Armstrong 80pr Cannon Wooden Chassis
by John
So, today I battled 1.5 hours of post covid lockdown Melbourne traffic to take a closer look at the wooden slide and carriage of this 1866 Armstrong RML cannon which I am intending to model. There are 2 of them in the Hopetoun Gardens, Elsternwick. They are more complex than I had imagined.
The barrel is identical to the barrels which I had modelled on iron slides. The iron slides were a later improvement – modification.
It was a beautiful spring 20ºc day. I spent almost 3 hours photographing and measuring the wooden components. Some parts have been restored, and it was lucky that there are 2 examples to check and compare.
I was climbing over and under the cannon, and groundsman came over to check. Then a pair of grandparents came over with their 5 yo grand-daughter, and a further pleasant conversation followed.
Some examples of the photos…..
And an example of many pages of measurements and sketches…
There are 11 pages filled with details like this, representing my 3 hours.
And I still do not understand how the barrel elevation mechanism functioned. It could have been a wooden wedge called a quoin, but there appears to be a metallic disk set into the wooden bearer. Could there have been a screw mechanism which has since been removed/stolen/lost? Pictures on Google Images do not help. Does anyone know?
johnsmachines 
Hi
There is a 64pdr RML at Nothe Fort in Weymouth and that uses a quoin.
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Thanks Richard. But it looks a bit different. And does not account for the round metal disk in the platform below the breech. Still searching…… Interesting site though! Must visit next time I visit UK. John.
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Thanks Richard, that seems close! John
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Perhaps one on the following page…
https://www.victorianforts.co.uk/art/gun1.htm
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Thanks David! That is a very helpful site which I had not previously known. No carriages which exactly match the 80pr Elsternwick pattern, but I can see features in others which would explain some of the fittings. It seems likely that the Elsternwick carriages had a quoin which sat on the iron hinged beam, and a screw mechanism underneath that. Thanks again! John
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I don’t know for certain what was used, but I made a “Smith’s elevating screw” for my 110 pounder model on a rear chock carriage. A quoin is used for coarse adjustment and the screw for fine tuning. This pdf has a drawing on page 171: https://sha.org/assets/documents/British%20Smooth-Bore%20Artillery%20-%20English.pdf
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That is excellent, Jeff, thankyou! I have been searching for that information. Drove 500km today to see some wooden carriages. I will post some pics in a day or two. But your reference answered my questions perfectly. I will be very interested to read the whole book. John.
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Jeff, I was unable to open your YT videos about the 110pr firing and rifling. Are those videos still available? (I was hoping to see your scale screw and quoin)
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The videos seem to be playing ok for me on both Youtube and embeded on my website. Check my build page here: http://jefenry.com/main/110PounderArmstrong.php for some pictures of the elevating screw I made. They’re towards the bottom. And that’s some dedication to get your pictures!
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Jeff, a very big thankyou! The videos played fine, and I really enjoyed watching them again
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(accidentally hit enter before I had finished). And that explains the Smith screw perfectly! Thank you so much. Heat shrinking the parts together obviously worked very well. Most impressive. I will work through all of your entries. Thank you again. John
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John, I think the Smith’s elevating screw, fitted into the iron pan at the bottom and beneath the iron bed at top, with a wooden quoin on the bed is the likely method. Did you notice that the west gun has “No/886” stamped on the pan? I took this to be a possible carriage registration. The east gun does not appear (paint?) to have any marking on the pan. I always check pans now for markings.
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Yes, that is the elevating mechanism on the wooden slides/carriages, but of the 5 examples which I have inspected, all are missing the screws and quoins. I have some nice old scaled drawings which show outlines of the arrangement.
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