Gradients and Greatness

Gradients and Greatness

Despite riding this line many times, it was only now, when I was travelling this route for Window Seater, gathering content and looking out the windows, that I was struck by something I’d never really noticed before – this line is flat.

I mean, it goes so through so many cutouts and embankments; walls rise up either side of it, or the land barely ever drops away beneath you.

Maybe you’ve noticed that too.

Sure it’s partly due to geography: the south of England is quite flat and steady, so it’s reasonable not to expect too many climbs and gradients. But still there’s a consistent quality about the line that I never appreciated.

The pursuit of speed

And that is, again, due to one man: the genius engineer Isambard Kingdom Brunel, the driving force behind the Great Western Railway.

Because Brunel built this line, his main line out of London and through the west of England, to be as straight and flat as is humanly possible: in an age of railway competition, this was to make his trains fast.

And the results of this obsession can be seen in these embankments, and in one particular place on the route: a brick bridge coming up at Maidenhead, across the River Thames.

A feat of engineering

You’ll go over this quick and might even miss it, but that’s because this bridge has two of the flattest brick arches ever built: they’re 128 feet or 39 metres wide, but only 24 feet or 7 metres high. This bridge is long and thin and flat.

And the result? The gradient on this line is just 1 in 1,320. In other words you’d have to travel a quarter of a mile, just to go up or down a single foot.

This line is an engineering marvel, perhaps one of the reasons why the line and this bridge feature in the famous Turner painting Rain, Steam and Speed, that hangs in the UK’s National Gallery.

Anyway, think about that. Next time you’re on a train somewhere in the world. How flat is the line? How fast is it? And how does it compare to the Great Western Railway?

(Image CC by Nancy)

~ For the travellers ~