John Rocque’s Map  (1756) shows the Coal Quay as "The New Quay" at the entrance to the then tiny harbour of Dunleary (or Dunlary).  The modern town of Dun Laoghaire has not begun to develop at that time.The Coal Quay is the oldest element of Dun Laoghaire Harbour, and pre-dates the main harbour.  It is clearly shown on maps of the 1850s, and is sometimes shows with an additional element on the end of the harbour wall.

The quay is quite shallow, and is no longer suitable for any significant heavy cargo trading.  Indeed, the amount of coal imported through Kingstown/Dun Laoghaire at any time was quite small