A few of weeks ago, I was sitting in a local café with my good friend Adam Blackburn. I can’t quite recall how we got onto the topic, but Adam turned to me and asked “How many sleepers are there in the UK?”, not being able to tell him, he decided it would be my ‘homework’. We laughed about it a bit, and somewhat forgot about it, but I was left pondering. A couple of weeks later, questioning a couple of people at work, and using my Google-fu I was able to give Adam an answer.
My first source was a colleague, a man who has been working on the railway for many years. He had no idea when I asked him, but helpfully said that in one chain there were roughly 22-23 timber sleepers. So, with there being 80 chains to one mile, all I multiplied 22.5 by 80, with the result of 1,800 sleepers per mile.
My second source was the Office of Rail Regulation. They publish a Current National Rail Trends yearbook (downloadable here). During the period 2010-2011, it claimed that there was 15,777km of track open to both passenger and freight traffic, this equates to roughly 9,803 miles of track.
Armed with these figures, I multiplied 9,803 miles by 1,800 sleepers per mile to give me an approximation of 17,645,400 sleepers on open railway in the UK.
I presented my findings to the surprised but seemingly impressed Adam last Thursday, stressing that it is only an approximation, it doesn’t cover sidings, depots, etc. it also assumes that all terrain is the same, that all the sleepers are made of the same material, and that they have all been installed 100% accurately.
A surprising fun research exercise, it was good to get Googling for answers to seemingly impossible questions!