(Paper No. 3118.) "The Pahartali Locomotive and Carriage Works, By CHARLES FREDERICK BAMFORD, Assoc. M. Inst. C.E. THE site of the Locomotive and Carriage Works of the AssamBengal Railway was chosen at a sufficiently high level to avoid damage from tidal waves, and in close proximity to the main line and to the terminal station at Chittagong. The surrounding land is capable of being well drained and is free from jungle; it is, as far as possible, healthy, and suitable for the erection of quarters for labourers and mechanics. The shops are lighted from the north to minimise the heat from the midday and afternoon sun, and the roofs of the buildings are arranged with their slopes of least resistance in line with the direction of the prevailing winds, which come from the south and south-west, and were designed to resist cyclones. The shops were also laid out so that the proper sequence of operations could be followed, to minimise labour and thus lessen the cost of construction and repair of the rolling stock. The general arrangement of the workshops and lines of rails connected to the north side of the main line is shown in Fig. 1, Plate 4. They are situated 2 miles distant from Chittagong terminal station of the Assam-Bengal Railway, and 1.87 mile from Chittagong Port, to which a branch runs from the main line at Pahartali. The three buildings, viz., foundry and smith shops, the machinery and erecting shops, and the carriage upholstering, painting and wagon shops, are placed side by side 80 feet apart; each is capable of future extension southwards. The centre line of the 40-foot steam-carriage traverser extends 800 feet east and west, and is 90 feet from the north frontage-line of the three main buildings. Twelve lines are laid at right angles from the traverser-line into the carriage upholstering, painting, and wagon shops, and three lines from the traverser through the erecting shop are connected with the workshop siding on the south side of the shops. The 40-foot steam traverser is also connected up from the south to the workshop siding by four lines running between and on each side of the three buildings. The Saw-Mill and Carriage-Building Shop is placed on the northside of traverser, opposite the carriage and wagon shop, 180 feet distant. Three lines are laid at right angles from the traverser line into the saw-mill and carriage-building shop, and at the northeast end of the traverser line are ten lines, for building and repairing iron wagons, and a line is laid completely round the shop to terminate at a turntable placed inside of the north-east corner of the boundary. The Time-Keeper's Office and tank-house has been placed at the north-west side of the workshop yard, and water is pumped to it from a well 650 feet distant. From this tank-house water is supplied to the shops and to engine shed. The site is also suitable for the time-keeper's office, as it is in close proximity to the station. The Engine Shed, which will be capable of holding sixteen engines and tenders when the extensions have been completed, has been placed opposite to Pahartali station and outside the north end of boundary wall; four lines pass through the shed and along each side of the building. Outside both ends of the engine-shed inspection pits are placed under each line, each 53 feet 6 inches in length. The General Store Building is situated opposite the foundry and smith shop, with store-yard at back covering an area of 61,193 square yards, and railed off from the locomotive yard by a wooden paling. A line is led from the workshop siding, through a gate into the store-yard at the south end, and out again at the north-east corner, terminating at the turntable placed at the north-east corner of locomotive-yard. The General Locomotive Superintendent's Office is a building of one storey, having a verandah on each side of the different offices so that a circulation of air can pass through each room from the doors and windows that look out on to the verandahs for coolness. Outside the west boundary-wall and parallel to the main line are three lines for carriage sidings, covering a length of 4,500 feet. In close proximity to the engine-shed has been placed a locomotive and carriage weigh-bridge and turntable, and between the machine and carriage and wagon-shops has been placed a carriage-examining pit 150 feet in length. The Erecting and Machine-Fitting Shops, Fig. 2, Plate 4, are contained in one building, measuring 200 feet by 164 feet 7 inches, which is separately divided by brick walls with arched openings into three divisions, each measuring 40 feet clear. The outside walls are 18 inches thick and have projecting pilasters, base cornice, and parapet wall. The walls are carried down 5 feet 7 inches below the floor-level, and rest on 1 foot 6 inches of concrete. The openings with semi-circular tops measure 12 feet 6 inches by 13 feet to crown. The division-walls, between the erecting shop and the machine and fitting shops are 2 feet 6 inches thick from the ground-level up to a height of 2 feet, and 2 feet 1 inch thick to the roof. The buttresses that carry the longitudinal traverser-girders are 1 foot 3 inches thick, by 2 feet 6 inches in width, also those that carry the cross-girders are 1 foot 3 inches thick, by 2 feet 6 inches. The arched openings with semi-circular tops between the buttresses measure 14 feet 2 inches by 15 feet 6 inches to crown. The centre division com prises the erecting shop; the east and west division, the machinery and fitting shop. These divisions are spanned by N girders, 20 feet apart, carried on? bed-stones let into the buttress-walls. The girders in the erecting shop measure 43 feet 4 inches over all, and are divided into six bays 7 feet 3 inch centres; those in the machinery and fitting shops are 41 feet 10 inches over all by 3 feet deep, and are divided into six bays, 6 feet 8 inches centres carrying at each apex a light roof truss. The upper boom consists of one plate 41 feet 10 inches by 1 foot 6 inches by inch, two L's 4 inches by 3 inches by inch, and the bottom boom of one plate extending over two centre bays, 16 feet by 1 foot 6 inches by inch. The vertical struts are each made up of four L's 3 inches by 2 inches by inch, which are riveted on to the angle-irons of the upper and lower booms. The diagonal tension members are made up as follows: end bays, two bars 3 inches by 1 inch, second bays, two bars 3 inches by § inch, centre bays each two bars 3 inches by inch, and two bars 3 inches by inch. The trusses that are carried on these girders are saw-shaped and carry the corrugated-iron roofing. These measure 19 feet 3 inches from centre to centre of intersections. The rise to the apex of pitch-line measures 6 feet 3 inches, which is set back 2 feet 43 inches horizontally from centre of intersection. The rafters are built up of T's 4 inches by 3 inches, by inch, and main tension members of 1 inch diameter rods; the short compression members are placed at right angles and are bolted to the main rafters set at a distance of 9 feet inch from end; they are also bolted at the lower end to the centre of the main tension members, which are two flat bars 2 inches by inch, bolted at ends to the Trafter and rod tension member; these bars are kept at a distance of 3 inches apart at the centre by cast-iron ferrules. The diagonaltension tie-rod is 1 inch in diameter with forged eye, bolted to gusset-plate, connecting the T rafters at their apexes, and also connected at the lower end, which is forked with forged eye, and pinned to the centre of the main tie-bar. The acute pitched rafter Tiron carries the four LI purlins, which carry the corrugatediron 18 B. W. G. flute, 3 inches by inch sheet roofing; these purlins are connected to the rafter by means of LI cleats. The obtuse pitched T-bar rafters carry the teakwood window-frames and windows that face the north. The gutters are of a large section, so as to carry away the heavy monsoon rainfall, and are made of thin sheet steel inch thick and bolted to the LI purlins at the ends of the trusses. In the erecting shop the height from floor-level to the bottom boom of the cross-girders is 28 feet; this height has been given so as to allow sufficient headway for a 30-ton traverser, which is carried on longitudinal rails and girders resting on the side-wall buttresses. This traverser is driven from the main shafting by rope gearing attached to the side walls. Between the two lines of rails that pass through the erecting shop are brick engine-pits 2 feet 9 inches wide by 3 feet 7 inches deep. A third pair of rails passes down the centre. The Erecting Shop has accommodation for sixteen locomotives. The frame plates are taken to a vacant berth on the side road of the erecting shop, and are there fixed in position over the engine pit. The cylinders are then fixed, and the boiler, by the aid of the travelling crane, is lifted into its place on the frame from the centre road, and the wheels with axles and axle-boxes placed under. The eccentric and connecting-rods having been fixed, and the valves set, the locomotive is lifted upon the running road that passes down the centre of the shop, and drawn to the weigh-bridge where the weight on each wheel is adjusted. It is then tested by water- and steam-pressure, and, with its tender, which is constructed in another part of the erecting shop, it is taken by the carrying traverser to the paint shop. The Machine and Fitting Shops are arranged in two bays, each measuring 200 feet long by 40 feet wide; they extend along and are placed on the east and west side of the erecting shop, and are divided off by brick walls with arched openings and semi-circular tops, measuring 14 feet wide by 15 feet 9 inches to crown of arch; these openings are 20 feet apart from centre to centre and are spaced between the buttresses carrying the cross girders. The outside, east and west walls have openings with semi-circular tops measuring 12 feet wide by 13 feet to crown; these openings are filled in with honeycomb 15-inch brickwork, or doors and windows as desired. The height from floor-level to bottom boom of cross girders is 18 feet. In both divisions two main shafts are carried along each of the side walls, and pass between the end bays of the cross girders; these shafts are supported by cast-iron brackets attached to the side walls and connected by belting. From the four main shafts are driven counter shafts, supported at a lower level in bearings with brackets bolted to the side walls, from which are driven the light and heavy machines; arrangement is also made for four other counter shafts being carried in bearings supported on the bottom boom between the second bays of the cross girders. The machine and fitting shop is provided with a large number of turning lathes, planing, shaping, milling, slotting, drilling, screwing and tapping machines. These tools are arranged in rows along the shop and driven from the overhead counter shafts. The machines stand upon solid brick and concrete beds. Also a number of benches is supplied for fitting work and setting out purposes. Running along the centre of the bay in each division is a single rail along which runs a walking jib crane, supported at the top in box girders attached to the centre of the cross girders and driven by overhead rope gearing. These cranes are used for lifting heavy pieces of machines and castings on and off the heavy lathes and machines placed on each side near the centre of the building. On the floor between the two rows of light and heavy machinery runs a light narrow-gauge line for use in transporting the materials required to be moved between the various shops. The engine-house measures 20 feet by 20 feet, and is joined on to the east side of the machine shop. The engine is of the compound horizontal type. The main shaft in the machine shop is driven directly off the main driving fly-wheel pulley by manilla rope belting. The steam-pipe from the Galloway boilers placed beside the foundry is carried across on columns. The Carriage Upholstering, Painting and Wagon Shops, Figs. 3, Plate 4, are contained in a building measuring 200 feet long by 212 feet 1 inch in width. This department is bounded on the east by the machine and erecting shop and on the north by the sawmill. The outside walls are 18 inches thick and have projecting pilasters, base cornice, and parapet wall; the walls are carried down 5 feet 7 inches below floor-level and rest on concrete foundations. The door openings measure 12 feet 6 inches by 13 feet to semi-circular tops. The bays five in number, each 42 feet, are placed transversely to the line of rails. Three lines of rails. |