Jump to content
I Forge Iron

Historical forge welding of sheet steel

Recommended Posts

I’m involved in a historical project looking at how the first metal cased rockets were made in the late 1700s, and I’m interested in drawing on the expertise of the forum.  So... if you had to make a cylinder, say 2” or 3” in diameter 12” long, from sheet steel, (wrought, I assume, possibly low  carbon), you can roll it into a cylinder but it then needs welding longitudinally. My questions are :

1. Roughly what temperature would be needed?

2. Would you expect to be able to see a seam when you finished or would it all be apparently homogenous? 

3. How thin would you be able to get your starting sheet steel? 

4. What tools would you use? 

5. Any other thoughts on how one might have made significant quantities in India in say 1790? 


Thanks in anticipation

Link to comment
Share on other sites

Funny I looked into this when I was asked about doing replicas for a TV program....Still have a copy of   "The First Golden Age Of Rocketry : Congreve and Hale rockets of the nineteenth century"  1990 by Frank H. Winter. (The project didn't pan out; but I did do some research.)

Definitely real wrought iron and probably a very fine grade of it and very low carbon. (Hmm the anchor chain being mentioned here might do...)   

1: Forge welding temps of 2300+ degF

2: Seams would be visible or not depending on the amount of work done to meld them in.  Take a look at armour that was made from real wrought iron sheet and welded together for examples of what can be done.

3: Thinner than you would want to use!  Look at the tinplate being used at that time!

4: Forge(s), hammers, anvils, mandrels, punches, tongs, files, drills, metal lathes---typical machine tools of the period

5: Lots and lots of labour!  These were precision items; but if you could source gunlocks locally these could be done.

I would try to get a copy of the book mentioned above and read it wrt what was being produced and try to map it to what was available in the 1790's India. For example sheet wrought iron was rolled in England but might be hand hammered in India.  Possible issues with homogeneity. etc. (Unfortunately my copy of "Metal Technology in Medieval India" would not be of use for tech status by that period...If you find a good source please post it.  I'll reread FGAofR and see if anything leaps out at me---and check it's bibliography!) 

Does the British Military archives have info on the rockets?

Link to comment
Share on other sites

Thanks TP, that’s useful. I have a copy of the Golden age of Rocketry. Indians have found some rockets, and examined them, but cannot find any apparent seam, but they are pretty rusty. From what you say, it’s possible their work simply hammered out the seam.  Someone is suggesting the forge welding would have been done at 600 C, (1100F) but that seems a little low to me, for steel 2- 3mm thick...any thoughts? Congreve takes a lot of credit, perhaps too much, and it’s clear the Indians were producing, in quantity, metal cased rockets a decade or two before Congreve, whose  contribution was a more formal, repeatable  industrial process and consistent propellant  My own contribution was highlighting that Irish rebels in 1803 used metal cased rockets against the Brits, (designs provided by the French who got them independently from the Indians..) and one of those rebels ended up working for Congreve... Congreve did have access  to captured Indian rockets,  but there is little in the archives. Two are in deep storage in a museum in UK and we cant have access. Congreve was very secretive... . But now the Indians have recovered so many rockets (in a well!), they are conducting research. Im meeting one of their team next week, so wanted to check some of the engineering concepts of manufacture. 

Link to comment
Share on other sites

Please keep us in the loop Roger. I have some Lay understanding of the Congreve rockets but no knowledge of that level of welding, it's definitely above my pay grade.

Were I to attempt such a project within that time period's industrial tools and machinery, I think I'd build a spring die and blow pipe torch. Process would involve rolling the tube with a folded seam. Then sliding it over the spring die as I passed it through the torch, welding and refining the weld it as it passed in a continuous process.

That has no historical foundation except what I've gleaned of period technology and how I'd apply it. I sure wish I could be of more help.

I'll be following the thread, it's chock full of juicy educational goodness. Thank you for the opportunity to partake.

Frosty The Lucky.

Link to comment
Share on other sites

Frosty, I too would have put a fold in it, something like this picture attached from a personal experiment, but I’m assured from India that it was not the case, and that their steel was thicker.     In my other life, I have written about the development of rockets here, http://www.standingwellback.com/home/2018/5/2/the-history-of-metal-cased-military-rockets-an-investigation.html  should you be interested. I’ll get permission from India and post some of their finds, which I think are fascinating. 


Link to comment
Share on other sites

You can also "spring load" the weld pieces to keep them in place; though the heating of the material for welding will affect that.

Any chance of getting a sample to a welding xray test system to see if it shows up a weld?  I assume that sectioning and doing a metallographic analysis is right out. (In fact I'd find a metallurgy department at a Uni that could do non-destructive testing on it!)

(Dr Alan Williams,  previously at the Wallace Collection in London has done massive amounts of studies on metallurgy of medieval/renaissance armour.)

Also have you asked on the Archeological Metallurgy Mailing list?

And I'd love to read up on the India finds!

Link to comment
Share on other sites

TP - They have done some sectioning and analysis, details to follow as soon as I get permission to post. Interestingly, Ive just seen that carbon comes out at 0.25- 0.35 %  in some rockets and less in others. Other trace elements negligible.  The metal is 2- 4mm thick, with an apparent clay coating on the inside.  The end caps are apparently hammered on both ends.  I hope to meet Dr Williams ar a meeting of the Arms and Armour Society at the Tower of London next week.  I’ll try and get permission to post the paper written by the Indian Team. 

Link to comment
Share on other sites

Mr. Rogerroger…,

The major use of iron encased rockets was  by the  (East)  Indians,  was in their war against Britain. That was in the first Anglo-Mysore war in 1792.  The British got a hold of some of those rockets after the resounding defeat of the Mysore kingdom and ruler Tipu Sultan in 1799.

Congreve started his rocket development, and research in 1801.  He carefully studied those Mysore rockets and furthered their development.

A reading of the seminal rocketry  book by Polish nobleman Kazimierz Siemienowicz "Artis Magnae Artilleriae pars prima" ("Great Art of Artillery, the First Part", also known as "The Complete Art of Artillery"), first printed in Amsterdam in  1650. It discloses many new developments by various people and the author himself.

There may be a mention of iron encased rockets therein.

I had no idea that there rocket enthusiasts on I.F.I. Bully that.



Link to comment
Share on other sites

Ok, got permission to reproduce the Indian analysis paper. i guess I can just post it as an attachment here?  Would that work?  Advice appreciated on now to post if its best to do it some other way.   Thanks for your comments, slag, got all that and Ive written elsewhere about most of that - see the link I posted earlier. 

Link to comment
Share on other sites

Cool topic!

Like Frosty, my approach is as if it is a job in my shop.

1: check out old wood working tools such as slicks and chisels with conical sockets, '17-'18 century bayonet construction, "The gunsmith of Williamsburg" and those who make hand forged barrels. They may be cones or heavier material, but the process is basically the same for all.

2: work to dimension. You must understand the concept of equivalent mass. This includes the needed thickness of the final product. Ya got me here, but it seems it would be in the resources above. If not, than I'm sure the weight and tube dimensions are available. Backwards engineer it. The weight of powder is possibly a constant. Subtract from known historical weight. Now you know the weight, length, and outside diameter of the wrought iron. Apply "equivalent weights" to solve.

3: the best forge weld is the one that has the smallest possible "scarf" modified by your experience(extra material at the forge weld to succeed in 2 above and how to get it . :) . This is because the less you deal with it, the less time involved. 

4: tolerance for error. IE how much bigger or smaller can my cylinder be so that slight changes in powder will not affect my "aim".

5: the forge welding temp is that of your material. This is readily available.  And I would use wrought.

6: My tools would be dependent on the aerodynamics of a rocket of the time. Lets face it, most went where they danged well wanted to go! And a good reason would be that the forge weld either was heavier than the parent material or a wasp waist,,, or a 2' combo of both!.  So Id start with a forge, anvil, mandrel, hammer(s), and files. Then go from there.  


Link to comment
Share on other sites

I now have two files from the Indian investigation into metal cased rockets, one the words and the other the pictures. I think they will overwhelm the attached file mechanism. I can however email them to anyone who would like to see it. Its pretty interesting.  Email me at the follwoing email address, inserting an @ sign where you see a capital A.  (Doing this to stop spam).  rogercdaviesAme.com    If there’s a better way of making files available, let me know. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...