Survey Data

Reg No




Categories of Special Interest

Architectural, Historical, Social, Technical

Original Use


In Use As



1770 - 1780


311373, 232831

Date Recorded


Date Updated



Double chamber canal lock, built c.1775, consisting of three mitre gates with timber footboards and balance beams, set within cut limestone lock chamber having limestone coping and splayed ends. Dressed limestone steps between centre gates and tail gates. Later concrete to lock chamber and to gates. Timber mooring bollards and cast-iron winding mechanisms to north and south tow-paths. Located to south-west of Inchicore, to immediate west of Blackhorse Bridge.


The Third Lock is an integral part of the Grand Canal and is one of a group of locks in Inchicore, designed to raise or lower boats between different levels. The Grand Canal is the southernmost of a pair of canals that encircles Dublin city, and provides a waterway connection between Dublin's River Liffey and the River Shannon. This is one of the earlier locks built in Dublin city, as the canal originally terminated at the City Basin off James's Street, and the circular line was only completed in the 1790s. Still in use today, the lock is of considerable social significance, and is a reminder of the canal network development in Ireland in the late eighteenth century, which encouraged the commercialisation and industrialisation of the country. It is of considerable technical and engineering interest, and is constructed of good quality stone with early timber lock gates that retain early mechanisms.