Martlet Mk.I

[MDriskill]

jabbajindrich, unfortunately I do not have any more detail of those areas to hand.

But here is another link you might find interesting:

http://www.flight-manuals.com/f4fmartlett.html

[jabbajindrich]

very interesting,

and thanks for advice,

I will order Martlet Mk.I in pdf format and let´s see what is hidden inside,

Jindrich Nepevny

Praha,

Czech Republic

[gengriz]

Just to add to the discussion, FWIW here is the FAAM Martlet in 2009:

[Max Headroom]

I found some pictures which may assist

http://www.aviation-history.com/grumman/f4f.html

http://crimso.msk.ru/Images6/MM/MM-164/0199-04-2-17.jpg

http://www.grandgeorge.com/images/USSHornet/USSHornet.html

http://www.abpic.co.uk/popup.php?q=1287384

Trevor

[BD1944]

Belated greetings ... Bri Derbyshire here, author of "9 Lives" back in 1990. (Is anybody still watching this strand?)

 

Google and I obviously differ over what constitutes a relevant search term, because I've been looking in vain for stuff like this for a year or more (so it's their fault that I had to wrench the canopy off my AZ MI and start again.) So thanks, everybody!

 

An addition or two:

Photogrammetry of the Archer-page-1 MI and the well-known -4 "41-F-8" - feeding in the station dimensions - gives the windscreen shift as 5". Originally the chord of the panels in the sliding hood was about 10", and they were increased by 3" (fwd) and 2" (aft.)  This of course subject to overruling by the Man With The Tape!

 

Forward ventilator OR aft scoop? Not so, see Sq/Sig 1084, pp. 29 & 33, both top left. They have both ...

 

Bruce and Seahawk - your cowl chord of 28" and aft-of-cowl 22" are a blissful blessing, but my recent photogrammetry attempts (in which I tried to allow for both "angle off" and "range") tended to give me a 29-1/2" cowl for a 22" cowl-to-LE. Where exactly did you measure from, Bruce? I've been assuming it was from "root chord" - i.e. L/E at root, no fairing, as defined by Willis Nye and used on the -3 and FM-2 GAs we've all been referring to.

 

Bruce - I failed to track you down last year to share my take on Martlet serials, which differs a bit from your "GW in FAA"  - please PM me, and allow for the fact that I'm a tyro at this forum lark!

 

See also the "F4F-4 Wildcat length" strand, I've attacked that too ...

 

BD.

[ClaudioN]

3 hours ago, BD1944 said:

Belated greetings ... Bri Derbyshire here, author of "9 Lives" back in 1990. (Is anybody still watching this strand?)

 

Great to have you on Britmodeller. Your article was my first encounter with the varied features and details of the Martlet/Wildact variants.

I very much liked it and I still keep it as one of my best references.

 

Claudio

[Max Headroom]

^^^^wotezed!

 

I think I still have your IPMS article "somewhere". I always considered your scribblings The Definitive Article! Not only for The F4F but also your  musings on the Mustang too.

 

Welcome on board👍

 

Trevor

[Grey Beema]

This one I have bookmarked?

 

http://www.clubhyper.com/reference/wildcatfaaba_1.htm

 

I also keep this bookmarked..

 

http://www.geocities.jp/yoyuso/fm2/fm2e-1.html

 

 

[BD1944]

Thank you for your kind welcome. Am I really playing with the big boys now?

 

There is a Mk.II "9 Lives" on file, but it's pending many things - and this strand's 2012 revelations (new to me, obviously) have just put it back even further. There are errors, but considering the state of the art back in 1989 it's stood up quite well.

Which is more than AZ's MI kit does, which is what set me off again after years of Mustangs etc. I got the noisy end blues .... Well, I busked the very similar Sword FM-2 according to my "9 Lives" sketches, but caught a dose of Doubt when it came to the MI - leading to measuring photos and tearing hair, see the "-4 length" strand.

 

Meanwhile (for those building AZ's kit) the Airfix windscreen plus a well-hacked and repolished Academy sliding hood have allowed the AZ canopy (which came off undamaged) to join the Stuff For Fixing the Huge Stash of Academy Kits heap. Airfix's SBD-5 cowl is still an excellent basis for a 9-cylinder F4F.

 

Yes, I have Bruce's article (and a list of minor corrections, when he calls) and it's lovely. But "http/clubhyper...etc" is far too long, can't we just refer to "Archer"?

Ditto the Pink Pussycat?

- Speaking of which, it's obviously a labour of love, but I can't read much of it. The drawings are faint, the numbers ditto and too small: they'll only copy as a GIF. which is practically pixellated - so how do I access the information? Presumably you lot know how, or it wouldn't be so revered!

 

Cheers - BD

 

PS I've now been shown how to blow them up and read 'em - thanks, TF... BD

 

PPS 26/6/17: Even better canopy fix .... Airfix windscreen,yes - saw off and discard sliding section. But for the sliding hood, a much better fit is the centre, non-sliding hood section from Airfix's old SBD. Shorten at both ends (leaving the nibs at the rear end of the rails) by the width of the moulded frame, and along the bottom, ditto. Re-scribe the edge frames (and add the centre top) with spring-bow ink compasses - clamp some card in the nib, set spacing, scribe with the point, works a treat. - B.

Edited June 26, 2017 by BD1944
Update

[MDriskill]

On June 12, 2017 at 11:05 AM, BD1944 said:

 

 

Forward ventilator OR aft scoop? Not so, see Sq/Sig 1084, pp. 29 & 33, both top left. They have both ...

 

 

 

Great catch, thanks for that! It would make sense to think a little scoop behind the cockpit was for something else anyhow, maybe just to help the radio and batteries stay cool?

[BD1944]

The forward "ventilator" or whatever was later a hatch marked "enclosure release" - see D&S N0. 30, .p. 13, lower left (though this looks like a restoration, and may be a guess.) Your radio-cooler idea sounds very plausible, but would need an outlet too, if only through the tailcone. Who's got the full manual?

Other trivia: MDriskill's post of 16/Nov/2012 reintroduced us to the mock-up TBF and No. 50. Barrett Tillman ("Avenger at War" p.12 suggests it's the 50th F4F. Seems reasonable to suppose it's really the 50th G-36A.

[BD1944]

This thread started out Mk. I, but other marks have crept in, and our various favourite articles have been aired, so how about some Mk. IIIs for a change?

Claudio forwarded me some useful places to look (thanks, mate) including

https://www.flickr.com/photos/billchilton/albums/72157623826178790/with/4508960044/
and I've been working through them.  Photos on this site are numbered (1 - whateve)r per album (or similar) but site pages pay no attention -so go first to p. 2 Photo 61, then onwards (not back!) to nos. 26/29/33/39. Here are a number of indubitable 805 sq. Martlet IIIs, some of them well known and some not. They all have the fixed wing, with rod pitot and close-grouped pair of guns: they all have the bulge for the (absent) R-1830-86 intercooler, and the large single cowl flaps. So far so good - but at least a couple of them (including AX744/D and HK142) have NO EXTERNAL LIP INTAKE. This is supposed to be an invariable F4F-3A recognition feature, from Dick Hills' article of the '80s.

There were overlaps, but in general the production sequence at the time was supposed to be:

Group B F4F-3 - no bulge, 2 cowl flaps, int. intake

Interim Martlet II, later redesignated III - no bulge,2 cowl flaps, ext. intake (at least on AM958, the only one on film: but now I wonder...)

Group C F4F-3A - bulge, 2 cowl flaps, ext. intake, mixed in with Group D F4F-3 - bulge, 8 cowl flaps, int. intake

Proper Martlet II - folding wings, bulge, 2 cowl flaps, int. intake

F4F-4 - folding wings, bulge, 8 cowl flaps,ext. intake
Are we to guess that Grumman were in the process of deciding that there was no difference in performance between internal and external carb. intakes; deciding the external was cheaper, or easier: and using up old stock on passing airframes at random? At this time, if there wasn't an 1830-86 ready to fit, they put in an 1830-90 and added an A, or called it a Martlet, so random isn't all that far-fetched ...

 

Any ideas will be gratefully clutched at.

 

BD
 

[Graham Boak]

I have some doubts about the top of the Airfix canopy, including the windscreen.  To my eye, the photos show a significant rise above the top of the flat front panel, which in side view looks approximately quarter-circular in shape.  This puts the top of the canopy higher above the horizontal frame than Airfix suggests - combined with the too-fat fuselage this brings the overall profile into line.   In the issue of Airfix Magazine dealing with this kit, there was an excellent article by Dana Bell, including one photo that showed this very well - I'm sorry I didn't keep the issue so can't provide a better reference.  Memory suggests that the Squadron/Falcon canopy is better, but getting it to fit to the Airfix fuselage might be more of a problem than it is worth.

[Seahawk]

On 13/06/2017 at 11:50 AM, BD1944 said:

PPS 26/6/17: Even better canopy fix .... Airfix windscreen,yes - saw off and discard sliding section. But for the sliding hood, a much better fit is the centre, non-sliding hood section from Airfix's old SBD. Shorten at both ends (leaving the nibs at the rear end of the rails) by the width of the moulded frame, and along the bottom, ditto. Re-scribe the edge frames (and add the centre top) with spring-bow ink compasses - clamp some card in the nib, set spacing, scribe with the point, works a treat. - B.

 

Simples!  And presumably the same section from the Falcon set for the AX Dauntless would work equally well.  You might just entice me into retrieving this kit from deepest stash, whither it had been consigned in disgust.

Edited June 30, 2017 by Seahawk

[ClaudioN]

On 30/6/2017 at 3:31 PM, BD1944 said:

This thread started out Mk. I, but other marks have crept in, and our various favourite articles have been aired, so how about some Mk. IIIs for a change?

Claudio forwarded me some useful places to look (thanks, mate) including

https://www.flickr.com/photos/billchilton/albums/72157623826178790/with/4508960044/
and I've been working through them.  Photos on this site are numbered (1 - whateve)r per album (or similar) but site pages pay no attention -so go first to p. 2 Photo 61, then onwards (not back!) to nos. 26/29/33/39. Here are a number of indubitable 805 sq. Martlet IIIs, some of them well known and some not. They all have the fixed wing, with rod pitot and close-grouped pair of guns: they all have the bulge for the (absent) R-1830-86 intercooler, and the large single cowl flaps. So far so good - but at least a couple of them (including AX744/D and HK142) have NO EXTERNAL LIP INTAKE. This is supposed to be an invariable F4F-3A recognition feature, from Dick Hills' article of the '80s.

There were overlaps, but in general the production sequence at the time was supposed to be:

Group B F4F-3 - no bulge, 2 cowl flaps, int. intake

Interim Martlet II, later redesignated III - no bulge,2 cowl flaps, ext. intake (at least on AM958, the only one on film: but now I wonder...)

Group C F4F-3A - bulge, 2 cowl flaps, ext. intake, mixed in with Group D F4F-3 - bulge, 8 cowl flaps, int. intake

Proper Martlet II - folding wings, bulge, 2 cowl flaps, int. intake

F4F-4 - folding wings, bulge, 8 cowl flaps,ext. intake
Are we to guess that Grumman were in the process of deciding that there was no difference in performance between internal and external carb. intakes; deciding the external was cheaper, or easier: and using up old stock on passing airframes at random? At this time, if there wasn't an 1830-86 ready to fit, they put in an 1830-90 and added an A, or called it a Martlet, so random isn't all that far-fetched ...

 

Any ideas will be gratefully clutched at.

 

BD
 

 

Great catch, Brian!

...and it had been there for anybody to look at, but it's true one needs to look really carefully to see something that is plainly there.

 

I'll try to write down my thoughts as neatly as possible, but I'd really need an engine expert to comment.

1) bulge - Bert Kinzey (D&S no. 65 - F4F Wildcat) says it first appeared on Bu. No. 3905, that is, the first US Navy F4F-3A. We know ex-Greek Martlets had it too. The F4F-3 at the Naval Aviation Museum, Pensacola FL, also has it, and it is the original Bu. No. 3872. Bu. No. 2525, that appears in LIFE colour photos, had no bulge. We might possibly say the bulge was introduced on F4Fs of the first large (243 aircraft) US Navy contract, in preparation for fitting the R-1830-86?

2) engine - the first F4F-3s had the R-1830-76 and no bulge. From the R1830-76 to the R-1830-86 something in the engine must have changed, as the bulge was meant to accommodate the latter. In between, F4F-3As had the R-1830-90, that required no bulge, although it was kept there on F4F-3A airframes. It sounds odd that Grummans randomly picked whatever engine variant was available. Purely out of logical reasoning, I'd rather think the R-1830-76 was fitted up to Bu. No. 3874, then the R-1830-90 on 95 aircraft, at last the R-1830-86. The airframes could accept any of the three.

3) external air intake - the table at the end of Bruce Archer's article gives known correspondences between British serials and US Navy Bu. Nos. From this, it turns out that AX744:D was Bu. No. 3900 and AX736:X was Bu. No. 3903, both having no external air intake on the engine cowling. I do not assume strict ordering by Bu. No., but I think it is likely that higher Bu. Nos. were, roughly, later machines. In this regard, British serial assignments are more random. For instance, AX746:H was Bu. No. 3876 and it did have the external air intake at the top of the cowling. Could we think the external air intake was deleted somewhere before Bu. No. 3900?

 

As a whole, seemingly the three aspects were independent. The Martlet is a fascinating topic, isn't it?

Edited July 2, 2017 by ClaudioN

[Fernando]

Hi, everyone,

 

Both Martlet Mk.I and Mk.IV being a sort of Holy Grial of FAA models builders, I always check new developments. Allow me some amateurish observations.

 

From the seminal Bruce's article in clubhyper, I have just noticed that the picture of the Mk.IV shows the rear windscreen frame clearly aligned with the panel line in front of the ventral window, while that of the Mk.I (both dead flat right side views) falls roughly in the middle inbetween that panel and the immediate one rearwards. The windscreen itself doesn't seem shorter or having the flat panel at a different angle (gunsight is closer to it, but the coaming is shorter) At the same time, the back frame of the sliding hood aligns to the same fuselage panel (and also, roughly, the hinge line of the flaps in the wing). The effect is that the canopy looks farther back in relation to the wing.

 

 

 

To compensate this "apparent" shortness, I can only discern that the back window panel in the sliding hood is shorter than the forward one in the Mk.I, and apparently of equal size in the IV. The distance between windscreen and cowling is longer in the Mk.I, quite logically, but where is the shorter measure behind it, given that the overall lenghts should be the same? Images shamelessly taken from Bruce's article.

 

Are my eyes confusing me?

 

FErnando

Edited July 3, 2017 by Fernando

[Graham Boak]

Placing a straight edge (i.e. a piece of paper) on the panel line in front of the ventral window: this aligns with the start of the windscreen on the Mk.I, and the middle of the quarterlight (the side of the windscreen) on the Mk.IV, showing that the Mk.IV windscreen is further forward.  That's the first piece of evidence.

 

Looking through the quarterlight to the gunsight, you can see that the windscreen unit is further forward.  That's the second piece of evidence.

 

Looking at the panel line to the rear of the ventral window (not immediately adjacent but one on), this appears to be only slightly ahead of the rear of the canopy on both aircraft, and all panel lines behind this agree.  That's the third piece.

 

Looking at the frames on the sliding part, the rear window appears narrower on the Mk.I than the Mk.IV.  That's the fourth, if a bit "eyeballing" rather than ideal.

 

So I've no doubt, based on these photos, that the argument consistent with all four pieces of evidence is that the airframe structure is identical but the windscreen is mounted slightly further aft on the Mk.I and the sliding part of the canopy is shorter.  I'm not sure that is is exactly the same line of argument as expressed before, but excuse me for finding them somewhat unclear so feeling the need to look again and express it my way.

 

What the lower photo does show is the curved rise at the top of the windscreen. which is what I was describing in my previous post, casting doubt on the Airfix canopy.  Whether any of the other kits have better canopies is another matter.

[MDriskill]

This was discussed at some length here (though most of the illustrations are now dead thanks to our Photobucket friends!):

 

http://www.britmodeller.com/forums/index.php?/topic/234929183-martlet-mki/

 

The fuselage structure was identical aft of the firewall (by which I mean the major bulkhead just behind the landing gear) in ALL Wildcats, including the Martlets Mk I and Mk IV, but the Mk I's sliding canopy was significantly shorter, and its windscreen further aft. Some of the early F4F-3 prototypes were the same, though the production -3 (built after the Martlet I) and all other later variants had the longer canopy. I think if you look closely at the proportions of the sliding portion, you can see both panels are actually shorter on the early canopy.

 

Also look at Jumpei Temma's Wildcat builds linked above, and scroll to the final page. There is a brilliant fuselage profile diagram comparing the three Cyclone-engined Martlets, showing perfectly the canopy and cowl changes in these.  

 

[Graham Boak]

JT's plans do look good, but has he (or anyone else) published the actual as-measured (or from company production drawings) correct dimensions for the canopies and their frames?  I'm afraid that from these two photos I cannot see any difference in the proportions of the front segments of the sliding canopy.   It may simply be that these particular photos do not make it clear.  

[Greenshirt]

It appears to me that proportionally, the sliding panels and fixed quarter panels are similar for both I and IV, yet the dimensions are smaller for the I vs IV. And yes, it does appear the rounded upper portion of the fixed windscreen is a bit higher, but I freely admit that may be a perception, not dimensionally different if the height of the spines are identical. The Airfix kit spine is dimensionally lower than drawings by about a mm, very noticeable given it's about 10%+ of the total dimension there. 

 

Extant examples of both the I and later F4F/FM/Martlets exist, does anyone have access to them to measure?  Or we can accept J-T's drawings as accurate and then it becomes moot. 

[MDriskill]

1 hour ago, Graham Boak said:

JT's plans do look good, but has he (or anyone else) published the actual as-measured (or from company production drawings) correct dimensions for the canopies and their frames?  I'm afraid that from these two photos I cannot see any difference in the proportions of the front segments of the sliding canopy.   It may simply be that these particular photos do not make it clear.  

 

I don't mean to be contrary, but the difference in canopy proportions is very obvious to my eye.

 

On the Mk IV, each of the two lower side panels in the sliding portion of the canopy looks more or less "square," I.e., width and height about the same. On the Mk I, both panels seem taller than they are wide--slight difference in the front one, but quite noticeable in the rear one.

 

As for factory drawings, they may not exist. Many moons ago in pre-net days, I contacted the history departments at both Grumman and General Motors (Eastern Aircraft) in an effort to find F4F drawings better than the simple diagrams in the Pilot's Handbooks and Erection and Maintenance Manuals, but was told that all wartime documentation had been discarded. I'd love to be proven wrong on that, needless to say! We really need a friend with a tape measure at Yeovilton...

 

Apologies for once again savaging Mr. Archer's photos...Mk I

 

Mk IV

Edited July 3, 2017 by MDriskill

[Graham Boak]

Be as contrary as you like - or feel necessary.  There may be no drawings but as you imply there are physical examples of both canopies.

 

As regards the Airfix example, it may be that the top line of the windshield is correct and the flat windscreen simply comes too high, upsetting the appearance.  My personal opinion is that I'm sorry I bought it because it looks wrong, but I would like to pin down quite why and to me that canopy is one of the key points.  Yet it doesn't seem to worry even those who fault the kit for other reasons, which I find slightly odd.    I don't get that feeling with the AZ Mk.I, at least not yet.  Maybe I will if I look again at those frames.

Edited July 3, 2017 by Graham Boak

[Nick Millman]

1 hour ago, Graham Boak said:

JT's plans do look good, but has he (or anyone else) published the actual as-measured (or from company production drawings) correct dimensions for the canopies and their frames?  I'm afraid that from these two photos I cannot see any difference in the proportions of the front segments of the sliding canopy.   It may simply be that these particular photos do not make it clear.  

 

The cynic in me finds it a curious thing that when "Gaston Marty" does it with photos there are usually howls of derision but when JT does it with photos and a beautifully made model there is a chorus of oohs and aahs.  

 

Nick

 

[Graham Boak]

Re Gaston: I think this came from Hyperscale.  It has (or perhaps had) regular posters with a pack mentality, and they turn on those they see as outsiders.  Not a unique attitude but Hyperscale is a very influential site.  Give a dog a bad name, and others come to think it real; other website users (including those who may know nothing of any real background) jump on the bandwagon.  Not a nice side of our hobby, but there's no reason to expect hobbies to be immune from the nastier side of our species.

 

Is that cynical, or a glimpse into reality?  Dunno.  Lets get back to Martlets, please?

[Seahawk]

34 minutes ago, Graham Boak said:

As regards the Airfix example, ....  My personal opinion is that I'm sorry I bought it because it looks wrong, but I would like to pin down quite why and to me that canopy is one of the key points.  Yet it doesn't seem to worry even those who fault the kit for other reasons, which I find slightly odd.   

 

Amen, amen and amen.