I have become hooked on watching British model railroaders on YouTube. I have noticed that several of their steam engines appear to lack pistons, at least exterior pistons. For example, a 0-6-0 will just have a rod connecting the three sets of drive wheels, but no rode to a piston. Is there a hidden under the smoke box interior piston driving the first set of drive wheels? What is going on? Thanks for your answers.
From https://en.wikipedia.org/wiki/Steam_locomotive#Cylinders
"Early steam locomotives had two cylinders, one either side, and this practice persisted as the simplest arrangement. The cylinders could be mounted between the mainframes (known as "inside" cylinders), or mounted outside the frames and driving wheels ("outside" cylinders). Inside cylinders are driven by cranks built into the driving axle; outside cylinders are driven by cranks on extensions to the driving axles."
Inside cylinder
Outside cylinder
While different types of valve gear in videos. The valve gear used is not dependent on whether locomotive is inside cylinder or outside cylinder
I tried to sell my two cents worth, but no one would give me a plug nickel for it.
I don't have a leg to stand on.
Aside from tucking the nasty mechanical bits tidily out of view (Victorians perhaps getting breathless even at iron 'limbs' pumping and twisting) inside cylinders had far less augment and the internal steam valves and passages, although amazingly twisted and convoluted by American standards, were up under the smoke box where they could stay warmer. Note that in general these are slide valves and they are mounted vertical, 'on their sides' compared to American practice, to get them into the space between wheels on the standard gauge.
The principle of inside mains remained valid and is a notable feature of Belgium's answer to the Hiawatha Atlantics-- one of which survives in running condition, one of the most interesting surviving steam locomotives in the world.
Any of these engines were ridiculously hard to maintain by comparison with a typical American 4-4-0 or 4-6-0, which used outside cylinders and valves both for easier access and larger ports and passages, but still drove them with inside eccentrics (via rocker-shaft bell cranks). A major technical feature on 'this side of the pond' was that the locomotive frame came apart into a back and front part easily to simplify maintenance...
Those locomotives were built by the Hogwarts Works and used magic to make the wheels turn.
On my trip out West last year, there was an inside cylinder industrial 0-4-0 at one of the train museum we stopped at.
It took me a while to figure it out. Neat locomotive to see. I wish I could remember exacly where I saw it.
-Kevin
Living the dream.
Thanks for the explanation and video clip examples. My curiosity is now satisfied.
In addition to the UK, some eraly US locos were inside connected
https://www.deviantart.com/prr8157/art/4-4-0-Inside-Connected-by-John-Souther-686229976