OLD DEVONPORT . UK
www.olddevonport.uk
 

ROYAL DOCKYARD  |  SOUTH YARD

DOCK 4

Designed by Mr Thomas Parlby (1727-1802), this was known as the New Union Dock or the North New Dock when it was completed in 1789.  It was built of granite and limestone ashlar between two Building Slips that had previously been known as "Medusa's Slip" and "the one on which the Anson was  built".  HMS "Anson" had been launched in 1781 and HMS "Medusa" in 1785.  It was the most northerly one in the Royal Dockyard at that time, being right next to the Dockyard Wall at North Corner.  While construction was under way, the Admiralty directed that it should be lengthened by ten feet at the head and the clearance at the Dock gates should be increased by a foot to 27 feet 6 inches.  It was thus 250 feet long by 85 feet 3 inches wide, one of the largest Docks in the country.

Also during its construction His Majesty King George III paid the Dockyard a visit and commented that as the planned dimensions had been exceeded he wondered why.  He was  told that the Dock had been planned to take the largest ships in the English fleet at that time -- HMS "Queen Charlotte" and HMS "Royal George" -- but the dastardly French, the country's sworn enemies, were in the process of building an even larger warship so the dimensions had been increased to receive her, if she was ever captured.  As it so happened, that very ship, the "Commerce de Marseilles", of 120 guns, was the first warship to use the Dock.

The New Union Dock was the only Dock or Building Slip at Devonport that was not given a timber roof when all the others at the Yard were.  This enabled a ship with its masts still in place to be docked in an emergency.

A document held by the National Archives in London gives the following dimensions of the New Union Dock/North New Dock: Length from gates to top of slope at head, 252 feet; length from gates to bottom of slope at head, 214 feet; breadth at upper stone altar amidships, 95 feet 10 inches; breadth at bottom of dock amidships, 41 feet; breadth at piers of Dock gates, 56 feet 6 inches; and depth of Dock amidships, 27 feet 11 inches.

In 1859 the New Union Dock/North New Dock, which at some point had become Dock number 5, was renumbered as Dock number 4.

Between 1874 and 1876 the granite sill was replaced and new Dock Gates fitted.  To do the work in the dry a Cofferdam was constructed in the Hamoaze.  Unfortunately it kept being washed away and so extra bracings and stays were put in place and thousands of tons of clay brought in to puddle down the base.  The contractor was Mr John Pethick, of Plymouth.  When the work was completed the first vessel to enter the Dock, on Wednesday September 20th 1876, was the former HMS "Conway", which was to be converted in to an Industrial Training Ship for Homeless and Destitute Boys in Devon and Cornwall, the TS "Mount Edgcumbe".

The official measurements of Dock number 4 were given by the Ordnance Survey in 1912 as being 274 feet in length and 64 feet 5 inches in width at the entrance, which was through  Caisson W.  The height of water over the  sill at high water spring tides was only 19 feet.

At the head of Dock 4 were the Boiler Shop and WD Cement Shop with Pattern Shop and Pattern Store behind it.  There was also a Pumping Engine and Boiler House.