Ask a railway company if they have any.
You could poke around the ATOC website for a list of companies and contacts. Or have a look at this www.rail.co.uk/ukrail/railcomp/towelcm.htm
(bogus official shove it up your cunt, Sun 10 May 2009, 12:29, archived)

Ta very much
I shall give it a go.
( wynoh kills threads by his mere presence, Sun 10 May 2009, 12:43, archived)