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B-17E remote-sighted lower turrets

Posted: Fri Feb 29, 2008 11:43 am
by SHAEF1944
First off, THANKS Bill/DryMartini for the info on the changes between block numbers in an earlier post of mine. For some reason when I tried to add a reply on that thread to say thanks, it wouldn't post ?

I'm currently looking for any info on the Bendix remote-sighted lower gun turret used on the 1st 112 B-17E's built. Model number, detail pics, specs .. anything. Especially trying to pin the model # down. Lots of places mention it as being used on the early B-25's, B-24's, and the B-17, but no details I can find. Any help would be greatly appreciated.

Turret info

Posted: Fri Feb 29, 2008 2:31 pm
by DryMartini
SHAEF,

No problem. Hope the info was helpful. I'll
see what I can get on the Bendix lower turret,
and post here for you.

So far

Posted: Fri Feb 29, 2008 3:50 pm
by DryMartini

All I have so far is:

Sperry Drawing - 645705D
Inst. & Outline, Lower Remote Control Turret

I'll keep looking.


From the B-17E E&M Manual

Posted: Fri Feb 29, 2008 7:24 pm
by DryMartini


From the B-17E Erection and Maintenance Manual
01-20EE-2

(4) BOTTOM TURRET - The bottom turret is installed
in the rear fuselage section just aft of the radio
compartment. Two installations are provided as follows:

(a) On airplanes, AC serial numbers 41-2393 to 41-2504
inclusive, the Sperry number 645705-D remote sighted
twin .50-caliber bottom turret is installed. The sighting station
for this turret is installed directly to the rear, and is operated
from the prone position with the gunner heading aft. Ammunition
boxes for 500 rounds per gun are attached to the turret.
Provision has been made on these airplanes for interchangeability
with the spherical turret.

I can fine no reference to a simple designation, except a B-25
manual which calls the turret a "Model K".


Posted: Fri Feb 29, 2008 8:40 pm
by SHAEF1944
Now I'm cornfuzzled even more. Sperry drawing numbers, but everything I've ever seen describes it as a Bendix turret. I just downloaded the AFHRA Historical Study " Development of gun turrets in the AAF ", and it says that 'because demand was greater than production capacity at the time, seperate turrets for different planes were not used, and the Bendix turret originally developed for the B-25 was considered for use in the B-17 and B-24.'

Could it be a Sperry design that was sub-contracted to Bendix for manufacture ? From reading the above study, I was under the impression that it was a wholly Bendix affair, tho. Any ideas on this? Thanks again, Bill ... your knowledge and "hunting" ability is greatly appreciated.

Posted: Fri Feb 29, 2008 9:47 pm
by DIK SHEPHERD
From some drawings that I've seen the remote controlled belly turret was (basically) the same as the upper turret, only it was turned upside down for installation. And, instead of clear segmented plexiglas panels it had metal plates.

My take

Posted: Sat Mar 01, 2008 8:17 am
by DryMartini


Well, it would make sense that if the remote turret could be
exchanged for a ball, that they were both Sperry designs.

If that is true, which I do not doubt, I would say that Bendix
was probably contracted to manufacture the turret. I know
that Emerson built ball turrets, as well as parts to others.
As a matter of fact, the Operation and Service manual for
the A-2A/A-2C ball turret state that Emerson Electric built them.

BTW - if it helps, the Sperry Ball turret had a part number
of 645849J

I also agree with Dik, that the remote is very similar to
the upper in size and shape.


B-17 remote lower turret

Posted: Wed Mar 19, 2008 1:45 pm
by Guest
The early B-17E used a Sperry remote turret, non retractable, with a sighting station in a seperate blister. The early B-24D and B-25B thru
B-25G models used the Bendix retractable turret with an integral sighting system. All were removed from the B-24s and most from the B-25s. The Bendix and Sperry were not related. The Bendix reappeared as a chin turret on the YB-40, late B-17Fs and B-17Gs