The Steam Side: 1895-1918
ENGINES—TURBINES—STOP VALVES
Engines
Reciprocating steam engines had fascinated Ferranti from childhood, and no doubt he derived great pleasure in putting them to use in his electrical schemes, but he did not actually build any on his own account until 1895. At Deptford he had engaged Hick Hargreaves & Co to build the colossal 10,000 horse-power engines incorporating some of his ideas (the engines were never erected), but at Charterhouse Square in London and Hollinwood in Lancashire he made engines of his own design, soon becoming one of the leading builders of steam engines in this country. Frank Bailey in his Anniversary Address of 1931 commented: 'The all-absorbing desire to improve on everything he saw must have goaded Ferranti to design and make his own engine, and perhaps we may be permitted to regret this enterprise, although we must admire and marvel at the novel and daringly ingenious methods and devices he produced.' However that may be, Ferranti was late in the day with steam engines and the wonderful progress of the steam turbine made it clear that this was to be the prime mover of the future for generating purposes.
ENGINES—TURBINES—STOP VALVES
Engines
Reciprocating steam engines had fascinated Ferranti from childhood, and no doubt he derived great pleasure in putting them to use in his electrical schemes, but he did not actually build any on his own account until 1895. At Deptford he had engaged Hick Hargreaves & Co to build the colossal 10,000 horse-power engines incorporating some of his ideas (the engines were never erected), but at Charterhouse Square in London and Hollinwood in Lancashire he made engines of his own design, soon becoming one of the leading builders of steam engines in this country. Frank Bailey in his Anniversary Address of 1931 commented: 'The all-absorbing desire to improve on everything he saw must have goaded Ferranti to design and make his own engine, and perhaps we may be permitted to regret this enterprise, although we must admire and marvel at the novel and daringly ingenious methods and devices he produced.' However that may be, Ferranti was late in the day with steam engines and the wonderful progress of the steam turbine made it clear that this was to be the prime mover of the future for generating purposes.
Turbines
It is possible that it was the 3,000 r.p.m. Parsons radial steam turbine running alongside the slow-speed 96 r.p.m. engine-driven Ferranti alternators at Portsmouth that stimulated Ferranti's interest in turbine operation. In any case, his patent (2565 of 1895) for Improvements in Steam, Hot Air and Other Engines showed a thorough grasp of the problems involved. In 1902 he expressed his conviction that the prime mover of the future would be an elastic-fluid turbine ultimately taking the form of one driven by the internal combustion of gas, although the latter would have to be approached through experience gained with steam as the working fluid. He commenced experiments at Hollinwood but carried out the major part of his turbine work at Vickers' River Don Works at Sheffield.
He became a recognised authority on turbines and was invited to give The James Watt Lecture at Greenock in January 1913. For his subject he chose `Prime Movers', and discussed in detail the prospects of the internal combustion engine and its rival the steam turbine. Of his work on turbines he said: 'I commenced experimenting some years ago, and have now, after many failures, and the expenditure of much money and time, produced a turbine which at the highest temperatures and with great and rapid variations of temperature is quite free from mechanical troubles. Indeed, I believe that this turbine is, perhaps, the strongest from a mechanical point of view that has yet been produced. Moreover, contrary to what might have been expected with a high temperature machine, it runs with certainty with a blade end clearance that is so small that it is almost negligible from the point of view of leakage loss, and the fear of the possibility of stripping appears to have been effectively removed. In this turbine I superheat the steam initially, and after
the first expansion, and whilst it is still superheated, re-superheat it before it does its work in the second stage of the turbine. After this it is exhausted in a superheated condition through a regenerator to the condenser. The whole of the blading is electrically welded so as to avoid the straining due to caulking at the high temperatures that are reached, and also the loosening that occurs due to the same cause. The blading is formed of mild steel, with a thin coating of pure sheet nickel electrically welded on to the surface. The blading is most accurately finished to shape by a process of step-by-step pressing under very heavy pressure. The blading, the sections of which are very exact, is welded in position with the accuracy of the automatic machine that is used for the
purpose, and every opportunity is thus given for realising the best results. Although the turbine is of the reaction type no balance dummy is used. The whole of the end load is taken on a specially constructed thrust, thus saving steam leakage. The steam is worked as a gas at high temperature throughout the turbine, and this coupled with the many improvements above referred to, has given very good results.... When the advantages of the turbine system in the way of lightness, simplicity, and certainty are borne in mind, and when they are compared with what is known of the complicated reciprocating oil engines now being introduced for marine purposes, the possibilities of the new system of high temperature gas steam turbine become of great interest.'
In 1950 Sir Henry Guy who was then Secretary of The Institution of Mechanical Engineers wrote: 'Ferranti's contributions to the development of the steam turbine and steam power plant were very great. They did not, however, depend on patent specifications, but they depend on the inventions which he put into design and operation, mainly in a special installation of power plant which was installed at Vickers' Works in Sheffield, and which incorporated the multi-stage bleeder heating and re-heating ... at the time it also represented some advance in pressure and steam temperature. Ferranti has just and well-established claims as one of the pioneers of bleeder heating and re-heating for steam power plant, and these claims rest on something much more substantial than the patent specifications themselves. I would not attach any importance at all to the reference to the combustion of gas and air as indicating him as a pioneer in the internal combustion turbine field. My recollection is that I found, when I had occasion to go into it, that there is a very long back history of patents covering what could be claimed to be
the basic principles of internal combustion turbines. Pioneering claims do not depend on such things, but on design and putting inventions into operation, and this Ferranti did in respect to steam re-heating and bleeder heating.'
It is possible that it was the 3,000 r.p.m. Parsons radial steam turbine running alongside the slow-speed 96 r.p.m. engine-driven Ferranti alternators at Portsmouth that stimulated Ferranti's interest in turbine operation. In any case, his patent (2565 of 1895) for Improvements in Steam, Hot Air and Other Engines showed a thorough grasp of the problems involved. In 1902 he expressed his conviction that the prime mover of the future would be an elastic-fluid turbine ultimately taking the form of one driven by the internal combustion of gas, although the latter would have to be approached through experience gained with steam as the working fluid. He commenced experiments at Hollinwood but carried out the major part of his turbine work at Vickers' River Don Works at Sheffield.
He became a recognised authority on turbines and was invited to give The James Watt Lecture at Greenock in January 1913. For his subject he chose `Prime Movers', and discussed in detail the prospects of the internal combustion engine and its rival the steam turbine. Of his work on turbines he said: 'I commenced experimenting some years ago, and have now, after many failures, and the expenditure of much money and time, produced a turbine which at the highest temperatures and with great and rapid variations of temperature is quite free from mechanical troubles. Indeed, I believe that this turbine is, perhaps, the strongest from a mechanical point of view that has yet been produced. Moreover, contrary to what might have been expected with a high temperature machine, it runs with certainty with a blade end clearance that is so small that it is almost negligible from the point of view of leakage loss, and the fear of the possibility of stripping appears to have been effectively removed. In this turbine I superheat the steam initially, and after
the first expansion, and whilst it is still superheated, re-superheat it before it does its work in the second stage of the turbine. After this it is exhausted in a superheated condition through a regenerator to the condenser. The whole of the blading is electrically welded so as to avoid the straining due to caulking at the high temperatures that are reached, and also the loosening that occurs due to the same cause. The blading is formed of mild steel, with a thin coating of pure sheet nickel electrically welded on to the surface. The blading is most accurately finished to shape by a process of step-by-step pressing under very heavy pressure. The blading, the sections of which are very exact, is welded in position with the accuracy of the automatic machine that is used for the
purpose, and every opportunity is thus given for realising the best results. Although the turbine is of the reaction type no balance dummy is used. The whole of the end load is taken on a specially constructed thrust, thus saving steam leakage. The steam is worked as a gas at high temperature throughout the turbine, and this coupled with the many improvements above referred to, has given very good results.... When the advantages of the turbine system in the way of lightness, simplicity, and certainty are borne in mind, and when they are compared with what is known of the complicated reciprocating oil engines now being introduced for marine purposes, the possibilities of the new system of high temperature gas steam turbine become of great interest.'
In 1950 Sir Henry Guy who was then Secretary of The Institution of Mechanical Engineers wrote: 'Ferranti's contributions to the development of the steam turbine and steam power plant were very great. They did not, however, depend on patent specifications, but they depend on the inventions which he put into design and operation, mainly in a special installation of power plant which was installed at Vickers' Works in Sheffield, and which incorporated the multi-stage bleeder heating and re-heating ... at the time it also represented some advance in pressure and steam temperature. Ferranti has just and well-established claims as one of the pioneers of bleeder heating and re-heating for steam power plant, and these claims rest on something much more substantial than the patent specifications themselves. I would not attach any importance at all to the reference to the combustion of gas and air as indicating him as a pioneer in the internal combustion turbine field. My recollection is that I found, when I had occasion to go into it, that there is a very long back history of patents covering what could be claimed to be
the basic principles of internal combustion turbines. Pioneering claims do not depend on such things, but on design and putting inventions into operation, and this Ferranti did in respect to steam re-heating and bleeder heating.'
Stop Valves
Ferranti also made a notable improvement in stop valves and something of this was related in an address given by Albert Hall, one-time assistant to Ferranti when he was engaged on turbine work: 'I have to record a solid success both technically and commercially which came as a very pleasant interlude in a life of striving after the more or less unattainable ideal. I refer to the Ferranti-Hopkinson Stop Valve, patent 21032 of September 1904. Ferranti had seen drawings which I had made of a Venturi meter and also a drawing . . . of their [Hopkinson's] full-way parallel slide valve. . . . One morning he brought me a sketch of the first Ferranti Stop Valve. He had adapted the sliding piece of the Hopkinson valve to the throat of the Venturi meter, so as to form a perfect path when the valve was open. Calculation showed with the steam velocities used in pipe lines at the time that . . . the loss of pressure in such a valve when the throat was half the pipe diameter would only be about one half of one per cent of the initial pressure,... The advantages of a valve with only half the leakage surface, of a quarter the area and so a quarter of the load at opening seemed very great. We fitted a valve to one of the works' engines for trial. This was controlled, for some unknown reason, by a 7 in. screw-down stop valve in a 7 in. pipe. From the known steam consumption we decided to fit a 3 in. valve, that is, one with a 1 1/2 in. throat, making 3 in. to 7 in. conical pieces to connect it at each end to the 7 in. pipe. This little valve created great excitement . . . and was known as "Ferranti's Folly" and both he and myself were deemed mad. It was fitted to the engine one Sunday night and at 8 a.m. Monday morning Ferranti and myself arrived to start up the engine. A large number of the employees had gravitated towards the engine room doors to witness the "fiasco". The engine had been warmed up, so I brought it up to speed and Ferranti signalled to the electrician to throw the load on to it. This gentleman's face, as he saw the ammeter and voltmeter, was a picture and in a minute or so everyone had disappeared. Ferranti enjoyed the joke and said to me "It is a pity they are all disappointed." Our mercury gauge showed that the drop of pressure across the valve was the small amount expected. Ferranti got Messrs. Hopkinson to manufacture and sell these stop-valves. They became very popular, enormous numbers were sold and Ferranti collected a large sum of money in royalties.' Today these valves, only slightly modified from the original version, play an important part in controlling steam pressures above 350 lb./sq. in. in a very large number of generating stations including the latest nuclear power stations, in industrial plants and in ships of all kinds throughout the world.
Ferranti also made a notable improvement in stop valves and something of this was related in an address given by Albert Hall, one-time assistant to Ferranti when he was engaged on turbine work: 'I have to record a solid success both technically and commercially which came as a very pleasant interlude in a life of striving after the more or less unattainable ideal. I refer to the Ferranti-Hopkinson Stop Valve, patent 21032 of September 1904. Ferranti had seen drawings which I had made of a Venturi meter and also a drawing . . . of their [Hopkinson's] full-way parallel slide valve. . . . One morning he brought me a sketch of the first Ferranti Stop Valve. He had adapted the sliding piece of the Hopkinson valve to the throat of the Venturi meter, so as to form a perfect path when the valve was open. Calculation showed with the steam velocities used in pipe lines at the time that . . . the loss of pressure in such a valve when the throat was half the pipe diameter would only be about one half of one per cent of the initial pressure,... The advantages of a valve with only half the leakage surface, of a quarter the area and so a quarter of the load at opening seemed very great. We fitted a valve to one of the works' engines for trial. This was controlled, for some unknown reason, by a 7 in. screw-down stop valve in a 7 in. pipe. From the known steam consumption we decided to fit a 3 in. valve, that is, one with a 1 1/2 in. throat, making 3 in. to 7 in. conical pieces to connect it at each end to the 7 in. pipe. This little valve created great excitement . . . and was known as "Ferranti's Folly" and both he and myself were deemed mad. It was fitted to the engine one Sunday night and at 8 a.m. Monday morning Ferranti and myself arrived to start up the engine. A large number of the employees had gravitated towards the engine room doors to witness the "fiasco". The engine had been warmed up, so I brought it up to speed and Ferranti signalled to the electrician to throw the load on to it. This gentleman's face, as he saw the ammeter and voltmeter, was a picture and in a minute or so everyone had disappeared. Ferranti enjoyed the joke and said to me "It is a pity they are all disappointed." Our mercury gauge showed that the drop of pressure across the valve was the small amount expected. Ferranti got Messrs. Hopkinson to manufacture and sell these stop-valves. They became very popular, enormous numbers were sold and Ferranti collected a large sum of money in royalties.' Today these valves, only slightly modified from the original version, play an important part in controlling steam pressures above 350 lb./sq. in. in a very large number of generating stations including the latest nuclear power stations, in industrial plants and in ships of all kinds throughout the world.