Wreck of the Railway Gun K12N

[PCB5656]

Attached (if I did it right) is a photo of the bombed wreck of the K12N artillery gun. The rear end of the main carriage has been blown off and is lying sideways across the rear bolster. Notice all of the apparent hydraulic structure sticking out of the piece. What is this equipment for? Let me say first the recuperator (or run-out cyclinder) for the main gun is under the barrel. The elevating structure for the barrel is located in the front of the carriage. This is the K12N not the K12V, so there is no elevating structure for the carriage. This is not the generator. The generator traveled on a separate car.

A friend of mine thinks it could be part of a recoil buffer system, unique to the K12N, that would be separate from the buffer system incorporated into the Voegle turntable. Apparently the N version did not have the connection yoke that the V had.

Any thoughts?

[jopaerya]

First Welcome PCB5656

I think this is the same place http://forum.axishistory.com/viewtopic. ... 0&t=179710

Regards Jos

[Manuferey]

Good eyes, Jos ! It looks indeed like the same entanglement as on the left background of 21 cm K12 picture in Holland you posted previously.

Emmanuel

[jopaerya]

Here some information on this specific gun at Sluiskil from the German Seacoast Defences .

Regards Jos

[PCB5656]

The report you reference with the two photos on German Seacoast Defences, is that available anywhere? Either online or hard copies would be fine, I am very interested in it.

I'm still looking for anyone who knows what the hydraulic structure is inside the blown off portion of the rear frame.

[Xavier]

not the generator but I think is the self-standing hidraulic power unit for the complete gun, ( aka power unit)
Xavier
Der autodidakt

[PCB5656]

It definitely looks hydraulic in nature, but I don't know what the hydraulics would be for. The only hydraulic mechanism I know of on the gun is the recuperator system for the gun barrel. The elevation of the barrel is similar to the K5 and K12V which is an electric motor driving a gear on a toothed rod, and that system is in the front of the carriage. Like I said since this is the second version of the K12, the carriage doesn't raise so there is no need for carriage hydraulics.

What else is there for hydraulic power on the railway gun?

[peeved]

Hydraulic jacks were used to lift railway gun carriages thus e.g. increasing trunnion height. Additionally at least the WW I Amiens Gun had a hydraulic rammer.

As pertains to the K 12 (E), according to Germany's Guns 1939-45 by Terry Gander, the design used hydraulic rams in its balancing gear to counter the muzzle preponderance; K 12 V and N having differing hydraulic balancing arrangements.

Markus

[PCB5656]

Understood, that is the function of the equilibrator. But as I understand it the equilibrator is a sealed system, isn't it? As the barrel is lowered it builds up gas pressure (or spring pressure) in a sealed system, i.e., it stores the energy. When the barrel is raised the stored energy is released as an aid to the raising, helping to overcome the weight of the front of the barrel. A barrel is naturally muzzle heavy, if it was equally balanced, the trunions would be so far forward you would need a huge hole under the breech to allow for recoil.

[MLW]

As I understand it, with heavy artillery, the barrel is not usually muzzle heavy. The breech end is the heavy end. Its weight is designed to offset the length of the barrel. The trunnions are set at the barrel's center of balance, which allows it to lay level for transport and loading. There are notable exceptions - perhaps the K12(E) is one, but in general, that is the optimal design.

[Clive Mortimore]

As I understand it, with heavy artillery, the barrel is not usually muzzle heavy. The breech end is the heavy end. Its weight is designed to offset the length of the barrel. The trunnions are set at the barrel's center of balance, which allows it to lay level for transport and loading. There are notable exceptions - perhaps the K12(E) is one, but in general, that is the optimal design.

As an ex-REME gun fitter I will have to disagree with what you have written. The ideal would be a gun balanced without the need for equilibrators but with most guns this would put the breach at a height where the crew could not reach, the gun would be too tall to conceal and unstable when transported.

A few examples of WW2 guns with some system of balance gear.
105mm M2 How
4.5 inch M1Gun
155mm M1 How
155mm M1 Gun
8 inch M1 How
8 inch M1 Gun
240mm M1 How
4.5 inch Gun MkII
5,5 inch Gun How MkI
6 inch Gun Mk XIX
7.2 inch How MkI
7.2 inch How MkVI
8 inch How MkVIII
107mm Gun M1940
152mm How M1938 (M10)
122mm Gun M1931 (A19)
122mm Gun M1931/37 (A19)
152mm Gun M1910/34
152mm Gun How M1937 (ML20)
203mm How M1931 (B-4)

All these weapons the crew were able to load the gun without being on an elevated platform, most were towable in one load and were fairly easy to conceal.

Some coastal artillery was trunnioned at the point of balance owing to the potential of only firing at a low trajectory but once there is a need to elevate the barrel you either raise the height of the carriage or dig a deep hole for the breach neither is practical.

The barrel is very muzzle heavy. One of my party tricks was move a 105mm Light gun on my own. I done this by elevating the barrel to approximately 150 mls then with a heave pick up the trail with the handspike. The barrel counterbalanced the trail so I was able to move the thing on its own.....the new gunners thought their skinny REME fitter must have super strength

Clive

[PCB5656]

I think I have an answer to my question. Thought I'd post it for others info. According to Ian Hogg in his railgun book, both the K12V and the K12N (pictured) were equipped with a double recoil system. The first system was in the gun cradle where you would expect it and could handle 65 cm of recoil. The second system was between the carriage and the bolster. On the first gun (the V), it was capable of 98 cm of recoil. On the second gun (the N) the system was capable of handling 1.5 meters of recoil. Between the two systems, very little thrust was actually transmitted to the axles, meaning only a small amount of rollback on firing. That would account for the hydraulics in the ends of the carriage.

Now, a new question. We know the Germans blew the carriage in half on the N because they couln't move it due to blown tracks, but what happened to the V?

[jopaerya]

Here a better quality picture as the one above .

Regards Jos