A horsey tale....

When the question of Railway Gauge is raised, it's often based on the spurious notion of "Roman Chariot Ruts" with the bizarre image of George Stephenson rushing off to Hadrian's Wall with his tape measure to measure the ruts in the Roman Roads which he then copied for his 4ft 8in gauge railway.

Or its said to be based on the idea of the width of a horse, and often its most muscular portion - its bum. But again, the width of a horse is only relevant where you have a horse in shafts - timber shafts connected to the vehicle being pulled which the horse stands in between. Horses on railways didn't use shafts. They used breast straps or collars and traces going to a transverse wooden bar called a swingle tree which hung behind its bum.

 

What *is* important is the span of the horse. The width between its hooves. So it needs sufficient space to be able to safely place his or her hoofs to be able to walk. And, the larger the horse, the greater the width between their feet, and thus a larger gauge is required creating space for them to walk.

And, of course, this is why early railways had the ballast level with the top of the rails so that there was a compact, solid surface on which the horse could walk without fear of tripping up over transverse sleeprs (hence the use of stone blocks) and which also put the centre line of the horse on a par with the centre line of the vehcile being hauled, thus increasing the efficienicy. There was also a hard metalled "footway" on either side for the horse driver to walk.

 

 

Horse Stature

Horses in the past were much smaller than today. A "Large" horse around 1810-1820 was no more than 16hh, We know from tax returns that the shunting horses used on the Liverpool & Manchester Railway were 14hh or less. So in today's terms ponies.

 

Horses from 14hh to 15hh needs approximately a width of three feet in which to safely plant their feet.

 

A horse around 16hh would need about 4ft to plant their feet.

 

Of course, horse can be trained to be accustomed to use a small space in which to plant their feet, but in general where farmers' horses or other hired horses were used as motive power, .eg. the Lake Lock Rail Road, Wakefield, these horses were not specially trained.

 

 

Hoofs and gauge

So it follows that, the smaller the gauge the smaller the horse: the Welsh narrow gauge lines like the Ffestiniog (1ft 11 1/2in gauge) is really too small for anything much larger than a pony. And quite a small pony at that. Having measured a 12hh Welsh Pony, they're 18inches wide accross their hooves. Thus a rail gauge of approximately 24 inches leave very little room for them to walk. It's doable but leaves very little "wiggle room". They would be much happier on a wider gauge: in fact the space in a horse box for such a Pony is 2ft 6in. wide. The loads hauled by a single animal would be very light.

It's not quite as simple as the earlier the railway, the narrow gauge because the horses were smaller as different gauges were used by different regions (narrower in Shropshire, wider in the North East) but in general narrower gauge = smaller horses, lighter loads. Quite what that also tells us about the size of horse geographically accross Britain is also worth studying.

 

The increasing prevelance of railways laid to a gauge of approximately 4ft to 5ft at the turn of the C19th is due in part to horses getting larger (and horses were bred to become much, much larger) as well as colliery owners using larger waggons to take more coal to market. 

 

So where does gauge come from? not the horses' bum, but its feet