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Spit Mk XIV prop question


Spitfires Forever
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Hello all

I have a question regarding the propellers used on the Mk XIV. Were there different manufacturers as there were for the Merlin Spits eg. De Havilland, Rotol etc? We're the chord and prop length different or was the same prop used on all versions of the Mk XIV? Any help on this would be great.

Cheers

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10 hours ago, Spitfires Forever said:

Were there different manufacturers

There were for blades.   The markings at the blade base were for these differences, different colour discs. 

"Regarding the markings within the coloured disc I can add that the Horden-Richmond Aircraft one shown in my first response above with the green disc and HRA text was made of Hydulignum with a Rotoloid covering and Armoured Sheath as identified by the disc and letters HRA.

Jablo Propellors Ltd blades had pink discs while Horden-Richmond Aircraft Ltd blades had green ones, Rotol Airscrew Ltd blades had white while Yellow ones were seen on The Airscrew Company Ltd blades. The lettering within the disc would vary which would indicate the Material , Covering and Sheath of the blade so marked."

 

 They may vary in shape, they do on other Griffon Spitfires.  Study photos. 

also

https://www.key.aero/forum/historic-aviation/103145-propeller-markings

 

Rotol%20Spec%201.jpg

 

https://www.key.aero/forum/historic-aviation/37940-help-required-spitfire-prop-blade

 

"

JP' are the code letters for blades manufactured by 'F. Hills & Son Limited'.

For future reference:-

'RW' manufactured by Rotol Limited'.

'D' manufactured by 'Airscrew Company Limited'.

'HRA' manufactured by 'Horden-Richmond Limited'.

This blade is from a five blade set as fitted to 20 series Spitfires.

The RS marking on a 'Pink' disc indicates the Material is 'Jablo Wood, the Covering is 'Rotoloid' and the Sheath is 'Simple'.

The RA denotes 'Rotol Limited' and always prefixes the Drawing Number"

 

I can't find the help manual drawings

 

also

http://www.spitfireperformance.com/jf319.html

 

note individual blade numbers.

 

@gingerbob  @Graham Boak  @Magpie22  @Peter Roberts  maybe able to add more details.

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Thanks again Troy. After looking at whatever pictures I could find ( old black and white photos of varying clarity) it seems that I could pick out at least two distinct types, one with slightly shorter and wider blades with pointed tips then the other type that had a less wider chord and a little longer length with tapered tips. I have resin blades for my 1/48 Mk XIV Spit but they are a bit warped with a pronounced outward curve which just doesn't look right. The Ultracast blades may be a better choice than the Daco's I have. I have seen several Mk XIV's up close and didn't think to take a picture directly of the props. Both were bubble top marks, one at the museum at Davis-Montham AFB in Arizona and the other owned by the CAF in Camarillo CA. But, my main question seems to have been answered so I can go from here.

Cheers

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The Mk. XIV prop is a Rotol R19/5F5/1 with Jablo or Hydulignum blades, pitch 35 deg. - 27 deg. 15 min, 10 ft. 5 in. diameter.

Source: Spitfire - The Story of A Famous Fighter by Bruce Robertson, Spitfire The History by Morgan and Shacklady.

 

Jun in Tokyo

https://www.flickr.com/photos/horaburo/albums

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Following from some model airplane information, Barracudacast makes two 1/48 scale resin replacement Griffin Spit five-bladed propellors:

 

Barracuda BR48026 - Griffon Spitfire 5-Blade Prop (Late) BR48026 'late style 11’ diameter prop'

 

Barracuda BR48093 - Spitfire Mk XIX 5-Blade Prop (Tapered) BR48093 'as fitted to many Spitfire Mk. XIXs, XIVs and XVIIIs. There were 2 styles of blades, a wide blade and a later tapered blade
seen on most Spit XIXs in service.'

 

The second one has narrower blades in the outer 1/3 of the propellor, subtle.  So, based on Roy Sutherland's research on these^, there is some variation in shape across these ac.

 

ilj

 

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On 9/13/2022 at 12:30 PM, tempestfan said:

I thought Jumpei Temma  may have drawn the XVI, but I haven't seen XIV drawings from a quick scroll. The old Aeromodeller drawings by Peter Cooke (1978/9 ?) would likely be of some help giving shapes.

This is a most interesting thread...the breadth of detail knowledge on this site is consistently amazing...!

 

Links to Mr. Temma's remarkable selection of Spitfire drawings, including the Mk XIV, are at the bottom of this page:

 

http://soyuyo.main.jp/spit5b/spit5be-1.html#drawing

 

Edited by MDriskill
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Ah, that's great! I just looked in his build article but didn't see any links, and didn't have the time to go through his complete works - which is impressive. Just one blade shape for the XIV drawn by him, however.

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2 hours ago, tempestfan said:

Ah, that's great! I just looked in his build article but didn't see any links, and didn't have the time to go through his complete works - which is impressive. Just one blade shape for the XIV drawn by him, however.

The Mk. XIV Side View page shows two similar blade shapes labeled "blade shape in front view" and "developed blade." The latter is generally broader, but still has the pointed tip:

http://soyuyo.main.jp/spitd/14side.gif

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4 hours ago, Seawinder said:

The Mk. XIV Side View page shows two similar blade shapes labeled "blade shape in front view" and "developed blade." The latter is generally broader, but still has the pointed tip:

http://soyuyo.main.jp/spitd/14side.gif

Those are the same blade.

 

Someone here will have a better explanation, but "developed" basically means what the blade would look like if you "flattened" it, i.e., with all the twist taken out. In other words, you are seeing its full width at every point.

Edited by MDriskill
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30 minutes ago, MDriskill said:

Those are the same blade.

 

Someone here will have a better explanation, but "developed" basically means what the blade would look like if you "flattened" it, i.e., with all the twist taken out. In other words, you are seeing its full width at every point.

 

Exactly, the "developed" view is a way to show the blade sections as they would be without any twist, useful to verify how correct each section of the blade is at any distance from the hub. Also useful for scratchbuilding a blade, keeping in mind that twist must be added at some point 

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I believe the propeller fittings for this mark were as follows:

 

Hub- R19/5F5/1

 

Blades- two blade types-both Jablo 10ft 5ins diameter, specifically:

RA 10127, and,

RA 10130

Theoretically and I believe this to be so, the later blade should be the ‘130,’ (although this is not always the case with the numbering system).

The ‘130’ was also used on the following aircraft:

 

PR Mk 19 (late aircraft and possibly all)

 

Mk 18 (one of two types)

 

In seeking to identify and differentiate between the two blade shapes in this instance, there is some helpful photographic evidence.

 

Here is an early Mk 14, with the blades suggesting a tapering trailing edge toward the tip:

 

https://www.iwm.org.uk/collections/item/object/205453201

 

url

 

Here is a PR Mk 19 where the blades display an almost straight trailing edge toward the tip:

 

1677089-medium.jpg

 

 

I hope those of you who are interested find this post helpful.

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Ministry of Aircraft Production. Hydraulic, Rotol, 5 blade, propeller model numbers.

 

In January 1944 Spitfire F.XIV, F.21, no model number given.

In March 1944. Spitfire F.XIV, PR, R19/-, R14/4F5/1.  Spitfire F.21, R24/4F5/2, R14/5F5/2

In July 1944. Spitfire F.XIV, PR, R19/-, R14/4F5/1.  Spitfire F.21, Spiteful, R24/4F5/2, R14/5F5/2

In September 1944.  Spitfire F.XIV, PR.XIX, R19/-, R14/4F5/1.  Spitfire F.21, Spiteful F.XIV R24/4F5/2, R14/5F5/2

In November 1944.  Spitfire F.XIV, PR.XIX, R19/4F5/1.  Spitfire F.21, F.22, Spiteful F.XIV, Seafire N.7/44 R14/5F5/2

In December 1944.  Spitfire F.XIV, FR.XVIII, PR.XIX R19/5F5/1.  Spitfire F.21, F.22, Spiteful F.XIV, Seafire F.45 R14/5F5/2

In June 1945.  Spitfire F.XIV, FR.XIV, F.XVIII, FR.XVIII, PR.XIX R19/5F5/1.  Spitfire F.21, F.22, Spiteful F.XIV, Seafire F.45 R14/5F5/2

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1 hour ago, V Line said:

I believe the propeller fittings for this mark were as follows:

 

Hub- R19/5F5/1

 

Blades- two blade types-both Jablo 10ft 5ins diameter, specifically:

RA 10127, and,

RA 10130

Theoretically and I believe this to be so, the later blade should be the ‘130,’ (although this is not always the case with the numbering system).

The ‘130’ was also used on the following aircraft:

 

PR Mk 19 (late aircraft and possibly all)

 

Mk 18 (one of two types)

 

In seeking to identify and differentiate between the two blade shapes in this instance, there is some helpful photographic evidence.

 

Here is an early Mk 14, with the blades suggesting a tapering trailing edge toward the tip:

 

https://www.iwm.org.uk/collections/item/object/205453201

 

url

 

Here is a PR Mk 19 where the blades display an almost straight trailing edge toward the tip:

 

1677089-medium.jpg

 

 

I hope those of you who are interested find this post helpful.

Thanks for posting. From what I can tell there is a slight difference in length and chord indicating that there was not one specific blueprint with strict dimensions issued by MAP. I have seen two MkXIV Spits which were bubble tops and one had the shorter, fatter blades whilst the other hand the longer more tapered blades. 

Cheers

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1 hour ago, Spitfires Forever said:

Thanks for posting. From what I can tell there is a slight difference in length and chord indicating that there was not one specific blueprint with strict dimensions issued by MAP. I have seen two MkXIV Spits which were bubble tops and one had the shorter, fatter blades whilst the other hand the longer more tapered blades. 

Cheers

The deficiencies in aircraft model propellers are what prompted my interest in the subject and I am glad to help.

 

There was indeed no MAP instruction on blade design. As far as Rotols are concerned the basic approach is described by Stait (The Rotol Story) and is based on the engine, physical aircraft parameters etc. The design work was undertaken by the lead manufacturer i.e. principally Rotol and dH.

 

MAP had a requirement for propeller type numbering (which to an extent accounts for the number of variants of both dH and Rotol hubs) but no design input.

 

The diameter of the Mk 14 prop at 10ft 5ins is not variable as stated above i.e. both blades were of identical length. There is an apparent difference in chord for at least part of the blade length of the two types to which I referred, but perhaps not at the lower section.

 

For completeness, I should also add that there were two alternative spinner types, a second being a later version used with other 5 bladers. There were also two alternative governors, the second also being a later introduction.

 

For some of the later marks with 5 blade props e.g. Mk 21, as helpfully listed by @Geoffrey Sinclair above, with different hubs/blades and engine variants the prop diameter increased to 11ft 0ins which was the maximum for the Spitfire.

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  • 1 month later...
On 16/09/2022 at 09:42, Graham Boak said:

The larger prop on the Mk.XX series was only permitted by the increased undercarriage length of these aircraft.  It was too large for earlier Spitfires.

That is a fair observation.

 

Within its’ new wing arrangement, the Mk 21 had oleo legs lengthened by 41/2 inches which according to Price enabled the fitting of the 11ft 0ins diameter prop.

 

I returned to my sources to check my memory in relation to the maximum design radius.

 

The maximum propeller diameter on all production Mk’s prior to the Mk 21 was 10ft 9ins. 

 

However, there is some conflicting info from de Havilland as to what was achievable. On the one hand, in one listing, the limit is stated as 10ft 9ins.

 

On the other hand, according to an associated listing, there were props of 11ft 0ins diameter fitted to both the High Speed Spitfire and the Spitfire Mk III. The respective dH blade drawing numbers for each aircraft do not denote ‘experimental’ and are identical. The blade is in fact that of the Hawker Hurricane.

 

Aside from length, the Hurricane/Spitfire blades were of different section and different chord distribution with the maximum of the former being slightly greater (approx 1/8 inch).

 

The only photo I could find of the H/S Spitfire with what seems to be this blade is that of the aircraft exhibited in Brussels in July 1939.

 

https://www.flickriver.com/photos/16118167@N04/44988744414/#:~:text=<a href%3D"https%3A//www.flickriver.com/photos/16118167%40N04/44988744414/">View on black</a>

 

(couldn't copy to post)

 

As to the Mk III, I seem to recall a recent board topic/thread which touched on the various prop types fitted to the prototype.

 

There are at least two photos which show this aircraft fitted with a dH 3 blade prop, apparently shortly after completion. It is hard to say definitively whether or not the blades are the standard model or the Hurricane types. On balance, I tend to the latter, although it’s not an easy call.

 

spacer.png

 

I also suspect that the Hurricane blade was used on Spitfire K9793 during the early vp propeller trials.

 

spacer.png

 

 

In view of the above it may seem reasonable to conclude that the pre Mk 21 Spitfire could be flown with an 11ft 0ins diameter prop although in general service terms this was not a practical option.

 

 

 

 

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16 minutes ago, V Line said:

In view of the above it may seem reasonable to conclude that the pre Mk 21 Spitfire...

 

The MERLIN engined Spitfire, I would say.

 

bob

 

p.s. Interesting comments about use of Hurricane blades- I had not heard that, but it makes sense.

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