In evidence to the Select Committee appointed to inquire into the amount of advances made by the Commissioners of Public Works in Ireland on 22 May 1835 James Pim, Treasurer to the Dublin and Kingstown Railway, said:
1431. Can you tell the average length of time which the [horse-drawn] cars took in going [between Dublin and Kingstown/Dun Laoghaire], and the distance? — I should think the average length of time taken by the cars after they got in motion, was probably 45 or 50 minutes, from Dublin to Kingstown.
1432. Are you not able to do it in 11 minutes? — Easily.
I’ve just had a look at the DART website. As far as I can see, the DART takes 19 minutes to travel from Dublin Pearse [Westland Row] to Dun Laoghaire [Kingstown]. Is the difference attributable to the number of stops?
Irish waterways history 
Primarily Yes – there are more stops now than in D&KR days. As an urban commuter railway the distances between stops negates the possibility of high speed.
Great; thanks. James Pim is very interesting: he wanted commercial traffic (incl cattle) from the Grand Canal to be transhipped at GCD and carried by rail to Kingstown. bjg