Scheduled Monument: Portsmouth Dockyard, the Block Mills and Stores 35 and 36 (1001851)

Site Description Details: Visit Date: 00/OCT/1967 This is a very important group of buildings sited on top of the 1691 Ship Basin which survives largely intact underneath. When No. 6 Dock was constructed, the Ship Basin was converted into a reservoir for the dock pumping system. In 1800, General Bantham put in two tiers of brick vaulting and roofed the top in level with the ground. The three buildings were erected shortly afterwards. It is possible to visit part of the Old Ship Basin. The upper layer of vaults were designed to be used for storage purposes but proved too damp once the steam engines were removed from the Block Mills. The lower tier of vaulting is still used as a reservoir for the docks. The upper tier has had blast-walls put in during the 1939-45 war, but the massive masonry of the ship is still largely intact. The buildings above are important from an industrial archaeology viewpoint, for it was here that Marc Isambard Brunel installed his block making machinery. This marked an important development in the history of woodworking plant but more especially in the history of mass production and automation. Brunel's machines broke the monopoly of the Taylor family of Southampton, and in the first year of use the new machines turned out 100,000 pulley blocks. Four of these original machines are still in place, and still in use. The overhead drive shafts and pulleys also survive, though now driven by electricity. The three buildings date from c.1800, though it is possible that No. 35 Store was heightened at some early period. The two outer buildings - 35 and 36 Stores - are three storey. They are connected by the single storey Block Mills, and the whole complex faces No. 6 Dock. Nos. 35 and 36 Stores are of red brick with grey headers, the Block Mills red brick. No. 35 Store: this has three storeys and cellar, a stone plinth, stringcourse above ground floor, brick cornice and parapet with stone capping. Behind this is a hipped slate roof with skylights at the E and W ends. The W end has three square-headed windows to each floor, with their wooden glazing bars largely intact. Part of the hall and parapet have been rebuilt. On the ground floor the central bay has a double door with a light above. Also on this level the drain pipes have been recessed into the brickwork. The S face has eleven window bays. On the ground floor there are two doorways, each with double doors with lights over. The stone cills on this level are badly worn, and some of the brickwork is renewed. The first floor has two doorways, one of which is modern and leads to a fire escape. The doorway in the centre bay was originally destroyed for loading purposes. There are double doors and an iron loading platform. This is now a second fire escape. On the second floor the loading bay is similarly a fire escape, though in addition it has a modern hoist. A modern doorway has been inserted into the adjacent bay to the W. The parapet above has been largely rebuilt. The E end of No. 35 originally had one very wide opening on the ground floor. The heavy wooden beam is still in position, but the centre has a brick infill, and there are two double doors at each end. The three windows on the first and second floors are square-headed, and have their glazing bars intact. The parapet is rebuilt. The interior of No. 35 Store is still largely original. The ground floor and basement at the W end provided the original home for Brunel's steam engine for driving the block machinery. Although the engine has long since vanished, the semi-circular brick arch which connected with the Block Mills still survives, as do the chimneys from the boilers. One of these is in the centre of the building, the other at the W end. Both are completely hidden from outside: both are square in section and rise into the attic storey. Here they have been cut off just below the ridge level. Neither penetrates the present roof. The ground floor has a single line of wooden pillars supporting the floor above. In the centre is a massive braced timber construction. This was almost certainly something to do with the flywheel of the steam engine which is known to have been large. In the cellar, which only extends for the first three bays at the W end, there is only one original pillar surviving. This is mounted on a granite base. The E wall of the cellar buts on to the top of the Old Ship Basin, and consequently is made of masonry, though brick infilling appears in places. On the first and second floors, the original double row of wooden pillars are still in place. These are generally stop-chamfered. On the second floor a wooden open-tread staircase leads up to the loft. The wooden linings are still intact on the second floor. The main staircase is in the NE corner of the building, and is almost certainly contemporary with the structure. The first floors of Stores 35 & 36 are connected by a covered wooden passage which runs across the top of the Block Mills. This passage is slate-covered and may well date back to early in the C19th. No. 36 Store. This is very similar to No. 35, the principal differences being that it has a pitched gable roof and its main doorway is at the W instead of the E end. A fair amount of the brickwork, particularly the gables, has been renewed. The W end has had a very wide doorway on the ground floor. This extended the full three bay width of the building, and although the beam remains in situ, the N quarter of the opening has been bricked up. On the first and second floors there are two square-headed windows with loading doors in between. The second floor still has its loading platform and wall crane. The N side of No. 36 has had all its eleven bays of windows renewed with metal frames. In addition, windows at the W end have been bricked up, and some renewal of brickwork has been undertaken. Part of the stringcourse is missing, and an iron fire escape is a later addition. The E end has three semi circular-headed openings on the ground floor. The outer ones have double doors in them. The centre one has been partially bricked up, but has a semi-circular window. The first and second floors have the same arrangement as the E end. The glazing bars are intact. Inside No. 36, the arrangements of the first and second floors are the same as in No. 35. The wooden pillars survive, most of them are chamfered, and the wooden window linings are also fairly intact. The roof is of unusual construction: it is a concertina one, which dates back to before 1924. Presumably when it was put in, the ends were altered into their present gable shape. The first and second floors are used in the block manufacturing process and contain some of Brunel's machinery and drive shafts. All the first and second floor windows in Stores 35 and 36, which overlook the Block Mill in between, have their glazing bars intact. The Block Mills: this is a later one storey addition filling up the space in between Stores 35 and 36. At the E end, it projects for two bays, though its end wall is largely hidden by a modern lean-to. Both ends have pediments hiding the slates behind. At the E end, this hipped roof has a clerestory projecting. The W front has three recessed round-headed arches, the outer with doorways with windows over. The central arch has a wooden sash window, its glazing bars intact. The pediment has a lunette window in the tympanum. A stone stringcourse runs the width of the building. Inside the building is a double row of turned wooden columns which support the pulleys and drive shafts for the machinery as well as supporting the roof.