The DSER was much affected by the Irish Civil War including 31 major incidents.

When added to shortages and inflationary costs arising from and after the First World War the DSER found itself, in common with other railway companies in Ireland, in difficult financial and operational conditions.

The DSER, being part British owned, stayed out of the merger which occurred on 12 November 1924, with a preference to merge with the Great Northern Railway of Ireland (GNRI) which covered lines north from Dublin and throughout the North of Ireland.

It was authorised in 1831, and the first part of the line running from Dublin to Kingstown Pier was opened on 17 December 1834, with an extension to Kingstown ( Dún Laoghaire station's current location) opened on 13 May 1837.

It used part of the Dalkey Quarry industrial tramway, which was earlier used for the construction of Kingstown (Dún Laoghaire) Harbour.

The entity that became the DSER was incorporated by the Waterford, Wexford, Wicklow and Dublin Railway Act 1846 (9 & 10 Vict.

A continuous route from Dublin to Wicklow was established the following year, when the section from the Dublin and Kingston terminus at Dalkey (atmospheric station) to D&W's Dalkey station was opened on 10 October 1855, and the extension from Bray to Wicklow (Murrough) opened 3 weeks later on 30 October.

This was followed by further extensions to Ovoca (Avoca) on 18 July 1863 and Enniscorthy on 16 November 1863 and branch line to Shillelagh in 1865.

The route from Enniscorthy to the original Wexford Station (Carcur) was opened on 17 August 1872.

With no lifting crane and poor workshop layout the works was increasingly stretched by larger locomotives and the shortages from the First World War and damages due to the Irish Civil War.

461) owned by the Railway Preservation Society of Ireland at Whitehead, County Antrim.