Museum Station.
In 1926 the Institution of Engineers Australia published a series of papers in Transactions describing the Electrification of Sydney and Suburban Railways up to that date. They were republished as a facsimile edition by the Australian Railway Historical Society, NSW Division, in 1987.
One of the papers, by John Job Crew Bradfield, titled The City Railway covers that project in detail and it is from that document, in Bradfield's own words, that the following description is copied. Where figure numbers are used they follow the numbering used in the original publication.
Museum Station. (Fig.20)- Situated at the southern end of Hyde park, this station is served by the two tracks, Down City East and Up City East[1], at a rail level of 50.00 ft., being 45 feet below the surface. As will be seen from the figure, the roof consists of a single reinforced concrete arch of 48 feet span, with a total length of 520 feet.
Platforms with a width of 12 ft. 6 in. on either side of the arch are served by 8 ft. wide longitudinal subways, located on the outsides of the main arch and leading to concourses at each end of the station. The main concourse is at the southern end, giving entrance and exit at the corner of Elizabeth and Liverpool Streets, while the smaller northern concourse serves Elizabeth Street at a point opposite Bathurst Street.
Separate ingress and egress subways, stairways and barriers are provided, the incoming passengers enter at either end of each platform, whilst the outgoing passengers have four openings, intermediately located, for exit.
At the southern end, in addition to the above entrances, a system of subways is provided giving communication to the station from the footpaths adjacent to the three buildings on the opposite sides of Elizabeth and Liverpool Streets, whilst the large 12-foot subway also gives direct connection to Mark Foy’s Store. This arrangement will be of the greatest convenience to the public as the necessity of crossing the streets at surface level at this exceedingly busy corner is obviated.
In the design provision has been made for handling the largest number of passengers that the lines are capable of carrying. Concourses, passage ways, stairs, barriers and all offices have been therefore kept of ample proportions and designed for the maximum traffic.
The concourse construction is of steel beams encased in concrete. The southern concourse has columns spaced at 14 feet centres or less, of rolled steel joists set in concrete, having a total height from floor level to underside of roof of 14 ft. 6 in. The roof joists connecting the side walls are spaced 5 feet apart and support a reinforced concrete slab of varying thickness. Side wall columns being centered at 5 feet, are framed with channel bars and held in position by ¾ in. dia. tie rods, the concrete wall being finished to a thickness of 14 in. The subways have an inside width of 8 feet. With a clear height of 10 ft. 6 in. to the underside of the semi-circular roof. The walls and roof have a uniform thickness of 24 in. The main entrance and exit subways to the concourses are 10 feet wide, with the flat top construction and side walls of rolled steel joists set in concrete, having a thickness from 12 to 14 inches.
The rise from platform level to southern concourse is 17 ft. 4 in. and from concourse level to street 17 feet, making a total rise of some 34 ft 4 in., while the northern end is somewhat greater, having a rise of 38 ft. 4 in. to the level of footpath in Elizabeth Street. The main arch with its span of 48 feet clear, and height above rail to underside of crown of 26 feet, is supported on abutments having an average width of 15 feet, with the springing line of the arch 14 feet above rail, giving a rise of 12 feet to the arch. The intrados of the arch is segmental to a radius of 30 feet, with the extrados set to a radius of 34 feet.
The thickness of the arch ring (Fig. 22) at the crown is 21 in., reinforced top and bottom, with ¾ in. dia. bars at 9½ in. centres. The maximum compressive stress produced in the concrete at the crown, from the dead load was found to be 590 lbs per square inch, which was increased some 60 lbs per square inch by stresses due to a variation of 20° temperature and arch shortening, making the total stress in the concrete 650 lbs. per square inch.
The thickness of the arch ring at the haunches was 2 ft. 6 in. A construction joint was made between the abutment and the arch ring at a point 3 in. above the springing line of the arch, the joint being normal to the arch thrust. The maximum pressure on the abutment foundations, which are on poor sandstone, is 11 tons per square foot.
The " Bucyrus " dragline excavator which proved so efficient and economical on the other sections of the railway was unfortunately not available for the excavation of this station, which was carried out by navvies, supplemented by two steam shovels for a portion of the period. The total amount of excavation, including the subways, was 107,902 cubic yards. During the progress of the work, considerable quantities of shale and pottery clay were excavated and sold, also bands of red oxide of iron, which was used for colouring roofing tiles. A seam of coal, about ¼ in. thick, was also found.
Actual construction started with the concreting of the side walls and skewbacks for the arch, which were brought up to the level of the construction joint already referred to.
The falsework for supporting the arch was then erected and the reinforcement placed in position. The concrete was poured in sections of 30 feet per day, care being taken to ensure a good construction joint. The expansion of the arch ring was provided for by the placing, at intervals, of expansion joints, a detail of which is shown on Fig 22. Six of these joints were placed in the total length or the station, at distances of 76 ft. 8 in. to 137 ft. 8 in. and have given entire satisfaction.
The whole of the roof is waterproofed with a layer of asphalt, ¾ in. thick, and protected with bricks laid in cement mortar. The earth filling was then placed in position and the surface of the park restored. The waterproofing of the subways and concourses was also carried out in the same manner. Both concourses have installed a complete system of ventilation, which ensures a change of atmosphere every 10 minutes in the concourse and offices and every 5 minutes in the lavatories.
The drainage scheme for the station provides for the drainage of subways and batteryroom as well as the sewerage from the lavatory block, the whole of which after concentrating in a main shaft on the south side of the principal entrance stairway, is diverted by a 6 m. pipe (in tunnel) to the main Bondi sewer in Liverpool Street. Provision has been made throughout for the trapping off from the sewers, all the flushing and floor drainage branches, and a number of inspection chambers has been provided at the junction and bends, for the efficient cleaning out of pipes in case of blockage.
The construction of the passenger subways, across Elizabeth and Liverpool Streets, at the southern end of the station, involved a considerable amount of alteration to the existing sewers, water supply mains and telephone tunnel in Liverpool Street.
A new 18 in. water main along Liverpool Street to connect with the existing mains had been authorised by the Metropolitan Water, Sewerage and Drainage Board, which if carried out would have interfered seriously with the construction of the subways. It was therefore decided to divert the pipe from a point in Liverpool Street near Commonwealth Street across Hyde Park to Bathurst Street to intersecting points at Elizabeth, Castlereagh and Pitt Streets. This work was carried out by the Metropolitan Water, Sewerage and Drainage Board.
A 16 in. pipe sewer from Bathurst Street to Hay Street sewer, with a depth below surface level of 10 ft. 6 in., was also an obstacle to the construction of the two western branches of the subway. It was therefore decided to cut out a section of this sewer between the limits of subway construction and to divert the portion between Bathurst Street and the north side of Liverpool Street into the main Bondi sewer.
The telephone tunnel, which is situated under the southern footpath of Liverpool Street, presented a still greater difficulty. The tunnel which is 5 ft. 10 in. high, has a clear width inside of 4 ft. 6 in. ; the walls and semicircular roof are in 9 in. brickwork, over a 12 in. concrete floor.
It Is the main trunk for the telephone cables to the whole of the eastern suburbs. The tunnel clears the Up and Down City East structures but runs transversely across the line of passenger subways leading to the southern side of Liverpool Street. A plan was prepared, and the work duly carried out, which entailed the underpinning and deepening of the old tunnel, without interfering with the telephone services during the construction, and yet at the same time provided for the maximum amount of headroom under the passenger subways.
The existing 9 in. drain immediately under the floor of the telephone tunnel, between the limits of reconstruction, was removed, and at a point on the northern end of the tunnel, was diverted by a 9 in. pipe into an existing manhole on the eastern side of Elizabeth Street near the intersection of Clark Street.
For engineering drawings of the work at Museum select the links below.
Main Arch and Subways Cross Sections
- ↑ For railways in NSW trains and tracks heading towards Sydney are styled as UP and trains and tracks heading away from Sydney are styled DOWN. For a closed loop like the City Circle this convention is problematical. In 1926 Bradfield deemed that the 'circle' would run first to Town Hall and then in a clockwise direction, 'ending' at Museum. Thus trains travelling from St James to Museum would be moving away from Sydney Central and therefore DOWN. Plainly in common perception such a train would be taking the most direct, and until 1956 the only, route to Central and might be considered as UP. The two pairs of lines through the city were named as the 'City West' (via Town Hall and Wynyard), and the 'City East' (via Museum and St James). This nomenclature was particularly strange between 1926 and 1932 when there was no trafficable route at all on the City West, and after 1932 while there was no connection between Wynyard and St James. The terminology was later abandoned and the two loops renamed as the clockwise CITY OUTER and the anti-clockwise CITY INNER, though the platform numbers at St James and Museum still maintain the convention that UP trains travel via Circular Quay.
