1 72 scale scratchbuilt 38 cm Max railgun dio.

[bazers]

Hi guys while browsing photos a while ago I came across pics of W W 1 German Max ,the largest -calibre railway gun built by the Germans, the first of eight guns were fielded in time for the spring offensive of 1918 and could fire from the rails.
I then realised this gun was missing from my collection even though I had made the gun carriage and bogies for the Paris gun(as that carriage only transported the Paris gun to sites and not fired from carriage.)
So I decided to remove the gun barrel, alter the carriage to a Max and make a new barrel and weights.
Will be using the Paris barrel to build the gun on its firing platform sometime.

[Gern]

Another beauty Barry! I'm curious to know though. What's that doohickey thingumajig (technical terms I learned from Ron) on the barrel above the pivot?

[Neil Merryweather]

Another beauty Barry! I'm curious to know though. What's that doohickey thingumajig (technical terms I learned from Ron) on the barrel above the pivot?

I reckon it's a portaloo

[spanner570]

Another cracker Barry. Great finish on the metalwork.
These dio's of yours are always busy... :thumb2:

I'm guessing the thingumajig is summat to do with lifting the barrel off and on.....:nerd:!

[bazers]

Another beauty Barry! I'm curious to know though. What's that doohickey thingumajig (technical terms I learned from Ron) on the barrel above the pivot?

Thanks Dave that thing over barrel is a weight to counteract the barrel length most German guns of w w 1 had them .

Another cracker Barry. Great finish on the metalwork.
These dio's of yours are always busy... :thumb2:

I'm guessing the thingumajig is summat to do with lifting the barrel off and on.....:nerd:!

Close Ron ,see post above

[spanner570]

Thanks for the explanation Barry.
Miles out really...

I've just had another look at the model and I'm still seeing things I missed the first, no second time around!

Pity such a great build has only received two/three comments thus far.

[Gern]

Thanks Dave that thing over barrel is a weight to counteract the barrel length most German guns of w w 1 had them .

Close Ron ,see post above

Thanks Barry, but I have to say I'm a bit confused.:upside:

If the counterweight is immediately above the pivot, it will have absolutely no effect in terms of balancing the weight of the barrel (Physics 101 - the turning moment is the product of the mass x the distance to the pivot. If the distance is zero, the turning moment is zero).

It does look like it is movable though as it appears to have pivot points at the bottom. Is that right?

[stillp]

Thanks Barry, but I have to say I'm a bit confused.:upside:

If the counterweight is immediately above the pivot, it will have absolutely no effect in terms of balancing the weight of the barrel (Physics 101 - the turning moment is the product of the mass x the distance to the pivot. If the distance is zero, the turning moment is zero).

It does look like it is movable though as it appears to have pivot points at the bottom. Is that right?

Wikipedia has a general arrangement drawing on which it's labelled "collapsing counterweight". It looks to be able to fold outwards, perhaps to get under railway bridges.

https://en.wikipedia.org/wiki/38_cm_SK_L/45_%22Max%22#/media/File:38cmEuBdiagram.jpg

I agree though, I can't see it being much use as a counterweight. Perhaps it just adds extra mass to help absorb vibration?
Pete

[stillp]

On the other hand, being fairly tall, it will have a counterweight effect as the gun barrel is raised from the horizontal, as the force acting directly downwards will be behind the pivot point.
Pete

[spanner570]

I wonder if it has anything to do with countering the weight of the shell once its loaded? i.e the front bit of the thingy opens out and sort of balances the barrel due to the extra weight of the projectile behind the pivot point....

This is fun.....

[JR]

Barry, while the physicists and engineers work out the counterweight I would just like to congratulate you on the very subtle weathering, which looks perfect.

[spanner570]

Perhaps when the pointed thing in the long hollow tapered stick goes BANG, it's just a mass of heavy stuff to stop the aforementioned long pointed stick from jumping out of the bit wot it rests in?

Barnes Wallis

[Guest]

I agree though, I can't see it being much use as a counterweight. Perhaps it just adds extra mass to help absorb vibration?

The Wikipedia article says:—

One obvious change made for land service was the placement of a large folding counterweight just forward of the trunnions to counteract the preponderance of weight towards the breech.

Which suggests to me that the counterweight isn’t exactly centred over the trunnions, but it still puzzles me why it would need a folding counterweight, let alone one that folds both to the front and the rear of the trunnions. I would have thought that a relatively small weight attached near the muzzle would be enough with a gun this long.

[Tim Marlow]

Great piece of work this, looks impressive. The counterweight is a bit of a conundrum though. It must weigh less than the shells and I can’t see how it does much apart from add a little deadweight to the pivot? Is there any footage of these being fired?

[Tim Marlow]

Just read through the Wikipedia entry, and it has this picture of the gun in travel mode.

it can be seen that the counterweight is folded down, so the hinges etc are definitely there to allow the gun to travel within the railway loading gauge. The only use I can think of for the weight is to centralise the loadEd weight, so reducing the power needed to elevate the gun on a rail mount. After all, I would assume this gun is loaded flat, then elevated to fire?