thousand advisers who know how build a pyramid, but have not one who can tell me whether to build it or not." - John Kennedy.

Whitworth Guns
In 1860, the US War Department purchased seven Whitworth's 12-pound breech-loading guns for familiarization. Guns and ammunition for them arrived in the country on the eve of the Civil War and turn up on the territory of the rebellious southern states. Although the Confederates had only one battery of these cannons, which was later captured by the Unionists, both were impressed by Whitworths thanks to their long range and accuracy. Such high performances were the result of two factors. First, Whitworth's 12-pounder was not made of iron, but of more durable steel, manufactured using special technologies. Secondly, its design belonged to systems with hard guiding elements like some American ones. But unlike the American guns, Whitworth's 12-pounder took more advantages of the system with hard guiding elements.

Hard Guiding Elements
How systems with hard guiding elements do differ from conventional systems with soft guiding elements?
The main difference is that the formation of soft guiding elements occurs in the barrel by the force of the shot, why they are also called "compression". This leads to the fact that the process of rifling a soft guiding ring or skin during a shot takes away many of the charge energy, and the high gas pressure and the rifling process itself create significant strains on the barrel.
In contrast, the formation of hard guiding elements occurs in advance during the projectile manufacturing, why they are also called "ready-made". Thus, systems with hard guiding elements are completely free from strains and other factors associated with the rifling process. With the same propellant charge, these systems have lower pressure at higher translation and rotation speeds. All this allows increasing the range, accuracy, and barrel lifetime, as well as the elongation and filling factor of the projectile.

However, after receiving rifled guns, the improvement of artillery did not stop.

_________________
"I have thousand advisers who know how build a pyramid, but have not one who can tell me whether to build it or not." - John Kennedy.

Further Ordnance Improvement During Civil War
During the Civil War, artillery designers knew already that the barrel withstands the breaking longitudinal strain between the rear wall of the chamber and the trunnions four times worse than the transverse pressure of gases. Therefore, there was an idea that the trunnions were better placed at the level of the cascabel, as in some mortars. Thus, the barrel would be freed from longitudinal strain while fire. We can find this idea, for example, in Holley A. L. "A Treatise on Ordnance and Armor," 1865.
By this time, the barrel had already lost unnecessary decorating elements, not only because this simplified production, but also because they believed unwanted tension concentrators in the barrel. However, there were still the most dangerous tension concentrators - trunions. So Blakely, Whitworth, Armstrong, and after they Brooke made the cannons with separate trunnion ring, leaving the tube completely smooth. Now the tensions of the trunnions no longer affected the barrel, but the fit of the trunnion ring was solid and the longitudinal strain of barrel by shot remained.
Dahlgren combined two solutions again, adding to separate trunnion ring a strap covering the breech part of gun. Thus, the barrel lost both, the last tension concentrators and completely the longitudinal strain while fire.

In the meantime, as we can see from the Whitworth cannon, Europe was already receiving breech-loading guns. What could the Americans have done in this regard?

_________________
"I have thousand advisers who know how build a pyramid, but have not one who can tell me whether to build it or not." - John Kennedy.

Experimental Breech-loaders During the Civil War
Now, when the gun was supposed to receive a breech-plug, this breech-plug became the rear wall of the chamber. Therefore, the strap now had to hold exactly it. Similar designs have been known since the 16th century. With start the Civil War, solutions combining a strap and a breech-plug appeared in a lot. They have been suggested and even tested by almost identic samples of Cap. R. R. Moffat (US35863), H. F. Mann (US2783, US33787, US257823), John B. Moody, George B. Brayton, Columbus Iron Works, and others.

But the most advanced design was probably suggested by Blakely.

_________________
"I have thousand advisers who know how build a pyramid, but have not one who can tell me whether to build it or not." - John Kennedy.

Here is a summary of the article in "The Engineer", July 3, 1863, p. 63 (unfortunately in the copy I have, the dotted lines are poorly visible):
The object of these improvements, by Captain Blakely, of the Army and Navy Club, is that the opening of the breech may be affected by the act of firing, so that the parts leave in a position to receive a fresh charge. For this purpose the breech-piece projects into the barrel, and is retained in position by weight or elastic pressure proportionate to the power exerted by the pressure of the charge in firing. The firing cause the propulsion of the projectile, and at the same time the recoil of the breech-piece, thus opening the parts for the supply of a fresh charge. The breech-piece enters the barrel to an extent sufficient to insure in not leaving the breech end thereof until the projectile passes out of the muzzle.
The breech-piece is affixed to the block, which has groove formed on each side of it to receive the rails, projecting from the end of the gun, by which the block with the breech-piece is supported, to be capable of sliding to and from the breech end of the gun in a line with the bore. The block has be drawn towards the barrel by a weight, which is connected to the block by chains, other end of each of these chains is connected to the weight, and thence passing over a pulley. The weight serves also as table for the fresh charge and projectile pervious to its being driven into the gun, and, by preference, a fresh charge is placed on table, whilst the weight is holding the breech-piece in the breech end of the gun. When the parts are in the position indicated, with the table raised, that table will hold the fresh charge correctly opposite the bore. The parts, as shown, are in the position after the firing, when the effect of the recoil has been to force out the breech-piece with its block, thereby overcoming the force exerted by the weight. And in other that the block with its breech-piece may then remain in the position indicated until a fresh charge has been introduced, there is applied to the weight a pawl, and to the framing a rack, by which when the weight has been elevated, it will be held up with the fresh charge thereon in position for loading. This charge must then be forced a short distance in to the gun, and then by lifting the lever handle affixed to the pawl, that will be released from the rack, when the weight will descend again and draw the breech-piece to force the charge fully into the chamber of the gun.

So, we collected all elements that actually existed among the Americans by the time of the laying of the New Fleet. By this the real-historical preamble ends, and begins the "amble". Well, let's now try using these elements to assemble a puzzle by name "New Fleet". Let's start, again, with what the American concept was based on - with the new ordnance.

_________________
"I have thousand advisers who know how build a pyramid, but have not one who can tell me whether to build it or not." - John Kennedy.