Beyond The Sprues

Modelling => Ideas & Inspiration => Engineering Dept. => Topic started by: jcf on May 09, 2014, 04:44:44 AM

Title: Aircraft turrets and flexible mounts ...
Post by: jcf on May 09, 2014, 04:44:44 AM
A thread for the stated subject: real, projected and imaginary.

To start the turret for the Westland-Hill Pterodactyl V (front engine/rear turret)
and VI (rear engine/front turret) escort fighters. The V was built but the turret
was never installed. The VI remained a project.

Prof. Hill was heavily involved with the turret design and it featured twin Lewis guns
mounted on their sides and an interconnected sighting/firing system. An extensive
description of the turret can be found on pages 440-443 of H.F. King's Armament
of British Aircraft 1909-1939
. The attached drawing is from that book, the photo
of the turret mock-up is from Westland Aircraft since 1915.

(http://i729.photobucket.com/albums/ww291/joncarrfarrelly/BTS/PTER_V_TURRET_01.png)

(http://i729.photobucket.com/albums/ww291/joncarrfarrelly/BTS/PTER_V_TURRET_02.png)
Title: Re: Aircraft turrets and flexible mounts ...
Post by: Old Wombat on May 09, 2014, 11:58:32 AM
I would NOT want to be a gunner in that cramped thing trying to change those magazines with a Me. Bf109 coming in for the kill! :o

(Give me a belt-feed any day!)
Title: Re: Aircraft turrets and flexible mounts ...
Post by: Rickshaw on May 09, 2014, 04:52:58 PM
Actually, it doesn't look too bad.  The gunner appears to have back and side armour, while JCF, I suspect the guns are mounted on their sides more to ease access for magazine change.   Weren't the Pterodactyls an early 1930s design which would have more than likely been out of service by 1939, replaced by more modern, faster designs?   Against the likes of the He51, it wouldn't have been too bad IMO.   Escaping might have been a bit fraught though.
Title: Re: Aircraft turrets and flexible mounts ...
Post by: Old Wombat on May 09, 2014, 05:26:21 PM
Looks like there is some back armour but the only metal I can see on the sides is the chutes for the Lewis magazines & the gun mounts.
Title: Re: Aircraft turrets and flexible mounts ...
Post by: jcf on May 10, 2014, 12:15:40 AM
Yes Brian, I know that, the captions are from the books, I did not add them.

As stated the King book has a detailed description, from Westland's documents, of
the turret design and operation which I have not yet scanned, OCR-ed and posted.


Title: Re: Aircraft turrets and flexible mounts ...
Post by: GTX_Admin on May 10, 2014, 01:56:49 AM
I would be interested to see how well that book compares to these ones which I have:

(http://ecx.images-amazon.com/images/I/618cmOuoc9L._SL500_SY300_.jpg)
(http://ecx.images-amazon.com/images/I/51qy8Q7lpKL._SX258_BO1,204,203,200_.jpg)
Title: Re: Aircraft turrets and flexible mounts ...
Post by: GTX_Admin on May 10, 2014, 02:04:57 AM
Speaking of turrets, I wish it was possible to get a kit or conversion that allowed one to model some of the German WWII tail turrets such as these:

(http://i37.photobucket.com/albums/e68/GTwiner/V-22/turr7.jpg)
(http://i37.photobucket.com/albums/e68/GTwiner/V-22/turr1.jpg)
(http://i37.photobucket.com/albums/e68/GTwiner/V-22/turr5.jpg)
(http://i37.photobucket.com/albums/e68/GTwiner/V-22/turr6.jpg)
(http://i37.photobucket.com/albums/e68/GTwiner/V-22/turr2.jpg)
(http://i37.photobucket.com/albums/e68/GTwiner/V-22/turr3.jpg)
(http://i37.photobucket.com/albums/e68/GTwiner/V-22/turr4.jpg)
Title: Re: Aircraft turrets and flexible mounts ...
Post by: jcf on May 10, 2014, 04:33:58 AM
I would be interested to see how well that book compares to these ones which I have:

([url]http://ecx.images-amazon.com/images/I/618cmOuoc9L._SL500_SY300_.jpg[/url])
([url]http://ecx.images-amazon.com/images/I/51qy8Q7lpKL._SX258_BO1,204,203,200_.jpg[/url])


A very different animal, arranged alphabetically by aircraft manufacturer and then chronologically
by type in each manufacturer chapter and is not limited to gun armament and related equipment;
bombs, bomb-carriers, bomb-loading and circuit diagrams, torpedoes and mounts etc. are also included.
The book was published in 1971, and stylistically is very much in line with King's other Putnam volumes,
the writing style is 'old school journalist' chatty, King worked for Flight for years and had personal
'ride along' experience with various inter-war types, including firing the guns, so many personal observations
and anecdotes are included. Kinda stuffy but jolly at the same time, if that makes sense.
Much less Col. Blimp than some other Putnam authors of the period.  ;)

It was supposed to be the first of a pair of volumes, Vol.1 listing the aircraft types and how they
were equipped, Vol. 2 detailing the equipment. Unfortunately Vol.2 never appeared, so a few bits
of tech info that were included in Vol.1 as teasers with the promise of the full story to come remain
as tantalizing hints.

That said the book is really quite good and includes drawings and photos of prototype/one-off
mounts/installations that I've not seen anywhere else. I will be scanning and posting more of
these, along with other 'standard' stuff that is of interest.
Title: Re: Aircraft turrets and flexible mounts ...
Post by: GTX_Admin on May 10, 2014, 05:50:01 AM
Some Russian turrets:

(http://imageshack.us/a/img94/5361/iali.jpg)
(http://i53.photobucket.com/albums/g64/PoorOldSpike/Photos%20Two/Russ-airgunner.jpg)
(http://i53.photobucket.com/albums/g64/PoorOldSpike/Photos%20Three/Pe-8-rear-gunner.jpg)
Title: Re: Aircraft turrets and flexible mounts ...
Post by: Weaver on May 11, 2014, 07:45:40 AM
Italian Caproni Lanciani Delta turret as seen on the Cant Z.1007 and a number of other Italian types:

(http://i38.tinypic.com/dd1d0m.jpg)

(http://www.alieuomini.it/files/anteprima/medium/caproni_ca_311_torretta_caproni_lanciani_delta,2736.jpg)

(http://imageshack.us/a/img819/4926/b2xe.jpg)

The turret was manually operated, and the problem with all such types was that when it was traversed to the side, the wind pressure on the gun barrel made aiming difficult because it tried to blow the turret round to face aft. This turret got around that by having a counter-balance tube which stuck out of the back of the turret and elevated with the gun (a Breda-SAFAT 12.7mm). It thus presented exactly the same profile to the slipstream as the gun barrel, but being 180 deg opposite to it, the wind pressure was in the opposite direction, thus cancelling it out.
Title: Re: Aircraft turrets and flexible mounts ...
Post by: Weaver on May 11, 2014, 07:47:56 AM
And while I was looking for that,  found this:

(http://sobchak.files.wordpress.com/2013/03/torrette108.jpg)

That's a diagram of the remote controlled turrets installed in the outer engine nacelles of the Piaggio P.108 heavy bomber. Apparently it was techincally clever, but not so good in practice, since it was unreliable, the turrets couldn't be accessed in flight to fix problems, and they only held 300 rounds per gun. You can see how they sit in the airframe here:

(http://img51.imageshack.us/img51/360/piaggiop108b.jpg)
Title: Re: Aircraft turrets and flexible mounts ...
Post by: GTX_Admin on May 11, 2014, 07:52:55 AM
The Italian turrets were truly an elegant design.
Title: Re: Aircraft turrets and flexible mounts ...
Post by: elmayerle on May 11, 2014, 08:05:04 AM
It could be interesting crossing those Italian remote-control turrets with the engine nacelle gunners' positions on the TB-7/Pe-8.
Title: Re: Aircraft turrets and flexible mounts ...
Post by: GTX_Admin on May 11, 2014, 08:43:35 AM
An interesting page on this topic:  http://users.telenet.be/Emmanuel.Gustin/fgun/fgun-de.html (http://users.telenet.be/Emmanuel.Gustin/fgun/fgun-de.html)
Title: Re: Aircraft turrets and flexible mounts ...
Post by: Silver Fox on May 11, 2014, 11:03:08 AM
How about a B-29 Escort Bomber using the same type of placement, but using the US remote turrets? Could make life interesting for any fighter that tried a stern attack to find itself facing the tail guns and both wing turrets shooting past the tail.
Title: Re: Aircraft turrets and flexible mounts ...
Post by: GTX_Admin on May 11, 2014, 01:02:04 PM
I have long liked the appearance of these style:

(http://www.lonesentry.com/blog/wp-content/uploads/2010/11/erco-tear-drop-gun-turret-erco-250th.jpg)
(http://www.lonesentry.com/blog/wp-content/uploads/2010/11/erco-teardrop-gun-turrets-navy.jpg)

It might be interesting to try to model a B-17 with these.
Title: Re: Aircraft turrets and flexible mounts ...
Post by: GTX_Admin on May 11, 2014, 01:09:11 PM
Of course, the original XB-17 did have something akin to that above (if only in external general appearance):

(http://static.thisdayinaviation.com/wp-content/uploads/tdia//2012/07/Boeing-299-NX13372-left-side-profile.jpg)
(http://i37.photobucket.com/albums/e68/GTwiner/imagejpg1_zpsbe61d436.jpg)(http://www.aviationspectator.com/files/images/Boeing-B-17-Flying-Fortress-063.preview.jpg)
Title: Re: Aircraft turrets and flexible mounts ...
Post by: GTX_Admin on May 11, 2014, 01:26:32 PM
Something else you might find interesting:

(http://www.lancaster-archive.com/lanc-turret-mu.jpg)
(http://www.lancaster-archive.com/lanc-turret-mu1.jpg)

The operating levers (aka Tabo arms) tracked along the top of the Cam Ring. As the arm rose a gun interrupter mechanism engaged and prevented the guns from firing. Which in turn stopped the gunner from shooting off the tail, Rudder or into the fuselage.
Title: Re: Aircraft turrets and flexible mounts ...
Post by: Buzzbomb on May 11, 2014, 03:50:48 PM
I would be interested to see how well that book compares to these ones which I have:

([url]http://ecx.images-amazon.com/images/I/618cmOuoc9L._SL500_SY300_.jpg[/url])
([url]http://ecx.images-amazon.com/images/I/51qy8Q7lpKL._SX258_BO1,204,203,200_.jpg[/url])


The Holy Book of Armaments !!

Chapter One, verses nine through twenty-seven ?
Title: Re: Aircraft turrets and flexible mounts ...
Post by: GTX_Admin on May 11, 2014, 05:39:18 PM
Indeed...

Monty Python-Holy Hand Grenade (http://www.youtube.com/watch?v=xOrgLj9lOwk#)
Title: Re: Aircraft turrets and flexible mounts ...
Post by: Rickshaw on May 11, 2014, 06:13:34 PM
Always seemed to me that the Germans never quite got the hang of aircraft turrets.  They usually added them as an afterthought, rather than designing the airframe and the turret at the same time, with the result their turrets were tiny, cramped and overly complex.  Seems to me that only the British and the Americans got the concept right.