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Spitfire DP845, Split flap hinges , 6 cannon wing, Any details?


Troy Smith
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a thread on Hyperscale caught  my eye

 

http://www.network54.com/Forum/149674/thread/1478431065/last-1478643786/(View+All+Messages+In+This+Thread)

 

had a look at Spitfire - The History and Spitfire Story, plus a google...  

https://forum.warthunder.com/index.php?/topic/84705-spitfire-mk-iv-xx/

 

in particular details of the 6 cannon wing and Fowler flaps

 

the Fowler flap mechanism  is seen here

DP845x2.jpg

 

DP845x1_zps2uffibvj.jpg

 

there is this paiting  of the 6 cannon wing bulges

spitfire-mk-iv_12_ss_l_121109153721-580x

 

the bulges look to high and square too me, 

There is a small drawing in Spitfire - the History of the 6 cannon wing, ,  though the bulges look different,  and I suspect they would be more like the wide 2 cannon bulge with an added centre part? (the drawing looks more  like this) 

 

in this shot 

6b02cd76285a4408e9dbfb98e40fe0f5.jpg

2013-12-11210100_zps8db856b4.jpg

 

part of a bulge can be seen just behind the prop blade on the starboard wing,  and I presume somewhere there are more pics of this configuration?

 

Also visible are two of the Fowler flap mechanism, I presume there would be 3 per side? 

 

Would  the small centre section flaps have been retained? 

 

Something for those not at  Telford to contemplate perhaps....

 

cheers

T

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It is hard to see how you could make those little centre section split flap sections do anything useful if you had Fowler flaps elsewhere. You certainly wouldn't need the drag from them.

 

I also don;t buy that flat square-edged bulge. It would be aerodynamic death.

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My understanding is that the 6xcannon installation was only a mockup,  I've certainly never seen a view of any actual installation with feed routes, let alone what would have been the resulting fairing on top of the wing.  However I think we can be sure that it would ramp down to the rear rather than end in a bluff shape.

 

Those are not Fowler flaps - Fowler flaps extend on tracks to the rear before curving down, look at the trailing edge of a Hudson.  These are slotted flaps (as STH says) and the view shows a simple hinge.  Thanks for the reminder - I'd forgotten about those and was thinking that a Mk.IV was a bit too similar to a Mk.XII to bother with a model.

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2 hours ago, Troy Smith said:

I was hoping you might have some of this info buried in your files though.

 

I probably do, Troy, but it is well buried.  Actually, I think my information is pretty sketchy.  I agree that the six-cannon is a mock-up, though simply hanging the debris on the front would involve some engineering if they flew it that way.  I'll poke around a bit more and report back if I come up with anything further.

 

bob

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Thank bob

so, for discussion, a couple of images from STH. No scanner set up so just photos, so apolgies for lower resolution, but they show details under discussion.

 

the six cannon wing sketch with large bulges

Spitfire%206%20cannon%20wing%20IMG_0592_

 

note bulge shape,  as I mentioned above, think the wide 2 cannon bulge, with a new centre section, and the frontal view of bulges.

wide 2 cannon blisters for comparison 

Cannon_cover_1.jpg

 

for comparison, here's a C wing drawing,  which with some imagination you can see where and how a 3rd cannon could  be fitted. 

spitfire-vc-wing-arrangement.jpg

 

 

 

 

 

2 cannon installation

0_fs.jpg


 

from http://www.clubhyper.com/reference/spitfirecwingbulgesf_1.htm

 

 

I'm having dim memories of a 3 cannon mock up photo on the Martin-Baker MB3 image somewhere..

EDIT

here https://get.google.com/albumarchive/109207897425941419378/album/AF1QipMBMJ6gp_OhZWVy_uwhZinxicDlOQ-zwBOtQGQe?source=pwa

not relevant, but a LOT of neat pics of the various MB types

a side view not online

 

Spitfire%20DP845%20w%20six%20cannon%20si

 

note the 'bump' just visible above the wing.    I assume somewhere there is a rear view shot, as these prototype shots seem to cover all these details.

 

Glad it's been of interest.

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Interesting thread Troy. I've long wondered if the wing was modified internally for the extra cannon & ammo feed, it would gave been a shoe horn job, especially the ammo feed to my mind & for what, the trade off in weight & loss of manouvreability would not have been popular I'm guessing.

Steve.

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I'm with you all the way, Steve.  Four cannon was found too cumbersome for the original Spitfire wing, and wasn't generally adopted until the new wing/ailerons on the 20-series.

 

The Meteor was however designed for six cannon, presumably the Ministry's logical advance on four cannon as the desired fighter armament, but it was found impossible to fit them in.  This was too late for the overall balance, and the design suffered for a long time through having to carry ballast in the nose.  Perhaps the diminishing Luftwaffe bomber threat convinced authority that four cannon would be quite enough for any type they were likely to meet.

Edited by Graham Boak
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Good thing I didn't like my first attempt at converting a Mk XII kit to a Mk IV. I missed the trick on the flaps so simply used a spare  "a" wing. I like the idea of creating a 6 cannon + slotted flaps configuration. Even if impractical on a Spitfire, it would look very unique on my shelf and provide a proper link in my Spitfire collection. 

 

Thanks Troy. 

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  • 2 years later...
On 12/11/2016 at 16:23, Graham Boak said:

These are slotted flaps (as STH says) and the view shows a simple hinge.  Thanks for the reminder - I'd forgotten about those and was thinking that a Mk.IV was a bit too similar to a Mk.XII to bother with a model.

Any other similar examples?

On 12/11/2016 at 17:41, gingerbob said:

 

I probably do, Troy, but it is well buried.  Actually, I think my information is pretty sketchy.  I agree that the six-cannon is a mock-up, though simply hanging the debris on the front would involve some engineering if they flew it that way.  I'll poke around a bit more and report back if I come up with anything further.

 

bob

Hi bob

Just a bump in case said info has surfaced

 

On 12/11/2016 at 18:04, Troy Smith said:

Thank bob

so, for discussion, a couple of images from STH. No scanner set up so just photos, so apolgies for lower resolution, but they show details under discussion.

 

the six cannon wing sketch with large bulges

Spitfire%206%20cannon%20wing%20IMG_0592_

 

And,  while looking at this thread again ( I was pondering on the flap question and thought I'd bump it up)  I just noticed (or maybe reminded myself) that the sketch above appears to show the high altitude extended tips...

I now the shots of DP845 don't show this, but was there any suggestion of this,  (most of my library is packed up so can't check) 

cheers

T

 

 

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  • Troy Smith changed the title to Spitfire DP845, Split flap hinges , 6 cannon wing, Any details?
On 08/02/2019 at 22:24, gingerbob said:

As for the rest, I'll try to pay more attention soon.

revisiting this one.

 

Just wondering if anyone has any information on the split flap hinges, as in better idea of what they look like, the photos are just not quite clear enough.  And just the 3 hinges on the main flap?

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  • 2 years later...

Been awhile, with the ongoing Spitfire III build, thought this might be worth bringing up,  especially any info on the split flap installation.

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On 31/07/2022 at 02:22, Troy Smith said:

Been awhile, with the ongoing Spitfire III build, thought this might be worth bringing up,  especially any info on the split flap installation.

 

I've done DP845 in late condition but I feel like turning my Airfix XII in to DP845 in early condition.

 

Another bit of controversy: I'm saying DP845 first came out in green and dark earth!

 

Neil

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6 hours ago, neilfergylee said:

I'm saying DP845 first came out in green and dark earth!

Note

 

DP845 IV Super GIIB Worthy Down 27-11-41 RAE 20-7-42 comparison test with Fw190 and Typhoon AAEE 3-9-42 trls Cv proto XII fit Griffon IV 4-43 fit Griffon VI 6-43 1MPRD SOC 1946

 

I suggest this wrong, as by the end of Nov 41 Day Fighter Scheme was standard,  though with yellow undersides.  The images suggest Dark Green/Ocean Grey from the higher contrast.

 

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On 01/08/2022 at 17:47, Troy Smith said:

Note

 

DP845 IV Super GIIB Worthy Down 27-11-41 RAE 20-7-42 comparison test with Fw190 and Typhoon AAEE 3-9-42 trls Cv proto XII fit Griffon IV 4-43 fit Griffon VI 6-43 1MPRD SOC 1946

 

I suggest this wrong, as by the end of Nov 41 Day Fighter Scheme was standard,  though with yellow undersides.  The images suggest Dark Green/Ocean Grey from the higher contrast.

 

 

Hi Troy,

 

I've tried to send you a PM but the forum states that you can't receive them.  Therefore, here's the bulk of my message:

 

I thought I would put the cat amongst the pigeons regarding the Mk.IV prototype!  I too thought DP845 would have been produced in Ocean Grey but an Ian Huntley column from Scale Aircraft Modelling in 1990 made me think again.

 

I have digitised Ian Huntley's article and the link below is a PDF version and I certainly found some surprising information, namely that Ocean Grey didn't appear to be specified until April 1942!  I guess my question has to be whether they were using the famous 'Mixed Grey' in the interim?

 

https://www.dropbox.com/s/84mlkdxy8l4s2qf/The Ocean Grey Era.pdf?dl=0

 

Neil

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As an aside, I made up a batch of Mixed Grey using seven parts MRP Medium Sea Grey and one part MRP black.  It certainly looks a LOT lighter than Ocean Grey.

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On 01/08/2022 at 18:47, Troy Smith said:

Note

 

DP845 IV Super GIIB Worthy Down 27-11-41 RAE 20-7-42 comparison test with Fw190 and Typhoon AAEE 3-9-42 trls Cv proto XII fit Griffon IV 4-43 fit Griffon VI 6-43 1MPRD SOC 1946

 

I suggest this wrong, as by the end of Nov 41 Day Fighter Scheme was standard,  though with yellow undersides.  The images suggest Dark Green/Ocean Grey from the higher contrast.

 

From the very white yellow (particularly on the roundel) and thd very dark blue, I'd guess the photos were taken with a red filter, which greatly increases contrast. The green would be darkened and if its DE then that would be lightened a bit.

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On 04/08/2022 at 10:01, neilfergylee said:

I too thought DP845 would have been produced in Ocean Grey but an Ian Huntley column from Scale Aircraft Modelling in 1990 made me think again.

 

I have digitised Ian Huntley's article and the link below is a PDF version and I certainly found some surprising information, namely that Ocean Grey didn't appear to be specified until April 1942!  I guess my question has to be whether they were using the famous 'Mixed Grey' in the interim?

Interesting article.

but

"Ocean grey turned out to be a base of medium seagrey to which a spot of yellow had been added, which imparted a slightly greenishtinge to themix. Then, a very small amount ofblack slightly darkened the finish"

 

I have a problem with this.   MSG is part of the Sea Grey family, They are slightly purple blue hued greys. 

Adding yellow will make it a browny grey.

I'll @Jamie @ Sovereign Hobbies @Casey  @John  on this.

 

Ocean grey was a specific green hued grey,   that was developed for a specific purpose, but was in short supply when the change over happened. 

Your model, your choice,  always interesting to see an idea presented with reasons.  

 

I have had a vague idea of scratching up a 'what if' 3 cannon bay...    my main stumbling block is what the flap attachmenst looked like, I was lucky enough to find some white metal blades that I could burnish up,  as well as an old P-40E spinner I was able to eyeball into a a new shape  using a 'lathe' made from a  cordless drill and some sandpaper...  

 

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Hm, I saw somewhere that it was Sea Grey Medium + Night in 7:1 ratio, but I would prefer to have it independently verified.

 

Night is an interesting color. @Nick Millman on this forum here said it was carbon black and ultramarine.

 

Does anyone have a real recipe there? @Jamie @ Sovereign Hobbies ?

  • Carbon black is a color that strongly absorbs all colors in visible spectrum, but it absorbs much of long waves (red) than short waves (blue) - it means it is having blue undertone.
  • Ultramarine blue is quite transparent in blue spectrum range and is strongest absorber around 580 and 630nm (green/yellow and red). But even at its strongest absorption level it is around 8 times weaker than carbon black in same spectral range, and the color is very poor scatterer.

In other words, you need a lot of ultramarine blue to even make a visible dent on carbon black. I find it bit unlikely that they used so much ultramarine blue on a paint, but I may be wrong here!

 

Now, if you have a strong color pigment like carbon black, the best way to bring its 'undertone' is to add scatterer (white paint is a very good scatterer). You can see this effect in any mixture of carbon black + titanium white, they are very noticeable blue, more like 'sea grey' family of colors than true gray.

 

And there are colors that are weak, transparent in most of the color range and are scatterers in blue color range. The example of such color is transparent yellow iron oxide.

 

Mixtures of black and yellow iron oxide gives me closest spectral match to Night sample that I have.

 

It was a surprise for me the first time my math spitted it out, and I thought my Night sample is just old and yellowed, but the 'add bit of very transparent weak brown yellow to make natural carbon black blue tone more prominent' phenomenon is real.

 

Just as real as adding 'pure' white to carbon black makes it blue-grey, and also it is why Black + Strong Yellow = Olive Green. A side note there: almost all computer drawing software (well, except this one - https://scrtwpns.com/mixbox/painter/) does it wrong because it uses wrong math.

 

Welcome to rabbit hole :D

Edited by Casey
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3 minutes ago, Casey said:

I saw somewhere that it was Sea Grey Medium + Night in 7:1 ratio,

this is the formula  for mixed grey,  which was proscribed substitute until Ocean Grey became available in quantity,  I think was first commonly  described here 

Supermarine%20Spitfire%20Camo%20&%20Mark

 

 

Supermarine%20Spitfire%20Camo%20&%20Mark

 

Supermarine%20Spitfire%20Camo%20&%20Mark

 

 

from https://boxartden.com/reference/gallery/index.php/Camouflage-Markings/Supermarine-Spitfire

 

Interesting to note the Sea Greys and being non blue hued.   @Casey  when I was trying to match Ocean Grey and Medium Sea grey using Tamiya,   I started with XF-82 for both,  MSG was mix IIRC 3ml XF-82, 3,5ml white XF-2 and 0.1 ml flat red,  as without the dash of red it lack a very subtle purple.

This of course was a by eye match, but it was the only way to get a match in direct sun, that would stay the same when twisting the samples in the light.

I think Ocean Grey was Xf-82 and a tint amount of yellow, but it's too late for me to go and try to find the mix list. 

 

Tamiya XF-83, their "MSG" is too buff/brown as the under tint.  I tarted with these as these are commonly though as being 'good' matches...  which was not what I found. 

i've not tried your Tamiya mixes for OG and MSG from  this thread as yet.

 

HTH

cheers

T

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58 minutes ago, Troy Smith said:

Interesting to note the Sea Greys and being non blue hued.

To make things more fun, some are :) I more meant this:

 

Left - Carbon Black + Titanium White (1:10), Right - Neutral gray

100x100100x100

 

The difference is very visible. To make N (fully neutral) colors you need to mix the pigments.

 

To mix neutral grey you need to mix Titanium Dioxide Rutile / Amorphous Carbon produced by charring animal bones / Calcined Natural Iron Oxide. Very similar to my recipe for Night, except the red iron oxide is balancing the blue of Carbon Black fully.

Edited by Casey
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As a prototype not flying to Europe, maybe the dark earth / dark green was the approved scheme, rather than whatever fighter command said?  It was about being camo’d when parked up or flying over UK, hence bomber command aircraft (on the ground or air testing over Britain in daylight) stayed in DE/DG throughout the war.

 

 

Even nowadays, the BBMF Lanc crew have noted the DE/DG Spitfires and Hurricanes are much harder to spot at a distance when forming or meeting up.

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On 05/08/2022 at 14:26, neilfergylee said:

I made up a batch of Mixed Grey using seven parts MRP Medium Sea Grey and one part MRP black.  It certainly looks a LOT lighter than Ocean Grey.

often appear like this in photos.   

9 hours ago, malpaso said:

As a prototype not flying to Europe, maybe the dark earth / dark green was the approved scheme, rather than whatever fighter command said?

The regs said fighter prototypes were to be finished as standard with yellow undersides.

For a new airframe,  I have never seen a combination of B?W film/filers that would give the high contrast between upper surface colours of Dark Green/Dark Earth.

If it had been built pre the switch for TLS to DFS, maybe it would not have been repainted.  

Anyway, has been an interesting discussions on the different greys and the composition and appearance. 

 

I'm still hoping for some info on those split flaps ;) 

 

 

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