Lancaster II vs Lancaster I and III

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Apr 23, 2005
As we are aware the Lanc II had the Hercules engines, around 300 were built and used by the RAF.

What I have often wondered is what the difference was in performance. Both engines, Hercules and Merlins were good engines, were reliable, had plenty of power and had similar (I think) altitude ratings.

In theory the Lanc II should have had a slight advantage as being Radials they were less vulnerable to shrapnel damage from flak as they didn't have the radiator to get hit, but the I and III were the ones which production concentrated on.

There must have been a reason for the short production run of the Lanc II and my guess is that it must have been performance differences but I have been unable to find out what that difference is. Whenever I have looked it up they simply say the performance was similar.

Can anyone help me find out what the performance difference was and / or why the production run was so small.

Any help would be appreciated.

Lanc IIs were produced because there was a fear that not enough Merlins would be available. American production put the fear to rest.
KK. Thanks I appreciate the post.
However having gone to the trouble of designing, building and using an alternative. It would have made sense to continue with one factory if the alternative had been a better aircraft.
The Hercules had more power for takeoff and I am starting to wonder if we went with the Merlin because it was a Merlin and let the prospect of an improved Hercules powered aircraft slip by.
Since posting the request I have been chewing it over and my brother reminded me that the Beaufighter with the same Merlin engine was considered to be underpowered compared to the Hercules. Also of course the Halifax significantly improved its performance when it switched to the Hercules from the Merlin.

I think you can see why I am interested in the performance figures of the Lanc II

I am wondering what light Lanc can bring to this.
well, for now i'll just say that the Mk.I/III outperformed the II, and production with merlins was already in full swing, and remember if you convert a plane like that, you've gotta retrain all crews at huge extra cost, i'll tell you more when i back from holiday in a few days...........
Glider, just a thought.

Is it better to have 2 a/c with 2 different engines than to have 2 a/c using different engines? From a logistics point (manufacturing and maintainance), I go with the second option.

The Bristol was better at low altitudes while the Merlin was better at high altitudes. Now, I know your are going to bring up the Mossie. :D

Best wait for lanc ka to get back from his vaca for Lanc II numbers.
KK, I agree with the comment about waiting for Lanc, if anyone knows, he will. Meanwhile I will be digging in the Imperial War Museum records and see what I find.
In this case I don't think maintenance would be an issue as both engines were widely used. As for production the Lanc II was concentrated in one factory so it could have continued producing them. Altitude could well be the deciding factor as height helped keep the losses down.
I don't think the Mossie comes into this as I am not aware of a version fitted with the Hercules.

As an aside, if the II does come out ahead at lower altitudes its a pity that they weren't passed to Coastal Command. When we were loosing so much shipping and crying out for a plane with a decent range to cover the Atlantic Gap. A Lanc with additional fuel tanks in part of the bomb bay would probably have fitted the bill nicely.
Where to start? :)

CC was always screaming for the 'heavies'. This though, would have depleted the BC forces. The biggest problem with the convoys was unloading due to lack of unloading facilities in the ports. The question then is, is better to loose some ships or hurt German production?

The only reason I mentioned the Mossie was that if could have been fitted with the Herc for its low level missions (yes, a big if :) ) since the Beau with the Herc was a better a/c (at least at low level).

I don't think Bristol had the manufacturing capability to produce enough engines to supply another a/c. When the threat of a lack of Merlins disappeared they then could consentrate on producing engines that were already powered by Herc.

Not sure how to put across the 1 a/c type/1 engine type is better. Lets try using the word 'standardization'.
KK. Before we go any further I must declare a vested interest as my Gradnfather was a Merchant Seaman and was sunk four times. Once in WW1 and three times in WW2 although once was an accident when they ran aground.

Being cold blooded its down to being what is the cost effectiveness of either action.
If the additional squadrons could save 1 ship per convoy they would be saving thousands of tons of materials. It would probably take a squadron to cover one convoy so the question is, would a squadron destroy thousands of tons of material if committed to BC. I hate saying it but at the peak in 1943 I believe the answer to be no. We didn't have the equipment to navigate or bomb accurately.

I do not believe that say three squadrons of Bombers withdrawn from BC would have made much of an impact in the bomber effort. Being bombed by 800 instead of 850 planes isn't going to be much different. The effect on a convoy would be huge.
And my father was in CC flying anti sub patrols (late war) in the Whimpy.

I agree CC was getting the short end of the stick. Still, one has to consider which was more cost effective, as you say. In 1943 there was not much of an air gap. Even in 1945 there was still an air gap mid Atlantic. Most of the ships sunk were within air range, at least according to the maps I have, of non-heavy bombers.
For those that are interested the following are the differences that I have found between the Lanc I and Lanc II.
Note this is with 7,000Lb bomb load

Speed Lanc I 286mph Lanc II 264mph

Ceiling Lanc I 21,500ft Lanc II 18,552ft

Range Lanc I 2,530 miles Lanc II 2,547 miles

Bomb load same

According to the test pilots they found the Mk II to be better at takeoff and low altitude with a better climb. However the Mk was certainly good enough and the big difference is in the Altitude as height had a direct bearing on the chances of survival.
Whilst the Mk I was faster they cruised at a similar speed so that would be more important than the headline top speed.

A number of sources quoted that the Mk II used more fuel, but I found an almost equal number saying that the Mk II had a longer range. I haven't been able to tie that one down but I suspect it probably depended on the height being used.
Also I found one reference to the max bomb load of the Mk II as being 22,095lb which seemed a very exact quoted figure and the same reference said that it couldn't carry the 22,000lb Grand Slam. This I ignored as a large number of sources gave the same bomb load as the MK I.

I will be interested to see what light Lanc can throw on this. The one thing everyone agreed on is that the Mk II was slower and flew lower.
well, i'm back (visited bovington tank museum it's amazing there!!)

well, you've pretty much got it between you, the Mk.II was popular with pilots, who, as glider said, liked her take off attributes..........

yes, she performed well at low level, but so did the merlins which everyone was already used to, and the lanc really needed high altitude performance, which the Mk.II severly lacked, fully loaded the Mk.II's ceiling was 15,000ft, which is danerously low, whilst the Mk.III could hit 22,000ft fully loaded (14,000lb payload, not 22,000lb), which is still low, but it's 7,000ft higher, which is a fair bit, and with smaller loads the II would struggle to hit 20,000ft, so ceiling was a large factor..........

next, the Mk.II would not be able to carry 22,095lbs, i have no idea where that figure came from, she could carry no more than 18,000lbs, at a struggle, carrying a grand slam was out of the question..........

(sorry if this post ceems a bit all over the place i aint too sure how to word it if you get me)

"the bristol" as it has become known in this thread it would ceem, was not only heavier then the merlin, but also induced more drag, so speed was affected, as glider said the top speed of the Mk.II was less, but as far as i'm aware so was the cruising speed. the Mk.III cruised at about 210mph with payload, the Mk.II as i've always known it was more along the lines of 180-200mph...........

range; glider is correst in saying the bristol had higher fuel consumption, but this did mean that the range was slightly less, with a 7,000lb payload you're looking at closer to 2,300-2,400 miles which isn't a great deal less........

(god this's harder to piece this together than i thought, i know the answers in my head, honest......)

strictly speaking the manufacturing transition from the Mk.I to the Mk.II wouldnt've been impossibly hard, afterall the Mk.II prototype was converted from a Mk.I, however in service this transition would've been very difficult, groundcrew and flying crew would've had to been retrained (well perhaps not the gunners, R/O, and nav.), as, whilst most things were the same, all the plumbing and electrics were different, which would cause many problems, which is also why the Mk.II was limited to very few squadrons, the Mk.I was already in widespread service and it was hoped the Mk.II wouldn't be needed anyway, infact after about 100 Mk.IIs had been produced packard said they'd make merlins, the other 200 Mk.IIs were only made so they could finish the batch and not mess up the works, so, whilst the Mk.II wasn't that bad in it's own right, the justification was why change everything, just to put a worse plane into production and serice, sorry this's all been a bit peiced together

and on a side note, there's no chance the Mk.II would've been allowed for use in Coastal Command, all almost all heavy bombers and all lancs were earmarked for bomber command, the war office deeming them more needy of them, CC was lucky to get the halibags they did, they got by on libs and smaller aircraft, well they had to! not until after the war when all the lend lease libs had gone home did they use the lanc for martime roles, when she proved more than good enough, yet she was more usefull as a bomber, i hope this's answered some questions...........
Many thanks for the time you spent on this and I hope you had a good break. At least we wern't far off the mark.

Thanks again

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