Aremarkable intuitive faculty and a firm belief in the value of experiment contributed largely to the success of Sir Charles Algernon Parsons, not only in the adaptation of the turbine principle to generators and marine propulsion, but also in his other scientific activities
BORN ON JUNE 13, 1854, Charles Algernon Parsons was the son of a brilliant astronomer, the third Earl of Rosse, of Birr Castle, Parsonstown, Ireland. Educated at Dublin and Cambridge, Parsons served with various engineering concerns before he established his own firm of C. A. Parsons &. Co. The name of Parsons is indelibly associated with the amazing development of steam turbines.
FROM his association with the steam turbine, Charles Algernon Parsons is fast becoming recognized as a genius entitled to rank with the famous James Watt. Both men made a change of fundamental importance to the engineering practice of their day, but beyond this there are not many parallels in the life story of the two great engineers.
Watt started life with few material advantages and was handicapped with a constitutional despondency which called for the constant support of his virile partner, Matthew Boulton. Parsons, though modest and unassuming, disregarded criticism and refused to be daunted by mischances. His early days, too, were spent in surroundings of culture and comfort.
Born on June 13, 1854, Charles Algernon Parsons was the fourth son of the third Earl of Rosse, of Birr Castle, Parsonstown, Ireland. The earl was a famous astronomer, a sound political economist, a good chemist and a brilliant amateur engineer. The historic 6-feet reflecting Rosse telescope, with a focal length of 54 feet and weighing 15 tons, was the largest of its day, and was not based on precedent. To build it the earl had to make himself familiar with the art of casting and polishing reflectors and had to train, step by step, men from the village of Parsonstown to provide labour. All the massive parts required were made in the precincts of the old castle.
The telescope was completed nine years before the birth of Charles Parsons, so that the boy grew up in the shadow of a great achievement and in an atmosphere of practical science and full-scale engineering. He was not sent to a public school, a circumstance he was afterwards known to deplore, but he had a succession of distinguished tutors, among whom was Sir Robert Ball, later Astronomer Royal. Sir Robert instilled in his pupil a love of scientific pursuits and taught him how to use his father’s telescope.
Astronomy, as such, however, made little appeal to the boy, as he was mainly interested in the, mechanical movements of the telescope. From this he turned to other engineering pursuits, and with one of his brothers, also still a youth, he built a steam engine to drive the apparatus for polishing telescope reflectors. The next production of the pair was a steam motor car which attained a speed of ten miles an hour and contained the modern devices of a cardan shaft, bevel drive and gearbox.
At the age of eighteen Parsons was sent to Trinity College, Dublin. A year later he went to St. John’s College, Cambridge, to study mathematics and to gain a further knowledge of optics and mechanics. As there was then no engineering laboratory at Cambridge, Parsons converted his rooms into one, filling his study with optical instruments and cardboard models of mechanisms of his own design. His analytical mind soon led him to the conclusion that the ordinary reciprocating steam engine was defective in so far as the to-and-fro movement of the piston had to be converted into a circular motion, whereas the energy of the steam ought to be expended in producing this circular motion without any intermediate stage.
Watt also had early realized the truth of this principle and had patented a rotary engine, not a turbine; but the idea was abandoned for the well-known reciprocating beam engine. Parsons’ faith in the rotative engine was not shared by his fellow students, and his production of a model to them, with the statement and demonstration that it would go twenty times as fast as existing engines, was followed by the prompt deposition of model and inventor underneath the table. Parsons left Cambridge in 1877 with the place of Eleventh Wrangler in the Mathematical Tripos.
From Cambridge Parsons went to the Armstrong Works at Elswick, Northumberland, as pupil-apprentice. There he experimented with a form of rotary engine in which the cylinders rotated round a revolving crankshaft at half the speed of that shaft. This engine was one of those he had visualized at Cambridge and four or five examples were made by Kitson’s, of Leeds, a firm which Parsons joined as experimentalist after having left Armstrong’s. At Kitson’s a subject Parsons investigated was the possibility of propelling torpedoes by rockets. The rotative engine was not abandoned, but he was not satisfied that a sufficient degree of simplicity had been reached and the principle of the turbine began to take a stronger hold of his mind. Having become a junior partner in the firm of Clarke, Chapman, Parsons & Co., of Gateshead, Parsons was able to develop his ideas. In 1884 two patents were filed which may be said to mark the beginnings of the modern steam turbine. Rather less than a year afterwards the first practical example of a turbo-generator was built at Gateshead. This machine, now in the Science Museum, South Kensington, developed only 4 kilowatts. From then until 1889, when the partnership was dissolved, several turbines were built, each successively showing improvement in design and increase in size, though the largest was of only 75 kW. This turbine was non-condensing and worked with a steam pressure of 100 lb. per sq. in, the temperature being 338° F. The steam consumption was 55 lb. per kilowatt-hour, that of the first turbine made being about 129 lb. per kilowatt-hour.
By 1930, the year before the inventor’s death, turbines were being made with a power of 50,000 kW, and consuming only 7.4 lb. of steam per kilowatt-hour. This last figure is the most significant, for the attainment of economy in fuel consumption is the ultimate aim of the mechanical engineer. The 50,000 kW turbine was, however, condensing, and had a steam pressure of 600 lb. Per sq. in. at a temperature of 800° F., the condenser having a vacuum equivalent to a barometric pressure of 29 in. when the barometer stood at 30 in.
Watt did not invent the steam engine, but he created a machine which departed fundamentally from the crude appliances of his time; similarly Parsons did not conceive, in the turbine, a thing which had never been thought of before. At the time when his patent was taken out, more than one hundred patents for rotating engines had been filed in the preceding century, and a distinguished Swedish engineer, Gustaf de Laval, was at work contemporaneously on a turbine of a different type.
Visions Become Realities
The de Laval turbine is in use to-day, though its field is somewhat limited. Numerous as had been the workers in the past, however, not one of them seems to have grasped what was really required. The genius of Parsons was needed to transform visions into realities.
The partnership at Gateshead was dissolved because of Parsons’ unfaltering belief in the future of his turbine, a belief not shared by his partners. The patents being joint property, some difficulties arose about their transfer to Parsons when he set up a firm of his own under the title of C. A. Parsons & Co., at Heaton, Newcastle-on-Tyne. It was not until 1894 that the matter was settled and he gained full possession of the patents, an immediate result being the formation of the Parsons Marine Steam Turbine Company.
The five intervening years were, however, by no means wasted by Parsons, for in them he did an enormous amount of work in developing an alternative type of turbine which would not infringe the original patent. This type was the radial flow turbine in which, as its name implies, the steam flow through the machine is radial, in either the inwards or outwards direction, relative to the shaft. The original patent was for a turbine with the flow parallel to the shaft, and it is this type which is now, in essentials, adopted — though numerous improvements in detail have been made. From this fact it may be rightly inferred that the radial flow turbine did not come up to expectations, yet the complete investigations made with it cleared the air for the successful design.
THE ORIGINAL STEAM TURBINE made by Charles Parsons in 1884 now rests in the Science Museum. South Kensington. The engine was used for driving a dynamo and ran at 18,000 revolutions a minute. Steam was admitted in the middle of the casing and passed outwards through the alternate moving blades of the rotor and the fixed blades of the casing in both directions.
The formation of the Marine Steam Turbine Company was signalized by the most revolutionary and spectacular developments of the Parsons steam turbine, namely, its use for marine propulsion. Before this the chief use of the turbine had been for driving the electric generator, a duty for which it is particularly well suited because of its uniform torque or turning movement. The development of the electrical industry of to-day began with the installation in the year 1888 of four 75-kW. turbo-generators in the power station of the Newcastle and District Electric Lighting Company, the first power station in the world to be thus provided. The boldness of this step is indicated by the fact that the Parsons dynamos were driven at speeds of from ten to twelve times faster than those of any machine previously built.
The story is told that Parsons announced his projects for marine propulsion in the simple statement that he proposed to build a ship for the purpose “of fitting it round his turbine and a propeller”. He was as good as his word, for be set to work on the 100-feet Turbinia. Engines, propeller and hull of the Turbinia were designed from his own researches. In default of a ship-testing tank, such as that at the National Physical Laboratory, Parsons used the condensing pond at the Heaton Works for his experiments on the model hull. His results, obtained with most primitive apparatus, were remarkably accurate, as they agreed within 1 per cent of those made long afterwards with all modern refinements on the same models at the National Physical Laboratory.
There was one thing, however, which the tests did not reveal — propeller cavitation. This phenomenon may be briefly described as the formation of vacuous cavities in the water near the propeller blades, and its discovery arose from the unprecedented speeds of the propeller with the new motive power.
The “Turbinia’s” 34 Knots
This trouble proved so serious and stubborn that, in all probability, any other man than Parsons would have been beaten. But he was determined to overcome it and finally did so, though it cost him about three years’ hard work and some £25,000. The model tests had led Parsons to expect a speed of 34 knots for the Turbinia and, sure enough, the vessel herself tore through the water at this speed at the Spithead Review of 1897.
Though this spectacular proof of the possibilities of the Parsons turbine aroused the attention of the Admiralty, it did not destroy its traditional caution. It was with extraordinary' safeguards that the Admiralty permitted two torpedo-boat destroyers to be built with turbine machinery. Both vessels were lost at sea before they had an opportunity of showing what they could do, but the Admiralty made a direct comparative test by having one of four light cruisers, H.M.S. Amethyst, fitted with turbines and the other three with the then standard reciprocating engines. That was in 1902. H.M.S. Amethyst proved over 1¼ knots faster than the fastest of the other ships and there was no vibration.
THE LARGEST MODERN TURBO-GENERATORS may have an output of about 50,000 kilowatts or more. The three Parsons turbines in Dunston-on-Tyne Power Station have a combined capacity of 150,000 kilowatts, running at 1,500 revolutions a minute. This plant, installed in 1930, is considered to have the highest overall thermal efficiency of any turbo-generating set in the world.
In 1905 the decision was made to fit all new armoured ships with turbines. In the merchant service the first turbine steamer was the Clyde passenger vessel King Edward, built in 1901. Her coal bill averaged 20 per cent less than sister vessels propelled by reciprocating machinery.
Then came the day of the big ships, among which H.M.S. Dreadnought (1906) and the liners Lusitania and Mauretania (1907) were famous. To-day, the Queen Mary, with her turbines of about 200,000 horse-power, has proved Parsons’s foresight to have been infallible. Parsons had many interests other than the turbine. The benefits conferred on the world by the invention of the Parsons turbine may be summed up in terms of the saving in coal that it has effected. The steam turbine of to-day needs only about 0.7 lb. of coal to obtain one horse-power. The reciprocating engine, at the time the turbine was patented, required about 2 lb. of coal to produce the same power. The first engine of James Watt gave one horse-power for about 5½ lb. of coal, and the Newcomen engine it superseded needed about 25 lb. Remembering the scepticism expressed in the early days of the steam turbine, views completely falsified later, he would be a rash man who would pronounce that no further progress was possible.
Parsons, though occupied with many other matters, preserved to the end the steam turbine as his main interest. As late as 1926, when he was 72, he experimented with higher steam pressures and temperatures in marine work. He equipped the Clyde steamer King George V with propelling machinery of which the boiler steamed at 550 lb. per sq. in. and at a temperature of 800° F., and drove a turbine of 3,500 horse-power.
The excellent work that Parsons did in another direction no doubt owed its origin to his early associations. As far back as 1887 he had perfected a method of producing parabolic reflectors for searchlights which cost much less and were lighter than those previously in use. The Heaton works became famous for its searchlights. Later Parsons took up the manufacture of large telescopes and other astronomical instruments and formed the firm of Sir Howard Grubb, Parsons & Co., also now at Heaton. It was largely due to him, further, that the decline in the production of optical glass in Great Britain was arrested, as he took over the Crown Glass Works at Derby. This move enabled him to effect a number of improvements in the manufacture of optical glass.
In less utilitarian directions Parsons early studied such subjects as the conversion of carbon into graphite, a change he successfully accomplished. Later in life, however, he failed to convert carbon into the diamond. Dr. Gerald Stoney, one of his close associates, tells us that the diamond-making experiments were heralded by the remark “We have now made a bit of money and deserve a little fun”.
Diamond-Making Experiments
This “fun” was, however, probably the most thorough investigation ever undertaken of a problem which had been attempted by a number of other workers. As heating carbon in an electric furnace and keeping it under great hydraulic pressure did not prove successful, Parsons, with characteristic boldness and originality, secured a combination of intenser heat and more immense pressure by firing bullets from a rifle at a muzzle velocity of 5,000 feet a second into a hole in a block of steel, the material to be compressed being placed at the bottom of the hole. Although pressures amounting to nearly 4½ million lb. per square inch were reached the material refused to crystallize. Another series of experiments was in the direction of increasing the volume of sound. The result was a sound amplifier embodying air-operated valves. On certain string instruments the auxeto-phone, as it was called, gave remarkable results and it was used on violoncellos and double basses in Sir Henry Wood’s Queen’s Hall Orchestra, London, in the winter season of 1906.
It would take too much space even to catalogue all the directions in which Parsons active and essentially practical mind was exercised, but one more may be mentioned. Dr. Stoney states that, about 1887, Parsons made a model aeroplane with wings having a span of about 4 feet. The motive power was an engine of similar construction to a steam engine, but, instead of water, the boiler contained methylated spirit. The vapour from the spirit, after having passed through the engine, was led to the boiler furnace, so that the one medium drove the engine and served as fuel.
As with Parsons’ minor achievements so with the honours bestowed upon him, which included the K.C.B. and the Order of Merit. Sir Charles died on February 11, 1931, while on a cruise to the West Indies. Though he had lived to the age of 77, it is almost certain that he never entertained the idea that there was nothing more left for him to do. His own words, “When you think you know everything about a thing, make some experiments and find out more about it”, may be taken as a reliable guide by those less generously endowed in the profession he so truly adorned.
MODEL OF 50,000-KILOWATTS PARSONS TURBO-ALTERNATORS installed at Chicago in 1923. In the background are the high-pressure turbine and alternator, behind the intermediate-pressure set. The casing of the low-pressure turbine is raised to show the blades. On the right are two vertical surface condensers, the originals having a total cooling surface of 56,000 square feet. The scale resting against the model indicates a height of 24 feet.
