Isn't it neat? It's railroading at its most primal. :)

The Beamish Museum (where the video was taken) is a must see for anyone interested in early industrial railways or industrial history in general if you're visiting the UK. The Pockerly Waggonway exhibit represents rail in the 1820s, the engines for which are housed in a replica of Timothy Hackworth's engine shed from Shildon which incorporates some building hardware from George Stephenson's original locomotive works (!). They also have a number of little 0-4-0Ts dating from the 1870s to the early 1900s at both the railway station and the colliery (yes, there is a recreated coal mine on the property, with a rail connection of course), and some truly unique rolling stock -- including an impressive collection of early 4-wheel "cauldron" type coal wagons. Several of the engines are operational. There are also trolleys/trams (cars from various northern English cities such as Sheffield, Newcastle, Gateshead, etc.) operating in a continuous loop around the museum grounds.

-Philip Marshall

For a taste of some of the other rail stuff at Beamish, here's a video from their 2011 steam fair -- enjoy! :)

https://www.youtube.com/watch?v=Ctw7EAk ... U6hzMXqRlw

-Philip Marshall

If you think the Pockerly steam waggonway is "primal", don't forget that there is also a replica wooden waggonway on site that has horses for the motive power: http://beamishtransportonline.co.uk/wp-content/uploads/2013/02/IMG_3148.jpg

Here's an even older one....

https://www.youtube.com/watch?v=pLJaboxC3Do

Note the plain wheels and flanged rail on that one. Probably one of very few plateways in existence.

That's simply amazing. I'd love to know how the valve gear is configured, since it seems to reverse without any problem despite having just a single cylinder.

It's funny, I'd somehow always imagined Trevithick's engine as being larger than this (perhaps because of the flywheel?). To be sure, it looks like this replica is supposed to be of his Coalbrookdale engine of 1802 rather than the somehow more famous Pen-y-darren engine of 1804; the gauge of the Pen-y-darren plateway is supposed to have been 4 feet 4 inches (that's measured outside the rails), but this one looks narrower, maybe 3 feet, so it makes sense the engine might be smaller. Does anyone know the actual gauge of the Coalbrookdale plateway?

-Philip Marshall

Here's a video of a replica of the Pennydarren locomotive:
http://www.youtube.com/watch?v=nZCfXIZGFhc

Note that the locomotive stalls and at 1:20 they have to pull on the flywheel to get her to reverse.

EDIT: Also note that Trevethick did more than just railway locomotives: http://www.youtube.com/watch?v=CTksFK9Rln4

Regarding questions about rail gauge of the Trevithick locomotive. In the clip below, after the loco is "bump started", it can been seen riding on specially laid rail inside the Stevenson gauged track.

https://www.youtube.com/watch?v=T9Bb931f1bw

Yes I saw that, thanks, but I was wondering about the original engine(s), not the replicas.

Trevithick is supposed to have designed two locomotives (plus some stationary engines and a steam carrriage). One was built for the Pen-y-darren plateway in 1804, which one reference I've seen says must have been 4'4" gauge because that's what the line's surviving stone sleepers indicate, but there was also his earlier locomotive designed in 1802 for Coalbrookdale which was probably what we would call "narrow gauge" -- something like 3'. I was wondering if anyone knew the real historical gauge of the Coalbrookdale plateway.

From the little bit of reading I've done on this topic recently, it's only the Coalbrookdale engine for which detailed drawings have survived (whether the original was actually built or not), and replicas of the Pen-y-darren engine have just used the same design scaled up slightly to fit a broader gauge. So, the different behavior of the two replicas is curious. (The engine in the first video is supposed to be Coalbrookdale, and appears to have a narrower gauge than the engine in the second video.) Why would one reverse smoothly while the other one stalls and requires a "bump start" if they were both built to the same design? It can't be just a matter of different engineers/drivers at the throttle/regulator. Different workmanship perhaps?

(Sorry if this is sounding pedantic! Maybe I'm just confused.)

-Philip Marshall

It's not at all pedantic. There really is a lot of neat equipment worldwide and the increasing interaction between railway groups internationally is really something to appreciate. When I was up at Montreal for the ATRRM conference there, we had the pleasure of riding their replica of the John Molson around the property. They've used it for switching equipment on occasion and for a locomotive of it's size and wheel arrangement, it has real pulling power!

Any single cylinder engine will need help starting if it is stopped on dead center, even with a modern valve gear. (Even close to dead center, the valve gear may need to be rocked back and forth.) It's up to the skill of the operator to make sure that doesn't happen.

The valves on these engines appear to be manipulated by the crosshead reaching the end of its stroke. At the end of the stroke, the "power" chamber is switched to "exhaust" and the other from exhaust to power. Modern valve gears bias the valve events in a way to operate more efficiently and at a higher speed. To reverse this engine, simply move the valve to select which side of the cylinder will be under power. The flywheel will keep it going.

Single cylinder steam tractors also dead center from time to time. The flywheels are pretty accessible from the footplate so not a big deal usually. Think of those huge beam engines that needed to be barred around to prewarm the cylinders, then again if they dead centered......

dave