1872 Institution of Mechanical Engineers: Visits to Works
Note: This is a sub-section of 1872 Institution of Mechanical Engineers
Visits to Works (Excursions) in the Liverpool area
General
The PRESIDENT moved a vote of thanks to the Mayor and Corporation of Liverpool, for their kindness in granting the free use of the Rooms in St. George's Hall for the purpose of the present Meeting of the Institution; to the Local Committee, and the Chairman, Colonel Clay, and the Honorary Local Secretary, Mr. Daniel R. Ratcliff, for their active exertions in promoting the success of the Meeting, and the very excellent arrangements made for the occasion. He also moved a vote of thanks to the Proprietors of the various Works so liberally thrown open to the Members during the Meeting; and to the London and North Western Railway Company for the important facilities so kindly granted to the Members for the Excursions, enabling them to visit the different Works opened to them.
These votes having been passed, the Meeting then terminated.
Laird Brothers
Laird Brothers
In the afternoon the Members visited Messrs. Laird's Shipbuilding and Engine Works, Birkenhead, where nearly 3000 men are employed. Five ships were seen in process of building, three of 3,400 tons each, and two of 2200 tons.
Two ships, the "Greece" and the "John Elder," were being lengthened 60 feet and 26 feet respectively, increasing their tonnage 700 and 300 tons, making a total of about 4300 and 4100 tons; and a very light steamer of only 2 feet draught was being constructed of steel, for use on one of the shallow western rivers of South America. Three pairs of compound marine engines of 600 horse power and two pairs of 400 horse power were seen in course of construction, and one pair of 450 horse power completed in the "Greece." These engines contain all the newest arrangements for ensuring economy and convenience of working; and among other things was observed an easy mode of access to the foot-valves of the air-pumps, by the introduction of a manhole in one side of the working barrel of the pump; the manhole cover is fitted in its place, and the air-pump barrel is then bored out with the cover in position.
The shops contain a number of heavy engineering tools for planing and boring the large and complex engine castings; and special facilities are provided for conveniently handling these heavy masses.
By the side of one of the docks, which can be used either as a floating dock or as a graving dock, is a large crane worked by steam power, capable of lifting 50 tons; and by this the engines and boilers made in the works are put into the ships after they are launched, while the roasting and outfit are being otherwise completed, so that the ships may leave the works practically ready for sea.
General
The Members were then conveyed by a special steamer, through the kindness of Mr. Charles MacIver, to visit the large Atlantic steamship "Scotia," lying in the Mersey. This is the last of the Cunard Co.'s paddle-wheel ocean steamers, and has a pair of single-cylinder engines of 100 inches diameter and 12 feet stroke, constructed by Messrs. Robert Napier and Sons; they are side-lever engines, the side levers being each formed of two solid wrought-iron plates bolted together; and the engine frames are an excellent combination of wrought and cast iron, giving great strength.
In the evening the Members were entertained at Dinner in St. George's Hall, by invitation of the Liverpool Engineers and Shipbuilders and Steam Ship Companies.
On Tuesday and Wednesday afternoons the following Engineering Works and Manufactories &c. were opened to the visit of the Members:—
- Messrs. Fawcett Preston and Co., Phoenix Foundry.
- Messrs. George Forrester and Co.Vauxhall Foundry.
- Messrs. James Jack, Rollo, and Co., Victoria Engine Works.
- The Mersey Steel and Iron Works.
- Messrs. Thomas Milner and Son, Phoenix Safe Works.
- Messrs. Francis Morton and Co., Galvanised Iron Works.
- Messrs. Walker Campbell and Co., Tinned Lead Pipe Manufactory.
- Messrs. Radford's Flour Mills. Buchholz system of decorticating grain, and making semolina and flour by means of fluted metal rollers.
- North Shore Flour and Rice Mills. Hungarian system of grinding. Carr's disintegrating flour mill.
- Ventilating Fan of Lime Street Railway Tunnel, Smithdown Lane.
- Liverpool Water Works. Audley Street Pumping Engine and Reservoir; Windsor Pumping Engine; Kensington Reservoir.
- Liverpool Gas Works.
- Chain-Cable Testing Works.
- Grain Warehouses. Hydraulic grain-traversing machinery.
- Messrs. Earles and King, Seed Crushing Works.
- Messrs. A. M. Smith and Co., Seed Crushing Works.
- Messrs. Cope Brothers, Cigar Manufactory.
- Ocean Steamers of the Liverpool Steam Ship Companies.
- The Bidston Observatory, Birkenhead.
On Thursday, lst August, an Excursion was made by the Members by special train from Liverpool to visit several Collieries and Iron Works &c. in the neighbourhood of Wigan.
Pemberton Colliery
The Pemberton Colliery of Messrs. J. Blundell and Son was first visited. At the working shaft, which is 640 yards deep and 17 feet diameter, the heapstead is constructed entirely of iron, the staging being carried on lattice girders supported by cast-iron columns with lattice bracing, the whole forming a very durable and stiff framework. The cages each hold six tubs, and have three decks; the ropes, cages, and tubs are all made of steel. The large conical winding drum is 30 ft. 6 ins. diameter, and weighs with the shaft about 49 tons; it is arranged for winding from the depth of 630 yards in 214 revolutions, the time occupied being 48 seconds, which gives an average speed of about 26 miles per hour in the shaft; the drum is driven by a pair of horizontal engines, with cylinders 36 inches diameter and 6 feet stroke, and Cornish valves. The pulleys over the pit mouth are 18 feet diameter.
The large Guibal ventilating fan is 46 feet diameter and 15 feet wide, constructed of steel, and driven by a horizontal engine with 36 inch cylinder and 3 ft. 6 ins. stroke, a duplicate engine being provided to meet any emergency. The fan is running at present at only about 38 revolutions per minute, giving a vacuum of 2.45 inches water gauge and a current of 155,600 cubic feet of air per minute; but when in full work it is intended to run at 50 revolutions, at which speed it is calculated to give 230,000 cubic feet per minute. Some of the boilers supplying steam to the winding engines and fan engine are fitted with mechanical fire-grates, some on Vicars' and the rest on Taylor's plan, the latter being a modification of Juckes' grate (see Proceedings Inst. M. E. 1869 page 155).
Rylands and Sons
The Members next visited Messrs. Rylands and Sons' Cotton Mill, recently erected and furnished with the latest improvements in the machinery for spinning and weaving cotton. The weaving shed contains 1158 looms, all of the same pattern, and the driving belts are led off horizontally on both sides of the main lines of shafting, and pass down over guide pulleys to the looms; the strains thrown upon each line of shafting by the pull of the belts are thus equalised, and the friction consequently reduced. The mill is driven by two pairs of single-cylinder horizontal engines, with cylinders 40 inches diameter and 6 feet stroke.
Wigan Coal and Iron Co
The Wigan Coal and Iron Co.'s Works were then visited. There are ten blast furnaces, five of which are 80 feet high and 24 feet diameter at the boshes, and five are 65 feet high and 18 feet diameter. They are all closed at the top with a bell and charging hopper, and the gas is taken off for the boilers and hot-blast stoves. The weekly make of each of the larger furnaces is about 350 tons, and of the smaller about 300 tons; the ore smelted is principally red hematite from the Ulverstone district, with a proportion of aluminous ore from the neighbourhood of Belfast.
The blast is supplied by three compound-cylinder blowing engines, each of which is an inverted beam engine with the high-pressure cylinder of 45 inches diameter at one end of the beam and the low-pressure cylinder of 66 inches diameter at the other end. Above each steam cylinder is a blowing cylinder of 100 inches diameter, the same piston rod passing through both. No flywheels are used to control the engines, and the stroke is about 11 1/2 feet, the speed being about 10 1/2 to 12 double strokes per minute; the steam valves are worked by tappet gear. An auxiliary blowing engine is provided, of vertical direct-acting type, having a 35 inch steam cylinder and 70 inch blowing cylinder, with 4 feet stroke.
A large chimney 350 feet high and 13 1/2 feet internal diameter is erected for producing the required draught in the boilers heated by the blast-furnace gas. Extensive coal-washing machinery is employed for purifying from sulphur the slack which is made into coke for use at the ironworks.
Rosebridge Colliery
The Members then proceeded to the Rosebridge Colliery of Mr. J. G. Morris, where they descended the shaft of 815 yards depth and 16 feet diameter, the deepest shaft at present in England. The time occupied by the cage in traversing this depth is not quite one minute, giving a mean speed of about 30 miles per hour in the shaft. The winding drum of 26 feet diameter and 40 tons weight is worked by a pair of horizontal engines with cylinders of 36 inches diameter and 6 feet stroke.
Platt Lane Colliery
At the Platt Lane Colliery of the Wigan and Whiston Coal Co. the working was shown of Messrs. Winstanley and Barker's Coal Cutting Machine described at the meeting. The machine was seen in operation in the hard seam of coal known as the "Pemberton Little Coal," of only about 2 feet 4 inches thickness, in which it has now been at work daily or nightly for the last two years. The compressed air by which it is driven is supplied by an engine at the pit mouth, having 16 inch steam cylinder with 36 inch stroke and air-compressing cylinder of the same size, compressing about 200 cubic feet of air per minute from atmospheric pressure to 40 lbs. per square inch above atmosphere.
Ince Hall Coal and Cannel Co
Ince Hall Coal and Cannel Co
The Ince Hall Coal and Cannel Co.'s Works were then visited. At this colliery the system of hauling the coal tubs by endless chains is extensively carried out, along tramways both on the ground level and raised on timber staging. By this means, with the expenditure of only a small amount of power, all the produce from the several pits is concentrated at one place, and there screened and sorted. The hauling chain simply rests on the top of the tubs, its weight giving hold enough for hauling them; and when not resting on the tubs, it is supported clear off the ground by cast-iron rollers. The endless chain working each section of tramway passes round a horizontal drum at each end of the section, one of these drums being the driving drum. The system of underground haulage by means of compressed-air engines is extensively carried out in the pits.
Ince Hall Rolling Mills Co
The Ince Hall Rolling Mills Co.'s Works were also visited. They have been recently erected, and contain a forge train of 20 inches diameter, with two finishing trains of 16 and 9 inches diameter; the forge train and 16 inch mill are driven direct from the flywheel shafts by two independent horizontal engines, with cylinders 26 inches diameter and 4 and 3 feet strokes respectively; the 9 inch mill is driven from the second motion shaft by an independent horizontal engine with cylinder 22 inches diameter and 2 ft. 6 ins. stroke.
Return to Liverpool
The Members were entertained at luncheon at Wigan by the Wigan Coal and Iron Co., refreshments having also been kindly provided at the several works visited; and they returned to Liverpool in the evening by special train.
The engine drawing the special train throughout the excursion was worked on Warsop's plan of injecting a continuous supply of heated air into the bottom of the boiler, for the purpose of preventing the formation of incrustation, and for increasing the evaporating power of the boiler by promoting a more active circulation of the water (see Proceedings Inst. M. E. 1870 page 229).
The locomotive was a six-coupled goods engine that had been running several months with the aero-steam boiler, the air being supplied by a single-acting pump of 6 inches diameter and 2 feet stroke, worked from one of the main crossheads. Before entering the boiler the air is driven through a coil of 1 1/2 inch lap-welded wrought-iron pipe, 61 feet long, arranged in the smokebox, and is then injected into the water through a perforated pipe lying inside the bottom of the boiler.
On Friday, 2nd August, an Excursion was made by the Members by special train from Liverpool to Runcorn and Crewe.
Widnes Metal Co
The works of the Widnes Metal Co. were first visited, where was seen the extraction of copper by the wet process and of silver by Claudet's process from the refuse burnt pyrites supplied from sulphuric acid works. The pyrites (bisulphide of iron) consists originally of nearly 47 per cent. of iron and 53 per cent. of sulphur, with minute proportions of copper and silver in the state of sulphides; but the burnt pyrites, from which most of the sulphur has been extracted for making sulphuric acid, retains only about 31 per cent. of sulphur, while the proportion of copper is increased to about 4 per cent.; about 12 dwts. of silver are contained in each ton of burnt ore.
The burnt pyrites, having first been crushed fine between rollers, is mixed with common salt (chloride of sodium), and the mixture is roasted in reverberatory gas furnaces, whereby part of the salt is converted into sulphate of soda, and the insoluble sulphides of copper and silver into chlorides, which are soluble in brine. The roasted mass is then exposed to successive washings in a series of large wood tanks; the first three washings serve to carry off the chloride of silver, and after the separation of the silver, these liquors, together with those from the further washings, are run into a tank containing a quantity of wrought-iron scrap, upon which the copper is precipitated from the solution by decomposition of the chloride. The rest of the solid matter left in the tanks, after the precipitation of the copper, is known as "purple ore," and consists mainly of peroxide of iron, containing from 60 to 70 per cent. of iron, and in this state is used as " bull-dog " for the lining of puddling furnaces.
The liquors drawn off from the first three washing tanks contain the chloride of silver in solution, and by the addition of soluble iodide of zinc the silver is precipitated as an insoluble iodide; this is afterwards treated with metallic zinc, which decomposes the iodide of silver, liberating the silver, and forming soluble iodide of zinc, ready to be used again for precipitating further quantities of silver from the chloride solution. Salt cake (sulphate of soda) is also recovered from the liquors by subsequent treatment.
William Gossage and Sons
The Members next visited the Widnes Soap Works of Messrs. Gossage and Sons. In the manufacture of soap, a weak solution of caustic soda, called "lye," is boiled in a large wrought-iron pan, with the addition of a certain proportion of fatty matter, such as tallow, or palm or cocoa-nut oil; and resin is added for yellow soap. The boiling is effected by blowing steam into the bottom of the pan, and the mixture is treated with successive additions of stronger lye, undergoing between each a thorough boiling, until the fatty matter has taken up all the soda possible and has thus become completely converted into soap; the excess of lye settles at the bottom of the pan, and is drawn off.
The charge of soap is then drawn off from the pan without hand labour, by means of air pressure; the top of the pan is closed by a cover, the joint being made air-tight by an india-rubber packing ring, and compressed air is forced into the top of the pan by a pump, whereby the entire liquid mass of soap, amounting to as much as 20 tons, is expelled from the pan, being forced up through a discharge pipe passing through the cover, and flows through a long trough into the moulds. These are 45 inches long, 15 inches wide, and 52 inches high, each containing about half a ton of soap, and are made simply of four cast-iron side-plates secured by clamps; the soap takes three days to cool and solidify, and the sides of the mould being then removed, the large block of soap is cut horizontally into slabs, which again are divided into bars by a wire frame.
The bars of the finer qualities are cut into cakes, which are stamped in a press having a heavy falling die lifted by a cam. The lye, or solution of caustic soda, is concentrated to the required strength for the soap-boiling pan by waste beat of the soda furnaces.
The manufacture of "silicated soap" was seen, in which a solution of silicate of soda is employed in place of a portion of the tallow or oil used in the soap-boiling pans, thus producing a much cheaper soap with equal cleansing power. As ordinary soap owes its cleansing power to the fact that the soda, which constitutes the real detergent, is only in a state of weak combination with the tallow or other fatty substance, the latter can be to a considerable extent replaced by silicate of soda, in which soda exists only in weak combination with silica, thereby retaining its cleansing power, as in ordinary soap. The silicate of soda, known as "soluble glass," is made by melting in a reverberatory furnace a mixture of fine white sand (silica) and soda ash (dry carbonate of soda); the melted charge is run out through a tap-hole, and solidifies in lumps of a kind of glass, which is soluble in water.
John Hutchinson and Co
The Alkali Works of Messrs. John Hutchinson and Co. were then visited, and the various processes connected with the manufacture of sulphuric acid and soda were seen. In making sulphuric acid, iron pyrites (bisulphide of iron) is burnt in kilns, and the sulphur being driven off in the form of sulphurous acid gas is conducted into large leaden chambers, 30 to 70 feet square and 20 to 25 feet high, along with air, steam, and nitric acid vapours, by which the sulphurous acid is oxidised; the floor of the chamber being covered with a few inches depths of water, the resulting sulphuric acid is condensed and collected in the water, and the dilute acid flows off continuously through the lute joint all round the bottom of the leaden chamber. This acid is employed without concentration for the manufacture of sulphate of soda, by mixing it in shallow cast-iron pans with common salt (chloride of sodium) from the Cheshire salt mines; hydrochloric acid gas is evolved under a moderate heat, and the residue being afterwards roasted in a reverberatory furnace till nearly free from acid, becomes "salt cake" (sulphate of soda). The hydrochloric acid gas driven off, which was formerly wasted by being discharged into the atmosphere, is now almost entirely saved by being made to pass upwards through a tower containing a mass of open brickwork or coke, through which a slight shower of water is kept constantly falling; the gas is absorbed by the water, and the acid thus formed is collected at the bottom of the tower. The salt cake (sulphate of soda) being roasted with small coal and limestone by Leblanc's process in a revolving furnace, these materials are converted into carbonate of soda and sulphide of calcium, the mixed product in this state being known as "black ash."
Hand furnaces are also used, and in some of these the mass is stirred during the roasting by Dormoy's rotary rabble; and when thoroughly converted the melted mass is drawn out, cooled, broken up, and placed in lixiviating vats, where the carbonate of soda is dissolved out of the black ash by water, leaving insoluble "waste." The solution of carbonate of soda, called "vat liquor," is treated either by causticising or by salting-down.
In causticising, the vat liquor is boiled by steam with caustic lime, whereby the carbonate of soda loses its carbonic acid and is converted into hydrate, the solution of which, after being concentrated in pans, is supplied for soapmaking and other manufactures; it is also further boiled down in iron pans till nearly red hot, and on cooling, the solid caustic soda is either packed in iron drums or run on to plates to be broken up. In salting-down, the vat liquor is boiled down by waste heat from the black-ash furnaces, till converted into a mass of grey crystals called "salts," which is calcined in a reverberatory furnace till quite white, when it is called " soda ash;" this is carbonate of soda, and is again dissolved in hot water, and the solution being allowed to settle and crystallise in iron pans forms hydrated crystals of carbonate of soda, the "soda" used for ordinary domestic purposes.
Bicarbonate of soda, from which effervescent liquors are made, is produced by placing the soda crystals in iron chambers, through which carbonic acid gas, generated by the action of hydrochloric acid on limestone (carbonate of lime), is passed for several days, driving out the water of crystallisation, and adding a second equivalent of carbonic acid to the carbonate of soda; the bicarbonate is gently dried in kilns and ground in a mill. The insoluble black mud or "waste" left in the lixiviating vat, consisting mainly of sulphide of calcium, was formerly altogether thrown away and wasted, but is now utilised for the manufacture of sulphur by Mond's process. For this purpose air is blown through it while still in the vat, to oxidise a portion of it into soluble hyposulphite &c., which is then lixiviated with water, and the solution mixed with hydrochloric acid; pure sulphur is thereby precipitated, which is washed, melted by superheated steam, and run into moulds. Bleaching powder is manufactured by Deacon's process; hydrochloric acid gas is decomposed by being passed over sulphate of copper heated to 800° or 900° Fahr., and the resulting chlorine gas after being washed and dried is passed into slate chambers containing slaked lime; hypochlorite of lime is thus produced, which forms the bleaching powder, evolving free chlorine when moistened with water.
Runcorn Railway Bridge
The Members proceeded from Widnes to the Runcorn Railway Bridge over the Mersey, which is constructed of lattice girders in three spans of 305 feet each in the clear, with 75 feet clear headway above high water level. The depth of the girders is 28 feet, and the top and bottom flanges are 5 feet wide and of box construction; the floor of the bridge is wholly of wrought iron. The deflection in the centre of each girder, when tested with sixteen of the heaviest locomotives on one span, did not exceed 1 inch. The river piers are of masonry and brickwork, resting on the red sandstone rock; the foundations extend to a depth of 45 feet below high water, and were put in by means of cast-iron cofferdams.
Crewe Works
The Crewe Locomotive and Steel Works were then visited by special train. In the extensive shops of the locomotive works a large number of engines were seen in all stages of construction and repair. In the boiler shop the testing was witnessed of samples from the Bessemer steel plates, 3/8 inch thick, now being adopted for the locomotive boiler shells; these plates are required to have a tensile breaking strain of 34 tons per square inch, and to stand an elongation of 25 per cent. before breaking, and a 5/8 inch hole punched in a sample strip of 3 inches-width, cut from each plate, is required to stand drifting out to 2 inches diameter without the metal cracking. In the extensive Bessemer steel works the process of tyre-making, the duplex hammers, and the reversing rolling mills, described at previous meetings of the Institution, were seen in operation. The Members were entertained at luncheon at Crewe by Mr. Webb, the Locomotive Superintendent of the London and North Western Railway; and the special train returned to Liverpool in the evening.
Marston Hall Rock Salt Mines and White Salt Works
Marston Hall Rock Salt Mines and White Salt Works
On Saturday, 3rd August, several of the Members visited the Marston Hall Rock Salt Mines and White Salt Works, near Northwich, belonging to Mr. William Hayes.
The bed of rock salt worked at these mines is situated at a depth of 110 yards from the surface, and has a thickness of about 50 yards, of which only the best portion of about 7 yards thickness is now being worked, the workings having been commenced in 1851. The roof of the workings is supported by pillars about 10 yards square at intervals of 30 yards; the extensive caverns thus formed were well displayed by the burning of coloured fire for their illumination on the occasion. There is no water to contend with, and no provision for ventilation except the two drawing shafts about 4 feet diameter and 15 yards apart, either of which serves as downcast or upcast, according to chance. The bottoms of the shafts open in the roof of the workings, no shaft pillar being left round the bottom of either shaft.
The working faces are pushed forwards in two banks, the upper one, of about 3 yards height, being carried a few yards in advance of the lower bank, which is worked as a quarry by blasting. The upper working face is undercut, and broken down with powder, and Walker's rotary cutting machine is employed for the undercutting, having a horizontal wheel 4.5 feet diameter, which carries a set of cutters fixed round its circumference, and gears by bevil teeth on its upper face with a driving pinion upon the crank shaft of a pair of horizontal cylinders worked by compressed air at a pressure of about 40 lbs. per square inch; as the cutting progresses, the machine is hauled along the face of the rock by a winch worked by manual labour. The groove is cut to a depth of about 27 inches in from the face and is about 3 inches wide, and the rate of advance of the machine is from 8 to 10 yards per hour.
The greater part of the rock salt is shipped to Holland and Belgium, where it is dissolved to form brine from which common white salt is obtained by evaporation. The rest is crushed fine between rollers and riddled, and is supplied partly for the copper and alkali works, but mainly for agricultural purposes, for which, owing to its containing 7 per cent. less impurities than common white salt obtained by evaporation, and these impurities being also of use as valuable fertilisers, it is gradually superseding the use of common salt; the latter takes 1/2 ton of coal to produce 1 ton of salt by evaporation, and consequently costs about 6s. per ton more than the screened rock salt.
At these works was also seen brine pumped from natural springs by shafts 75 yards deep; the brine is run into shallow evaporating pans, and white salt is deposited by evaporation.
See Also
Sources of Information