A Horse's Arse

The US Standard railroad gauge (distance between the rails) is 4 feet, 8.5 inches.

That's an exceedingly odd number, so why was that particular gauge used?

Because that's the way they built them in England, and the US railroads were built by English expatriates.

Why did the English people build them like that?

Because the first rail lines were built by the same people who built the pre-railroad tramways, and that's the gauge they used.

Why did they use that gauge then?

Because the people who built the tramways used the same jigs and tools that they used for building wagons, which used that wheel spacing.

Okay, so why did the wagons use that odd wheel spacing?

Well, if they tried to use any other spacing the wagons would break on some of the old, long distance roads, because that's the spacing of the old wheel ruts.

So who built these old rutted roads?

The first long distance roads in Europe were built by Imperial Rome for the benefit of their legions. The roads have been used ever since.

And the ruts?

The initial ruts, which everyone else had to match for fear of destroying their wagons, were first made by Roman war chariots.

Since the chariots were made for or by Imperial Rome they were all alike in the matter of wheel spacing. Thus, we have the answer to the original question.

The United States standard railroad gauge of 4 feet, 8.5 inches derives from the original specification for an Imperial Roman army war chariot.

Specs and Bureaucracies live forever. So, the next time you are handed a specification and wonder what horse's arse came up with it, you may be exactly right, because the Imperial Roman chariots were made to be just wide enough to accommodate the backends of two war horses.

Now the twist to the story....

There's an interesting extension of the story about railroad gauge and horses' behinds.

When we see a Space Shuttle sitting on the launch pad, there are two big booster rockets attached to the sides of the main fuel tank. These are the solid rocket boosters, or SRBs.

The SRBs are made by Thiokol at a factory in Utah. The engineers who designed the SRBs might have preferred to make them a bit fatter, but the SRBs had to be shipped by train from the factory to the launch site. The railroad line to the factory runs through a tunnel in the mountains. The SRBs had to fit through that tunnel.

The tunnel is slightly wider than a railroad track, and the railroad track is about as wide as two horses' behinds. So a major design feature of what is arguably the world's most advanced transportation system was determined by the width of a horse's arse.

The Haines manual

I wonder whether this is the best place to put this, but it's about technology - in a way. I mean cars are technology, right?

Well, whatever, this is for all those poor saps - like me - who have tried to fix problems on the car, thinking, "How hard can it be?" usually before we've lifted the bonnet and looked at an engine bay that's so stuffed full of nothing recognisable, we may well have bitten off more than we can chew.

Haynes	Translation
Rotate anticlockwise.	Clamp with molegrips then beat repeatedly with hammer anticlockwise.
This is a snug fit.	You will skin your knuckles!
This is a tight fit.	Not a hope in hell matey!
As described in Chapter 7...	That'll teach you not to read through before you start, now you are looking at scary photos of the inside of a gearbox.
Pry...	Hammer a screwdriver into...
Undo...	Go buy a tin of WD40 (industrial size).
Retain tiny spring...	"Christ what was that? It nearly had my eye out!"
Press and rotate to remove bulb...	OK - thats the glass bit off, now fetch some good pliers to dig out the bayonet part.
Lightly...	Start off lightly and build up till the veins on your forehead are throbbing then re-check the manual because what you are doing now cannot be considered "lightly".
Weekly checks...	If it isn't broken don't fix it!
Routine maintenance...	If it isn't broken... it's about to be!
One spanner rating.	Your Mum could do this... so how did you manage to botch it up?
Two spanner rating.	Now you may think that you can do this because two is a low, tiny, ikkle number... but you also thought that the wiring diagram was a map of the Tokyo underground (in fact that would have been more use to you).
Three spanner rating.	You are seriously considering this aren't you, you pleb!
Four spanner rating	OK - but don't expect us to ride it afterwards!!!
If not, you can fabricate your own special tool like this...	Hahahahahahahahahahahahahahahahahahahahahahaha!!!!
Compress...	Squeeze with all your might, jump up and down on, swear at, throw at the garage wall, then search for it in the dark corner of the garage whilst muttering "bugger" repeatedly under your breath.
Inspect...	Squint at really hard and pretend you know what you are looking at, then declare in a loud knowing voice to your wife "Yep. Just as I thought. We're going to need a new one!"
Carefully...	You are about to cut yourself!
Retaining nut...	Yes, that's it, that big spherical blob of rust.
Get an assistant...	Prepare to humiliate yourself in front of someone you know.
Turning the engine over will be easier with the spark pugs removed.	However, starting the engine afterwards will be much harder. Once that sinking feeling in the pit of your stomach has subsided, you can start to feel deeply ashamed as you gingerly refit the spark plugs.
Refitting is the reverse sequence to removal.	But you swear in different places.
Prise out plastic locating pegs...	Snap off...
Using a suitable drift...	The biggest nail in your tool box isn't a suitable drift!
Everyday toolkit	Ensure you have an RAC Card & Mobile Phone
Apply moderate heat...	Placing your mouth near it and huffing isn't moderate heat.
Index	List of all the things in the book bar the thing you want to do!