Home Introduction Greenwich Rotherhithe Excursion Riverboats Woolwich

The Forgotten Highway


English Heritage

Notes from archeological Survey taken before the site was demolished for the block of flats


The Greenwich Steam Ferry was opened on 13th February 1888. The engineers were Clark and Standfield, a -company which survives today as part -of the Lobnitz Marine Holdings Group.

The Ferry had three basic elements - two purpose-built steamers, and on either shore a landing stage and two carriages connecting the stage with the riverbank. -It is recorded that each landing stage was some 70 feet long by 50 feet wide, with a dead weight -of 27 tons, and the carriages 60 feet by 23 feet wide with a weight -of 125 tons (The Engineer 1892, 487). To cope with the tidal regime both the landing stages and carriages were designed to move -on wheels and rails up and d-own an inclined concrete ramp some 15m Wide, with the stage synchronised to the movement of the tide. There were four sets of rails on each ramp, laid on a standard railway gauge -of 4 feet 8½ inches: the landing stage had sixteen pairs -of wheels whilst each of the carriages had twelve.

The power for this operation was provided by stationary steam engines on both sides of the river, located within engine rooms immediately behind the river wall and below the adjacent roadway.' The contemporary account (ibid) records that the traveling carriages were linked by 4-inch steel wire cables to pair of 16 inch cylinder coupled engines, whilst the much slower-moving landing stage was hauled by a separate 6½ inch two cylinder engine. The cables passed through openings m the upper part of the river wall and were wound onto geared drums. To assist in the operation of the carriages the cables were also coupled to counterweights of over 20 tons, which were suspended within deep shafts inside each engine room.

The steam was supplied by three boilers of locomotive type, reportedly producing up to 140 lb. per square inch although seldom used to capacity. However, with the exception of the some there do not appear to be any detailed contemporary records of the Steam Ferry operation.

The ramp with its four sets of rails is clearly shown, whilst the Engine Room lies immediately to the south (the northeast corner of the present site). One of the carriages is illustrated on wheeled bogies drawn up to the shore. The section also shows one of the two counterweight shafts below the Engine Room floor. Each shaft was nearly 50m deep and about 3m in diameter.

The Steam Ferry did not prove a success - partly through competition, although it is arguable that the system was just too complex - and having been suspended in the early 1890s was finally closed around 1900. It is likely that the principal machinery, boilers, and other equipment were removed soon after this, although some elements such as the external rails may have survived longer.

Sometime after 1914 a single storey building was constructed on the ground above the Engine Room, and there is also a reference to the use of the Room itself as a wartime air raid shelter. More recently the inside face of the riverside wall was heavily reinforced with concrete. This latter has obscured all internal features, and based on the 1892 description of the river wall (ibid) probably extends at least 0.5m over the original floor. However, the approximate positions of the cable ports can still be seen on the external face of the wall.


8.2  The Engine Room -general description

The Engine Room survived up to the present day and remained a structure of some significance, although not listed or scheduled. In general appearance it formed a single large chamber, devoid 'of in situ machinery but with a number of features indicating its former use. Internal measurements were about 20m by 9m in plan, tapering at the western end to just over 1m. The main standing structure was of solidly mortared yellow stock brick, apparently frogged, over a concrete base. The room was divided into a series of bays east to west by more or less centrally placed iron pillars, supporting beams and a roof of the same material

The Engine Room floor was also constructed at two levels, with the finished surface in the eastern part at about I.80m OD and the western end (slightly less than one-third of the overall area) some 0.85m to 0.90m lower. These areas were separated by two steps that ran north south across the room: the roof height was also consequently higher to the west, up to 3.50m against 2.65m to the east. The other most notable feature of the floor surface was the two open counterweight shafts, located within the northern part of the upper area and each about 3m in diameter.

Although the Engine Room was only in use for about twelve years (1888 to c 1900) some changes may have been made to the operation of the layout: for example, it is known that the Ferry was suspended in the early 1890s.

The following sections describe the Engine Room in more detail, and broadly in terms of its constituent elements from the base up - foundation slab, evidence for machinery below and above floor level, roof support and construction, etc.


8.2.1 The foundation

The Engine Room was founded on a continuous slab of concrete, which during development works was broken -out to the west and south (although not exposed to the north in the vicinity of the river wall). Where observed the concrete was generally about 1m or 1.1m thick, this variation simply reflecting the two different floor levels (west to east) from a formation level that was more or less flat. There was no proportionate increase in thickness to the west, and in fact one area of about 2.9m by 2.3m in the southwest comer had a shallower base and was only about 0.1m thick. It is not certain whether this extended under the adjacent walls, and there is no obvious explanation for the change.

Although not reinforced the slab was generally very solid. The concrete mix was fairly coarse but homogeneous, with medium flint gravel aggregate plus scattered larger flints and brick rubble in a few areas. There was a finer surface screed (c 40-60mm thick where observed), and in some areas a looser basal layer up to 340mm thick.

 

Deposits immediately below the slab (with the exception of the earlier drain varied from a 'foreshore' type material of mixed gritty or sandy silt with a few fragments of shell and ceramic building material to a solid grey-green alluvium with occasional organic material. Where present the first of these deposits was quite shallow (generally <0. 1m) ,and probably associated with the construction, thereafter giving way to the sterile alluvium.

The main slab was therefore constructed as a raft over alluvial deposits, and did not {except probably to the north below the river wall) make contact with the underlying River Terrace gravel. This latter deposit was exposed during excavation of the earlier 19th century drain {cf section 7.), its surface recorded just over 1m below the base of the concrete slab {c-O5mOD).


8.2.2 Ground floor layout and features

The differing floor levels in the Engine Room reflect the two basic elements of steam power: the lower Western -end evidently forming the boiler area (Originally about 1m by 8m in plan), whilst the larger and higher level to the east contained the principal machinery. It was obviously desirable that the engines themselves would be more or less in line with the external cable ports and foreshore ramp.

The Boilers

Although defined Iv the general layout of the Engine Room, the position of the boilers is: also reflected in two sets of discrete features:


At floor level in the southern side there were three circular features within the concrete. The Western of these was heavily disturbed and the eastern had been partly removed by a small drain that probably postdates the operation of the Engine Room. However, the centre feature survived as an unbroken circular trough, just over 1m in external diameter and about 100mm wide by 60mm deep.

It seems clear that these mark the positions of supporting rings for one end of each of the three recorded locomotive-type boilers.

. Within the adjacent southern wall and in line with the above features were three circular shafts, each 1.3m in diameter and between 1.06m and 1.66m deep. The shaft linings had been prefabricated from iron plate riveted together to form sides and end, and then built into the waft during construction.

It is assumed that the shafts were to give access to the smoke box and tubes at the front end of each of the boilers. It is not known whether the markedly shallower depth of the western shaft indicates a different (?smaller) boiler.

There was no evidence for coal storage within the boiler area (or elsewhere in the Engine Room), although it is possible that there were one or more bunkers set against the now- obscured northern riverside wall, in proximity to the fireboxes. However, it seems likely that the bulk of the coal was stored at ground level. Similarly, there was no sign of a base for a chimney: nor; is this indicated on the contemporary OS map) although it does appear prominently in the diagrammatic section.

A few other features in the boiler area are worth noting, although not fully understood. One of these was metal shelf some 460mm square that was attached to the base of the westernmost roof pillar, some 0.6m above floor level. The western end wall also exhibited some evidence- a solitary metal rung 0.39mwide and 1.5m above the floor and about a metre to the south two offset slots c 150mm square and 124m to 1.13m above floor level. Given that this was the only area from which the Engine Room could have been accessed, it is quite possible that both features relate to a ladder or stairs.


The Engines

The upper floor area retained considerable evidence for the siting of machinery, including a central flywheel pit and a series of symmetrical features to the east and west that presumably relate to the coupled engines that moved the traveling carriages. The features included further wheel pits, a considerable number of bolts and rebates up to 250mm deep set into the floor surface, and various pipes and channels.

The dimensions of the central flywheel pit (2.3m long by 0.8m deep) suggest that the wheel itself was up to 2.2m (just over 7 feet) in diameter: it is evidently this feature, partially obscured; it can be seen in the contemporary cross-section (Fig 8). On the same basis the smallest pits either side of the flywheel would accommodate wheels with a diameter of about 1. 15m.   

The various pipes in the Engine Room floor included two of 25mm (1 inch) internal diameter, which had been laid around three sides of the presumed engine bases. Each pipe had six junctions (three to the east and three to the west) to take vertical feeders from the engines themselves, and then ran northwards apparently to discharge into one of the counterweight shafts. Elsewhere to the east there is evidence for other equipment, including several features with adjacent pipe channels that may have supported tanks. The circular impression in the southeast comer included a central hollow with a residue of heavy oil, which perhaps indicates storage of this material.

Evidence for the separate two-cylinder engine that was attached to the landing stage is less obvious. However, there are a number of features in the northern part of the area that may relate to the engine and its associated worm gearing (this latter to give the very slow rate of progress required by tidal movement). It is possible for this reason that the engine itself was set out at right angles to the two coupled engines. It has been suggested that the machinery may also have included an electric generator.

Above floor level there was limited evidence for the operation of the Engine Room, notably the two sets of brackets attached to the each of the central roof pillars. These were identical and both south-facing, set just behind and above the projected line of the east-west crank that held the flywheel. The possible route of feed pipes from the boilers was also marked along the southern wall of the Engine Room. To the west this included a group of holes in a pattern some of 15m square, and to the east pairs of projecting bolts set vertically c 0.25m apart and at intervals of about 2.4m.


 The shafts

At floor level within the northern part of the main Engine Room there were three shafts (Fig 9). The larger of these, to east and west, are readily identifiable as the counterweight shafts that -complemented the operation of the coupled engines and travelling carriages. It is likely that the drum!. for the respective cables would have been sited directly over the shafts, although no direct evidence survived. The tops of both shafts were surrounded by a circle of loose fill some 150mm to 200mm wide to which the concrete &or base formed a rough outer edge, which would suggest that a substantial supporting ring or similar has been removed.

The contemporary description gives the depth of both counterweight shafts at over 145 feet (44.2m) below the roadway (The Engineer 1892, 487). In recent years the eastern shaft has been dived and subsequently plumbed to the same depth from within the Engine Room - so in fact nearly 3m lower than the roadway.

The counterweight shafts were of similar although not identical construction. Both were lined by a series of -cast iron rings. which at top and bottom were flanged inward and securely bolted together. However the external diameter of the western shaft at ground level was 2.15m (9 feet) as against 3.05m (10 feet) for the eastern shaft. The depth and thickness of the lining rings were otherwise almost identical - respectively 1.53m and 38mm. Both also had an internal horizontal band at their mid-points this could not be closely examined but no corresponding external feature was exposed when the adjacent floor slab was removed. Thus it seems most likely that the band formed part of the original casting, to give added strength to the ring.

At floor level there was one further slight contrast between the shafts. To the east the -exposed ring had rectangular bolt holes of c 30mm by 3-8mm in a plain flange, whereas the slightly smaller ring to the west had circular holes of c 32mm diameter in a flange that had been cast with brackets on its underside.

Following excavation of the floor slab around the western counterweight shaft a more significant feature came to light. The smaller iron ring (and that directly below) were set within a larger ring, apparently identical to those used in the eastern shaft (Figs 16 & 17). The reason for this is unknown, although it may be noted that the -contemporary account given in The Engineer (1892) mentions that the shafts increased in diameter by 18 inches from top to bottom.

Between the two counterweight shafts was a smaller and quite different shaft, some I.84m (6 feet) in overall diameter. This was recorded in plan and subsequently during reduction of the adjoining slab to a depth of about 0.9m. The interior remained full of water but was plumbed to a depth of about 5.8m.

The shaft lining was constructed from iron plate formed to a cylinder and close-riveted, not unlike the inspection casings set in the southern wall of the boiler area (see above). The shaft included an integral top plate with a central cutout measuring c 0.9m (3 feet) square, and rivet heads -cut flush with the external surface (Fig 19). Internally the shaft was divided into two halves by a north-south metal plate, fixed to the adjacent lining. The top of this was just below the central cut-out: the base was not seen although the plate extended down fur at least 1m.

The purpose of this third shaft is unknown although it may well have supplied the fairly large quantities of water that would have been required by the boilers. In Operation this might not be easily obtained from the counterweight shafts, whilst the tidal and sometimes muddy river would not be an attractive source.

Next  Page Previous Page