Zara class cruiser

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Zara class cruisers in Trieste
General characteristics
Displacement:	Zara 11,870 t standard, 14,530 t full load Fiume 11,508 t standard, 14,168 t full load Gorizia 11,900 t standard, 14,560 t full load Pola 11,730 t standard, 14,360 t full load
Length:	182.8 m
Beam:	20.6 m
Draught:	7.2 m
Propulsion:	8 three-drum Thornycroft boilers 2 Parsons turbines 95,000 hp (71 MW) total
Speed:	33 knots (61 km/h) (Gorizia and Zara) 32 knots (59 km/h) (Fiume and Pola) Full load sea speed: 31 knots
Range:	4,500 nautical miles (8,300 km) at 16 knots (30 km/h) 2950 nautical miles (5,500 km) at 25 knots (46 km/h) 1700 nautical miles (3,100 km) at 31 knots (57 km/h)
Complement:	830
Armament:	8 × 203 mm(8Inch) / 53 caliber 6 x 100 mm / 47 caliber 4 x 40 mm / 54 caliber AA 8 x 12.7 mm AAMG
Aircraft:	2 reconnaissance
Protection:	belt 100 to 150 mm (3.9 to 5.9 in) deck 70 mm (2.75 in) turrets 120 to 140 mm (4.7 to 5.5 in) barbettes 140 to 150 mm (5.5 to 5.9 in)

The Zara class was an Italian heavy cruiser design of the Regia Marina from the early 1930s, considered by many to be one of the best cruiser designs of World War II. Four ships of the class were completed, Zara, Fiume, Pola and Gorizia, all of which saw extensive service during the war.

Zara class was essentially an improved Trento class, tasked with dealing with the latest French designs. Trentos had sacrificed armor for speed, allowing them to make high-speed dashes up and down the long Italian coastline, however this left them unable to deal with newer ships facing them in a gunfight.

On Zara the armor was thick enough to withstand hits from guns equal to her own (this meant that they were designed to fight directly other heavy cruisers), resulting in the best armored cruisers in the world at the time. This was an important achievement, because the standard for many of the cruiser born with the Washington Treaty was, as example, only 76mm for armour belt, and even less for the turrets and barbettes. These armour plates were reasonably good only against destroyer and light cruiser weapons, but absolutely insufficient against the 120 kg shells that 203mm fired, capable of piercing even 150mm at medium range. But to achieve this, the Zaras were made almost 2000t heavier (as standard displacement) to this limit, even if, fully loaded (because the modest amount of the fuel load) they weren't heavier than, as example, British heavy cruisers. Over the armoured, main belt, up to 150mm thick, there was also a very thick main deck, 70mm. Turrets and barbettes were as well protected by over than 100mm armour. Over these main armour scheme, there was even another series of minor armours: the upper deck was 20mm, and the flank hull above main belt was 30mm. Almost no other cruisers were equipped with two armoured decks and two armoured belts. This scheme followed, in fact, not quite a cruiser layout, but that of a small battleship. Until Salem cruisers, no other heavy cruisers were more armoured than these four ships. But this was only possible ignoring the treaty limitations under which other constructors operated with their 203mm cruisers.^{[citation needed]}

The 203/53 mm (8 in) gun, shared with the last of Trentos Bolzano, had a high muzzle velocity of 939 m/s (3,080 ft/s), giving it excellent range and allowing it to engage its equals at a very long 34,400 yards (31,500 m) with 125kg shells (Trento and Trieste had a less advanced model, with 110kg x29,000m), although at the price of a greater dispersion of shots and barrel wearing than normal. One odd feature was the aircraft catapult on the front deck, which made it impossible to prepare for launch while firing, perhaps a minor consideration. Anti-aircraft performance was not good, due to the slow tracking process and an inadequate fire control system, although the weapons were acceptable. The armament for the a/a role was enhanced as well, compared to the standard of those times: 16 100/47mm guns were fitted in eight dual turrets, four for every flank, again following a scheme similar to a small battleship. Later, four of these guns were removed to be replaced by eight 37mm Bredas, more useful for close defense. All these guns were reasonably modern, especially at their time, even if not outstanding performers.

Originally intended to conform to the Washington Naval Treaty limits of 10,000 tons, the extra armour made this impossible. Extras such as a high superstructure and torpedo tubes were removed in an effort to save weight, but in the end the ships ended up considerably "overweight" anyway. The removal of the superstructure made placement of radar difficult, and in the end none of the class would ever carry one. This would prove to be a fatal omission.

Construction of Zara started in 1929 and she was launched the next year, and commissioned in 1931. The remaining units of the class followed in 1932 and 1933. The French immediately responded with a new heavy cruiser of her own - Algérie - but were not able to match Zaras design when launched in 1934.

Zaras were organized into their own 1st Division of three ships (the fourth being held in reserve) and operated in most early naval actions. During this part of the war the Zaras were a serious problem for the Royal Navy, which had nothing comparable in the Mediterranean Sea, and were seriously out-gunned by them during the inconclusive Battle of Calabria and Battle of Cape Spartivento.

However, Zaras were eventually taken to task during the Battle of Cape Matapan. After Pola was hit by an air-dropped torpedo and stopped, the rest of the 1st Division (at this time Gorizia was in reserve) ran in to protect her. Three Royal Navy battleships and a host of additional units were able to approach them closely at night — the lack of radar on Zaras making them unaware of their approach. They quickly sank all three cruisers and two of their escorting destroyers in a one-sided gunfight. The Regia Marina squadron was unprepared for a night action and their guns were in their rest positions when the British opened fire.

Gorizia survived until it was taken over by the Germans after Italy left the war in 1943. In that year, its armour had the only opportunity to display its effectiveness, when this ship was hit by three bombs, launched by American bombers, but the main deck resisted them all and the ship continued to fire against the high-flying bombers. Later she was able to reach La Spezia, but the damage to the mid-ship was really heavy, with almost all the structures over the armoued belt devastated and a 100mm turret thrown into the sea. Ironically, at beginning of 1941, a modest British attack, at night, over Naples hit Zara. There were only two bombs, 113kg, launched by low altitudes, but they pierced the hull and almost sank the ship.

Gorizia was sunk in port in 1944, rather ironically, by Italian manned torpedoes.

So the sad fate of these ships, one of the most admired classes of Italian Navy in the inter-war period (they looked quite pretty, also, and were often portraited in cards) was so. Ironically, all their heavy extra-armour was useful only to help them to sink more quickly: none of these plates helped them against close fire by 381mm battleship's guns or sabotage with underwater explosive charges.

[edit] References

• Italian Heavy Cruisers www.regiamarina.net