York, Beyond Expectation

I know what you're thinking. York's got to be great! You have high expectations. There's the Minster! There's the city walls to walk around! There's the medieval part! There's the Viking stuff! How could anything be beyond expectation?

I went to the National Railway Museum. I know some people are really into trains, but I'm just not. Who cares except that it gets you from point A to point B safely and quickly at not too much cost? I don't.

Until I saw this:

This, my friends, is a steam locomotive that's been carefully cut-away and painted in color-coding. What's even better, an explainer comes around and explains how the steam locomotive works. It's incredibly ingenious, interesting, inherently inspiring, even. (I couldn't help myself.)

Starting at the far left of the first picture, is where the coal is. And here's where the driver and the fireman work. The driver drives (and there's a lot to that), and the fireman feeds coal into this hole (helpfully painted orangy-red). And it's not just a matter of tossing coal in, but the fireman has to make sure the coal is all burning evenly and going to burn as hot as possible.

On the other side of that hole is the fire. Where the fire is was painted yellowy. The part that's blue, with the pieces sticking out is where there was a double wall of metal (iron? steel), with space in between and supported and held together with those sticking out pieces, which were riveted into the two sides. That space was filled with water (indicated by the blue on the train here). And not just water, but water that was getting very, very hot.

At the bottom here, is where the ashes could be moved and air let in, and the arrows up indicate where the hot air is going. And that's really hot air, remember.

There's a brick wall thing that angles into the area from the lower right, which forces the hot air to circulate just so, and helps the fire burn hot and evenly, so they said.

What we have so far then is a big space filled with burning coal, surrounded mostly by a double wall filled with water getting hot, and with the hot air rising. But the hot air doesn't just rise anywhere, no indeedy. It's forced by pressure and hotness to go into those many, many tubes that you see the entry for in this picture.

You know the part of a steam locomotive that looks like a long cylinder with nothing happening? Well, what's happening is that the cylinder is filled with tubes full of really hot air, and all surrounded by more of that water that's getting hot. The massive surface area of all those tubes means that there's a LOT of heat transfer.

The blue here indicates the part filled with water, and of course you have to imagine that the cut away tubes are actually there. And as the water turns to gas, it goes up, and that's indicated by the light blue. But that hot steam gas is then forced to go BACK through the small tubes inside tubes that you see on the right part of this picture, which superheats it! (Enbiggen the picture and you'll see the blue tubes inside the yellow/orange tubes) (This is so cool!)

Then that superheated steam is forced into one of the thingies that runs the pistons, first on one side (piston goes one way, wheels make a half a turn), then on the other side (piston returns, wheel makes another half turn), and then the steam gets to escape.

Meanwhile, that hot, sooty air hits the big strainer looking thing, which catches the embers (mostly), and keeps them from flying up the smoke stack and catching the whole country on fire.

Now, you can tell why I found this unexepectedly and amazingly cool. Who would have thought?

And I also saw this.