Audace-class destroyer (1971)

Class overview
Operators	Italian Navy
Preceded by	Impavido
Succeeded by	De la Penne
In service	16 November 1972
In commission	2 October 1971 - 28 September 2006
Completed	2
Retired	2
General characteristics
Displacement	4,554 tons full load
Length	140.7 m
Beam	14.7 m
Draught	4.5 m
Propulsion	2 shaft geared steam turbines 4 Foster Wheeler boilers providing 73,000 hp
Speed	33 knots
Range	4,000 miles at 25 knots
Complement	380
Armament	As built: 2 × Otobreda 127 mm gun 4 × Oto Melara 76/62 mm Compact gun 1 × Tartar SAM system 2 x 324 mm triple torpedo launchers 2 x 533 mm triple torpedo launchers Post 1987-1990 modernization: 1 × Otobreda 127 mm gun 4 × Oto Melara 76/62 mm Super Rapido gun 1 × Mk.29 octuple launcher for Sea Sparrow/Selenia Aspide SAM 1 × Mk 13 launcher with 40 Standard SM-1MR missiles 8 × OTOMAT SSMs 2 x 324 mm triple torpedo launchers
Aircraft carried	2 AB-212ASW helicopters

The Audace class destroyers were two guided missile destroyers built for the Italian Navy during the Cold War. An improvement of the Impavido class, these ships were designed for area air defence and also had a heavy gun armament. They were fitted with contemporary American radars and sonars, but also they were fitting, just as the next Italian ships, they fitted all the new weapons made by Italian industry of the time, such torpedoes, helicopters and guns. Also some indigenous radars were fitted.

Design

The design of these ships was related to the previous Impavido class, but they were meant as a decisive improvement over these older vessels. In fact, they were built with a hull capable of better resisting high sea conditions, and this hull was also lengthened enough with an aft superstructure capable of accommodating 2 AB-212ASW helicopters. This gave the capability for anti-submarine warfare, with improved sonars and torpedo tubes.

The superstructures,which were quite tall, were built with aluminium alloys, in two blocks with one mack (this is the combination with the funnels supporting metallic, short trees used for radar equipment) each. The distance between the two superstructures block was notably high, because at midship there were both the propulsion systems, and over this, the 76 mm gun battery. The aft superstructure was dedicated to Tartar/SM-1 missiles and hangar.

The propulsion had two powerful steam-turbine system, on two shafts. It allowed around 33 knots and a quite good endurance.

Armament

With this new design, in order to perform ASW tasks, it was decided to adopt a powerful dedicated weapon. But instead of adopting ASROC, it decided to use the A.184 wired torpedoes. These weapons had both ASW and AS capabilities, and while it did not have impressive performance (roughly 10–12 km/36 knots, 24 km/24knts) being a conventional electrical torpedo, it was one of the better models of its time and was modernized with several updates. It was also one of the first to have both ASW and AS (Anti-ship) capabilities, while in 1970s many torpedoes were built to have one or the other capability, lacking wire-guidance or homing sonar guidance. Twelve examples were on board, just as many as the smaller light torpedoes A.244 or Mk46 models with triple ILAS-3 launchers. A.244 had better shallow-waters capabilities, but basically they were limited in performances to Mk.44 level, while Mk.46 were better suited to attack depth and fast targets.

The gunnery armament consisted of 6 guns of a new generation, fully automatic and with high rate of fire: 2 Compact, 127mm guns (foredeck) in single mounts, capable to fire at least 40 shells/minute, while (in substitution of unsatisfactory Model MM guns) new 76mm Compact were at mid-ship. Despite weighting only 7 t, they had enough firepower: 80 c.min, with 85 ready ammunition under the deck in a rapid reloading system similar, as example, to T-72 or T-80 gun reloading systems. Together with 127 mm and the main air-defence system (Tartar/SM-1), all this weaponry made possible an effective air defence, both long range and close-in.

Helicopters

Aft, there was the hangar for two AB212ASW, medium helicopters modified (after the experience with the smaller AB205ASW) by Agusta to perform naval roles, like anti-submarine tasks, SAR, anti-ship search and attack (with only small AS-12 missiles). These helicopters were quite big, comparable to the Westland Lynx, and so, the hangar literally sieged the SM-1/Tartar depots for the Mk 13 launcher. These two helicopters were second in importance only to the SM-1 missile systems, because torpedoes and guns were mainly useful for close defence of the ship. Audace were meant to carry an effective area-defence SAM and helicopters, while guns and torpedoes were short range defence systems. All by all, Audace had six modern guns (of two different calibers) and four torpedo launchers (with 14 tubes, two different caliber as well), a really uncommon amount for a modern ship.

Electronics

As electronic set, there was

• an SPS-52 3-D radar, in the aft 'mack', a US model that explored the air space measuring also altitude, up to 300 km
• a RAN20S, 2-D radar on the fore mack, Italian model coupled with the other long range radar. The combination of two radars, one 3-D and the other 2-D was normal for a Standard missile ship in US Navy.
• an SPQ-2 for low-altitude air search and surface, a 3M20 navigation radar where placed in the fore mack. Both served for surface and low level aircraft detection
• 2 SPG-51 illumination radars for SM-1/Tartar, in the aft superstructure
• 3 RTN-10x for gun controls, one over the turrion, the other two at midship, (in the aft superstructure) to serve 76 mm guns. Each of these guns served a couple of guns.
• a CWE610 hull sonar
• a pair of SCLAR, rocket launcher for decoys, also capable to fire HE rockets if necessary.
• several others systems, for ECM and communications
• SADOC-1 combat and communication system, similar to NTDS.

Despite the improvements in anti-aircraft warfare, and maybe even more marked, in the ASW capability, there were still limitation and shortcomings in this new vessel design.

The weaponry lacked a specific anti-ship missiles system, except the AS-12.Within short range, however, there were many systems able to engage naval targets: A.184, 2x127mm and 4x76mm guns, the Tartar/SM-1MR missiles in their second role (like many naval SAMs). There was not a real CIWS system on board, relating only to the massive firepower of artilleries, but at aft ship none of them can fire, so despite so many guns, there were still blind spots in the defence at low altitudes, covered (in the aft sector) only by Tartar/SM-1, not meant as anti-missile system.

Modernisation

In 1988-1989 they underwent extensive modernisations: it included the replacement of one 127 mm gun turrets and also the A.184 torpedoes with new weapons: a Teseo SSM system (midship, between the 76mm guns) and an eight-cell Albatros Aspide SAM launcher (directly replacing the 127mm turret). The four 76/62 mm guns remained, but the Compact model was replaced by 76/62 Super Rapido (120 rpm, meant especially for anti-ship missile defence). The Tartar SAM complex was replaced by the RIM-66 Standard Missile SM-1 system. So, with this new systems, these ships were able to cope with all the requirements: thanks to the Superapido and Albatross they had a much improved close-defence, especially against missiles, while OTOMAT allowed a long range, anti-ship capability, together with AB-212 for targeting over the horizon. All this helped to bring these ships almost to the same level of the new de La Penne class, in 1991 still under construction, with even more weaponry (1 Super Rapido gun).

What remained unsolved was the lack of a VDS (variable depth sonar), the construction vulnerability, with the tall supestructures made in aluminium (and so vulnerable to fire), the excessive amount of weapons and explosives in the small hull (especially in the aft superstructure, that in 20 meters concentrated both hangar and SAM depots), some spartan solution for hosting the crew of 380, and the lack of an aft close-defence weapon (solved only with de La Penne), despite 6 were available at flanks and foredeck (but the 4 Super-Rapido were placed at mid-ship, unable to fire directly both forward and behind, while the only tree of de La Penne were able to cover all 360°). Also, the engine was of an outdated model, potentially (boilers) also dangerous and slow to operate as start. All these ships suffered also for the age and the intense sea service, so their operative life was almost expired at the end of the 20th century, and only the delays of Horizon program allowed them to service for several years than expected.

Ships

Name	Pennant number	Builder	Laid up	Launched	Commissioned	Status
Audace	D 551	CNR of Riva Trigoso	17 April 1968	2 October 1971	16 November 1972	Decommissioned 28 September 2006
Ardito	D 550	Italcantieri Castellamare di Stabia	19 July 1968	27 November 1971	5 December 1972	Decommissioned 28 September 2006

The units were based in La Spezia and took part in many missions, such as the Lebanon crisis in 1982, and Gulf crisis in 1990-91.

They were both retired in 2005 [1].

References

• Conway's all the World's Fighting Ships 1947-1995
• Page from Globalsecurity
• Po, Enrico, i caccia de La Penne, Rivista italiana Difesa (RID) n.6/93.
• Armi da guerra enciclopedia, pag 863, De Agostini publisher, 1984. This was the Italian edition of War Machines, Limited aerospace publishing, London.