The Littorio class were some of the most powerful and advanced battleships of WW2. The Roma was the last and best of these ships which corrected many defects of the previous versions and lessons learned. Including increased length, flared bow for improved seaworthiness, improved torpedo defense, improved decapping plates with added cement armor, better anti aerial defense and increased range. Unfortunately the Roma ran into a German radio controlled 4 ton explosive weight glide bomb. Some redeeming features:
1. The 15″ Guns Were Powerful!
The Littorio class battleships had some of the most powerful 15″ guns of the entire Second World War that actually exceeded larger calibre weapons in many regards. They were armed with the Cannone da 381mm/50 calibre Ansaldo M134 naval guns. These 15″ weapons, designed and manufactured by the Ansaldo company, were incredibly powerful. Due to an exceptionally high muzzle velocity of 2850fps, these guns could fire their 1,951lb shells at ranges exceeding 26 miles (42.25km). Each Littorio class battleship was armed with nine of these potent guns carried in three triple turrets. These weapons allowed the Littorio class to compare favorably with their peers. In fact, the kinetic energy of these shells was even higher than that of the Yamato and Iowa. The biggest problem with the guns was that the quality control of the shells and powder was extremely poor. Inconsistent shell sizes and poor quality powder/dosage created inconsistent range and dispersion. Would have been resolved in time, but time was not on Italy’s schedule. From a ballistics perspective, the Italian 381mm/50 surpassed every other 15″ weapon of the Second World War. It even surpassed larger weapons such as the United States 16″ weapons and even outranged the massive 18.1″ guns of the Japanese Yamato by roughly 900 yards. This was largely due to a relatively heavy shell for a 15” gun combined with highest muzzle velocity of any WW2 gun. However, this did come at the cost of poor barrel life for the naval guns. However, it was deemed that the barrels would perform well for multiple encounters before requiring change outs. Due to the high velocity, these guns would be devastating in close range encounters (below 12 miles) where a horizontal path rather than plunging fire would be instrumental in defeating other battleships. The whole plunging fire notion was never put in practice by other battleships since hits beyond 20 miles were extremely rare and ineffective. Recent information suggests that the accuracy issues were more the result of poor manufacturing of both the shells and powder. In any regard, the powerful guns of the Littorio class were a serious threat to any battleship they might engage. Even with dispersion issues, the guns were noticeably more powerful than the 15″ models aboard French, German and British battleships, the two most likely opponents that they might face.
In addition, these guns were some of the most responsive guns of WW2. Consider that a 4-5 degrees per second is typical for turrets on other battleships, 2 seconds for the Yamato, and the Roma’s turn rate was designed for 7 degrees per second. Finally, the guns had some of the finest and sophisticated stabilization systems to maintain target tracking even under the most rough conditions.
2. Great Armor Design, decades ahead of her contemporaries:
The Littorios used Krupp cemented steel (KCA), an evolved variant of Krupp armor (carbon 0.35, nickel 3.90, chromium 2.00, manganese 0.35, silicon 0.07, phosphorus 0.025, sulfur 0.020). KCA retained the hardened face of Krupp armour via the application of carbonized gases but also retained a much greater fibrous elasticity on the rear of the plate. This increased elasticity greatly reduced the incidence of spalling and cracking under incoming fire, a valuable quality during long engagements. Ballistic testing shows that KCA and Krupp armor was about 30% superior normal armor. That is, 10” of KCA was equivalent to 13” of normal steel used by other nations. Why does this matter? It shows that the Italians had access to the highest quality metallurgy possible. This extremely high quality steel technology allowed the Littorio Class the use of decapping plates on the decks and sides. The Roma perfected this technology to protect her from shells that would be encountered during WW2. The subject of decapping plates had long intrigued naval designers as a method of defeating incoming projectiles by removing the main projectile from the explosive charge at contact. Despite the research, most navies utilized them rarely if at all. Italy was a major exception as they conducted more research into the use of decapping plates than anyone else. What is a Decapping Plate? Naval armor piercing shells relied on a cap (some use hardened steel, some use softer steels) fitted over the shell to penetrate armor. If this cap is removed or damaged in anyway, it could severely reduce the shell’s ability to defeat an armored plate. A decapping plate was intended to damage or remove the shell’s cap, in effect “decapping” it. The decapping plate, a special very high quality steel alloy would be fitted in front of the main armor. It would in theory decay an incoming projectile, weakening it and giving the primary layer of armor a better chance of resisting it. The Roma added one more feature to the decapping plates, a hard layer of concrete fill, which increased the de-capping ability. Concrete being stiffer and lighter than steel worked perfectly with this technology. It is the same steel/concrete technology that is used in today’s steel doors of Earth Covered Munitions storage buildings to protect surrounding buildings from a 500,000 explosion within the building. When combined with the de-capping design to make sure that most projectiles passing through the side armor were in pieces, these internal plates would stop a very large portion of the pieces of a penetrating projectile and the chunks of armor that it ejects from the belt plate during penetration. They would, in effect, add on several thousand yards of protection to the ship’s “vitals” within, making the effective protection of this ship much greater than it seems if merely the belt armor alone was considered. Of all of the non-German designs, the Roma was probably the most efficient for the weight of armor used at protecting its “vitals” from side hits at or above the waterline. In addition, she had two inclined bulkheads of high quality steel armor spaced behind the main belt alongside its entire Citadel region. The deck armor also had decapping plates. All in all the steel used in the Roma was of equal quality of the HMS Vanguard. Finally, the Roma used an external armor scheme which was considered superior to the internal armor scheme used by the Americans. In fact, the British used external armor, as did the USN Montana design (which was an Iowa upgrade). So please don’t get caught up with arguments that “my armor is better because it is thicker”. There are other factors.
3. The Torpedo Defense System was Effective.
A majority of battleships during the Second World War utilized a torpedo defense system comprised of several layers of bulkheads, flooded with sea water and fuel between the outer skin and the internal armor, which was designed to resist enemy torpedo attacks. This was a very weight intensive solution. The Italian Navy went in a completely different direction with their unique design, the Pugliese torpedo defense system. The system was defined by its innovative pair of cylinders along the side of the hull. This outer cylinder was intended to contain the blast from an explosion and direct it to the inner cylinder. The inner cylinder would then be crushed by the explosion of a mine or torpedo, absorbing the majority of the blast and sparing the rest of the ship. Even areas that did suffer flooding were ingeniously designed to channel the water to the bottom of the ship’s hull, reducing any detrimental effects to stability. The system was relatively compact (In that it didn’t protrude outside the hull very far) and did not require as much material as a multi-layered torpedo defense system. Unfortunately, the legacy of the Pugliese system has become somewhat tarnished due to claims of underwhelming performance during the Second World War. Most of these claims stem from the British attack on Taranto where three ships equipped with the Pugliese system, one of which was Littorio, were torpedoed. This resulted in damaged and the ships were forced to undergo repairs. However, two of the three ships were torpedoed outside of the torpedo defence system. Littorio, the only ship to be torpedoed in her Pugliese system, actually handled the explosion fairly well and the system did withstand the blast. In fact, there was only one recorded case where the Pugliese system failed after being hit by a torpedo and this was due to the torpedo striking an area where the system was at its thinnest (Vittorio Veneto, December 14, 1941). Taking all that into consideration, the Pugliese system was not as bad as most have deemed it. In fact, the system handled itself remarkably well, especially considering that the system had roots that began during the First World War. While the system might not be perfect (No design ever is), the Pugliese system is another example of Italian naval innovation. In the Roma case, the Pugliese system was extended from lessons learned, from the earlier Littorio ships, and probably would have worked well. I also would like to point out that no battleship ship could sustain a torpedo hit near the rudders or bow without severe damage. See Prince of Wales which was sunk by a torpedo near the props and the Bismarck which was disabled by Swordfish torpedo bombers, with a hit near the rudder, causing massive fuel leaks. The Iowa for example had zero torpedo protection over most of the bow and stern, and not very deep at the midsection due to the inclined inner armor, and was good for only 700 lb torpedos, while most torpedos after 1940 were around 900 lbs. Aside from the Pugliese system, the Roma had some of the deepest torpedo defense systems outside of the Richelieu. The Richelieu was considered to have the best torpedo defense system when compared to the British, Japanese, US and German ships. However, the Roma also had a triple double hull, which I would say the Roma was even better than the Richelieu.
4. The Littorio Class Enjoyed Exceptional Firing Arcs.
A unique and defining feature of the Littorio class battleships was height of their aft and second bow 381mm turret. These turrets were raised some 10′ over the main deck, placing it at about the same height as the second super firing turret. This arrangement was completely unique to the Littorio class and was not seen on any other battleship in service during the Second World War. At first glance this layout would seem to add substantial top weight to the battleship. However, this arrangement did provide substantial benefits that no other battleship had. Due to the height of the aft and second forward 381mm turret, she could fire over the 152mm secondary gun turrets. from either the rear or front The aft and forward sections of the ship’s superstructure, as well as the location of the mainmast, was specifically placed to not interfere with these turrets. This allowed the aft and forward turret to attain an incredible firing arc of some 320 degrees around the battleship. This allowed the Littorio class to fire full broadsides at targets so long as they were not more than 20 degrees off the bow or the aft. This gave the Littorio class the ability to fire all nine of her guns while chasing a target and fire six guns while retreating. No other battleship enjoyed this ability, giving the Littorio class an advantage that was theirs alone. Some publications state that the height of these turrets was also to provide a level of safety to her embarked aircraft. However, this is probably not accurate. While it might have given the battleship’s aircraft some additional working room on the quarterdeck, they would have most certainly not been safe from the tremendous muzzle blast of the 381mm/50 guns.
5. Three Rudders helped Prevent a Loss of Steering
Rudders had always been the Achilles heel of battleship design. No matter the size or armor of the dreadnought, the rudder was always a vexingly vulnerable component of the ship. Nations had tried several methods to better prevent damage to the rudders, but none were ever successful. To make matter’s worse, the quest for agility saw the fitting of larger rudders or an additional one, making them even more vulnerable. An underwater detonation at the stern area of a battleship was very likely to damage these critical components. If a battleship couldn’t steer, it was a much easier target. In response to this issue, Italy introduced a rudder layout that only they ever fitted to a dreadnought. A single main rudder was supported by two auxiliary rudders for a triple rudder layout. The auxiliary rudders were mounted just after the outer screws, some 25m (82′) ahead of the main rudder. This layout prevented a single torpedo from damaging all three rudders. In addition, it seems that two rudders were sufficient to maneuver the battleship even with one rudder inoperable. The only instance of this occurring happened on March 28, 1941. Vittorio Veneto was torpedoed by a British aircraft. The torpedo damaged the outer port shaft and severed the screw. In addition, her port auxiliary rudder was jammed. Though initially dead in the water, quick repairs allowed her to depart the area on only her starboard engines. In addition, she still retained the ability to maneuver as her starboard auxiliary rudder and main rudder were still operable. This allowed her to escape a pursuing battleship group and return to port. Though no navy ever found a way to protect the rudders from damage, Italy found a way to help their battleships retain steering through simple redundancy. The triple rudder layout was unique to the Littorio class and for all intents and purposes appears to have largely been a success. While the auxiliary rudders, due to their placement on the outer reaches of the hull, might have been somewhat more vulnerable to damage, they were still supported by two additional rudders. Overall, it would appear that the Italian Navy had figured out a way to better protect the ship’s steering than any other navy during the Second World War. Another noteworthy benefit of the three rudder system was that it provided a very responsive change in direction ability, with a turn radius under 800 meters at 24 knots (Iowa was around 1000 meters at 30 knots).
6. The Roma was fast and an extremely seaworthy ship
She hit 32 knots at 10% overload and 31 knots at the rated horsepower. She was very seaworthy because her citadel sat fairly low, which lowered the center of gravity. Also, the bow was extended and flared outward which made her an excellent ship under extreme weather conditions while increasing stability (think better targeting ability). This also kept her front turrets dry, giving her the ability to shoot from the forward position, and being able to cross the “T” when attacking other ships. The same can’t be said for other battleships such as the Iowa, KGV and the Bismarck which had their turrets very wet when going forward. These ships essentially had to maneuver into a sideway position to be able to use their guns. Only the Richelieu, Roma and the Vanguard could fire from the forward position. This is a HUGE advantage. Her turning radius was under 800 meters. Compare that to the Iowa at 1000 meters and the Vanguard at 940 meters. I don’t have the exact numbers, but the Roma’s big attribute and bragging right was that she responded very quickly to the rudders. Sorry, but I can’t quantify this. However, because of the poor Italian fuel quality, the Italians were rarely capable of exploiting Roma’s speed or range. Regarding range, the Roma certainly did not need it in the Mediterranean. If you look at the Pugliese system diagrams, you will quickly see that the Roma clearly had the capacity to increase her range by flooding the area between the outer skin and the Pugliese cylinders with fuel, which is very similar to what the Iowa and the KGV did.
7. She had some of the most powerful secondary guns of any battleship.
Four triple turrets x 152mm (6″)/55 Model. These were mounted in 1936. They had a shell weight of 110 lbs and a 28,150 yard range, and rate of fire of 8 rounds per minute (the earlier Vittorio Veneto had a 5 round per minute rate). One could argue that these secondary could cause a lot of damage to fire control radar and other systems on a modern battleship in conjunction to the 15” guns. The 28,150 range is ludicrous, even by today’s standards.