A Shipbuilding History. 1750-1932 (Alexander Stephen and Sons): Chapter 9
CHAPTER NINE. Linthouse Engine and Boiler Works
IT was not until the Firm arrived at Linthouse from Kelvinhaugh, in 1870, that it possessed an engine works of its own. The buildings which were then erected for the construction of engines and boilers are still in existence although now more than doubled in size, and equipped with the most up-to-date machinery and handling-plant.
It is a far cry in the evolution of the engineering industry from 1870 to 1932, although as time goes, it is a comparatively brief period. The original portions of the buildings erected sixty years ago, at that time the last word in industrial architecture, appear ponderous and unsightly to the modern eye, accustomed to light steel and glass. The roofs, though liberally provided with glass, were otherwise entirely of wood, while the supporting-columns were of cast iron. These cast-iron columns served various purposes besides the usual ones of carrying the roof and providing support for the travelling-crane girders. One column in each bay acted as the bed of a vertical single-cylinder steam-engine, some 8 or 10 ft. above the floor, which supplied power for driving machine tools through a shaft running the length of the shop. Other columns formed the base of the heaviest machine-tools, viz., the vertical and horizontal planing-machines, or "wall creepers," to give them their familiar name.
Until shortly after the year 1900, the power of the machine and boiler-shops was derived from the aforementioned steam-engines. As soon as electrical power production became a practical proposition, the Firm installed a large plant to produce its own electricity, and gradually changed over from a complete steam-driven plant to a completely electric one. When the distribution of electrical power from the city power stations became available, a proportion was taken from this outside station, which ultimately became the sole source of power for the works. This in its turn, is now being gradually changed over to the National grid system, which, incidentally, means the alteration of many motors in the works, to suit the common frequency.
During the period of change from steam to electric power, the engine and boiler works were both doubled in size, and a corresponding increase in equipment added for greater output.
Until 1912, the products of Linthouse engine and boiler works consisted of steam reciprocating engines and Scotch marine-type boilers, commencing in the 'seventies with compound condensing engines for paddle and propeller drive. A gradual increase in speeds and powers brought with it the triple-expansion, and finally the quadruple-expansion engine, balanced on the Yarrow-Schlick-Tweedy system. Although the Firm had become licensees of Messrs Parsons for the building of turbines, in the year 1905, and two ships — the yacht Emerald in 1903, and the Allan Liner Virginian in 1905 — had been built at Linthouse and fitted with turbine machinery made at Parsons' works, it was not until 1912 that the first turbines were built at Linthouse. In that year an order was received from the Anchor Line for a twin-screw single reduction geared turbine passenger liner for their Glasgow—New York service. This vessel, the Tuscania, had a power of 10,000 S.H.P., and a sea speed of 17 knots. The Tuscania, which went on service in February, 1915, and is not to be confused with the post-war Tuscania, was torpedoed during the War. There followed during the War, and after, a long series of turbine-driven ships both of the Parsons' reaction and Brown-Curtis impulse type. During the War the boiler shop had also its experience of turning out water-tube boilers of Yarrow and Company's design.
From 1912 onwards, an almost complete metamorphosis has taken place in the machine shops and boiler works, due to the belief of the management that only the best and most up-to-date plant is suitable for turning out the class of work for which Linthouse is celebrated. To-day, it would be difficult to find half a dozen pre-war machine tools in the works, and continual additions and renewals are made from time to time.
The advent of the Diesel engine caused another revolution in machine-shop methods and standards of accuracy. In 1920, the Firm, after carefully weighing the advantages and disadvantages of the various types of engine then on the market, took out a licence from Sulzer Brothers, of Winterthur, Switzerland, for the manufacture of their famous two-stroke engine. The first order obtained for Stephen-Sulzer machinery was in 1922. This installation was for the M.V. Dalgoma, a twin-screw cargo vessel for the British India Steam Navigation Company Ltd. The power developed by the two 4-cylinder engines was 3,200 B.H.P., and the principal dimensions were — stroke 1,100 mm. and cylinder bore 680 mm., the revolutions being 86. This ship continues to give good service at the present day.
ENGINE SHOP
The engine shop consists of four bays, each over 400 feet long, two of which are served by overhead cranes. At the end of one of these bays there is a special test-bed suitable for testing Diesel engines up to 6,000 H.P. with a water brake.
The most interesting machine tool in the engine shop is probably the recently installed high-speed planing-machine. This machine has a capacity of 5 ft. x 5 ft., with a table stroke of 16 ft. The table is divided so that one half can be working while the second half is being loaded.
A Lancashire drive with a 30 H.P. motor is fitted, giving cutting speeds up to 250 ft. per minute and return speeds up to 300 ft. per minute, while a special tool lifting device, operated by compressed air, is fitted to all tool boxes. This tool lifting device, which has been developed at Linthouse, is almost essential when using the new Tungsten carbide tools, in order to prevent chipping of the cutting edge on the return stroke.
Another new machine, which is rapidly revolutionizing numerous operations, is the oxygen-cutting machine. This machine, which has been developed from the oxy-acetylene blow pipe, is capable of cutting to templet from mild-steel billets up to 16 inches in thickness. The surface of the cut as it leaves the machine is so good that in a large number of cases no machining of the surface is required. Such parts as crank webs, eccentric straps, large spanners, valve bodies, mast bands, and many other items previously forged in the Smithy, are now cut direct from steel billets. Recently, a large mast band for use in connexion with a 40-ton derrick, was cut from a billet ten inches thick, in a little over an hour, with an expenditure for oxygen of just over twenty shillings. It was calculated that it would have taken two smiths about a fortnight to forge a similar article.
Several interesting machines have recently been installed in the tool room, among which may be mentioned an electric-furnace for tool tempering and hardening; a dynamic balancing machine for balancing the fan impellers used in connexion with oil fuel plants, and a rotary converter which is capable of supplying alternating electric current at any voltage, frequency, and phase, for testing motor-driven oil fuel plants.
Electric welding is another process which is rapidly expanding in marine engineering, and a number of single operator machines, using alternating current, have recently been installed, as well as two spot-welding machines.
In 1930, the plumbers' shop was rebuilt, and among the new tools installed at that time the outstanding one is a large flash-welding plant of 120 kw. capacity, capable of welding steel flanges on to pipes up to seven inches in diameter. The operation is carried out as follows:
The flange, which has a spigot of the same diameter as the pipe, is held against a copper head by two triggers operated hydraulically; the pipe is also held in hydraulic grips, and is brought into a concentric position with the spigot on the flange, and into touch with it. A low voltage current is then passed through the flange and pipe and an arc forms at the point of contact at the same time an hydraulic feed moves the pipe a certain predetermined distance towards the flange, the hydraulic pressure depending on the diameter and thickness of the pipe. The current is cut off a few seconds before the hydraulic pressure is released, with the consequence that a forging action takes place on completion of the weld. The resulting weld is practically equivalent in strength and resistance to fatigue to the original material, and microphotographs show a structure completely free from oxydized material. The Board of Trade and Lloyds have now approved this type of flange for high pressure water- and air-pipe lines. The highest output of the engine shop in a year was 135,000 indicated horse power.
BOILER SHOP
The boiler shop is of ample size to produce all the boilers required for Linthouse-built ships. There is, in fact, a considerable margin, and many boilers have been constructed to replace old ones, or for firms whose establishments do not include boiler shops.
The maximum turnover of the shop is, approximately, one single-ended Scotch boiler of, say, 15 ft. diameter per week, or fifty boilers per year.
The plant in the shop, which consists of two large and two smaller bays, is modern, and adequate for all the demands so far made upon it for Scotch or water tube types of boilers. The usual heavy hydraulic flanging press and riveting machines are in evidence, the latter for riveting both front and back circumferential seams of the boiler shells. The main plate-heating furnace is oil fired on the "Clyde" system, manufactured in the Firm's works.
All the most up-to-date facilities for electric welding, pneumatic riveting, etc., have been added in recent years.
The boiler works, although threatened with extinction by the Diesel engine, may yet have a long and useful life ahead.
It would occupy too much space to give descriptions of the many outstanding sets of machinery produced by the Linthouse shops, or installed in Linthouse-built ships, in recent years, but the following brief account of a few should prove of interest.
TWIN-SCREW PASSENGER VESSEL VICEROY OF INDIA
Although the main propelling machinery of this now famous ship was not constructed in the Firm's works, the whole installation marks a new step in the sphere of marine engineering in Britain, and Europe.
The turbo-electric machinery, supplied by the British Thomson-Houston Company Ltd., of Rugby, consisted of the following: Two slow-speed synchronous motors, each coupled direct to a propeller shaft and capable of developing together 17,000 S.H.P. at 109 r.p.m. The motors receive their power from two high-pressure steam turbine-driven alternators having a maximum speed of 3,110 r.p.m. Steam is supplied by six Yarrow boilers and two Scotch boilers, working at pressures of 375 and 230 lbs per sq. inch respectively. The high-pressure steam is superheated to 700 degrees F., for which the turbines are specially designed. The working of the ship, including cooking, deck machinery, and steering-gear, is almost exclusively electrical, the latter being of the well known electric hydraulic type manufactured by Brown Brothers, of Edinburgh. This vessel realized all her owners' and builders' highest expectations, both as to performance and popularity, as a passenger-carrier on the Bombay mail run. TWIN-SCREW STEAM YACHT ROVER
Though vastly different in size and power from the last-mentioned vessel, the machinery installation of the S.Y. Rover has also its points of interest. The majority of large yachts built in recent years have been fitted with Diesel machinery, but unless a yacht is to be used for extended ocean cruising, where a large radius of action without re-fuelling is of primary importance, the Diesel engine can hardly justify its high initial cost. While fuel economy at sea is of importance in a yacht, as in any other vessel, fuel economy while at anchor also plays a large part in overall running costs, while low maintenance charges for repairs are essential. Silence and absence of vibration at all times are imperative, and these can most readily be obtained with steam machinery and boilers.
The main propelling machinery of the Rover consists of two four-crank triple-expansion balanced engines, capable of developing 3,000 I.H.P. at 160 r.p.m. In addition to being fully balanced on the Yarrow-Schlick-Tweedy system, each engine has in the centre of its crankshaft a heavy cast-iron flywheel. The balancing was so successful, and the turning moment so even, that it is impossible to tell at any speed that the vessel is not driven by turbines or other rotary engine.
Another feature of the engine room is the attention paid to reduction of staff, by making so far as possible, all lubrication automatic.
Steam is supplied by three large Scotch boilers using oil fuel, and fitted with superheaters.
All electric power on the ship is supplied by three 60 kw. turbo generators. A large secondary battery is installed, of sufficient capacity to supply lighting throughout the ship at night, thus allowing all machinery to be shut down.
PASSENGER STEAMERS CORFU AND CARTHAGE
As an example of the most modern installations of high-pressure water tube boilers and single-reduction geared turbine, no better choice could be made than the above two ships, completed at the end of 1931.
The main propelling machinery, all built at Linthouse, consists of two sets of Parsons' single-reduction geared turbines, six turbines in all, developing 15,000 S.H.P., at 120 r.p.m. propeller speed. The turbines, of the all-reaction type, are designed for a stop-valve pressure of 400 lbs. per sq. inch and an initial steam temperature of 725 degrees F. The steam consumption of 7.5 lbs. of steam per S.H.P. at full power is equal to the very best modern practice. The fuel consumption, also, at .68 lbs. of oil per S.H.P., is a most satisfactory achievement. Steam is supplied by four Yarrow water-tube boilers.
REFRIGERATED MOTOR CARGO VESSEL OPATVA
There is no better example of the Firm's latest Diesel engine output than the above twin-screw motor ship Opawa, engined by twin 9-cylinder Stephen-Sulzer engines constructed in the Firm's works in 1930-31. The power developed is 9,400 B.H.P. at 120 r.p.m. giving a sea speed of 15.25 knots. The principal dimensions of the engines are — cylinder bore 680 mm., piston stroke 1,200 mm.
As this vessel is designed for refrigerated cargo, the list of auxiliaries is particularly large. There are three Diesel-driven electric generators, each of 300 kw., and, in addition, a 100 kw. turbo generator, taking steam from waste heat boilers at sea, and from an oil-fired boiler in port.
From the foregoing instances of the variety of engineering work produced, it will be evident that the Linthouse engine and boiler works of 1932 must be equipped with every variety of up-to-date machinery and tools to deal with the construction of machinery of all powers, with marine engines of every type, steam reciprocating, steam turbines, gearing, and internal combustion Diesels, and with boilers of all makes, water tube, Scotch, and vertical. This very variety of marine propulsive machinery is indeed one of the difficulties of the engineering trade at the present day, as a shop equipped yesterday for the efficient output of, say, turbines, may to-day require expensive extension and re-organization for Diesels, and to-morrow may find it necessary to again extend for electric propulsive machinery, or whatever other type may evolve in the future. The works are, however, fully equipped to deal with this variety of types, and the foregoing description is merely a general outline, with some notes on the more important tools and plant.
WORK CARRIED OUT FOR OTHER FIRMS
(1) GEAR CUTTING
In the year 1917, when it appeared that the geared turbine had been proved a success and was beyond the experimental stage, it was decided that the cutting of gears should be undertaken at Linthouse.
A Muir-Melloy machine was installed, and up to the present time twenty-five sets of gearing have been cut for the machinery of vessels built at Linthouse. These include, with one exception, all the torpedo-boat destroyers built by the Firm, the remainder being for merchant ships.
In addition to those required for Linthouse-built ships, contracts have been carried out for nine other well known marine engineering firms. To the firm of Barclay, Curle and Co. Ltd. alone, ten sets of gearing have been supplied. In 1928, Messrs. Scott's S. and E. Co. Ltd. placed an order for the gears for one of the latest British torpedo-boat destroyers, H.M.S. Ardent. Another important contract, carried out in 1931, to the order of Messrs. Yarrow and Company Ltd., was a twin set of gears for a 40,000 S.H.P. flotilla leader, the Dubrovnik, for the Yugo-Slav navy.
Modern marine gear-cutting is an extremely precise form of work, and all hobs used are tested for accuracy at the National Physical Laboratory, while the machine itself is frequently dismantled and the slightest error corrected. To this care and attention bestowed on the machine, the Firm attribute their conspicuous success in gear cutting.
(2) CONDENSERS FOR ELECTRIC POWER STATIONS
Large condensers have been built in the Linthouse boiler shops for Worcester and other land power stations. This, and other work in the form of steel shells for evaporators and feed heaters, has been carried out to the order of Messrs. G. and J. Weir Ltd., of Glasgow.
(3) OILY WATER SEPARATORS ("COMYN" PATENT)
With the increasing use of oil as fuel on board ship, and the resulting waste and nuisance caused by discharging overboard oily water from bilges or tanks, the necessity for some form of separator is obvious. With this in view, the Firm took up the manufacture of the "Comyn " separator for Messrs. Separators Limited. The work is of a nature suitable for the boiler shop, and the demand for the article is increasing as its advantages become known.
(4) OIL BURNING PLANT: CLYDE OIL FUEL SYSTEM LIMITED.
The manufacture of oil fuel burning plant has occupied a prominent place in the engine works of the Firm since 1921.
By agreement with the Clyde Oil Fuel System Limited, formed in 1920, Alexander Stephen and Sons Limited became sole manufacturers for all their products. Practically the whole field of oil burning is covered by the large variety of apparatus turned out of the shops at Linthouse. A list of these includes the largest installations on marine and land boilers of all types, boiler plate heating furnaces, rivet heating furnaces, lime kilns, cooking ranges, central heating installations and many others.
Marine installations of note are to be found in vessels belonging to the Royal Mail Steam Packet Co, Peninsular and Oriental Steam Navigation Co, British India Steam Navigation Co Ltd., and most of the other large British ship owning companies.
Central heating installations range from those required by the largest buildings, hotels, offices, factories, etc., to the smallest domestic automatic sets for private houses. The latter have recently become very popular and are selling in large numbers in this country.
Some of the buildings so fitted are the new Bank of England building, London; the North of Ireland Houses of Parliament, Belfast; the Royal Mail Company's new offices, Leadenhall Street, London; the Royal Mint (for gold refining); J. and P. Coats's factories, etc.
In addition to supplying the home market, a large export trade is carried on with India, South America, and Continental countries.
VACUUM CLEANING
Another side-line in engineering, which has proved most successful, is the manufacture of the "Clyde" turbo exhauster for vacuum cleaning purposes.
As in the case of the oil-burning plant, Alexander Stephen and Sons Limited are sole manufacturers for the firm of Barr and Company, Glasgow, who sell the machine for the purposes of factory dust collection, railway carriage cleaning, passenger ship cleaning, power station duty, public buildings, restaurants, warehouses, theatres, cinemas, hotels, etc.
The apparatus consists of a multi-stage electro-turbo blower or exhauster, designed to blow or draw through a very efficient filter.
The whole plant, which is extremely compact and simple in its construction, is placed in any convenient or central position. In buildings it is generally in the basement or on the ground floor, and a system of piping is led to the points at which the dust extraction or cleaning takes place. This up-to-date labour-saving device has achieved great popularity in many large buildings throughout the country, and may be seen in operation at the Gleneagles Hotel, Perthshire, and a large number of similar establishments.
UNUSUAL ALTERATIONS
The records of a firm engaged in shipbuilding, from the dawn of the industrial age until to-day, must naturally include a number of highly interesting and specialized undertakings outside the ordinary requirements of the trade.
Earlier examples of unusual structural alterations, such as the lengthening of the Oscar, in 1813, have already been mentioned, but the present century has also its share of "major operations" which merit special attention. Since 1901 three existing ships have been lengthened at Linthouse, the length added in the first case being thirty feet, and fifty feet in the other two.
In the first instance, in 1901, the ship, Port Morant, was still on the stocks, while the other vessels, the Miltiades and Marathon, returned to their birthplace in 1912, after nine years' service, to be lengthened in dry dock, their finished weight being increased by about 1,000 tons.
In every case the vessels were cut through at near amidships, but forward of the engine and boiler space, so as to necessitate no alterations to the machinery. One half of the ship was then moved by tackles along greased ways, similar to launching ways, for the required distance; the extra structure was then built in and made one with the separated portions. Though simple enough to describe, the operation demanded great care and forethought to ensure the separated portions remaining in line during their journey apart; in order to provide the extra strength necessary for a longer vessel it also entailed the addition and riveting on of considerably more steel than that merely required for the new midships.
These operations were undertaken at a time when the facilities for such work were still very limited; in 1912, for example, the method of cutting steel plates by burning was not in existence. In the case of the Miltiades and Marathon, the weight of the one end was about 2,500 tons no small weight to be moved and placed in a new position without deviating a hair's breadth!
Further important structural alterations to existing vessels were also undertaken in 1925. In this case the problem was to cut away the under-water portion of the forward end of two large liners, of 17,000 tons, and fit structures of new form without disturbing the upper portions of the ships, or rendering the alterations so extensive as to be economically impracticable.
The vessels so altered were the California and Caledonia, two of the class of five liners built by the Anchor Line when reconstructing its fleet after the War. The lines for all five ships had been designed by the owners' naval architects and tested by model experiments at the Teddington tank, to ensure the most economical power and fuel consumption. Although the unusually full underwater lines of the bows gave excellent results in the still waters of the experimental tank, when the first ships of the class went into service (before the Linthouse vessels were completed), their commanders reported severe slamming in heavy weather in mid-Atlantic; in fact, the bottoms of their foreholds were found to have rivets started and plates stove in.
The owners called a general meeting of captains, naval architects and builders, and, after considerable discussion, the Stephens' representative proposed a bow form of V-shaped section, which could be built without undue alteration and at reasonable cost. This new bow form, after being tested under wave conditions in the Teddington tank, was approved, and it was decided to perform the operation on the California, which was nearly ready for launching. Her bows were, therefore, cut away, leaving the heavy weight of the top decks to be supported on shores, while the new form was built in underneath. The alteration was entirely successful, not only in curing the slamming and resultant structural damage, but in improving the fuel consumption in Atlantic weather. Following its success, the other ships of the fleet, including the Caledonia, were dry-docked and altered to the same model.
Apropos the Teddington tank referred to above, it may be noted that Froude's method of ascertaining the resistance of a ship, by means of scale models towed in a tank, has always been of great interest to the Firm. Indeed, many years before the ship-model testing tank was installed at the National Physical Laboratory, Teddington, an apparatus was erected over the condenser-tank at Linthouse.
In this latter tank, which was about 45 ft. long and formed the roof of the power-house, many models were towed, their speeds and resistances being measured by an apparatus devised by Fred J. Stephen. The most obvious part of this apparatus is a pendulum, adjusted to record half-second beats on a rotating drum, and the machine, though crude, and exposed to all the winds that blow, gave remarkably accurate results.
The tank was used on many occasions when the Firm estimated for vessels of unusual form or speed, such as the small channel steamer, Mourilyan. An outstanding instance of its accuracy was that of the Wyandra, built in 1902 on the measured mile this vessel exceeded her contract speed of 14 knots by .002 knots, thus evading a heavy penalty, largely by the help of the model experiments carried out in the Linthouse condenser tank. Such accuracy could hardly be exceeded to-day with even the most approved appliances.
In later years a more modern tank was built, and a special shed erected for the old apparatus which, equipped with certain improvements, continued to do valuable work until the tank authorities at Teddington introduced the system of testing models equipped with working propellers — a most important improvement, which put an end to the testing of models alone.
The aforementioned testing apparatus is but one of the many inventions which have originated at Linthouse. Indeed, it is safe to affirm that few ships of to-day have been built or equipped without the aid of some Linthouse-devised gadget, and certainly every Stephen-built vessel has many distinctive fittings designed to enhance her efficiency.
Until welding takes the place of riveting, for instance, a steel ship can hardly be constructed without the use of the countersinking machine described elsewhere, while as long as wooden decks continue to be laid, use will be found for the Linthouse electric deck-caulker. Again, all ships with pretensions to efficient equipment will be fitted with the hydraulic skylight-lifter, and the Ralston stability indicator in the chartroom, besides other Linthouse devices of more recent date.