Mk 24 was (and is) an ASW weapon. It was never considered a primary weapon for use against surface targets. Mk 8 filled the anti-surface role until superseded by Sub-Harpoon.

I understood that the Mark 24 Tigerfish in service in 1982 was the dual-purpose version. While I’d agree that the primary (and more technically difficult) mission was anti-submarine I don’t see any reason why this would prevent its use against surface targets.

However to put it terms of a tactical decision, Conqueror had an attack solution that indicated a high probability of success with the Mk 8, therefore that was what was used.

And a very low probability of success with the Mark 24 due to its unreliability.

Post war five Mark 24 were fired at ‘a target hulk’…..not one hit the target!

Belgrano was a more difficult target…..while on the other hand HMS Sir Galahad was a no risk target.

And the submarine HMS Onyx missed that!

The reason was one of reliability, the Mark 8** was over fifty-years old and was utterly reliable, the Mark 24 Tigerfish was new, untried in combat and had performed badly in trials.

It has been said the captain of HMS Conqueror also appreciated that the ARA Belgrano was an armoured cruiser and the warhead of the Mark 8** was bigger and more suited to attacking ships of that era; in a supreme twist of irony.

The Conqueror had six tubes, three were loaded with Mark 8**, three were loaded with Mark 24 as a insurance policy, but the captain got very, very close before he fired and I think this speaks volumes.

It has also been written, by those who did not agree with the sinking of Belgrano, that a Mark 24 could have been used to explode close to the Belgrano (as they are designed to do) rather than actually hitting her, and that this would have damaged her without causing unnecessary casualties. This is a very uninformed view; I dread to think what an under-the-keel shot would have done to the Belgrano.

…like trying to drive a car with one gear, a fixed pitch prop has to be a bad compromise on a high performance aircraft…

That is a very good way of thinking about variable-pitch propellers; as the aircraft’s (almost) infinitely-variable transmission (gearbox).

I’m sure this is a very complex issue with no simple answer…..but it is very good ‘brain exercise’ to think about.

Broadly aero-engines run at a fixed RPM and so do propellers (constant-speed). The tips of the blades mustn’t go supersonic and (at constant RPM) the longer the blade the faster the tip. When the engine produces more power the angle of the blade must increase to produce more drag (and more thrust of course) or the RPM would rise (but the blade length is limited by tip speed). There must be an optimal blade angle for all engine-power and aircraft-speed conditions and increasing the blade angle beyond that must be inefficient (imagine blades almost flat to the direction of rotation – high-drag but low thrust).

So as engine powers increase the blade length, and blade angle, are limited by these factors and the only (efficient) way for the propeller to convert more engine power into thrust is to have more blades!

I know there are a lot of generalities in there…..just thinking out loud. 🙂

…there is no getting away from the fact that they are linked to a sad event, and that on their own (without history) would be worth less.

There is no doubt that parts would be ‘worth’ more if they were from a particular aircraft, or even better a well known aircraft, but surely nobody would be prepared to pay more for parts because the aircraft was involved in a fatal crash!

The seller suggested that this aircraft is being rebuilt…..is this in fact the case?

The seller possibly used Merlin in the title of his listing as there would probably be many more searches for Merlin than Griffon…..although far less than for Spitfire. He may also just have assumed that all Spitfires had Merlin engines!

Interesting what you say about this possibly being removed before the crash.

Yes, the firewall did look big but it was that square grille that clinched it for me. I was pretty sure my Lancaster guess was wrong as the rear profile of the radiator scoop was all wrong.

So is it from a Balliol or a Sea Balliol?

I didn’t realise until I checked some photos that the Sea Balliol had folding wings and was used for carrier landings!

About the only thing I did know about these was that they were the last (RAF) aircraft built with a Merlin engine and that there was one at Cosford.

Lancaster?