Panzer tank hull being quenched

[Saltfever]

Interesting! Consider the weight of the whole tank. Then it is being suspended by 4 chains (that are also being heated and weakened!) attached to 4 stubs that have been heated and lost strength. Timing of this operation is non-trivial.

[buck]

Interesting! Consider the weight of the whole tank. Then it is being suspended by 4 chains (that are also being heated and weakened!) attached to 4 stubs that have been heated and lost strength. Timing of this operation is non-trivial.

that is not the whole tank, just the raw casting of the as yet unmachined tub, its still very heavy

[Frank S]

While the weight of the tank frame is significant it is only about 1/4 of the total tanks empty tactical weight. the 4 stubs would most likely be considered expendable then probably removed during the machining process
The 4 chains would not have been in the furnace with the tank and would only receive heat radiating from the mass
Visiting a large foundry such as that one would be a great bucket list item. I've been to smaller ones and a couple of steel mills
The one I would really like to visit is the Hyundai

[Saltfever]

The point I am making is the steel is at red heat. I didn't look it up but steel has probably lost 60%-80% of its tensile strength at that temp. The chains are in direct contact and are getting weaker by the minute. Obviously all accounted for; but someone was watching the clock . . . or the color of the chains!

BTW, heat is being conducted directly into the chains by the stubs!

[Frank S]

I know what you are saying about someone watching the clock. or accounting for the amount of time elapsed from initial opening of the oven hooking the chains and dunking the mass in the quenching vat. the watching the clock in this case I imagine would be metaphorically speaking.
Once as a kid in the blacksmith shop where I worked I picked up a pair of tongs a little to close to the business end I immediately dropped them in the quench tank the Blacksmith asked what's the matter son were they too hot for you?
Nope it just didn't take me long to look at them.

[Saltfever]

Sorry, wrong word. Instead of "tank" it should have been "casting". Besides that it doesn't even look like the tank or tub. It appears to be the truck casting which is a part of the overall assembly and likely only a very small part of total assembled tank weight.

[Jon]

Can anyone speak to the use of casting to manufacture this tank hull, as opposed to welding or riveting/bolting? Or is this practice simply common for the tank hull, but other processes are combined to manufacture the entire tank? I'm curious about differing strengths, cost, and how different processes may have been used over the years, especially with varying military resources available in peacetime vs. wartime.

Also, here is a fullsize image version more suitable for offline reproduction:

[Frank S]

Jon I couldn't say about the Abrams but many of the US tanks and others around the world the hulls and turrets were essentially made from large steel castings many of the other large components were steel forgings. Casting the hull in one piece saves time and money not to mention is makes structurally stronger than mere welding riveting or bolting could ever achieve.
I imagine that the process of creating a single casting of that size probably required more than one crucible of molten metal then re heating it if the oven and quenching would insure good molecular adhesion and alignment

[buck]

Jon I couldn't say about the Abrams but many of the US tanks and others around the world the hulls and turrets were essentially made from large steel castings many of the other large components were steel forgings. Casting the hull in one piece saves time and money not to mention is makes structurally stronger than mere welding riveting or bolting could ever achieve.
I imagine that the process of creating a single casting of that size probably required more than one crucible of molten metal then re heating it if the oven and quenching would insure good molecular adhesion and alignment

that could not be a forging, it has internal cavities,, its possible many castings welded into a single piece, then heating would normalize stresses, quenching might then harden the hull/tub, that hull is upside down, there are more plates to be welded in,,the square holes showing, one of the holes would be the emergency bottom hatch buck

[Frank S]

These cutaway displays are not cut in half as one might think. First whatever the model to be cut open happens to be the first step is a complete disassembly
then they are cut by which ever happens to be the favored method. For the unusually thick Steel this is often done much like the breakers at scrap yards do by using a huge cutting torch some things are cut with demolition saws like my Sthil AS510 Av mine has a 12" blade guard but up to a 16" can be used



other methods could include the diamond cable saw like those sometimes used to cleave granite slabs
or a band saw on anything that could be fit through one.
Once the sections are cut apart the model is cleaned and painted then re assembled sometimes even the smaller assemblies are cut open as well
A guy told me one time that it can very easily cost double or triple to make a cutaway model as it did to manufacture it as a whole machine.
Some manufactures will actually cast or build a cut away model at the time of the machines original production run.