Beyond The Sprues

Modelling => Ideas & Inspiration => Engineering Dept. => Topic started by: dy031101 on August 12, 2016, 02:12:39 PM

Title: Tank Turrets
Post by: dy031101 on August 12, 2016, 02:12:39 PM
On the turret of ARL-44, the Wikipedia entry made the following remark: "an obvious makeshift solution, somewhat crudely welded together, made necessary by the simple fact Schneider as yet couldn't produce complete cast turrets large enough to hold a 90 mm gun."

(http://i.imgur.com/6IGGZnN.jpg)

This reminds me of Germany's vaunted (justified or otherwise, I don't know) late-WWII tank designs; they weren't that into cast turrets, either.  Some of the designs even have armour plates interlocking where they are welded together "for strength".

(http://i.imgur.com/ucVBUT4.jpg)
(http://i.imgur.com/emNc56R.jpg)

Was it also because making whole cast turrets was either beyond WWII Germany's capability or just too much of a hassle for the Germans?

And in your opinion, which one implemented welded turrets better?  The French with their ARL-44, or the Germans with their late WWII designs?

Thanks in advance.
Title: Re: Tank Turrets
Post by: Old Wombat on August 12, 2016, 03:05:38 PM
The Germans, from memory, made excellent rolled, face-hardened steel which had a much harder surface than cast steel & they preferred welding to rivets flying around inside their tanks.
Title: Re: Tank Turrets
Post by: dy031101 on August 13, 2016, 03:04:55 AM
The Germans, from memory, made excellent rolled, face-hardened steel which had a much harder surface than cast steel & they preferred welding to rivets flying around inside their tanks.

Is the lack of access to such techniques the reason why the French resorted to casting the turret front instead of adopting a wholly-welded turret?
Title: Re: Tank Turrets
Post by: Old Wombat on August 13, 2016, 06:35:56 PM
Don't know, but probably.
Title: Re: Tank Turrets
Post by: Rickshaw on August 18, 2016, 04:48:22 PM
The Germans, from memory, made excellent rolled, face-hardened steel which had a much harder surface than cast steel & they preferred welding to rivets flying around inside their tanks.

Is the lack of access to such techniques the reason why the French resorted to casting the turret front instead of adopting a wholly-welded turret?

Not necessarily.  Many different nations adopted different methodologies to produce a tank turret.  The quickest way often was to cast the turret - the British, the Soviets and the Americans took that route often with their heavier tanks.  Casting offered advantages of speed and the ability to shape the turret.  One only has to think of the Churchill, the JS series and the US heavies from the M26 onwards.   Casting however required expertise in making cast armour - something the French lacked in 1944-45.   The French were experts in making tanks until they were defeated.   After that, they were forced to wait out the war, unable to design or build any heavy armour until liberated.

Another alternative war was a composite system - mixing cast components with the flat plate and welding it together.  The British were masters at this and the late model Churchills had cast wide walls and plate turret roofs.  The Americans used it to a lesser extent in their M4 Sherman.  It was often forced on a manufacturer out of expediency but usually worked rather well.

The Germans were seeking heavier armour and speed of manufacture.  Flat plate, welded together, often with interlocking plates became their trademark as the war progressed with the Panther and Tiger II being the most obvious methodology.  The British copied this method with their Centurion hull, with the upper and lower glacis interlocking at the nose and sides.  The Germans carried the concept over into their Sdkfz 250 and 251 APCs and their SWS half-tracks.  It worked, why not?

Title: Rangefinder
Post by: dy031101 on August 30, 2016, 12:22:36 AM
I've been on an inspiration-hunt for a future 3DS Max hobby project, with the overall idea drawing heavily from the KV-4 (see attachment).

But right now I have a hurdle- I've been under the impression that heavy tanks with emphasis on long-range anti-tank role (M103 and Conqueror...... I think the projected E-75 was to have one, too, and I don't know how the last iteration of AMX-50 planned to work it out) seem to commonly feature coincidence or stereoscopic rangefinders to make the most out of their guns.

Of the ones that I can find pictures for, these rangefinders seem to all require their operator (the tank commander) to sit in the middle of its optics emplacement- the M103 has its commander sitting along the centreline of the turret behind the main gun's recoil path, and Conqueror has the rangefinder mounted on the commander's cupola......

Right now I am planning to roughly follow the drawing in the attachment- two-man turret (except with a mortar à la AML-60 instead of the 45mm gun) for the commander.  I am not sure if I would like a Conqueror-style cupola on top of that subturret since I still don't want to needlessly add height even though that option does seem simplest......

Is there an alternative for me?  Or is it possible for me to put a rangefinder on the commander's subturret itself without having the commander located along its centreline?

Thanks in advance.
Title: Re: Tank Turrets
Post by: Old Wombat on August 30, 2016, 09:09:02 AM
The aimer/commander doesn't have to be in the centre, as long as the light-path from the external optics to the internal sighting unit are equidistant. So, if you have precision machining & construction techniques, which are robust enough for armoured vehicles in combat, then it shouldn't be an issue off-setting your aimer/commander to one side or the other.

It may not be the easiest thing to achieve but it is doable. :)
Title: Re: Tank Turrets
Post by: dy031101 on August 30, 2016, 09:55:28 PM
The aimer/commander doesn't have to be in the centre, as long as the light-path from the external optics to the internal sighting unit are equidistant. So, if you have precision machining & construction techniques, which are robust enough for armoured vehicles in combat, then it shouldn't be an issue off-setting your aimer/commander to one side or the other.

Is it like...... putting some periscope(s) between the eye piece and that internal sighting unit?
Title: Re: Tank Turrets
Post by: Old Wombat on August 30, 2016, 11:35:59 PM
Yep. :)
Title: Crusader Cruiser Tank Machinegun Turret
Post by: dy031101 on October 31, 2016, 12:33:27 PM
Does anyone know the vertical gun arc of the BESA machinegun turret on early marks of the Crusader cruiser tank?

Also, what's the cylindrical thing that's seemingly-co-axial to the MG itself?

Thanks in advance.
Title: Re: Crusader Cruiser Tank Machinegun Turret
Post by: apophenia on October 31, 2016, 03:04:10 PM
Also, what's the cylindrical thing that's seemingly-co-axial to the MG itself?

Telescopic gun sight.