Upnor

Upnor Castle was built as an artillery fort between 1559 and 1567 in order to protect Chatham Dockyard and the associated naval anchorage. It was called into action in June 1667 when the Dutch Navy conducted a raid on the ships moored in the river; the castle proved ineffective in repelling the attack and it was decommissioned soon afterwards. Though the castle was only operational as a fort for about 100 years, it was retained as a gunpowder magazine and ammunition store until the end of the First World War; continuing in military use through World War II, it was opened to the public as a museum in 1945.[9]

A Thames Barge sails past the depot: Upnor Castle (left), 'B' Magazine (centre), No. 5 Shell Store (right).

Upnor Castle served as a gunpowder magazine for the Board of Ordnance from 1668, providing powder for the defences of Chatham Dockyard and for the fleet based in the Nore. In 1810 a new magazine with space for 10,000 barrels of gunpowder was built downriver from the castle (which had long needed to expand its capacity) along with a 'shifting house' for inspecting powder that had arrived by sea (though demolished, its surrounding earth traverse is still in evidence, midway between the magazine and the castle).[10]

In 1856 a second magazine was constructed alongside the first, to the same design but with more than double the capacity; (this still stands on the river bank, the earlier magazine having been demolished in 1964). At the same time, buildings were constructed (alongside the shifting house) for storing and maintaining artillery shells; but these soon proved too small, so the site began to be extended to the north, where additional shell stores were built from the 1860s onwards.[11] A little further to the north, a group of large houses were bought to serve as offices for the depot. There was not enough space, though, for further bulk storage of gunpowder, so in 1875 a separate set of five magazines were built, inland at Chattenden, and linked to Upnor by a narrow-gauge railway (see below);[12] the Upnor magazines were then converted into filled shell stores.

In 1891 Britain's Ordnance Yards were split between the Admiralty and the War Department, Upnor going to the former, Chattenden to the latter.[13] The Admiralty therefore embarked on building a new inland depot, next to Chattenden, at Lodge Hill; opening in 1898, it dealt principally with cordite. At Upnor itself further Shell Stores was built in the 1880s, supplemented by new buildings for storing wet and dry guncotton (used in torpedoes and mines) in 1895. The site was extended further to the north in the early 1900s to allow construction of a much larger store for filled shells and another for mines. At the same time a complex of buildings for filling shells with powder (and later also with trotyl and amatol) were added behind the original 'A' and 'B' magazines.[11]

The three sites, Upnor, Lodge Hill and Chattenden, were active as Royal Naval Armaments Depots until the mid-1960s. Thereafter they remained in military hands as part of the Royal School of Military Engineering until the mid-2010s.

The Lower Upnor site was put up for sale in 2014. Two years later, the Grade II* listed 'B' Magazine was being converted into offices, while a residential building of similar proportions was being erected on the footprint of the demolished 'A' Magazine alongside; behind the magazines, more apartments were planned within the surviving concrete traverses (blast walls) of a demolished set of shell-filling rooms (dating from 1906).[14] Meanwhile, the surviving buildings to the north were also being refurbished for light commercial and retail use. The inland depots, latterly known as Chattenden and Lodge Hill Military Camps, were put up for sale in 2016.[15]

• 
  Former 'B' magazine (1857) undergoing refurbishment.
• 
  Former dry guncotton store (right, 1895)
• 
  Left to right: former No 3 shell store (1883), mine testing room (1905) and wet guncotton store (1895)
• 
  Left to right: main entrance, former filled mine store (1904), former filled shell store (1904)

The army used this area to train a railway engineering force. They built a standard gauge railway from Chattenden to Upnor in 1872–73. This was abandoned before 1881 and a 2 ft 6 in (762 mm) gauge line was built in 1885[8] or by the 8th (Railway) Company R.E. in 1898.[16] One branch went to Lower Upnor, and the other to the camp by Tower Hill. This line was used to supply armaments from Chattenden, the Lodge Hill Ammunition Depot and the standard gauge at Sharnal Street, to the warships and the Upnor Magazine. The service closed on 19 May 1961.

In 1965–1967, the Royal Engineers converted the route from Lower Upnor to Chattenden into a road, including building a new bridge over Four Elms Hill (the main road through Chattenden village). The new road is named Upchat Road.

Royal Engineers assault boat training at Upper Upnor

The Royal Engineers still have a presence in Upper Upnor; the Royal School of Military Engineering (Riverine Operations section) maintains classrooms, workshops and a hard in Upnor for training Royal Engineers assault boat operators and watermanship safety officers, who continue to operate craft on operations all over the world. The section operates Mk 1 and 3 Rigid Raiders, and combat support boats, as well as teaching use of the Mk 6 Assault Boat. The area is also used for other training purposes by the Royal School of Military Engineering including practice and test bomb disposal tasks by the Defence Explosive Ordnance Disposal School, until its move to Bicester.