The Type 11, Type 41, and Type 61 Frigates

Towards the end of the Second World War, the Royal Navy identified the need for three types of frigate (an anti-submarine frigate [Type 11], an anti-aircraft frigate [Type 41], and an aircraft direction frigate [Type 61]) that could act as convoy and amphibious group escorts.

They were to share a common hull design and be powered by Admiralty Standard Range ASR1 diesels. They would therefore have long range and a maximum speed of 24 knots which would mean that they were not expected to operate with the navy's aircraft carrier groups. In the end, it was decided not to build the Type 11 (the Type 12 Whitby-class anti-submarine frigates were built in their place) but the other two designs were built … but in smaller numbers than originally planned.

HMS Jaguar, a typical Type 41 anti-aircraft frigate.

HMS Chichester, a typical Type 61 aircraft direction frigate.

It is interesting to note that all these frigates were designed to carry the same main and anti-aircraft armament, namely the twin 4.5-inch (114mm) guns Mark 6 (as fitted to the Daring-class and Australian Battle-class destroyers and later the Type 12 frigates) and twin 40mm Bofors anti-aircraft gun STAAG (Stabilized Tachymetric Anti-Aircraft Gun) Mark 2.

The ship’s characteristics were as follows:

• Displacement: 2,520 tons (full load)
• Dimensions:
• Length: 340ft (100m)
• Beam: 40ft (12m)
• Draught: 16ft (4.9m)
• Propulsion:  8 x Admiralty Standard Range ASR1 diesels driving 2 propellors
• Speed: 24 knots
• Range: 7,500 nautical miles at 16 knots
• Complement: 235
• Sensors & processing systems (Both classes): Type 960 air search radar (later Type 965 AKE-1 or AKE-2 air search radar); Type 293Q target indication radar (later Type 993 target indication radar); Type 277Q height finding radar (later replace in the Type 61 by Type 278 height finding radar); Type 974 navigation radar (later replaced in the Type 61 by Type 978 navigation radar); Type 275 fire control radar on director Mark 6M; Type 262 fire control radars on director CRBF and STAAG mount; Type 110 Cossor Mark 10 IFF; Type 174 search sonar
• Sensors & processing systems (Type 41): Type 164 attack sonar
• Sensors & processing systems (Type 61): Type 982 aircraft direction radar (later Type 986 aircraft direction radar); Type 170 attack sonar
• Armament (Type 41): 2 x twin 4.5-inch (114mm) guns Mark VI; 1 x twin 40mm Bofors anti-aircraft gun STAAG Mark II (later 1 × single 40mm Bofors anti-aircraft gun Mark 9); 1 x Squid anti-submarine mortar
• Armament (Type 61): 1 x twin 4.5-inch (114mm) guns Mark VI; 1 x twin 40mm Bofors anti-aircraft gun STAAG Mark II (later 1 × twin 40mm Bofors anti-aircraft gun Mark 5 or 1 x Sea Cat GWS-20 surface-to-air missile launcher); 1 x Squid anti-submarine mortar

Type 41 or Leopard-class anti-aircraft frigates

A total of seven ships were built: HMS Leopard, HMS Lynx, HMS Puma, and HMS Jaguar for the Royal Navy and INS Brahmaputra, INS Beas, and INS Betwa for the Indian Navy. HMS Lynx and HMS Jaguar were sold to the Bangladeshi Navy and became BNS Abu Bakr and BNS Ali Haider respectively.

A fifth member of the class (HMS Panther) was ordered for the Royal Navy, but the order was later cancelled.

Type 61 or Salisbury-class aircraft direction frigates

A total of four ships were built: HMS Salisbury, HMS Chichester, HMS Llandaff, and HMS Lincoln. HMS Llandaff was sold to the Bangladeshi Navy and became BNS Umar Farooq.

Three additional ships of the class were planned: HMS Exeter, HMS Gloucester, and HMS Coventry. The order for the first two was cancelled whilst the third was re-ordered as a Leander-class frigate (HMS Penelope).

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Type 11 anti-submarine frigate: A 'what if ...'

The Type 11 anti-submarine frigate was never designed. but one can conjecture that its characteristics would have been something like the following:

• Displacement: 2,520 tons (full load)
• Dimensions:
• Length: 340ft (100m)
• Beam: 40ft (12m)
• Draught: 16ft (4.9m)
• Propulsion:  8 x Admiralty Standard Range ASR1 diesels driving 2 propellors
• Speed: 24 knots
• Range: 7,500 nautical miles at 16 knots
• Complement: 235
• Sensors & processing systems: Type 293Q target indication radar (later Type 993 target indication radar); Type 277Q height finding radar (later Type 278 height finding radar); Type 974 navigation radar (later Type 978 navigation radar); Type 275 fire control radar on director Mark 6M; Type 262 fire control radar on STAAG mount; Type 110 Cossor Mark 10 IFF; Type 174 search sonar; Type 162 target classification sonar; Type 170 attack sonar
• Armament: 1 x twin 4.5-inch (114mm) guns Mark VI; 1 x twin 40mm Bofors anti-aircraft gun STAAG Mark II (later 1 x Sea Cat GWS-20 surface-to-air missile launcher); 2 x Squid or Limbo anti-submarine mortars; 8 x 21-inch (533mm) anti-submarine torpedo tubes

The above is based on the armament and sensors carried by the Type 12 Whitby-class frigates. Had the Type 11 been built, it might well have received an midlife upgrade that would have seen the removal of the anti-submarine torpedo tubes (if they had ever been fitted) and one or both of the Squid or Limbo anti-submarine mortars and a hanger and landing pad installed in their place so that the ship could carry a Westland Wasp HAS.1 anti-submarine helicopter.

As for possible names ... who knows? ... but I would like to have thought that the Royal Navy could have re-used the names of dog breeds that had previously been used for destroyers (e.g. HMS Afghan, HMS Beagle, HMS Basset, HMS Bulldog, and HMS Greyhound).