Sometimes there is pleasure in watching an expert demonstrating his craft, particularly so when the craft is unusual or disappearing. A video came our way of just such a thing, and it’s of a craft so rare that it’s possible few of us will have considered it. We’re used to buying tyres for our motor vehicles that come pre-made in a mould for the size of our wheels, but how many of us have considered where the origins of the rubber tyre lie? How did a 19th-century horse-drawn buggy get its tyres? [EngelsCoachShop] take us through the process, putting rubber on a set of wooden carriage wheels.
These wheels would originally have had iron rims, that must have provided a jarring ride on cobbled roads of the day. English coach-builders of the mid 19th century were the first to fit solid rubber tyres, and it’s this type of tyre that’s being fitted in the video. Instead of the rubber ring we might expect the tyre is cut from a length of vulcanised rubber extrusion with a significant overlap, then a pair of high-tensile wires are fed through holes in the extrusion. The impressive part is the jig for creating the tyre, in which the rubber is compressed to a tight fit on the wheel before the wires are cut and their ends brazed together. Once the wheel is released from the jig the compressed tyre expands to the point at which its ends meet, making a perfect circular tyre held tightly on the rim. Few of us will ever see this for real, but we’re privileged to see it on the screen.
We may not deal with wooden wheels very often, but this isn’t the first set we’ve seen.
Thanks [Andy Pugh] for the tip.
I had airless rubber tyres on my push bike back in the 80’s they were horrid- but slightly better than running on a steel band I guess. And they never got punctures :lol:
Oh, I love it how he seems to _listen_ whether the tension on those wires is correct :D. What a hero.
I don’t know if he’s listening for proper tension, but I’m pretty sure he’s listening for equal tension.
I don’t expect there’s a single level of tension that is always appropriate. The frequency of the sound will depend at least in part on how long the free sections of wire are. How much tension you need will depend on the circumference of the tires and how hard and thick the rubber is. The pitch of the struck wires is more of a rough guide – you don’t want a “thummm” and you probably don’t want a “tinggg,” but something inbetween that indicates enough tension but not too much.
You wil, of course, want the two wires at pretty much the same tension. If they’re different they might work against each other and cause the rubber to “walk” itself out of the channel.
In the YouTube comments, one Cemal Hussein says “I remember being taught to ‘twang’ the wire tension to ‘middle c’.” – that sounds listening to “proper tension” at least, though without perfect pitch that would still be difficult :).
You can fake perfect-ish pitch. Sit down at a piano and play the lower notes and sing them and find the lowest note you can sing well and remember what it is, and you can later octave up to close and then fine pitch up to the note you hear. It’s not perfect: if you don’t sing regularly you probably aren’t going to be able to tell F from F#. But it’ll get you pretty close and it can be a useful skill. Plus if you spend a lot of time playing with this, pretty soon you’ll start being able to recognize middle of the keyboard notes and you’re on your way to developing perfect pitch.
That part makes me nervous. I once used a compressor with a broken pressure gauge and had a bike tire explode right next to my ear. I wasn’t sure my hearing would come back!
I know, not the same thing. There is no inflation here. But it’s still unnerving for me to watch!
*clears throat*, “we are saying ‘tyre’, today.”
But the video is in Montana, so it’s tire.
The entire channel is well worth a watch. Mr. Engels is certainly the type that takes his time on everything, but in this case I think the sometimes more sedate pace works very well and his video’s are often very informative and enlightening. There’s a lot of knowhow and old school technology that goes into coach building, much more than I would initially have imagined
https://www.youtube.com/watch?v=5zUV0jg1TUU
this is sort of how push lawn mower, pram tires, Cyclops bikes and trikes had “tyres”
they work well until you wear down to the wire!
way back when (late Jurassic) my mates and I were making “go carts”/”billy carts” we used these wheels
push lawn mowers could use the handle tubes for axles, lit was an exact fit!
I actually do this regularly at work! We have a fleet of big horse-drawn carriages that all run on these tires. Equal tension is indeed more important than the overall tension, but the latter is harder to get right. At least with our setup, there are too many other variables to make resonance a useful measure. It’s just a practiced feel, really.
The almost-last step of tossing the tire to close the gap is one of my least-favorite things to do. Some wheels are close to 100lbs, and they always seem to need fixing on the worst weather days…
Why no glue on the ends of the rubber?
Well, it wouldn’t really do anything. The rubber is several inches longer than the actual circumference, so combined with the right wires the ends are forced together. Failure mode is typically the wires fatiguing and breaking. I don’t think any glue could hold together after that, not to mention the heat, cold, water, and other things a tire has to withstand.
“These wheels would originally have had iron rims,”
Well according to all books on engineering and the pictures shared, the rims were wood and the tyre is Iron.
The Tyre wraps around the rim and the rim is held to the hub with the spokes.
And BTW trains still use metal tyres!
“And BTW trains still use metal tyres!” Train’s use wheels, a tire is a component of a some wheels but not the entire wheel itself, but if you can show me a picture of a train with a metal tire (a separate, ring of metal encompassing the actual wheel on an operating train) I’ll admit you’re right.
Google for “resilient train wheels”. They use a steel rim and a steel tire separated by a rubber insert in order to reduce noise, vibration and harshness on some passenger trains.
The technology was rather infamously the root cause of Eschede derailment when one of the steel tires suffered a fatigue crack and failed at speed. (Usually train wheels of this design are only used on low speed trains)
High speed Pullman carriages used paper wheels with steel rims.
How about this?
https://en.wikipedia.org/wiki/Train_wheel
“Modern railway wheels are usually machined from a single casting. Some wheels, however, are made of two parts: the wheel core, and a tire (“tyre” in British English, Australian English and other variants) around the perimeter. Separate tires are a component of some modern passenger rolling stock. The purpose of the separate tire is to provide a replaceable wearing element – an important factor for steam locomotives with their costly spoked construction. In modern times the tire is invariably made from steel, which is stronger than the cast iron of earlier eras. It is typically heated and pressed on to the wheel before it cools and shrinks. Resilient rail wheels have a resilient material, such as rubber, between the wheel and tire.
“
Thanks, this is why I love being wrong, I get to learn something new when I’m corrected. :)
Seems if you had a different style of iron “tires” that you could just nail the rubber “tires” on to the wheel, but this method is more durable I suppose.
On a theme of ancient technology, us Brits will be familiar with the likes of Mary Bears trying to explain it, but sometimes it takes someone with engineering knowledge to understand the actual challenges being faced. One such person is Spanish engineer Isaac Moreno Gallo, who has presented a wonderful series of programmes for Spanish TV, Ingeneria Romana which go deeper into the subject than any other programmes I’ve ever seen. Here’s his examination of Roman roads, together with a look at the suspension systems used on various chariots. It’s in Spanish, but if you click on subtitles, then autotranslate you’ll have no trouble following.
https://www.youtube.com/watch?v=FFFnUM-cG14
If you enjoyed that then try his look at mines which examines how the pumps which kept deep Roman mines dry worked. Or Aqueducts, which focuses more on pipes than masonry. Have you heard of the Pergamom siphon which carries water across a valley, dipping 300m lower in the centre than at the ends. That means that the bottom section has to withstand a pressure of about 30 atmospheres.
No, still one atmosphere because it’s not sealed.
The pressure in the valley is due to the height of the water column and even though it’s not sealed on the ends, the pressure at the bottom will be ~1 atmosphere for every 32 ft of water height above.