Maestrale class frigate

The Maestrale class is a class of frigate in the Marina Militare (Italian Navy). The class is composed of eight vessels, all of which were built by Fincantieri S.p. A, Riva Trigoso, except for Grecale, which was built by Fincantieri S.p.A. - Muggiano, La Spezia.

The Maestrale class frigates were primarily designed for anti-submarine warfare, however the ships are highly flexible so they are also capable of anti-air and anti-surface operations. Ships of this class have been widely used in various international missions, either under NATO or ONU flag, and during normal operations of the Italian Navy.

The first of these ships entered in service in early 1982. The rest of the fleet was launched over the next three years. in much less time. The ships of the Maestrale class are scheduled to be replaced by the Rinascimento class starting in 2011.

Design

These ships were built with the experience and the technology already developed for the previous Lupo class, the most successful warship design built by the Italian Navy after the Second World War. The Maestrale were quite bigger and heavier, so they were slower, but still capable of around 32 knots. The ships have a large superstructure, with one large turret and only one funnel. There are two trees, one of which is quite low, the other much taller. The superstructure continues without interruption until the hangar, and is made, as usual, with light alloys.

The propulsion system is based on two gas-turbine LM-2500 and two diesel engines, in a Combined diesel and gas configuration, that make use of diesel for cruising and turbines for high speed. The only problem with this configuration, which is highly economical, is to make the diesel engines powerful enough to achieve sufficient cruising speed without overloading them, or assist them with a continuous use (at low, uneconomical power) of the turbines. In this case, the solution, already developed for the Lupo class ships, was successful. The ships have an maximum range of 5,000 miles at 15 knots.

Armament

The Maestrale class ships are armed with an array of systems. Mounted on the foredeck is an Otobreda 127 mm gun, capable of shooting 40 rounds per minute. Despite its large size, it was possible to fit it in the relatively small hull, since the Lupo class ships were fitted with the same weapon. It has 66 shells on three ready-fire carousels. It also had low reaction times and high elevation, with a 32kg shells and 23km range.

The ships also carry the Albatross missile system, with an octuple cell capable of firing Sea Sparrow or Aspide missiles. This modern weapon contains a monopulse guide and a powerful rocket-engine, and advanced flight controls. The ships carry a supply of 16 missiles, and the system is reloaded by a Riva-Calzoni system, which is capable of loading up to four missiles at once, making virtually all the missiles in the magazine ready to be launched.

After the turret there are two CIWS DARDO, with 2x40mm L70 Bofors guns. They have very rapid mechanical systems, and depots with over 700 shells, and can fire around 600 rounds per minute. The proximity fuses and the fire control systems help this unmanned turret to react quickly to incoming missiles.

Also on deck are four Otomat anti-ship missiles, capable of striking a target 160 km or more away, with a 210kg warhead. They are fitted over the hangar, where there are two AB-212 helicopters ASW multirole machines.

Finally, there are four torpedo-launchers, two triple ILAS-3 (similar to Mk 32) with 324mm caliber, with 12 torpedoes available (not known if they are shared also with helicopters), and the most particular weapon, the A.184, a modern wired torpedo with two launch tubes and six to eight torpedoes. This is the main weapon for ASW tasks, but it also be used as an anti-ship weapon, even though its propulsion system (electric) does not allow great speed and range. Compared to ASROC, this weapon has many advantages, and does not require a bulky launcher, but needs several minutes, even at 35 knots, to reach nine kilometers, while Asroc can do this

Electronic warfare outfit

These ships have also have several electronic systems: one radar air and surface search RAN10S (160km) is placed over the smaller tree, a radar of navigation and surface search SPN703 is fitted on the main tree, where a navigation radar is present as well, and finally, three radars: one RTN-10X for gun and Aspide control, and two smaller RTN-20X for the DARDO systems, all fitted in the forward superstructure, separated from the aft by the funnel and the heat dissipaters. As two submarine search, there is a VDS DE 1164 sonar, and DE1160B hull mounted. As ECMs, there are two SCLAR rocket-launchers that are capable of launching chaff, flare, and HE rockets up to ten kilometers.

Several electronic and communication systems are fitted as well, and an IPN20 command and control system is present to integrate all the tactical information and use the weapons on board.

Comparison of Maestrale and Lupo Classes

The Lupo class entered in service in 1977. The Maestrale class is an upgraded version of its predecessor. Maestrale shares the same, extremely slim hull (with a length/width of 10:1) but this was enlarged to accommodate many more systems. The Lupos is three knots faster, and has eight OTOMAT. Maestrale had much of Lupo's equipment, but arranged differently. Endurance was increased with the Maestrale class from 5,000 to 6,000 miles.

Maestrale has half the OTOMATs but twice as many torpedo launchers (with the introduction of the new heavy torpedoes), twice the helicopters, and twice the sonars, having also a VDS. This, coupled with heavy torpedoes and two helicopters, improved dramatically the ASW capabilities. The use of more modern equipment and an Albatross missile system improved in some aspects the air defense.

Maestrale has some shortcomings. The most prominent is the air-defense layout: while Lupos has the four weapons distributed across the entire hull length, Maestrale, because of the double hangar, lacked this ability, resulting in all of the weapons systems being placed on the foredeck and midships. This arrangement leaves dangerous blind spots in the ships' defenses.

After their entry in service, Maestrales were modernized with some minor programs, but as many other Italian ships, no major improvements were made. The equipment present on the Maestrale class ships is almost equal to what it was in 1982, except for a pair of 20mm guns installed as 'anti-fast vessels close defense', in 2005.

Ships

Pennant number	Name	Builder	Launched	Commissioned
F570	Maestrale	CNR Riva Trigoso	2 February 1981	7 March 1982
F571	Grecale	CNR Muggiano	12 September 1981	5 February 1983
F 573	''Scirocco	CNR Riva Trigoso	17 April 1982	20 September 1983
F575	Euro	CNR Riva Trigoso	25 March 1983	7 April 1984
F572	Libeccio	CNR Riva Trigoso	7 September 1981	5 February 1983
F574	Aliseo	CNR Riva Trigoso	29 October 1982	20 September 1983
F576	Espero	CNR Riva Trigoso	19 November 1983	4 May 1985
F577	Zeffiro	CNR Riva Trigoso	19 May 1984	4 May 1985

References

• Enciclopedy Armi da guerra, De Agostini, 1984, pag. 1414-1415
• Po, Enrico I radar navali di Alenia, RID 12/1997