HK B-17 G Sperry turrets

[thierry laurent]

Hi,

 

I have one question for B-17 experts:

 

Does anyone knows when the top and belly Sperry turret types changed?

 

Initially, the ball turret had internal ammo boxes whereas the late ones had external boxes. Mary Alice, a type 95 restored in Duxford has the initial type whereas the Collins Fundation Nine o Nine earlier G has the later type! However, as planes were restored, I think this probably does not correspond to the wartime configuration.

 

With regard to the top turret, the situation is even more confusing. Some had a mechanism with vertical bars linking the turret to the cockpit floor. It seems Shoo, Shoo, Shoo baby, a block 35 still has that one. On the other hand, Mary Alice has a quite different one with sloped bars. This is the one scratchbuilt by David Parker in his mid-G kit of Little Miss Mischief.

 

Last, it seems that this type that seems to depict a later mechanism has been added in the new E/F kit whereas the one with the vertical bars (shown in the Aero Detail book) was in the late G kit. So, which turret turret type should we put on each kit...? Saying I am puzzled is an understatement...!

 

Thierry

[ssculptor]

There was always pressure on each squadron to get as many aircraft in the air as possible for each mission. Thus it is possible that in cannibalizing parts from a/c in the graveyard some parts from other manufacturing batches were adapted to fit so the plane would make the next bombing run. 

Thus one may find strange combinations of parts. You can find data on these field changes only if records were kept. Even if they were where would you find them? Unfortunately it is 70 years since the war ended and most of the guys who made the changes are no longer alive..

There are also instances where the factory was under pressure to get the planes out and over to the fighting fronts. Thus some a/c could be completed with parts from earlier batches or even from the next batch. Here maybe you can find the manufacturing records from the archives of Boeing and other companies that built the planes under contract. 

If I were building a Fine Scale model of a B-17 I would go by the restored aircraft.  How would you know if the change was made 70+ years ago in the field or more recently in the restoration?  

Stephen

[thierry laurent]

Thanks Stephen,

 

I know there were many exceptions and the First In Last Out principle sometimes invalidated the "normal" batch rules. Moreover, B-17 were often rebuilt out of many wrecks. So, there were surely many valid options.

 

However, the fact there were exceptions does not mean there were no rules, even theoretical ones. This is what I am looking for. It is quite possible somebody knows which type theoretically applied to which factory or production batch.

 

Last, with regard to B-17 warbirds, nearly all of them lost their turrets after the war. So, when planes were refurbished decades later, I guess restorers did their best to find original parts without taking too much care about the fact this or that batch was the most accurate. This is a common restoration problem.

 

Thierry

[Iain]

I started going down the route of trying to work out exactly how 'Bit O'Lace' was configured/painted - but there are so many variations - from factory/batch/field modifications/battle damage repair and replacement that I came to the conclusion that I'd never get anywhere (and probably go mad trying) and have gone for best guess on mine (for things that are easily visible).

 

Suspect that unless you can find images of a specific airframe, on a particular day...

 

Sorry - not much help I'm afraid.

 

Iain

[thierry laurent]

Thanks Iain,

 

And in the case I mentioned, finding such internal wartime pictures of a specific plane is simply impossible...!

 

It is the fact that HK seeminly inverted the top turret mechanisms between the early and late B-17 that puzzled me. I have yet to understand why the one included now in the E/F is the type scratchbuilt by David Parker in his mid-G because as far as I understood this type is a late one.

 

Is my analysis wrong? Do I miss something? I have a 30cm pile high of B-17 books and for a frustrating reason, I have tons of information about the other gun stations but not a lot about the Sperry turrets, and more particularly regarding the top one.

 

Thierry

[thierry laurent]

This may interest you to detail the most visible part:

 

http://www.twinbeech.com/sperryturretforsale.htm

 

T.

[ssculptor]

This may interest you to detail the most visible part:

 

http://www.twinbeech.com/sperryturretforsale.htm

 

T.

Wow! That is just what I need to spruce up a 1957 Imperial limousine. With the giant fins on the rear fenders this turret will fit right in. Then I could safely drive through any inner city neighborhood I desire. Talk about a drive by shooting.

[thierry laurent]

Found on a French site (information given by a B-17 mechanic):

 

B-17E & F: Sperry A1-A

http://heroicrelics.org/wpafb/b-17-top-turret/index.html

B-17F & G: Sperry A1-B

http://www.twinbeech.com/sperryturretforsale.htm (restored but without the support bars I mentioned in my original post)

B-17G: Sperry A1-C (last version)

http://i150.photobucket.com/albums/s97/MGUNSCH/photos/sentimentaljourneytopturret.jpg

 

The question now is which one in each kit is which full scale one...

[Juggernut]

From all the information I have, there were no B-17 ball turrets equipped with external ammo cans during WWII.  The link below is what I did a couple weeks ago on the ball  turret.  I can get serial number breaks later on this evening.  I'm still researching the upper local turret A-1 and A-1A.  I can tell you what is supposed to be in the B-17G and if there is more than one, I can probably provide serial number breaks.

 

http://forum.largescaleplanes.com/index.php?showtopic=64751&hl=

Edited October 10, 2016 by Juggernut

[thierry laurent]

Wonderful!

 

I had a look at the other thread and I am happy to know that this will ease the job. Indeed, scratchbuilding the box ammo feed chutes would not have been a one hour job... Thanks as well for looking after the relevant information for the upper turret.

 

Thierry

[D.B. Andrus]

Thanks, Thierry and Juggernut for posting.

 

Cheers,

 

D.B.

[Juggernut]

From the factory, the following turrets were equipped on B-17G's as follows:

 

Upper Local Turret A-1A (SP2475) -  B-17G 42-31032 thru 43-38589

Upper Local Turret A-1B (SP4720) - B-17G 43-38590 and subsequent

 

Lower Turret Assembly A-2 (645849J) - B-17G 42-31021 thru 42-31554

Lower Turret Assembly A-2A (30126) - B-17G 42-3155 and subsequent

 

The Upper Local Turret is an enigma and I cannot find a Turret manual to read to help me understand the nuances between the types.  Most of what I can see in the factory drawings contain two vertical members attached to the underside of the turret ring while a bearing and post secure it to the floor of the pilot's compartment.  Beyond that is anyone's guess for now.  The work continues....

 

Hope this helps....

Edited October 10, 2016 by Juggernut

[thierry laurent]

At least a little bit as I know now that the A-1A was the most common one on the G. I am not surprised you had such difficulties identifying which type is which as this was the main problem I had! To complicate things further such types had sub-variants as they were progressively improved... Hopefully, additional information will finally emerge.

[thierry laurent]

Hi guys,

 

I am puzzled seeing this thread moved as it is clearly related to these initial questions from me: which top turret type should be in which HK kit and how should be corrected the ammo boxes for the ball turret?

 

Do I misunderstand something here or did you moved this a little bit too quickly?

 

Thanks

 

T.

[D.B. Andrus]

As an aside:

 

Poor quality shot of a Sperry Ball Turret w/ external ammo cans. (B-32 Dominator)

 

 

 

(Source:  Dominator, The Story of the B-32 Bomber, by Stephen Harding & James L. Long; Pictorial Histories Publishing Co.,1984/1986; ISBN 0-933126-38-7)

 

Cheers,

 

D.B.