what IS a corvette?

In the early part of WWII, when escort ships were in short supply, the Brits started building the Flower class corvette, based on a whaler design. Subsequent designs where first improved (revised Flower class, Castle class) and then enlarged (River class). These larger ships were called frigates and designed primarily to remedy what were considered defects in the Corvette design, such as a lack of range, speed, and seakeeping ability. In order to do this, the basic Corvette hull was widened and lengthened, and was given twin screws. This resulted in a faster ship with twice the range.

Note that the Flower class corvette was about the same displacement as ships such as, for example, the WWI Town class destroyer and the 1930s River class destroyers. The River class frigates displaced almost as much as the WWII Tribal class destroyers. Much of the difference between corvettes/frigates on the one hand and destroyers on the others was in their machinery (i.e. in low speed + longer range versus high speed + shorter range) and armament (primarily ASW versus primarily ASuW oriented) . In other words: different role resulted in different armament and machinery for ships of similar tonnage.

Flower class corvette
Original 1939-1940 Programme:
Displacement: 950 tons
Dimensions: 62.5 x 10.0 x 3.5 meters (205 x 33 x 11.5 feet)
Propulsion: 2 fire tube Scotch boilers, 1 4-cyl. triple expansion steam engine, 2750 hp., 16 knots
Range: 3500 nm. at 12 knots
Crew: 85
Radar: SW1C or 2C (later)
Sonar: Type 123A, later Type 127DV
Fire Control:
EW: none
Armament: 1 4″ BL Mk.IX single, 2 .50 cal mg twin, 2 Lewis .303 cal mg twin, 2 Mk.II depth charge throwers, 2 depth charge rails, 40 depth charges.
Originally fitted with minesweeping gear, later removed

River class frigate:
Displacement: 2,216 tons full load
Dimensions: 91.9 x 11.3 x 4.0 meters (301.5 x 37 x 13 feet)
Propulsion: 2 shafts, VTE, 2 boilers, 5,500 ihp, 19 knots
Range: 7200 miles at 12 knots.
Crew: 141
Radar: Type 271, or SU type (varied)
EW: HF/DF (High Frequency Direction Finder)
Armament: 1 4″ single (later dual), 1 12 Pdr, 4 20mm guns, 1 Hedgehog ASW mortar, 4 Mk.IV depth charge throwers, 150-200 depth charges.

Town class destroyer
Displacement: 1,069 (1,190 for BUXTON, ST CROIX, and ST FRANCIS) tons
Dimensions: 95.7 x 9.3 x 2.7 meters (314 x 30.5 x 9 feet)
Propulsion: 28 knots
Crew: 153
Armament: 4 4″ single guns, 12 21″ TT

Tribal class destoyer
Displacement: 2,800 tons full load
Dimension: 114.9 x 11.4 x 3.4 meters (377 x 37.5 x 11 feet)
Propulsion: Parsons geared steam turbines, 2 shafts, 3 Admiralty 3 drum type boilers, 44,000 shp, 36.5 knots (max), 32 knots (service)
Crew: 259
Armament: 3 4.7″ twin mounts (2 forward, 1 aft), 1 4″ twin mount (aft), 1 2 Pdr. quad mount, 6 20mm guns, 4 – 21″ TT

An American sport’s car,looks good and has an awesome engine,but can’t corner for toffee 😀 ………………

I’ll get me coat 😮

Funny, I was going to say pretty much the same thing :diablo:
________
Threesome spanish

An American sport’s car,looks good and has an awesome engine,but can’t corner for toffee 😀 ………………

I’ll get me coat 😮

I always think that corvettes are downsized frigates and is often used as cheap substitutes for larger combatants, am I correct?

Well, yes and no IMO.

A 2000 ton corvette is not that much cheaper than a 3500 ton frigate, with similar equipment.

The think is, that costs are not just the buying price of a ship. Crew costs are quite high and it is certainly more economical to have a crew of 80 than a crew of 200 (highly trained professionals, I hasten to add…).

So, if all you need is a seaworthy vessel with SSM, PDMS, CIWS, a medium gun, a sonar and basic helicopter capabilities, then a 1500ton corvette is very appropriate. And, yes, some nations will call such a vessel a “frigate”, just for internal consumption. :p

I always think that corvettes are downsized frigates and is often used as cheap substitutes for larger combatants, am I correct?

I am very much a novice when it comes to Naval topics, however what is the definition of a corvette? the dissonance between the displacement of some is completely staggering, especially if you compare something such as the Qahir class or Mako A-200 with the Visby, of which all three are technically classified as corvettes.

The Meko A-200 is clearly a frigate. It is just being called a corvette for political reasons. Also you must remember that the Visby class is made of composite materials, so the displacement is lower than it would have been for a vessel of that size built with traditional materials.

http://www.amiinter.com/vessel_type.html#corvettes

It would seem today that the boundaries between ship classes are becoming vague if non-existent. Classification seems more to be the result of function or of politicial necessity. Also, more and more ships are becoming multi-purpose so the mission distinction is not as clear either.
I guess if you want a ship to be a corvette then it is a corvette, if you want it to be a frigate then so it is.

http://www.factmonster.com/ce6/history/A0813683.html