The Enigmatic Spitfire Mk.III Prototype in 1/48

[neilfergylee]

This is the conclusion of a build described here:

 

The Spitfire III was intended to be the first significant development of the Spitfire, the prototype first flying in March 1940.  Principal changes were:

• Strengethened fuselage
• Improved windshield with internal armour plating
• Retractable tailwheel
• Clipped wings
• Merlin XX engine

 

This last item was the Mk.III's most significant change (I'll come to the wings) and, ultimately its reason for not entering production.  The Merlin XX was not the first but it was the first significant production version of what was known as the 'two-stage' Merlin: This meant that the supercharger impeller could turn at two speeds, allowing it to pump air into the engine more efficiently by changing speed at higher altitudes.  This gave a significant boost in performance.  The higher performance required greater cooling, so the underwing radiator was enlarged, while the retractable tailwheel was an aerodynamic improvement that would be see in later versions of the Spitfire.  The wings were clipped.  Not 'Low-level Spitfire' clipped but really clipped, taking six feet off the span.  The effect of all these changes was to give the Spitfire III a significant upgrade in performance.  The team 'Superiority Spitfire' was often used.

 

The problem with the Merlin XX was production.  The two-speed supercharger was harder to build and production was limited.  As a result, the Air Ministry chose the limited production variant to be used by bombers and the Hurricane which, approaching Obsolescence even in 1940, would benefit from the greater performance of the Merlin XX.  As a result, the Spitfire III was stillborn with just two prototypes being built, N3297 (as modelled here) and W3237 which, curiously, was built in 1941, long after the M.III had been cancelled.

 

The Spitfire Mk.IV was the Griffon prototype and so the next (and most produced) version of the Spitfire was the Mk.V, which used the Merlin 45 series which was, effectively, a single-speed version of the Merlin XX.

 

Do take a look the link above as I have put in more about the Mk.III.

 

The model is the Airfix Mk.I / II modified as follows:

 

1. Fuselage extended by a scale 4 inches, including a Mk.XIV fuel tank with an angled firewall.
2. Modified windshield
3. Radically clipped wings
4. Enlarged radiator, modified form one used in an XIV
5. Quickboost Mk.V propellor and spinner
6. Quickboost exhausts
7. Eduard photoetch flaps

 

 

 

 

 

 

 

[stevehnz]

That has come out very nicely Neil. the first time, that I can recall anyway, I've seen this variant modelled. It has enough different about it to make it to show up in a shelf full of Spitfires. I like it very much. Maybe down the track in 1/72.

Steve.

[neilfergylee]

1 hour ago, stevehnz said:

That has come out very nicely Neil. the first time, that I can recall anyway, I've seen this variant modelled. It has enough different about it to make it to show up in a shelf full of Spitfires. I like it very much. Maybe down the track in 1/72.

Steve.

 

Thank you Steve!  Those wings really are dumpy: here's a comparison with the Mk.XX prototype and the difference is quite striking.

 

 

Cheers,

 

Neil

[stevehnz]

They do look a bit weird, kind of like some of the older reno pylon racers. what it did for the roll rate must have been lost on the turning ability.

Steve.

[Troy Smith]

1 hour ago, stevehnz said:

Maybe down the track in 1/72.

@Greenshirt  did a build, and it's on his blog, pics seem to have gone 

https://greenshirtmodeler.blog/2016/06/spitfire-mk-iii-fin/

 

 

Model is very impressive @neilfergylee

 

[Greenshirt]

1 hour ago, Troy Smith said:

 pics seem to have gone 

 

Ruh roh.  I’m moving to a new site and trying to get my photos moved.  I’ll be back soon when I find the originals and upload to the new site.

 

Tim

[Shorty84]

Hi Neil,

 

I've followed your WIP and have to say you've really pulled off a nice conversion. She looks really different (not to say weird) with this stumpy wings. Nice one 👍

 

Cheers

Markus

[Greenshirt]

20 hours ago, Greenshirt said:

 

Ruh roh.  I’m moving to a new site and trying to get my photos moved.  I’ll be back soon when I find the originals and upload to the new site.

 

Tim

Well, I was able to recover 2 of the original 5 photos.  I took a few quick pictures to salvage the post.  Post is here.

 

I confirmed the original photos for the earlier progress posts made it.  Those posts are:

1. 18/6/2011 - Spitfires
2. 21/6/2011 - Spitfire Mk III radiator
3. 15/2/2013 - Spitfire Mk III Redux
4. 12/1/2014 - Spitfire III Part 3

Tim

[jackroadkill]

Whilst she looks very different from the archetypical Spitfire shape there's no denying that she's a striking looking airframe.  Excellent modelling, sir.

[noelh]

That's  really interesting. I had no idea the MkIII was clipped. 

 

The history is fascinating.

 

Nice  one.

[Back in the Saddle]

A great build of an unusual subject. I’ve never seen the Mk.3 Spitfire before!

[Learstang]

Excellent model of a very unusual Spitfire! It's a shame the Mk.III's retractable tail wheel wasn't introduced from the Mk.V on as it would have improved the inflight appearance quite a bit. I've always thought that gangly fixed tail wheel on the Spitfire looked like the crippled claw of a bird hanging down whilst flying.

 

Regards,

 

Jason

[k5054nz]

Magnificent work - now I want one too!

  

On 8/28/2022 at 10:19 AM, stevehnz said:

They do look a bit weird, kind of like some of the older reno pylon racers.

Exactly what I thought when I saw the comparison!!

[Wulfman]

Beautiful and very interesting build !

 

Wulfman

[wellsprop]

Excellent conversion!

[Dave Klaatu]

Beautiful! You gave me something to shoot for when I build a clipped wing Spit- I won't alter it as you have, but it's a great guide!

 

Dave