Wheel bulges on Seafire XVII wings

[Tomas Enerdal]

Dear All,

I just noticed a detail on the Seafire XVII wings I had not noticed before:

There are wing bulges above the wheel wells.

They seem to be the same size and shape as seen on later universal wings with e-armament. According to one reference; "this was introduced when the axle geometry was changed to reduce the toe-in on the existing legs, thus reducing the wear on the wheels when these aircraft operated from tarmac, concrete or PSP runways..."

 

after a quick look in some references I could see these bulges on several Seafire XVII but not on the Seafire XV. The restored SX336 has them, but I have yet to find a pic of SX137 where their presence or absence can be determined.

(I will go through my references more thoroughly to see if I can determine any patterns.)

These bulges appear on the Tamiya 1/32 and Eduard 1/48 Spitfire Mk.XVI respectively.

I don't think they're on the Airfix Seafire XVII.

 

-Is this a previously known fact? This type of folding wing is unique to Seafire XV and XVII (the Seafire III had the separate oil cooler and one radiator)

-Are separate bulges available in 1/48? (they are fully integrated in the Eduard upper wing parts)

Edited January 8, 2020 by Tomas Enerdal

[72modeler]

I don't believe the Mk XV and 17 have the same landing gear geometry, with the XV being a wartime variant and the 17 being postwar and having the revised strut geometry catering to hard-surfaced runways and carrier decks, thus requiring the upper wing blisters due to the wheel assemblies lying higher up in the bay due to the "straight" gear strut axle. The beautifully restored Mk XV based here in the U.S., is an original Seafire 17 and you will  note it lacks the blisters, whereas SX336 has them. Betting one of our resident Seafire/Spitfire experts who knows far more than I can be more informative. See the attached history/walkaround and look at the photos that show the upper surface of the wings. I have also attached a link to the story behind the restoration of this XV- off-topic, to be sure, so I apologize in advance. Spitfire XVI's have the same blisters as they were also fitted with the landing gear struts with the straight axles.

Mike

 

http://www.salute.org/Seafire.html

 

https://www.historynet.com/sea-spitfire-soars.htm

Edited January 13, 2020 by 72modeler
added link, added text

[Graham Boak]

My understanding of the Spitfire hard runway mod was that it changed the axle rather than the leg.  Therefore the tyre sat at a different angle requiring more room in the well.  It is possible that the Mk.17 had changes to the leg to improve the carrier landing characteristics, but I would expect that to be a matter of internal oleo changes rather than changes to the leg geometry.

[Tomas Enerdal]

Hmm,

Monforton calls these bulges "wheel blisters" and there were even blister differences between c- and e-wings. Again, I made a quick look yesterday night, still have to look this through thoroughly.

But since the Monforton book deals only with Mk.IX and XVI I suppose we're talking wartime introduction of this runway modified landing gear/axle?

I remember earlier discussions about various types of landing gears; splines, the introduction of scissors links, rear and front. Can the part no of the different types of landing gear help us? Unfortunately I have no other access than to the normal printed references/books. 

[gingerbob]

The Seafire 17 should have a different oleo than the 15 (longer stroke, if I remember right), so that could have something to do with one having the bulge and not the other.  I'll have to look into this a little later!

[Tomas Enerdal]

I think I have found the answer to the first question, in Morgan/Shacklady:

(Chapter about XVII) "... the long stroke undercarriage under typical service conditions. The wheel wells had been modified to accommodate the chassis which had corrected, toe in wheels. ..."

Richard A. Franks refer to these legs as part no. 92178D

-The second question remains, how to model them on a kit? 

 

Edit: I found a note on Jumpei Temma's drawing; here It states that the modified landing gear/blister was introduced "late", from SX332-SX389. I'll see if that can be confirmed somehow. The shape of blister looks exactly as in one of the few clear pics I have, however. (SX334)

Edited January 9, 2020 by Tomas Enerdal

[Graham Boak]

The toe-in is the axle change, presumably the same as on the Spitfire.  A longer stroke oleo wouldn't affect the angle in the well - a longer oleo would mean new wells.

[gingerbob]

You mean like Seafire Mod 481 "To modify wheelwell to accommodate longer stroke oleo with no toe-in"? (looks like Jan '45 for initiation)

There's a cluster of activity:

Mod 483 To introduce Oleo leg No. 92236 (this incorporates strengthened axle and lever arm but retains toe-in) (apparently cancelled)

Mod 485 To introduce Oleo 92228 (long stroke) or 92360 (interim type)

Mod 487 To introduce stronger wheels, tyres and associated equipment (ref. Spit Mod 1517)

 

These mods generally say "15, 17", though it appears that there was some prevarication on the last.  Of course, this doesn't necessarily mean that the mod ended up being embodied on both Marks 15 and 17.  There is, in fact, some confusion about the improvements that were intended for the Griffon Seafire.  My interpretation so far is that a more gradual phase-in was originally imagined, but it turned out more along the lines of "The Seafire XV with this package of improvements embodied will be known as the Seafire XVII".

[Seahawk]

Somewhere on this site there is a thread in which the dear departed Miggers discussed this topic in some depth.  He demonstrated, to my satisfaction at least, that early Seafire F.17s had 4-spoke wheels and no wheel bulge and that Seafire F.17 SX330 and onward had 3-spoke wheels and the big over-well bulges to accommodate them (the 4-spoke wheels are 10.25" wide while the 3-spoke ones are 12".).  It also included the clearest photos I have seen of said bulge.  The Airfix 1/48 Seafire F.17 kit has both types of wheel but does not have the bulge: this means that some of the marking options are not strictly applicable unless the wings are modified. 

 

Good luck in finding the thread.  I've tried!

 

No, no-one that I have heard of has produced these wheel bulges in 1/48.

[gingerbob]

Here's a thread that Miggers contributes to, though no photo.  This thread has a link to some photos- I came to one, but clicked "back to album" at upper left to see the series.  Perhaps that was it?

Edited January 11, 2020 by gingerbob

[Seahawk]

On 1/11/2020 at 9:34 AM, gingerbob said:

Here's a thread that Miggers contributes to, though no photo.  This thread has a link to some photos- I came to one, but clicked "back to album" at upper left to see the series.  Perhaps that was it?

Good tries.  Near misses, but not the thread I had in mind: I know because I scissors-and-pasted parts of it.  And, because Microsoft Word has apparently had the temerity to take all my Open Office Writer files hostage unless I pay the evil beggars the licence fee for a product I don't want, I can't paste them back here.

Edited January 12, 2020 by Seahawk

[alt-92]

22 hours ago, Seahawk said:

because Microsoft Word has apparently had the temerity to take all my Open Office Writer files hostage 

OT: set your Open/Star/WhateverForkoftheday-Office word processor as default for all types of docxs and done.
use the "Choose default apps by file type" option.