The significance of Deptford's dockyard basin

Museum of London Archaeology has published brief information on its website about the continuing excavations at Convoys Wharf. The latest post focuses on the Dockyard Basin, one of the most important below-ground structures on the site which lacks any kind of statutory protection.

MOLA says:

"The excavations... have unearthed several phases of the Dockyard Basin. This large pool probably began as a natural pond at the confluence of the River Thames with the small stream identified earlier in the excavation. Historical sources suggest that the basin was adapted to moor several of the King’s ships in the early 16th century and later used to season masts. By 1688, the Dockyard Basin (or ‘Wett Dock’) was hexagonal in plan, with slipways on the west side and a canal connecting it to the river. Once the ships were largely complete, they were launched into the basin to be fitted out.

"Excavations have identified a timber revetment wall that probably dates to the 18th century when the basin was remodelled. The revetment was held in place by large horizontal timber beams, called land ties, on the landward side.

(copyright MOLA)

The east wall to the canal linking the basin to the river, built in 1814 to John Rennie’s design. The recess to the right of the depth gauge would have housed an iron and timber gate. The wall replaced an earlier timber version, seen in the background of the image.

"The early 19th century saw a dramatic increase in the size of warships and the four slipways at the edge of the basin shown in the c1774 model had been replaced by two much larger stone slips by 1868. These stone slipways were protected from the weather by an open-sided cover building, now known as the Olympia building (listed Grade II). The cover building is one of only two structures visible above ground that date to the Dockyard period (the other being the Shipwright’s House outside the boundary of the site).

(copyright MOLA)

The same canal wall looking west from the landwards side; this side of the wall would not have been visible when the basin was in use as it was below ground level.

"The excavation has revealed the evidence for two phases of canal walls linking the basin with the river. The later phase, built in brick and stone in 1814 to a design by John Rennie, is shown in the first of these images with the earlier timber version, just beyond, to the east. Depth gauges were identified in both phases of walls – Roman numerals cut out of copper plate and nailed to the timber wall and carved into stone in the later phase."

But the extent of the excavations being carried out on this enormous site, which has huge significance for the nation's maritime heritage, are woefully inadequate. While the condition of the underground structures that have been uncovered has been found to be variable, it is impossible to state conclusively – as developer Hutchison Whampoa is doing – that these heritage structures cannot be saved. Only a tiny percentage of the dockyard has been excavated, yet the developer is dismissing any suggestion that these major structures be incorporated into the masterplan, instead proposing 'preservation in situ' which essentially means that no foundations will theoretically be allowed to damage the remains, but they will still be buried below a permanent building.

The current masterplan for Convoys Wharf completely disregards English Heritage guidelines on maritime & naval buildings (2011), which highlight works by John Rennie as worthy of a high grade of protection and describe sites such as the basin, basin slipways, basin slipway covers and caisson gate infrastructure as 'sites of collaborative genius'.

In the case of Convoys Wharf, these below-ground structures are all works by eminent Georgian and early Victorian engineers.

Deptford was the first of the royal naval dockyards to have a wet dock or basin and this technology was exported to outlying dockyards such as Chatham in about 1650. Under the administration of Sir George Carteret, Deptford's skilled workmen and naval dockyard officers built the wet dock at Chatham.

The basin is also where John Evelyn carried out the first diving bell experiments, where Cook hoisted the pennant on board the Endeavour in 1768, where Bentham built the dry dock in 1802 with Edward Holl, where in 1814 John Rennie rebuilt the basin entrance with the latest caisson gate technology, where Capt. Sir William Denison built the slipways to the basin with slipway covers built by George Baker &Sons, where George Biddel Airey tested the effect of a ship's magnetism on navigation instruments, and from where in WWI and WWII, supplies were sent out to troops stationed around the world.

The developer's design team has also ignored English Heritage London area committee comments from 2003 and 2005 which requested that the Olympia building be visible from the river. Hutchison Whampoa has dispensed with the Richard Rogers proposal, which was to create a public plaza on the site of the basin – the current masterplan all but cuts the Olympia building off from the river, preventing the building and its importance to the site and the former dockyard from being properly understood, and making a mockery of PPS5 guidelines on planning for the historic environment.