Graving Dock No.1, Clarendon Quay, Belfast, Co Antrim, BT1 3AL

Graving Dock No.1 at Clarendon Quay, Belfast, is one of two small masonry graving docks constructed by the Belfast Ballast Board. Built between 1796 and 1800 to the design of William Ritchie, a ship builder from Ayrshire, it is the earlier of the two docks, predating No.2 Dock by approximately 30 years. Ritchie had established a ship building and repair yard nearby, where the Harbour Office now stands.

The dock is aligned east-west at right angles to the west side of Clarendon Dock and south of No.2 Dock. It measures 235 feet long by 28 feet wide and is of sub-rectangular plan with a rounded west end. The dock's north, west and south sides comprise sandstone steps running down to a flat bottom. These steps were used to prop the ends of timbers for keeping vessels from toppling over once the dock was drained.

The dock is equipped with five inclined slides (miniature ramps) running down the sides for bringing equipment and materials to and from the bottom during ship repairs. Two slides are positioned at the west end, one in the middle of the north side, one at the northeast end, one at the southeast end, and a fifth in the middle of the south side. Some slides have been topped with concrete and timber boards. Alongside each slide is a flight of steps with a single-bar metal handrail. Beyond the southernmost slide is a hand-operated winch with a small metal roller guide mounted on the edge.

At the seaward (east) end of the dock is a pair of timber lock gates with a replacement cantilevered metal footway running across the tops on their outside faces, fitted with five-bar steel handrails on each side. The footplate facilitates movement across the dock and provides access to threaded rods for opening and closing single vertical sluices in each gate. Each gate is closed by means of a hand winch mounted on its dock side. The north-side winch bears the inscription "To lift/ direct/ 20cwt" and "Fellows Bros Ld/ Engineers/ Cradley Heath", as does the corresponding opening winch on the seaward side at the southeast.

The side walls on the seaward side of the gates are of sandstone blocks laid to courses with recesses to accommodate the gates. Each recess contains smaller recesses for the sluice gate mechanisms when gates are open. Vertical slots at the very outside end of the side walls held stop timbers when gates required attention. The dock edge is finished with granite blocks. A safety railing comprising two detachable chains supported on slender cast-iron posts runs round the dock. Two metal posts of unknown function are positioned towards the east end of the south side, and removable steel cover plates are arranged at the top of the slides at the east end of the dock.

Three fluted swan-neck cast-iron lamp standards, inscribed "Harbour Commissioners", are arranged along the north side. Originally gas-lit, they are now electrified. The dock measures on the 1832-33 Ordnance Survey map and subsequent editions. In the late 1990s, the entrance walls to No.1 dock were underpinned. The dock is now disused; a small building north of the east end formerly housed an electric pump.

The dock lies immediately west of Clarendon Dock, which connects via lock to Belfast Lough. The area immediately south has been landscaped with grass and ornamental trees, with three anchors and a ship's propeller displayed. The area to the west and north is paved with stone flags. A former pump house, subsequently refurbished as offices for Laganside Corporation, is aligned parallel with the dock on its north side. The present functioning pump house stands between the east ends of the two graving docks.

No.1 and No.2 graving docks are fine examples of 18th and early 19th century dock technology, presenting interesting contrasts in construction detailing such as the shape along the sides, the form of the lock gates, and the routing of the gates' closing mechanisms. Their relatively small scale reflects the size of vessels of the time. No.2 Dock, constructed 1826 by Messrs Henry, Mullins & McMahon under the supervision of David Logan to a design by Thomas Burnett, measures 285 feet by 34 feet and is larger than No.1, reflecting the ever-growing size of shipping—a trend even more clearly evident in the subsequent Hamilton, Alexandra, and Thompson docks. The establishment of these docks laid the foundations of a shipbuilding industry which, in the form of Harland & Wolff on the County Down side of the river, rose to international importance. No.2 dock remains in use by the Belfast Harbour Commissioners for inspection, painting and repair of small vessels. Both graving docks are scheduled rather than listed, as a more appropriate form of protection.