[WWII] Gabbiano-class corvette (Italy)

[copeab]

Gabbiano-class corvette
Copyright 2010 by Brandon Cope

The Gabbiano-class corvettes were possibly the best escort vessels of the war for the Italian Navy, but they arrived too few in number and too late in the war to have a significant impact. The 42-strong class did not begin entering service until late 1942 and many were taken over by the Germans after September 1943 (some even completed by them). Twenty of the class were lost in combat. Aside from convoy escort and ASW operations, they were also used to evacuate injured troops from North Africa. The lead ship of the class participated in sinking two British submarines in April 1943 and, along with a dozen others in the class, went on to serve in the Italian Navy for over 25 years.

There were certain limitations necessitated by a requirement the ships be capable of rapid production. One flaw was that their diesel engines, which combined with being mounted to the frame (in order to speed production) and the small, high speed screws which created a great deal of cavitation, made the ships quite noisy to sonar (and reduced the effectiveness of her own sonar). However, most unusual for a surface ship, it mounted low-power electric 'creep' motors for stalking submarines, which rendered the ships very quiet and eliminated the problem of the loud diesels. There was no radar and no fire direction center for the guns or torpedoes.

The crew is normally 108-112 men. The ship uses 128 gallons of diesel per hour. At a speed of 12 mph, this gives a range of 3,980 miles.

Subassemblies: Medium Corvette chassis +8, waterproofed Medium Conning superstructure +5, partial rotation Large AFV open mount #1 +3, two full rotation Medium Weapon open mount #2-3, three full rotation Small Weapon open mounts #4-6 +0, fixed Small TD open mount #7-8 +4.
P&P: 2x1,604 kW marine diesels and 2x56-kW electric motors w/2x1,604-kW screw propellers, 26,700-gallon standard fuel tank; 400,000-kWs batteries
Occ: 8 NCS Sup, 6 NCS Body
Cargo: 100 Body

Armor
Body: F 4/90, other 4/30
Superstructure: 4/30
100mm mount: F 4/25
20mm mounts: F 4/25

Armament
105mm Medium DP Guns/100mm Mod 35 [OM1:F) (200)
4x20mm Long Ground ACs/Breda-SAFAT Mod 35 [OM#2-3:F] (2,000 each)
3x20mm Long Ground ACs/Breda-SAFAT Mod 35 [OM#4-6:F] (2,000 each)
2x450mm torpedo tubes [OM#7-8:F] (2 total).
8xmedium depth charge throwers [Body:R,L] (24).
2xdepth charge racks [Body:B] (48).

Equipment
Body: 1,000 bilge, 10 bilge pumps, 100 cargo, 2x2-ton crane (for torpedoes), 5 fire extinguishers, 105 hammocks, 3 cabins, 8 crew stations, 2 hospital beds, 125 man environmental system, 1,800 man/days provisions, precision navigation instruments, very large radio transmitter and very large radio receiver, radio direction finder, 2 mile passive sonar, workshop. Superstructure: Autopilot, 8 crew stations, precision navigation instruments, fire extinguisher, 2 cabins. OM2-6: Universal mount.

Statistics
Size: 211'x29'x40'
Payload: 329 tons
Lwt: 728 tons
Volume: 8,000
Maint.: 16 hours
Price: $160,000
HT: 12

HP: 51,000 [body], 1,200 [superstructure], 285 [open mount 1,7-8], 75 [open mount 2-3], 45 [open mount 4-6]

wSpeed: 21
wAccel: 2
wDecel: 0.5(1)
wMR: .02
wSR: 5
Draft: 8'
Floatation Rating: 960 tons

Design Notes
The historical displacement of 728 tons was used to calculate performance data. Design draft was 10'; the historical number was used instead. Top speed on the electric motor was 7 mph. Design wSpeed was 23 mph; his has been reduced to the historical trials speed (in service, the ships were rarely pushed to this limit).

Not all ships had the torpedo tubes installed.

The two Gatteschi depth charge racks could release 12 depth charges at a time. The eight depth charge launchers (four per side) could each fire three charges in rapid succession up to 110 to 155 yards. The depth charges carried were 330 lbs (150 kg) each.

[Michele]

Thanks, Brandon, another interesting write-up.