Lincoln engines

certainly makes for an interesting read, i guess you never forget some things 🙂

cheers

Ben

Pressurised Shacks

Don’t know if it counts, but we used to reckon the Shacks were mildly pressurised

because the holes at the front were bigger than the ones at the back.:p

Actually, joking apart, there were some large gaps here and there. On more than one occasion, I can remember putting my book down with the intent of going from the nose gunners position back down to the tail to the elsan. Only to realise that there was snow on my boots.

However, even when I spoke to some of the design staff at at the Shack 40th aniversary in Woodford back in 1989, there was no mention of a truly pressurised version being submitted for consideration as the maritime role was still foreseen to be all low level work.

As Merlin Pete states, the Griffon 57’s, 57A’s and 58’s were low altitude (LF)engines. The ratio of supercharger gearing was 6.615 to 1 for low gear and 7.7 to 1 for high gear, not really that high compared to HF type engines. For the 58, full throttle hight in low gear was 2000 feet. Full throttle height in high gear was 3000 feet. Due to the reduced exhaust back pressure at altitude, the power in low gear at sea level was 1960 Hp and 1990 Hp at 2000 feet with a boost of 67 inches of mercury (18 psi above atmospheric). For high gear, power at sea level was 2450 Hp, 2490 Hp being available at 3000 feet. However, that 2450 to 2490 Hp was with 81 inches of mercury (25 psi above atmospheric) boost while injecting between 18 and 22 pints per minute of Water Methanol into each engine into the eye of the supercharger. The two Water Meth tanks held 26 gallons each and supplied two engines each. If a water Meth supply failed, the affected engine would automatically drop back to 69 inches of boost, but the charge temperature would climb fairly rapidly. With the Water Methanol injected, the fuel delivery to the engines automatically reduced from 187 gallons per minute to 178 gallons per minute, the methanol content acting as supplementary fuel while the water content very effectivly cooled the charge (from 100 degrees C down to 50 degrees C). Once again, Rolls Royce had produced an engine perfectly suited to the aircrafts requirement. And all of this dross is from memory. I am sad, but probably correct.

Although we used the terms low gear and high gear, Rolls Royce terminology was Moderate Speed and Full Speed.

And I have digressed even further. Apologies for the thread drift.

camlobe

Affirm, never heard of the proposed Mk.4 being pressurized either.
Even the similar role Argus was a de pressurized Britannia.
Anyway, we digress!

I didn’t think the Shacks were ever pressurised…. Could all the rivets take it? LOL! Perhaps the proposed Mk.4 might have been…

Kind regards
Scotty

Correct, it was a low-altitude aircraft with a single skin construction.
The FS setting of the two-speed superchargers was unique in that it was used for take-off power augmentation.
Pete

Shack pressurised?

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The Shackleton was a post war development from the Lincoln for a specific maritime role rather than as a bomber replacement, it benefited from the hindsight of design, and access to the current technologies, and was developed with a new pressurised fuselage, Griffons and contra-rotating props.

I didn’t think the Shacks were ever pressurised…. Could all the rivets take it? LOL! Perhaps the proposed Mk.4 might have been…

Kind regards
Scotty

slow design process

Lincoln first flew (as Lancaster MK IV) on June 9th, 1944 – the second on Nov 9th, 1944. The European war was “Going well” and Avro had one eye on the civil market as well. The longer range of the Lincoln was initially aimed at eastern Europe but the Russian advance curtailed this, and the far eastern requirement was second in the mindset. (Not my own knowledge, blagged from Lincoln at war – fine book)

also, having been whinging on the modern forum about the slow dleivery, if you get the international air power review, there is a great piece in issue 24 about Lancs and Lincolns in Argentina, used during the military coups, Lincolns attempting to copy Dam Buster missions, testing with copies of German henschel guilded missiles….. really interesting and well worth a shufty to pick up some info about the two types thats far from mainstream.

and back to the Lincoln, what is it with that nose design?! – all that glazing ? seems they spent years on the design but did that bit in 5 mins flat !

The Shackleton was designed for a long term of service from the start, I’m under the impression that the Lincoln was more of a stop-gap design, a very useful one at that.

.
The Lincoln was originally developed in 1943 as the Lancaster “IV & V”, it was simply a Lancaster with an improved wing design (greater span) and lengthened fuselage to provide greater range and payload, the prototype first flew in June 1944 and the type entered service in August 1945.

In 1944 the Lancaster marks I, II, III and X were deemed to be doing the job so there was no rush to switch production over to the Lincoln for the European theatre with the complications of conversion training and spares, but numbers were being built up in 1945 for the Pacific RAF campaign against the Japanese in what was known as Tiger Force, but the Lincoln’s greater range was still far short of that being delivered by the B29, and the nuclear capability of the B-29 brought that need to an end.

The RAF had proposed in-flight re-fuelling for the Lincoln in the Pacific to achiever the island hopping ranges the US was achieving with the B-29 and there was resistance by MacArthur in regards to that situation.

The Lincoln did not have the speed or high altitude performance of the B-29/B-50 and therefore was not a suitable post war bombing platform for Nuclear weapons, a Griffon engined example may have created the speed, and the Lincoln was fitted with many other more exotic engines for trials, but the Lincoln was not pressurised, and it seems likely by that time Britain was developing jet bomber solutions such as the Canberra and other Jet Bombers, and further development of the Lincoln was not warranted.

The Shackleton was a post war development from the Lincoln for a specific maritime role rather than as a bomber replacement, it benefited from the hindsight of design, and access to the current technologies, and was developed with a new pressurised fuselage, Griffons and contra-rotating props.

Although interestingly these features were not really ever used operationally to deliver significant extra speed or high altitude or nuclear stand-off capability in that maritime role they were the natural improvements the Lancaster/Lincoln design required to achieve B-29/50 performance.

The First flight for the Shackleton was in March 1949 with production deliveries commencing in 1951, some 5 years after the equivalent dates for the Lincoln, and 8 years after the equivalent dates for the Lancaster so plently of room for hindsight and improvements.

Regards

Mark Pilkington

I can understand that they would not have taken the design much further (even if the Merlins did play up) as the jet age was just around the corner. I’m just surprised they didn’t build them with Griffons in the first place.

Shackleton – I think that adds to my argument – if they were good enough for that why not the Lincoln?

Bazza

I seem to remember reading about those Merlins oiling up if not kept above a certain RPM making the type tricky to taxy.