Merlin engine mark Nos?

Hey I’m a lawyer we NEVER do things quickly!!! :p

TT

ROTFL!

😀

TT

It’s only a month on , “but I can wait”!!

Did the origins of the phrase ,”clipped ,cropped, and clapped”, lie with the Spitfire mk Vd?

ROTFL!

😀

TT

Though recording of engine marks is a bit hap hazard, on accident cards I can find Merlin XX and Merlin 20 and also from the same time period Mk.X and Mk.10.

I am quite positive I have seen Spitfire V movement/accident cards with ‘Merlin XLV’ on them. I think I also saw Spitfire IX ones with ‘Merlin LXI’ or ‘LXIII’.

From what I have seen roman numerals were used by British manufacturers up to and including XX beyond there is was arabic.

Though recording of engine marks is a bit hap hazard, on accident cards I can find Merlin XX and Merlin 20 and also from the same time period Mk.X and Mk.10.

I generally work on the principle that up to 20 use roman.

Did the origins of the phrase ,”clipped ,cropped, and clapped”, lie with the Spitfire mk Vd?

😀 😀 That appeals to my sense of humour.

Fokker Aircraft used Roman numerals up until the 1934 F.XXXVI which is quite a mouthful. Therefore the system reverted to Arabic numerals after WWII. Another interesting designation is the F.XVIII.

What does this add to the discussion? Not much to be honest, but there are some interesting images on the webpages linked to above 😀

“The Air ministry agreed to buy the imperfect Merlin F (ramp head) as the Merlin I and from july 1936 a total of 180 were delivered for the battle mk I “.

It would appear that the Merlin II was the Merlin G with the standard flat combustion chamber; externally, the ramp head engine was a very different shape, and Hawkers had to redesign engine mounts, cowlings and coolant tank for the Hurricane I.

Quoted source ; RR aero engines Bill Gunston

But was it the original engine fitted??

Well I wasn’t around when she was in service (I wasn’t even born) so I don’t know

And it is the original engine recovered from the Icelandic crashsite.

But was it the original engine fitted??

Of course we are dealing with one of the world’s more obscure aero-engines. No wonder it’s difficult.

Oh, for ‘obscure’ read ‘famous’. 😉

And there were only a small number of them built and they were only fitted to a few different types.

Of course, for ‘small’ read guargantuan and for ‘few’ read ‘great many’.

Are there similar foibles with the designations of other aero engines of the time? Might that shed any light on the issue?

Am I right in thinking that the Mark numbers for the Fairey Battle was related to the Mk number of the Merlin it used rather than as an indication of a development in the airframe?

Well I’m not too sure about that, and my reasons are….

The RAF Museum Battle, L5343, we are restoring down at MAPS is a Mk.I but the Merlin is a Mk.II or III (can’t for the life of me remember which, pretty sure its a Mk.III)

Sorry to muddy the waters…..

And it is the original engine recovered from the Icelandic crashsite.

I’m really not helping am I?

No, your not. Back in the bad boy corner… 😀

Of course we are dealing with one of the world’s more obscure aero-engines. No wonder it’s difficult.

Oh, for ‘obscure’ read ‘famous’. 😉

To further obfuscate, wasn’t the Merlin II originally known by Rolls as the Merlin ‘G’? So you had the Merlin A through F becoming the Merlin I retrospectively.

Doesn’t get any easier does it?

Am I right in thinking that the Mark numbers for the Fairey Battle was related to the Mk number of the Merlin it used rather than as an indication of a development in the airframe?

I’m really not helping am I?

In the back of Merlins in Perspective (RRHT) there’s a list of military Merlin engine numbers.
The only Roman numerals were the ones JDK first listed, plus XII later changed to 30.

At a pure guess, either RR or the Ministry of Aircraft Production thought the Roman numerals were going to get too confusing and Arabic would be much simpler. Apart from RR actually building them, there must have been thousands, if not tens of thousands, of bureaucrats creating mountains of paperwork. It’s a fair bet some would have struggled with Roman numerals.

:rolleyes: I’m glad it’s not just me! I was thinking “This is something I should know” (or “know where to look up” – which is more accurate… ) :p

Hmmm, yes. That doesn’t work. Spitfire Mk.IX with a Merlin 66 doesn’t fit. Well, it was a thought.

The shift for aircraft mark nos was postwar – and is documented, PR.XIX upto then, PR.19 after. No one’s offering the engine equivalent?

Did the early wartime Meteors have anything other than Arabic designations? I don’t recall ever seeing Meteor F.3s being referred to as Mk.IIIs.

Best wishes
Steve P

Very good Stuart. 😉

Not that change James. Wasn’t there a previous policy where numbers up to XX were Roman and higher numbers were Arabic. Mosquito B.XVI and B.35 for example.

This one of those areas where some of the problem is people ‘reverse engineering’ explanations to fit. I’d like to see a contemporary source quoted, rather than us trying to work it out, or basing it on Raff scuttlebutt…

Wikipedia gives the following under the Spitfire:

There is an apparent discrepancy in Spitfire numbering schemes in that sometimes Roman numerals are used and sometimes Arabic numerals are used. This is down to changes in RAF numbering schemes. Up until the end of 1942, the RAF would always use Roman numerals for mark numbers. 1943 to 1948 was a transition period during which new aircraft entering service were given Arabic mark numbers but older aircraft retained their Roman numerals. From 1948 onwards, Arabic numerals were used exclusively. This article adopts the convention of using Roman numerals for the marks I through XVI and Arabic numerals for the marks 17 through 24.

Did the origins of the phrase ,”clipped ,cropped, and clapped”, lie with the Spitfire mk Vd?