PDU Blenheims 1939/40

[ben_m]

Well spotted Graham- I thought at first it could be the smooth paint having hight reflectivity, and the snow on the ground, but the fuselage one is the same. I've not seen it before on other PDU aircraft. Compared to a contemporary Sky Spitfire, the roundels definitely look lighter on the Blenheim:

Even though the documentation of these schemes shows the roundels the same colours:

Re: operational use, as Andy said back in post #3, I don't think there is evidence for this (e.g. in ORBs, pilots log books), but the PDU was far from conventional, and the detachment in France was probably even less likely to record everything. If they brought back usable photos, then there might be notes on the prints in an archive somewhere. It would be interesting if the two PDU Blenheims increased the focal length of the lenses over those in use by other RAF Blenheim photographic Units (5" or 8" were used from about 7,000-12,000 ft, IIRC). As they had sorted the icing issues, maybe the Blenheim wouldn't have been quite so vulnerable at 20,000 ft or so?

[mhaselden]

I'm not convinced they're toned-down roundels. They might be but it's tough to tell given the angles and snow cover which causes unusual lighting conditions. I'd have expected PR Spits to also wear "low-viz" markings if such markings were employed by PDU.

Incidentally, ben_m, your photos aren't showing up in my browser. Are the linkies correct?

Cheers,
Mark

[ben_m]

Incidentally, ben_m, your photos aren't showing up in my browser. Are the linkies correct?

Cheers,

Mark

The links are to my own domain- the host is not super-fast, but there are no hot-linking rules or anything. Try re-loading the page?

[Test Graham]

I suspect the Blenheim might have been a bit slow at 20000ft.

I'm unsure about the fuselage roundel, as that's in sunlight on snow. However the underwing roundel is out of the direct sunlight.

[gingerbob]

Re: operational use, as Andy said back in post #3, I don't think there is evidence for this (e.g. in ORBs, pilots log books), but the PDU was far from conventional, and the detachment in France was probably even less likely to record everything. If they brought back usable photos, then there might be notes on the prints in an archive somewhere. It would be interesting if the two PDU Blenheims increased the focal length of the lenses over those in use by other RAF Blenheim photographic Units (5" or 8" were used from about 7,000-12,000 ft, IIRC). As they had sorted the icing issues, maybe the Blenheim wouldn't have been quite so vulnerable at 20,000 ft or so?

Ben, thanks for reminding me- that tipped-up Spit has roundels under the wings, too! Same style as the others, and not toned down. I agree that the one Blenheim photo may just be a trick of snow-glare, exposure, or what have you. (Note that the Hurricane's in the background seems to have a similar appearance.)

Re records, I actually was surprised by how many meticulous records of early PDU/PRU activity I found. There may be a gap in the detachment, I don't remember without doing a bit of digging. But I doubt something like Blenheim operational use would have just been "forgotten about".

I'll get the rest of the "type consideration" to you later- give me a nudge if you haven't heard from me in a day or so!

bob

Edited March 20, 2014 by gingerbob

[occa]

Isn't it pointing to something that they depicted this in a sort of a sky blue (maybe with a slight green tint) instead of the actual sky color we know?

Could it not be the early camotint Sky (the infamous duck egg blue?) was different from the later yellow green color that was widespread?

That they initially labelled it a duck-egg blue cannot be a coincidence

Edited March 21, 2014 by occa

[Dave Fleming]

I suspect the lighter appearance of the roundels is due to the snow covered ground acting as a reflector and the film stock used - the roundel appearance is not unlike other 'bright' blue ones appeared in the 30s.

[ben_m]

I agree that the one Blenheim photo may just be a trick of snow-glare, exposure, or what have you. (Note that the Hurricane's in the background seems to have a similar appearance.)

Now that I take a look at the Hurricane roundel- it looks exactly like the Blenheim's.

Thread deviation: Am I right in thinking those Hurricanes are in silver dope undersides, apart from the night port wing? That's my guess as the roundel white appears lighter than the background, but I might be wrong as it is so small! How does that fit with the known history of underside colours?

[brewerjerry]

Hi

there are more photos on the IWM site in the same ' collection'

i.e.

http://www.iwm.org.uk/collections/item/object/205259692

worth a browse

cheers

jerry

[gingerbob]

Nevermind, I think I answered my own question... at least for the time being!

Edited March 21, 2014 by gingerbob

[AWFK10]

I discovered L1348 by chance, and have for quite a while been pondering its story. Some sources suggest that it was the Cottonised Blenheim. However, some things didn't add up- Cotton's detailed explanation of the fitting of spinners, and the absence of teardrop windows (Cotton would not have left them off). The most respected source of this theory is Graham Warner's 'The Bristol Blenheim- the Complete Story':

If anyone has the book, and can fill in the blank, I'd appreciate it.

A bit late to answer the question now, but for the benefit of others who have just come across this thread, the missing words from the quotation in #12 are:

".......Titanine finish, fairing the flat lower-nose glazing panels......."

[Edgar]

Isn't it pointing to something that they depicted this in a sort of a sky blue (maybe with a slight green tint) instead of the actual sky color we know?

No, it means that the reproduction above is not completely accurate; the original, available to view in the National Archives, is green.

Could it not be the early camotint Sky (the infamous duck egg blue?) was different from the later yellow green color that was widespread? That they initially labelled it a duck-egg blue cannot be a coincidence.

Not according to this letter from the Air Ministry (and this is not the first time I've shown this):-

Also, in their first descriptive signal of 7-6-40, the Air Ministry said that Sky type "S", " may be described as a Duck Egg Bluish Green."

Edgar

[gingerbob]

And I also saw one document concerning paint supplies that specifically said "Dark Earth (Type S)" and... uhh, green (sorry, not looking at it right now!) "(Type S)", too.

bob

[occa]

...; the original, available to view in the National Archives, is green.

Is there a photo / scan of the original anywhere to view online?

Also, in their first descriptive signal of 7-6-40, the Air Ministry said that Sky type "S", " may be described as a Duck Egg Bluish Green."

Edgar

How was the original camotint of the PDU from 1939 described?

Wasn't that the infamous 'duck-egg blue'?

Edited March 21, 2014 by occa

[Edgar]

Is there a photo / scan of the original anywhere to view online?

Doubtful, but any image will only be as good as the screen settings, anyway.

How was the original camotint of the PDU from 1939 described?

Wasn't that the infamous 'duck-egg blue'?

It was called Camotint (note the capital letter, signifying its title, not a description,) since it was invented, and registered, by Sidney Cotton.

Sky type "S" (note the capitals, signifying its title) had "duck-egg blue" (normally in small case, signifying a description, not a title) added to it; Camotint has never, to my knowledge, had any other words added.

Edgar

[occa]

OK thanks Edgar for elaborating.

I just put the PDU drawings aside to a color chip of MAP sky and the difference is minimal anyways with the color on the drawings being only very slightly bluer (on my screen at least).

Seeing the drawings alone had me tricked into believing the color there was much bluer ...

Edited March 21, 2014 by occa

[Blimpyboy]

On ‎2‎/‎10‎/‎2014 at 2:22 AM, ben_m said:

After many years of hoping one existed, I have located a photo of an all-over Sky Blenheim! And it was at the IWM- I'm not sure how long ago it was scanned, but today is the first time I have seen it.

The caption states it is P4899.

From IWM, used under Fair Use for the purposes of discussion and education.

I believe this modification was the +18 mph version, as described in Cotton's description of the mods, i.e. without retractable dump valves under fuel tank, without doors for tailwheel retract, and without new main gear doors.

Really good timing for this to turn up this year, with the Airfix kit on the horizon.

Is there a yellow surround to the fuselage roundel? I can't help but wonder if I don't see some kind of surround to the fuselage roundel when I look at a blown up version of this picture. In the same vein, what kind of roundels are likely to be on the wings' upper surfaces?

[Graham Boak]

Good to reread this thread.  The presence or not of a yellow ring around the roundels would date the photo to before or after May 1st 1940 - with maybe a day or so's delay in application?

 

On the "faded or not" underwing roundels: it would be very odd indeed to have a glare effect that lightened the underside roundels yet darkened the underside paint.

[Dave Fleming]

On 9/2/2018 at 9:50 AM, Graham Boak said:

Good to reread this thread.  The presence or not of a yellow ring around the roundels would date the photo to before or after May 1st 1940 - with maybe a day or so's delay in application?

 

On the "faded or not" underwing roundels: it would be very odd indeed to have a glare effect that lightened the underside roundels yet darkened the underside paint.

 

The underside roundels are exactly the same shade of grey as the fuselage ones in the image (Bit of cut and paste proves this). My suspicion is still that it's a film effect.

[Blimpyboy]

I am in two minds about the yellow fuselage ring. I'm not sure I see one because it's there, or because I think it might be there...

 

As to the faded roundel effect, I too am leaning toward it being a phenomena of the light and film. Certainly, the Spitfire doesn't seem to have used toned-down roundels.

[Blimpyboy]

To revive this thread...

 

 I have just acquired Almark decal sheet A36 (PR Markings Europe) which has markings for a Blenheim Mk.IV from April 1941.

The Blenheim is listed as being overall PRU blue 🤔 with a yellow surround to the fuselage roundel and no underwing roundels. The unit codes ‘LY’ are on the fuselage, aft of the roundel.

 

My main question is: has there been any other research that confirms or disproves the accuracy of these markings?

 

https://www.scalemates.com/kits/almark-decals-a36-pr-markings-europe--965349#
 

Thanks in advance,

BB

 

Edited June 19, 2020 by Blimpyboy

[Tweener]

On 2/9/2014 at 10:22 AM, ben_m said:

After many years of hoping one existed, I have located a photo of an all-over Sky Blenheim! And it was at the IWM- I'm not sure how long ago it was scanned, but today is the first time I have seen it.

From IWM, used under Fair Use for the purposes of discussion and education.

I believe this modification was the +18 mph version, as described in Cotton's description of the mods, i.e. without retractable dump valves under fuel tank, without doors for tailwheel retract, and without new main gear doors.

Really good timing for this to turn up this year, with the Airfix kit on the horizon.

Does the photo not show the fuel dumps under the wings still? And what do you mean by tailwheel doors? My understanding is that only the first few Mark 1s had retracting tailwheels.

Any clarification is much appreciated as I plan to make something of an attempt at building this airframe soon.

Thanks,
Tweener

[ben_m]

On 11/30/2022 at 3:30 AM, Tweener said:

Does the photo not show the fuel dumps under the wings still?

And what do you mean by tailwheel doors? My understanding is that only the first few Mark 1s had retracting tailwheels.

 

Yes, the photo shows the fuel dumps are normal, and no tailwheel doors, so the modifications that Cotton claimed on a further modded aircraft were not carried out on this one. Off the top of my head, he claims (in Aviator Extraordinary, and maybe also reported in Evidence in Camera) +30 mph top speed in the most modified version- which was said to have retractable tailwheel, modified main gear doors, and retractable fuel dumps. This version with just paint and filler, etc. was said to be 18 mph faster. But I'm very sceptical of what Cotton said, so the photo evidence is the main guide for me.