Gas warning paper on Spitfires MK I

[ArmouredSprue]

Hi all

I'm building a spitfire to represent a bird from No.610 Squadron (County of Chester) and I've seen some images with spitfires displaying a yellow (I'm assuming) square losange on the upper left wing.
I was told these were paper used to detect gas in case of a gas attack, that were stick to the wing.

I would like to have more details on this, such as: size, colour, how often it was changed etc.
My Google search brought any results (probably not using the correct key words).
Any help would be highly appreciated!
Cheers
Paulo

 

[Airframes]

I've posted info re the size, colour and exact position in your model thread.
It was approximately 18 inches square, normally painted, but could be thick paper, taped into position with the predecessor of 'Gaffer' or 'Duct' tape, which was a fabric tape, normally coloured black. The position on the Spitfire was 6 feet six inches from the center line of the fuselage, at the rear of the center line of the wing chord. On the Hurricane, the position was similar, but 9 feet 6 inches from the fuselage center line.
Little information exists as to how often it was changed or replaced, if at all, and it wasn't always present on all aircraft of the period, and removed, or painted over, if the aircraft was returned to a MU for deep service and re-paint.
The colour was pale yellow, with a very slight green tinge, which changed colour in the presence of various poisonous gasses, the colour change hue depending on the type of gas.
By late summer 1940, with the threat of gas attack apparently diminished, these patches were seen less and less, eventually falling out of use, although, as stated in my previous reply, gas warning panels remained in use on military bases, and around Government and 'official' buildings in the UK throughout WW2, with the carrying of gas masks obligatory.

 

[stona]

The British used paper patches rather than reactive paints. They seem to have been taped into position (as Airframes said) but with what is a mystery. There is no specific evidence for the red border sometimes portrayed, though the tape may have been red of course .

Up to the second quarter of 1940 1.25 million "Type A Mk.1" detector papers were produced, with another 160 million "Type A Mk.2" produced up to the end of the third quarter of 1942.

They were stuck on everything including vehicles and on what are described as "lecterns" on just about every street corner.

Eye witness accounts describe them as a "funny" yellow or a greenish yellow, not unlike many proprietary model paints representing Zinc Chromate Yellow.

Cheers

Steve

 

[Airframes]

Thanks for the additional info Steve.
I've been looking for an old Civil Defence booklet, as this mentions the painted version, so presumably 'reactive' paint was also used - the circular version on the Lancaster pilot's head armour comes to mind. Many years ago, I used to have a 'tin' plate painted in the stuff, which measured approximately 6 or 8 inches square, from what I remember, and this had come from a post sited outside a war time shelter near where I lived at the time.
Where a red border to the panel is seen on aircraft, there's a very good chance that this will be the same red-doped fabric material used to seal gun ports, which could either be dope into position, or, as I've seen in some film footage, an adhesive tape variety could have been used.

 

[stona]

I've certainly seen pictures of US aircraft with areas of "reactive" paint on them.

I'm not sure about that dot on the Lancaster pilot's sliding head armour being an example. I've heard all sorts of explanations (which side was hardened, something to do with magnetic fields/compasses to name a couple) but never that it was for gas detection. The Mosquito armour was similarly marked and both continued to be so long after gas detection patches/paint were abandoned.

In November 1940 there was a short lived modification to the Spitfire (cancelled after nine days) "To paint yellow markings on magnetic armour plates." It was abandoned because the armour was found not to affect the compass. This lends some credence to the magnetic field/compass theory.

The external patches were to indicate the need to decontaminate the aircraft (if exposed) which apparently involved washing with water. This was to protect the ground personnel from contamination. Having the paint inside the aircraft seems illogical.

I suspect that this is one of those questions like "what colour were the wheel wells of my Spitfire?".......we may never know for sure

Cheers

Steve

 

[Airframes]

Yep, you're right Steve!
Lancaster squadrons which eventually formed part of 100 Group carried a disc of gas detection paint on the outside nose, beneath the turret. This, apparently, was actually paint, as I've been told in the past by former ground and air crew from one of the squadrons, and of course served the same purpose as those patches on other aircraft types
The same flight crew member also told me the disc on the head armour was for the detection of carbon monoxide inside the cabin, which could possibly leak from the heating system, driven off the engine exhaust, which fed into the cabin at the wireless op's position. This may or may not be the case, but I'll admit that the carbon monoxide detection 'badge' in light aircraft I've flown was more of a pink, rather than yellow colour, so the magnetic I.D. seems to make more sense.

 

[buffnut453]

Not entirely sure the "standard" position of gas detection panels was followed with 100% consistency (let's be honest, how many rules are?). Check out this old thread on Britmodeller - the first photo seems to show a gas detection panel on the starboard tailplane.

609 Sqn questions - WWII - Britmodeller.com

I've also seen pics with detection panels applied as a diamond on the fuselage behind the cockpit.

 

[Airframes]

All the patches I've seen in photos have more or less been in line with the "Approximately 18 inches square" directive, and applied and positioned in the appropriate place for the aircraft type - that is, starboard wing on fighters, rear fuselage deck for trainers, and rear fuselage for 'communications' types or multi-engine/multi crew position other types.
The pic of Mamedoff's 609 Sqn Spit, which I have in a number of books including Chris Goss's coverage of the Squadron in the late BoB, appears to show a BDR patch, and it is much smaller than the 'regulation' size, as well as appearing darker than the expected tonal reproduction, even allowing for variations in printing processes.
Just going off photo evidence alone, I've seen more BoB period aircraft without the patch than with, but, of course, this may be due to relatively high turn over of aircraft, damage, wear or loss of the patch (especially if not a painted variant), and lack of time, with more pressing requirements during the period, to maintain or replace them.
Generally, I would expect a fighter in the front line up to around early July 1940 to be more likely to have the patch, but after that, as the Battle progressed less likely.
If I could just find the booklet, and another reference source, I'm fairly certain there is brief mention of the patch, and it's lapse of use and eventual abandonment (along with other 'binned' regulations) and the reasons. It's this info, based on wartime accounts not necessarily related to this specific subject, on which I'm basing my replies on, along with a small dose of logic!

 

[vikingBerserker]

Very cool fellas, this is pretty interesting.

 

[buffnut453]

Hi Airframes,

'Fraid I don't buy the BDR patch. BDR patches were either small pieces of linen applied over the damage and then doped, as per the fabric muzzle covers on BoB-era RAF fighters, or they were metal sheet welded/riveted in place, often from the inside of the hole (the BBMF's Spit MkII has evidence of this latter type of repair). I've never seen a BDR patch that has tape around the perimeter with the centre undoped.

I'm not arguing that there wasn't a directive, simply that it wasn't universally applied. The plethora of contemporary photos showing Fighter Command Hurris and Spits without any gas detection patches (indeed, there are more of them than there are photos showing the gas patches), would seem to confirm this view. Then there's the application style - some are large, diamond-oriented patches while others are oriented squar to the wing and are smaller. One thing I won't do is nitpick your comment about patches being applied to the starboard wing when, typically, they were applied to the port wing...oops, guess I just did! Of course you'd never see me making a mistake like that....NOT!!

Bottom line - the modeller can pretty much do what he/she likes 'cos there's seldom evidence to prove one way or the other (at least in this instance)

 

[ArmouredSprue]

Thanks guys!
Very interesting information.
So for what I've understood if I do decide to apply to my 610 sq. plane mid July '40 Spitfire is ok!
I'll probably paint a decal with zinc chromate lightened a bit with yellow, what do you think?
Cheers
Paulo

 

[stona]

I don't know how commonly they were or were not applied, but there must have been an order to apply them.

I agree that there are many images from the relevant period (September '39 to mid '40) in which the patches are not visible but then how many show the upper surface of the wing?

The two sizes may be the MkI and Mk II

Everyone was expecting gas to be used, hence the issue of tens of millions of respirators, but it became evident fairly soon that this was unlikely. The RAF might have been less than rigorous about applying gas patches but my mum never went anywhere without her gas mask

Cheers

Steve

 

[Airframes]

Oops! You're right Buff - that was a typo, should have read 'Port' wing, as in my other posts.
I agree about the style of BDR patches, and have, in fact shown the three on the BBMF Spit to a number of visitors in the past. However, that patch on the 609 Sqn Spit just doesn't appear to have the 'right' tones for the colour reproduced if it is a gas patch.
If it is a patch, then it's logical to reduce the size, and the location, to avoid the relatively small compromise of the camouflage, and as Steve and I have both mentioned, as the threat of gas was seen not to materialise, the use of patches seems to have lapsed, with the possible exception of the use being continued for some time at training establishments, as evidenced by photos from later periods.