Most Donegal coaches were 31 foot long or later ones were 36 foot long with the exception of the ex LMS coaches. In Michael Bunch part 1 he explains that the 14 coach train was split on arrival. With 11 CDR coaches in both platforms. Therefore say 6 coaches in one you have a length of about 210 feet or 70 yards. The Bunch book is excellent and you can buy both volumes from the CDRRL in Donegal Town. Finally lots of photos of Victoria Road in Railway Archive Volume 2.