The Evolution Of The Nobel Diesel Engine
Nobel Diesel
A key part of the Nobel system was diesel technology. In 1893, the German engineer Rudolf Diesel received a patent for the engine that would forever bear his name. He sold manufacturing licenses to companies in several countries, including Maskinfabrik Ludvig Nobel. The negotiations leading up to the deal were handled by Emanuel Nobel himself, “the cold Swede” as Rudolf Diesel called him.
The diesel engine was powered by fuel from Branobel’s own refineries. The engines powered the company’s tankers and power stations. Diesel engines were an important product for Maskinfabriken, which during the 1890s was the world’s largest diesel engine manufacturer. Advanced applications were also developed, such as portable diesel-powered power plants for the Russian army and diesel engines for the navy’s submarines.
After the revolution of 1917, the production of diesel engines ended up in Sweden. It was the only part of Nobel’s system that could be saved from the confiscation of all private property in Russia. In 1919, some of the brothers formed AB Nobel-Diesel in Nynäshamn. It was something of an attempt to re-establish what had only three years earlier been the engine department of Maskinfabriken Ludvig Nobel in St. Petersburg. One of the reasons for starting the company was to make use of the expertise of the many Swedes who had worked there but had been forced to flee the revolution.
One of the foremost diesel engine designers of the time was Anton Carlsund. He had been employed by the Nobel works in St. Petersburg and was personally acquainted with Emanuel Nobel. Carlsund lived in Sweden in 1919 and was employed as director of Nobel-Diesel. He is the one standing next to the first finished engine in Nobel-Diesel's workshop, a 1,600-horsepower reversible two-stroke diesel. The engine was one of the world's largest diesel engines in 1921, but it is still only a fragment of Nobel's enormous system.
The company AB Nobel-Diesel could not survive on its own, and was liquidated in 1926.
The Evolution of The Nobel Diesel Engine
By Baron George J. Steinheil, B.Sc., M.I.N.A., M.I.Mech.E, M.I.A.E. (Member).
READ Tuesday, November 14, at 6.30 p.m.
Chairman: Mr. P.B. Fielden (Vice-Chairman of Council).
From a publication from 1922 from Institute of Marine Engineers.
In July, 1897, Dr. Rudolf Diesel, of Munich produced in conjunction with the Maschinenfabrik Augsburg the first engine bearing his name.
The experimental work to produce a commercially possible engine from the original design took about eight years to accomplish, but by July, 1897, according to Dr. Diesel’s statement, the experimental stage was finished and drawings of the engine were sent to the drawing office of the Augsburg works, in order to start manufacture on a commercial scale.
There was a considerable amount of controversy in this country as well as in Germany, whether the Diesel engine was actually Dr. Diesel’s invention or not, and whether it should be called by any rival name or simply a “ high compression oil engine.”
It is not the subject of this paper to discuss the vexed question, as to do this, references would have to be made to patents, to transactions of various technical societies in this country and on the Continent, etc.
However, it is enough to say that the engine developed by Dr. Diesel bears in everyday engineering life his name, and therefore the author proposes to call it by such in the paper. As soon as the first commercially practical engine was ready, representatives of various engineering concerns came to Germany to witness the tests of that engine with a view of obtaining the manufacturing licences for that type of engine for their respective works.
Among those who saw the tests of this first engine was Mr. Anton Carlsund, at the time chief engineer of L. Nobel, Ltd., of Petrograd.
He immediately appreciated the great possibilities of the new prime mover, especially from the Russian point of view, as in Russia the natural oil supplies were very great and incidentally practically the whole of these were controlled by Nobel interests. On his return to Russia he persuaded Mr. Emanuel Nobel, the head of the Nobel concern to acquire a licence for Diesel engines for Russia.
In autumn 1897 all licence arrangements were completed and Nobels proceeded at once to build their first Diesel engine.
All this happened 25 years ago.
Thus the Nobel Works were among the very first firms in the world to take up Diesel engine manufacture, and among other pioneer firms may be mentioned such well-known concerns as Mirrlees, Watson, Co., Ltd., of Glasgow, now better known as Mirrlees, Bickerton and Day, Ltd., of Stockport; Maschinenfabrik Augsburg A.G.; Fr. Krupp, Germania Werft, Kiel; Carels fréres, Ghent; Sulzer Bros., Winterthur, and others. It must, however, be admitted that the German Diesel engine of 1897 was found to be in many details quite unsuitable for Russian conditions, and the Nobels had the heavy task of re-designing the engine to suit these local conditions. Of the most important alterations were those of the fuel pump and pulveriser. The German engine was designed to work on paraffin, but the abundance of cheap raw naphtha (crude oil) in Russia, made it necessary to make the Russian engine to work on that fuel, and therefore the fuel pump and pulveriser had to be altered accordingly.
In general outline, however, the Nobel engine followed closely the German design which was of the single cylinder stationary crosshead four-stroke cycle type, developing 20 b.h.p. at 200 r.p.m.. The cylinder dimensions of the engine were:-— Diameter 260 m/m. (10-¼ in.) and stroke 410 m/m. (16-⅛ in.). Fig. 1).
Tests carried out on this engine by Professor G. Doepp, of Petrograd Institute of Technology, in 1899, showed that the engine easily developed as much as 25 b.h.p. at a fuel consumption (crude oil) of 220 grams (0-486 lbs.) per b.h.p. hour with a colourless exhaust *. In 1900 a new type of 30 b.h.p. per cylinder crosshead engine was put on the market, built in one and two cylinders per shaft.
The first customers for Nobel engines were the Nobel Bros. Petroleum Production Co., and the Russian War Office, while the general public and even the majority of engineers of the time looked upon the new engine with considerable suspicion. Several engines were put in the Nobel Oil Refinery at Baku in 1900.
The management of the Caucasian Railways, who were then busy building the great pipe-line from Baku, on the Caspian Sea to Batum on the Black Sea, a distance of about 500 miles, for the conveyance of paraffin (kerosene), decided to install Diesel engines in their pumping stations on the pipe-line. Their decision was influenced by the great economy of a Diesel plant and also by the lack of suitable feed water for boilers of steam engines in the Baku district. The first pumping station at Baku was to be of three pumping sets of 100 b.h.p. each. If steam engines were to be installed the fuel oil consumption per station per annum (4,000 working hours) would have been about 650 tons, assuming IT lbs. of oil per h.p. hour, whereas a Diesel plant of the same power would consume about half of that amount.
Owing to the lack of fresh water supplies in Baku, the question of cooling of Diesel engine cylinders presented certain difficulties, but eventually it was decided to use the cooling water in a closed circuit, the outlet water entering a special watercooler, from which it was pumped again into the water jackets of Diesel engines. The cooling medium for the circulating water was the paraffin, which was pumped by the engines through the pipe line, the cooler having been connected for the purpose with the main pipe. In the semi-tropical climate of Caucasia this arrangement was considered more efficient than ordinary cooling towers. A new type of Diesel engine was designed for the purpose of developing 100 b.h.p. in two cylinders. The crosshead was abolished and ordinary trunk pistons were used. Three such sets were installed at Baku pumping station in 1902, and gradually all the other pumping stations on the pipe line were lniilt and fitted with Diesel engines. By 1903 ten different sizes of Diesel engines were already marketed by Nobels in powers ranging from 10 to 100 b.h.p. per cylinder.
The 10 b.h.p. single cylinder stationary engine was specially brought out to meet the demands of farmers and small power users. Another interesting instalation of three sets of single cvlinder trunk piston engines of 75 b.h.p. each was made in 1902 at the Tenteleff Chemical Works, of Petrograd. These engines were driving air compressors supplying air for the manufacture of sulphuric acid, and the nature of the work demanded continuous working of several davs’ running. To prevent excessive corrosion all exposed bright parts of the engines were coated with paint. It is quite possible that in future, rustless steel will be used by Diesel engine makers for this kind of work. In those early davs it was rather difficult to get Diesel engines t- I t o cv built on a manufacturing basis, as practically even* engine made was an improvement on the previous one. On the original 20 b.h.p. Diesel engine the injection air was sucked from the atmosphere and compressed to full blast pressure of 50-60 atm. (700-850 lbs. per sq. inch) in a single stage air compressor direct driven by a rocking lever from the engine.
This design gave fairly satisfactory results so long as the power output did not exceed 30-40 b.h.p. per cylinder, but when higher-powered engines were produced, considerable difficulties were experienced with this type of compressor. The volume of air to be compressed was so large, that the coolers could not cool the air well enough and not infrequently explosions occurred in the cooler coils and air supply pipes, due to ignition of oil present in the air. To overcome this defect it was suggested bv Dr. Diesel to make the compression of blast air in two stages, by by-passing the cylinder air during the compression period from the cylinder to the air compressor proper, where it was to be compressed to the blast pressure. The air from the cylinder was by-passed at a pressure of about 10 atm. (142 lbs. per square in.) into the air compressor by way of an intermediate cooler.
Thus the air compressor had to compress comparatively cool air from 10 atm. to 50 atm., instead of from 1 to 50 atm. This arrangement, though it partially did away with the danger of explosion, introduced drawbacks of its own, in the shape o'f particles of dirt and carbon deposit, which were carried by the by-passing air into the compressor cylinder, often causing seizure of compressor pistons. Dr. Diesel, Professor Mayer, and the German makers, were greatly in favour of the by-pass arrangement, considering it a great improvement over the single stage compression in spite of its drawbacks, which they said were purely accidental. The Nobel engineers were, however, of a different opinion, which was based on the difficulties experienced with both systems of air compression. With the trunk piston type of engines they introduced the two-stage compound air compression proper, in which the air was compressed in two separate air compressors, driven by links from the engine. In the case of multi-cylinder engines, the L.P. and H.P. air compressors were separate units, but in single cylinder engines the air compressors formed one unit' and the two connecting rods were driven by a common link.
The atmospheric air entered the L.P. stage compressor and was then compressed to T atm. (100 lbs. per square in.) then, after passing through a cooler, it entered the H.P. stage cylinder and was compressed from 7 atm. to 50-60 atm. (700-850 lbs. per square in.). Eventually on large stationary engines a three-stage compression was introduced, the compressors being all separate units, driven by links. The German Augsburg Works, soon after Nobels, also dropped the by-pass' compression and introduced two-stage, air compressors of the tandem type. As already mentioned, considerable prejudice existed among prospective customers- against Diesel engines. They were afraid of the high pressures used, and of occasional breakdowns and accidents, which were in most cases due to the inexperience of attendants. However, after some time, confidence was established, and the demand for Diesel engines in Russia became so great that the Nobel Works could not cope with the orders. Arrangements were accordingly made in the autumn of 1903 for the Kolomna Works in Golutwin to take up the manufacture of four-stroke Diesel engines under licence from Nobels, the Kolomna Works, securing, to begin with, a part of the contract for pumping sets on the Baku-Batum pipe-line.
The majority of orders for Diesel engines about that time were for engines suitable for belt drive of workshops, flour mills, textile mills, and small power stations for lighting purposes, etc. The electrical engineers were at the time of the opinion that a Diesel engine could not be made to run with enough cyclic regularity to be able to drive a dynamo direct coupled to the crankshaft, and especially a direct driven alternator running in parallel with engines of other types and speed (gas, steam, water turbines, etc). To prove the fallacy of that idea, the Nobel Works installed in the power station of the Petrograd Institute of Electrical Engineers in 1905 an 80 b.h.p. twin-cylinder Diesel engine direct coupled to a D.C. dynamo, which supplied current, in parallel with steam driven dynamos, for the lighting of the premises as well as driving of various electro-motors in the laboratories and buildings. In the same year later a 400 b.h.p. three-cylinder engine direct coupled to an alternator was installed in the power house of the Perm Ordnance Works in the Ural district, and this alternator was run in parallel with an alternator driven by a steam engine. After that successful experiment the demand for high power stationary engines became very great and most of the principal provincial towns in Russia, as well as various works and shipyards, put direct-driven Diesel generators into their power houses. The largest type of four-stroke stationary engine built by Nobels was that of 200 b.h.p. per cylinder at 150 r.p.m
The cylinder dimensions of that engine were: Diameter (100 m/m. and stroke 800 m/m. Three and four-cylinder sets of this size were built, developing 600 and 800 b.h.p. respectively. Two such 600 b.h.p. engines were installed in the steel rolling plant of Moscow Metal Works, Ltd., in 1907, one of these engines being direct coupled to the mills. Such work put very heavy stresses on the engine, as it had to work at a constantly variable load from practically 110 load to overload and vice versa. The fact that this engine has done this work already for fifteen years, only proves the reliability of the modern Diesel engine. Another interesting installation of an 800 b.h.p. engine was at the Tzaritzin Flour Mills. The engine was a four-cylinder set with a heavy flywheel pulley between the second and the third cylinders. The pulley was arranged for rope drive. The crankshaft was so designed that either pair of the cylinders could be uncoupled from the flywheel, the engine working then 011 two cylinders at lialf-power. The reason for such an arrangement was the doubt of the owners in the reliability of the Diesel engine, they preferring to have at least half the power than nothing at all in case of breakdown. It must be remembered that even a short stoppage of machinery in a flour mill entails considerable inconvenience and even loss to the millers, as most of the grain and flour in the middle of the process must he sent again from the start, and therefore the attitude of the Tzaritzin Mill owners was understandable, as to them at the time a Diesel engine installation was quite a novelty. However, it must be said to the credit of the builders of the engine that there never was an occasion to run the engine 011 two cylinders. Although the building of stationary Diesel engines formed a considerable branch of the Nobel Diesel business, it was for the designing and building of marine Diesel engines that Nobels spent most of their energies, and therefore the author will proceed to the description of a few interesting types of marine engines.
Four-Stroke Nobel-Diesel Marine Engines.
Not counting a small 20 b.h.p. French Diesel engine fitted into a small canal barge in France, it is to Nobels that belongs the credit of having built in 1903 the first marine Diesel engine and in which the speed could be varied by hand. That engine was a four-cylinder one of “A” frame trunk piston type and developed 180 b.h.p. at 240 r.p.m. The cylinder dimensions were: Diameter 320 m/m. and stroke 420 m/m. The outside view of the engine is shown in Fig. 2. Two such engines were fitted in 1904 into the motor-tank-ship "Ssarmat", of the Nobel Bros. Petroleum Co.
The ""Ssarmat"" was a ship of 800 tons D.W. capacity and therefore of very humble dimensions as compared with present-day tankers of 15,000 tons. Her hull dimensions were: length B-P 244ft. 6 in., breadth md. 31 ft. 9in., and draught fully loaded 6 ft. She was built at the Ssormovo Shipyard, on the River Volga, and was suitable for both river and sea navigation. The engines were non-reversible and the necessary astern motion of the propeller shaft was obtained on the Del-Proposto system. That system consisted of a dynamo direct coupled to the engine crankshaft and an electromotor coupled to the propeller shaft, between those two was interposed a friction clutch. For ordinary ahead running the clutch was coupled in and the propeller was direct driven by the engine. The dynamo and electromotor were not working, but rotating simply as additional flywheels and the speed of the ship was regulated by the speed of the engine.
For astern running the clutch was released, current switched on and the electromotor turned the propeller shaft in a direction opposite to that of the engine (Fig. 3). The engine was run at constant speed, whereas the electromotor could be run at variable speed, thus regulating the speed of the ship. The "Ssarmat" has been in commission for nineteen years, having- still the original engines (Fig. 4). A sister ship to the "Ssarmat", named Vandal, was built at the Ssormovo yard a year before the former, and was also fitted with four-stroke Diesel engines, but of the ordinary stationary type, the propeller shaft drive being purely Diesel-electric. These engines had direct coupled dynamos, which supplied current to electromotors on the propeller shafts. Three of such three cylinder engines, built by the works now owned by the New Atlas-Diesel Co., of Stockholm, were fitted into the Vandal.
The cylinder dimensions were: diameter 290 mm and stroke 430 mm., each engine developing 120 b.h.p. at 240 r.p.m. The "Vandal" and the "Ssarmat" were actually the two first motorships in the world, and, although comparatively little publicity was given as to their performance, it must be said that they played a very important part in the development of motor-shipbuilding in Russia.
The fact that the two motorships in those days could maintain a regular service for single voyages of over 3,000 miles long, year in and year out, carrying petroleum in bulk, set many Russian shipowners thinking, and the performance of these two ships was closely watched.
The behaviour of these two ships in service was so satisfactory that the Nobel Bros. Petroleum Production Company had decided then to convert the whole of their steam fleet into motor ships.
Such a conversion was probably the biggest one ever yet undertaken, as the tonnage of the fleet was over 650,000 tons D.W., and some of the tankers were of 10,000 tons D.W. capacity.
The programme was arranged for the gradual conversion of ships, starting with tugs and the smaller tankers first.
As the conversion could not be accomplished by the Nobel Works alone, because they were very busy with naval orders, part of the conversion work was given over to the Kolomna Works in Golutwin, who were Nobels’ licensees.
These two firms supplied the bulk of the engines for the fleet, but a few ships were fitted with engines purchased abroad.
In many cases quite good triple expansion steam engines had been removed and replaced by Diesels.
It was expected that by 1924 the conversion would have been completed, but unfortunately the outbreak of the war in 1914 and of the Russian revolution in 1917, completely upset the programme, as in 1918 the Bolsheviks had “nationalised ” the Nobel fleet, with the result that only a comparatively small number of old tankers are running at present.
It is of interest to note however, that of the two first marine Diesel installations, that of the "Ssarmat" with Del-Proposto drive, proved to be more reliable and economical than that of the "Vandal", which had a Diesel electric drive.
The "Vandal" was broken up in 1913.
The replacement of steam machinery in paddle tugs by Diesels required a considerable amount of ingenuity, as the speed of the paddles was so much below the slowest normal speed of Diesel engines and it naturally required the adoption of some sort of reduction gear.
It was out of the question, of course, to put slow speed land type engines, as they were much too heavy and cumbersome for the weak hulls of the river tugs. A special type of high-speed light multi-cylinder direct reversible engine had to be designed for the purpose.
In 1907 such an engine was already on the test bed at the Nobel Works and it developed 120 b.h.p. in three cylinders at 400 r.p.m. The cylinder dimensions were: diameter 275 m/m. and stroke 300 m/m. (Fig. 5).
It was of the enclosed crankcase type with a two-stage air compressor at the side of the engine, driven by rocking levers. This engine was the first direct reversible four-stroke Diesel engine ever built in the world.
Reversing was performed through the shifting of cams by means of forks fitted to a layshaft and actuated by the hand-wheel seen in Fig. 5 near the top of the vertical shaft.
Each cylinder had two sets of cams, and to allow for their shifting, the rocking levers of the valves had to be pressed down by means of the long hand lever seen on the top of the engine, so as to lift the rollers clear of the cams. This type of reverse gear is known as Carlsund’s gear.
The manoeuvring lever is seen near the middle of the vertical shaft, and it actuated the lower layshaft, which in its turn threw the starting and fuel valves in and out of gear when necessary.
The manoeuvring lever could he rotated round a dial.
The position of that lever shown in Fig. 5 is the “ Stop ” position, when the fuel and starting valves are out of gear. Two-stroke starting was provided, i.e., admission of starting air was on every downward stroke, as otherwise with a three-cylinder four-stroke engine at certain crank positions no starting valve may he open.
Turning the manoeuvring lever clockwise, there came the first “ Start” position, when the three cylinders were working on air, then came the second “ Start ” position, when the first cylinder was on fuel, and the other two on air, then the third “ Start ” position, when two cylinders were on fuel and the third on air and finally came the “Work” position when all the three cylinders were working on fuel.
This type of starting gear was the invention of Mr. Nordstroem, of Nobels (Nordstroem’s patent, Sweden, 1907). The fuel regulation could be performed in two ways, firstly by a small hand-wheel at the lower end of the vertical shaft, which could vary the tension of springs of the centrifugal governor and secondly by a small hand lever, which controlled the lift of the suction valves of the fuel pumps.
The lubrication of the engine was of three kinds: forced for cylinders and air compressors, by means of a mechanical lubricator and gravity for main bearings, which were watercooled, whereas the crankpins had banjo ring lubrication.
Two of such engines were installed in the Russian submarine "Minoga", in 1908, and it may be stated that the above submarine, though comparatively ancient as submarines go, did very good work during the great war. A number of these engines were built for naval purposes as well as merchant marine, and, in the 11011-reversible design as lighting sets in ships and as stand-by engines in power stations.
In Table I. are given results of official 120 hour trials carried out by Professor N. Bykoff, of Petrograd Institute of Technology upon “Minoga” engines in 1908. This type of engine, however, was too small and of too high a speed to work satisfactorily in the paddle tugs, and therefore a more powerful engine of similar design was brought out in 1908.
The design of that new engine was later standardised, and it was produced in three, four and six cylinder models. Besides river paddle tugs, that engine was fitted in 1909 into the Russian submarine "Akula" (three four-cylinder sets of 300 b.h.p. each at 3T5 r.p.m.) That engine in general appearance was similar to the “Minoga” engines, with the exception that in some of the later engines tandem air compressors were direct driven from the forward end of the crankshaft.
The reverse gear in that type of engine was simplified—the shifting of cams having been performed by a hand lever that actuated the layshaft, instead of by the handwheel as was on the “Minoga” engines.
On the later engines of the “Minoga” type the reverse gear was also altered to hand lever cam shifting and a tandem air compressor was fitted at the forward end of the crankshaft.
The paddle tugs had their engines placed transversely, i.e., parallel to the paddle shafts. In the case of larger tugs two direct reversible engines were fitted, driving the shafts through electro-magnetic clutches. The Nobel Bros, motor tug "Ssamoyed", was a typical example of this class of river tugs. She was built in 1909 for service on the upper reaches of the River Volga and Northern Canal system for the towing of oil barges. The hull dimensions were: length B-P. 132ft. 9ins., breadth md. 19ft., depth md. 8ft. 3ins., draught 3ft. 3ins., D.W. capacity 10 tons, and Cargo towing capacity 3,200 tons. She had two three-cvlinder reversible four-stroke engines, developing each 140 b.h.p. at 260 r.p.m., whereas the paddles turned at 35 r.p.m.
The paddle shafts were separate, each engine driving through an electric-magnetic clutch one paddle only, which considerably added to the manoeuvring qualities of the tug. The necessary speed reduction was obtained through herringbone gears of the Citroen type (Fig. 6).
The cylinder dimensions of' these engines were : diameter 330 m m. (13ins.) and stroke 380 m/m. (15ins.). Motor tug "Lesgin", built in 1910 for the same owners, had two four cylinder engines of the above type developing 200 b.h.p. each, as the size of the boat was larger (90 tons D.W., 4,800 tons tow L. 175ft., B. 27ft., 1). 8ft. and draught 2ft. 4ins.).
The drive from the engines to the paddle shafts was through Dohmen-Leblanc clutches and Citroen gears (Fig. 7).
Motor tug "Ossetin" (Fig. 8) of slightly smaller dimensions than the "Lesgin", was fitted also with two four-cylinder 200 b.h.p. engines, but these were placed longitudinally side by side, driving through Dohmen-Leblanc clutches two propeller shafts (Fig. 9).
The speed of the engines was 270 r.p.m. These two larger sized tugs and their sister ships were used for towing purposes on the lower reaches of the Volga. The first motor tug on the Volga was the "Belomor", built in 1908. She was smaller than the above-mentioned tugs, her dimensions being: eight tons D.W. capacity, 1,600 tons tow, L. 110ft. 6in., B. 17ft., D. 8ft., draught 3ft. 3ins.
Only one reversible three-cylinder engine of 140 b.h.p. was fitted, driving a paddle shaft common to both paddles through an electric-magnetic clutch and Citroen gears.
This arrangement of solid paddle shaft had the drawback that both paddles could only be turned in one direction at a time and therefore for the turning of the ship only the rudder was available. In 1911-1912 three slightly larger single engine paddle tugs were built for the service on the Vistula in Poland.
They were called the "Mazur", "Polia", and "Madjar" (Fig. 10). They were captured by the Germans during the war and used by them for army purposes, upon the signing of the Versailles peace treaty these tugs were returned to their rightful owners, and are now in service again.
In Fig. 11 is shown the engine of motor tug "Mazur".
It is interesting to note, as a special proof of the economy of the motorship, that the Nobel Bros. Petroleum Production Company found it cheaper to carry their oil from Baku on the Caspian Sea to Warsaw on the Vistula, via Astrakhan, Volga, Northern Canal System, Neva, Petrograd, Finnish Gulf, and the Baltic Sea into Vistula, a total distance of 3,200 miles, instead of using railways, the distance in the latter case being only 1,900 miles.
Considerable amount of trouble was experienced at the beginning with the above mentioned Citroen type of gear drive, the fault having been not with the gears themselves, but with the design of the arrangement of machinery in the ship.
The hulls and engine foundations of river paddle tugs and boats in general, were made very light as the water surface was usually smooth and the inertia forces of slow speed (25-40 r.p.m.) horizontal paddle steam engines were quite negligible.
With the adoption of Diesel propulsion the conditions become quite altered, as the comparatively high speed vertical Diesel engine with its heavy pistons and connecting rods was likely to set up considerable vibrations in the foundations and in the hull, especially if the inertia forces were not properly balanced and the period of engine vibrations synchronised with that of the hull.
Such vibrations were likely to cause deformations in the hull structure, so that the gears could get out of alignment, sometimes with disastrous results.
The author remembers having seen a breakdown of such gears in one of the earlier tugs, due to the abovementioned cause, when the teeth of the large wheel were stripped clean off.
This difficulty was eventually overcome by a suitable design of the hull and strengthened engine foundations, combined with a better system of balancing of engines.
It is not the intention of the author to go into the question of engine balancing and hull vibrations in this paper, as the subject is too important and voluminous, and it could easily form a paper by itself.
During the Russo-Japanese war of 1904-1905 the water communications of the Russian armies in the Far East were very much hampered by bands of lawless Khunghuses, who attacked defenceless tugs and barges on the River Amour, causing considerable delays in the delivery of supplies and munitions.
In order to bring these brigands to book the Russian Government commandeered several river steamers and converted them into some sort of river gunboats, by arming them with small naval guns and machins guns.
These boats helped a lot to stop looting, and even policed the river after the conclusion of war in peace time. But as these boats had log-fired boilers and only a limited supply of wood could be taken on board at a time, it was decided in 190G to build eight new river monitors, armed with two 6in. Q.F. and four 4.7in. Q.F. guns, and driven by Diesel engines, which would give them the ability of making long runs without replenishing their fuel tanks.
The total power of the engines per ship was estimated to be 1,000 b.h.p., which was to give the ship a speed of 11 knots. The order for all these engines was secured by Nobels, but as the Admiralty was in a hurry to get the ships ready as soon as possible, it was decided not to wait until the completion of the tests of the reversible engines, but fit in non-reversible engines with a Del-Proposto drive.
Every monitor got four engines of 250 b.h.p. each in four cylinders running at 350 r.p.m., the engine being similar in other respects to the tug engines of Nobel Bros. Co. As the whole contract of 32 engines could not be finished by Nobels in time, a half of that number was given over to the Kolomna Works, who built those engines from Nobels’ drawings.
The hulls of these eight monitors (known as “Shkwal” class) (Fig. 12) were built at the Baltic Shipyard in Petrograd, and were sent in pieces to an erecting yard on the River Amour, where they were assembled.
The first monitor, "Shkwal", was ready in 1908, and after having undergone her trials in the Gulf of Finland, she was shipped in pieces to the Far East.
Among the sea-going motor tankships can he mentioned Motorship "Robert Nobel", of Nobel Bros. Petroleum Co. (Fig. 13. She was originally a twin-screw tank steamer of 1,700 D.AV. capacity (L. 260t't., B. 34f't., ]). 17ft., draught 14ft.) In 1909 she was to undergo a complete overhaul of engines and boilers, but instead of that it was decided to convert her into a motorship.
Two four-cylinder Nobel-Diesel engines of the enclosed crankcase type of 400 b.h.p. each were fitted in 1910, driving propeller shafts through Dohmen Leblanc clutches at 215 r.p.m. The engines had the following cylinder dimensions: diameter 450 mm and stroke 510 mm. and were direct reversible. The reverse gear, however, was different from Carlsund’s gear used on the smaller power engines, as it consisted of two set of rollers on the links of valve rocking levers.
Only one cam was required for every valve for both ahead and astern running, and the cams were fixed solidly on the camshaft, i.e., there was no shifting of cams for reversing, which was performed by placing the second roller against the cams through a suitable movement of the links. This type of reverse gear is known as Nordstroem’s gear (Nordstroem’s patent, Sweden, 1909).
The reason for the change of design in the reverse gear was that at the time it was considered that the shifting of cams by hand could only be performed on engines of comparatively small powers, and that in larger sizes it would be beyond the power of an ordinary man to shift the cams and thus a servo motor would have to be introduced.
The Nordstroem’s double roller reverse gear was so designed as to abolish the cam shifting and the whole of the reversing operation could be performed in 7-8 seconds. The idea about the impossibility of cam shifting by hand on large engines proved, however, to be false, and it will be shown later that all modern two-stroke Nobel-Diesel engines up to the very largest powers have hand camshifting, without the use of any servo motors whatever.
This Nordstroem’s double roller reverse gear, though not used at present by Nobels, has been revived lately by a well-known Swiss concern on their two-stroke engines.
In 1908 it became necessary to police the communications on the Caspian Sea and protect Russian shipping from assaults of Persian pirates, and therefore it was decided to build two sea-going gunboats of 680 tons displacement and 141/2 knots speed, armed with two 4,7 in. Q.F. guns and four 3 in. Q.F. guns.
Owing to the fact that these gunboats might be called to leave port at a moment’s notice, and also to the presence of local cheap supplies of oil, they were designed with Diesel engines as their propelling machinery, because to keep steam always up would have been too costly.
Tenders were invited from various Bussian (by that time two more firms got licences to build Diesel engines in Russia) and foreign firms for non-reversible engines with Del-Proposto drive.
Among these tendering firms were the Nobel Works, who sent in a tender for direct reversible engines of 500 b.h.p. each. The comparative simplicity and compactness of Nobel design with direct reversible engine installation as compared with a Del-Proposto plant, appealed considerably to the Russian Admiralty, with the result that new tenders were asked from various firms for direct reversible engines. A few of the firms sent in those new tenders for reversible engines, but without any guarantee.
This made the Technical Department of the Admiralty decide again in favour of Del-Proposto drive, as their own experience with direct reversible engines was at the time only with engines of submarines "Minoga" and "Akula", which in the latter case did not exceed 300 b.h.p. per shaft, and they were afraid to take the risk of installing reversible engines of nearly double the power per shaft.
After a lot of arguments the Nobel Works persuaded the Admiralty to adopt direct reversible engines, the Nobels installing them at their own risk, so that in case of failure they were to convert the engines to non-reversible type with Del-Proposto drive.
This was a rather daring proposition, as it meant to the engine builders a loss of at least £2,000 per ship, in case such a conversion would have been necessary. The hulls of these two twin-screw gunboats "Kars" and "Ardagan" (Fig. 14) were built by the Petrograd Admiralty Dockyard.
Every ship had two direct reversible six-cylinder engines, developing 500 b.h.p. per shaft and running at 310 r.p.m.
The cylinder dimensions were: diameter 375 m/m. and stroke 430 m/m. In general design these engines were similar to those of the Motorship "Robert Nobel", and had the Nordstroem’s twin-roller reverse gear (Figs. 15 and 16).
Two twin-cylinder auxiliary sets of 60 b.h.p. each were also provided. The cooling of the engines was with fresh water, which circulated in a closed circuit and was cooled before entering the cylinders in special coolers provided for the purpose. Such an arrangement was considered necessary, as at the time it was thought that the cooling of cylinders by seawater from the Caspian Sea, which contained a considerable percentage of salt, would be detrimental to the engines. In autumn 1909 the "Kars" was ready for trials, which took place in the Gulf of Finland. While turning under her own power in the River Neva the gunboat nearly dashed into the granite embankment of the river.
The situation was critical. The captain of the "Kars" having raised the Russian Naval Ensign before the trials, automatically took all the responsibility from the builders for the safety of the ship.
Common sense told him that to save the ship and his own job it was necessary to reverse the engines, but being a steam man, he had little experience with Diesel-driven ships, and naturally, mistrusting the new type of engine, was afraid to reverse them.
Seeing- the captain’s indecision, Mr. M. P. Seiliger, Manager of Nobels, who was standing on the bridge near the captain, took the matter in his own hands and pulled the engine room telegraph of both engines to “full speed astern.”
Before the usual reply came from the engineroom the ship stopped and started moving away from the shore. The captain, who was rather angry at first with the impudence of an ordinary “civilian” giving orders on a warship, did not know afterwards how to thank Mr. Seiliger for the saving of the ship.
In the early spring of 1910 the two gunboats "Kars" and "Ardagan" were to proceed to their stations on the Caspian Sea.
Originally it was intended to dismantle their machinery and armament and tow the hulls along the Northern Canal system and Volga to Astrakhan, where the machinery and guns were to be put in again. But by that time the captains and the crew became great Diesel enthusiasts, and it was decided to send the boats via the same route direct to Baku under their own power.
Having left Petrograd the gunboats encountered floating ice-fields in the Ladoga Lake, and had to work as ice-breakers in order to be able to proceed.
While under tow, negotiating some rapids on the River Svir, the tow rope of the "Ardagan" broke, and, if it were not for the instantly started Diesel engines, the ship would have got on the rocks.
During the journey on the Volga it was found that for continuous running at full speed the piston tops were likely to give trouble, as several cases of cracking were observed. This was quite a new experience, as up to that time the high speed engines were of a small enough diameter not to produce these troubles.
Two solutions offered to that problem, either to introduce piston cooling or re-design the piston tops and make them of some more suitable material.
The Nobel Works had chosen the latter course in the case of these engines, as the adoption of piston cooling meant too many alterations in the installation.
On the way from Astrakhan to Baku the gunboats got into a severe gale, which taxed their propelling machinery to the utmost.
In military operations
■of 1919, in the Caspian Sea, these gunboats took an active
part. Two sets of similar engines were fitted in 1911 into the
Black Sea Revenue Cruiser Yastreb, whose hull was built at
the Nicolaiett Shipyard (Fig. IT).
One set of such engines was built for the Admiralty icebreaker train ferry Galerny,
for the conveyance of railway goods trucks across the River
Neva.
This latter ship had propellers at both ends, driven
through friction clutches from each end of the engine, one
propeller moving at a time. This arrangement was adopted
in order to do away with the turning of the ship in the river (Fig. 18).
Up to 1910 all tlie Russian submarines, with the
exception of Minoga and -1 kulci had petrol or paraffin engines;
but owing to several fatal accidents due to petrol explosions, the Russian Admiralty decided in 1909 to replace these light petrol-paraffin engines by Diesels, as risks of fire in the latter case would be less.
This was no easy proposition, as the weight of marine Diesel engines of that time was in the neighbourhood of 40 kg per b.h.p., whereas the weight of petrol or paraffin engines was 20-25 kg per b.h.p.
Tenders were invited from various Russian and foreign firms for light high speed Diesel engines, and the most suitable tender showed a weight per b.h.p. of 25-30 kg. (55-65 lbs.), but unfortunately the overall dimensions of all these tendered engines were far too large to enable the engines to be put into those submarines.
Eventually, however, the Admiralty specially requested the Nobel Works to take the whole order for the conversion of fourteen submarines to Diesel power.
Owing to the lack of available space in the engine room the Diesel engines had to be designed of about the same overall dimensions as the petrol engines, and, in order to reduce their weight, resort had to be made to high grade materials, such as chrome, nickel steels, aluminium, etc.
All this meant considerable experimental work, before a suitable engine could be produced. With a view of coming nearer to the practical solution of that problem Nobels had built in 1909 a special experimental marine Diesel engine of extremely light weight. After exhaustive trials in the shops, that engine was fitted into Mr. L. Nobel’s motor yacht "Intermezzo", and tested under actual sea-going conditions. The engine was of the V type, the angle of V being 90°. There were eight cylinders of 200 m/m diameter and 220 m/m stroke, placed four on each side of the V.
At the end of each row of cylinders were placed the air compressors, the L.P. cylinder on one side and the H.P. cylinder on the other. Both compressors had no suction valves, the suction being through small ports. The engine developed 200 b.h.p. at 600 r.p.m. (Fig. 19).
The cylinders were of cast iron with copper water jackets. The crankcase was of aluminium and the connecting rods of alloy steel.
The crankshaft, which was made at Fagersta in Sweden from Swedish carbon steel and tough hardened by Brinell process had a diameter of 100 mm. The tensile stress of material was 80-90 k.g. per sq. mm. with an elongation of about 12%.
The ball bearing camshaft was on top of the crankcase between the cylinders, the reversing being performed by the shifting of the camshaft bodily endwise.
The valve gear and the general appearance of that engine resembled very much those of the present-day aero engines.
The lubrication was
forced. The weight of that Diesel engine was only 2,000 kg.
or 10 kg. (22 lbs.) per b.h.p., which made it the lightest Diesel
engine ever produced.
Very valuable experience was obtained
with the running of that engine, and many points of
its design were embodied in the new engines specially built
for the conversion of submarines.
These fourteen submarines
were of three different types and sizes: Ssovv
class, six boats of Lake type of 110 tons displacement
had petrol engines of 160 b.h.p.: Jlakrel class, seven boats
of Holland type, and 115 tons displacement, with engines of
120 b.h.p. and the Delphin class (one boat) was of Russian
design with petrol engines of 200 b.h.p. Therefore, owing to
the difference in size and shape of engine room, three entirely
different types of engines had to be produced.
The conversion
began in 1910 with the Lake type boats first, and instead of the old petrol engine was installed in each boat one six-
cylinder 160 b.h.p. non-reversible Nobel-Diesel engine, giving
the boat a surface speed of 9^ knots. In general appearance
these engines resembled also very much the present-day aero engines, as can be seen from Figs. 20 and 21.
The cylinder dimensions were: diameter 225 m/m and stroke 300 mm, and the engine developed its full
power of 160 b.h.p. at 440 r.p.m. The weight of the engine was
only 2,900 kg. (6,400 lbs.), which worked out at 18-1 kg. (40 lbs.)
per b.h.p. In order to get such light weight combined with necessary strength and stiffness, the usual orthodox design of Diesel engines had to be departed from, and the engine designed on entirely novel lines.
Thus the bedplate consisted of two parallel longitudinal girders with four cast iron box shaped cross beams carrying the main bearings.
A very light cast iron crankcase did not take any vertical stresses as special run through bolts held it down to the cross girders of the bedplate.
The three cast-in-pairs blocks of cylinders were bolted
down to the crankcase top by the usual studs. The size of the
main bearings was kept as small as possible, and in order to
allow for their efficient working their lower halves were water-
oooled and had forced lubrication by an oil gear pump driven
from the lower end of the vertical shaft at the front part of the
engine.
All the four box girders of main bearings were connected
together by water pipes at the level of the side members
of the bed plate.
The pipes connecting the first with the
second, and the third with fourth main bearing? were on the
off side of the engine, whereas the pipe between the second and
third bearings was on the near side of the engine.
The whole of the cooling water circulated through the bearings before entering the water jackets of the cylinder.
Means were also provided for the cooling of the lubricating circulating oil in the forced system.
For that purpose the delivery pipe from
the oil pump passed through the water pipe between the first
and second main bearings. The lubrication of all the crank-
pins including that of the compressor overthrow at the forward
end of crankshaft, w'as of the banjo ring type, part of the oil
from the main bearings dropping into the rings. The lubrication
of the cylinders, air compressors and gudgeon pins was by
a mechanical lubricator. To collect the oil at the bottom of
the bed plate a thin sheet steel undershield was provided with
a sump at the forward end containing the oil strainer and oil
pump. To prevent splashing of oil the large openings in the
crankcase were covered with detachable sheet steel covers.
In the design of the cylinders racing motor car practice was
followed in many respects. Each block was of cast iron with
heads and liners forming an integral part of the cylinder.
But the water jackets were of thin sheet copper screwed to the
flanges on the cylinder walls. Each cylinder had the usual
assortment of valves (inlet, exhaust, starting and fuel valves),
actuated from an overhead ball-bearing camshaft driven from
the vertical shaft already mentioned. The inlet and exhaust
valves were directly below their respective cams, and therefore
had no rockers or levers of any kind, the cams actuating
these valves through the usual type of motor car tappets (Fig.
22). The starting valve situated vertically between the inlet and exhaust valves on one side of the cylinder, was actuated
by a bell crank rocking lever, w'hile the inclined fuel valve
had two bell crank rockers connected by a link. The design
of the pulveriser of the fuel valve required special study, so
as to obviate one-sided injection of fuel into the cylinder, and
means were provided to push the fuel by blast air in the direction
opposite to that it had the tendency to take. The fire
plate had a horizontal fan-shaped opening, so as to spread the
fuel right across the combustion chamber towards the centre of
the piston top. It is a known fact that in high speed engines,
owing to the inherent restriction in the size of valves, the
exhaust valve works under very unfavourable conditions, as
exhaust gases of very high velocity and of considerably high
temperature go past it, causing the usual overheating of the
exhaust valve. To obviate this drawback, small exhaust ports
were provided in the lower part of the cylinders of that engine,
which ports were uncovered by the piston at the lower part of tlie stroke, so that the hot exhaust gases could escape through
the ports, leaving comparatively cooled exhaust products at
a much lower pressure to be expelled through the exhaust
valve. The water cooled exhaust pipe was connected with
both the exhaust valves and exhaust ports. There was one
fuel pump for each pair of cylinders, and the three pumps
were combined in one group driven from the rear end of the
camshaft. A flywheel centrifugal governor controlled the speed of the engine by altering the lift of the suction valves
of the fuel pumps. As the engine was driving the submarine
on the Del-Proposto system, a hand regulation for the fuel
pump was also necessary for ahead running, a handwheel at
the rear end of the engine having been provided for the pur pose. The starting and fuel valves were put in and out of the
action by the usual eccentric shaft arrangement controlled bv
the starting lever. The whole of the camshaft, rockers and
tappets were enclosed in an aluminium casing containing the
four ball bearings of the camshaft and the thrust bearing
taking the end thrust of the skew gear of the vertical shaft.
That casing had three detachable covers and was hinged, so
that in case valve inspection was necessary, only four pins and
the coupling at the upper part of vertical shaft had to be taken
away and the whole of camshaft could be swung clear of the
valves. The engines of that type had a two-stage air compressor
driven from the forward end of the crankshaft, but in
the two first engines the L.P. stage had only one delivery
(ring type) valve, the suction air entering from the inside of
the crankcase into the compressor cylinder through ports at the
lower end of the cylinder. The high pressure stage had a combined
suction delivery ring type valve. This design considerably
simplified the compressor, but it had also its drawbacks
which soon made themselves felt in service. The air
drawn into the L.P. stage was not clean atmospheric air, but
air mixed with an oil vapour, which usually was contained
inside an enclosed crankcase of a high speed Diesel engine.
Admission of such oily mixture into the compressor was very
undesirable as the oil was likely to ignite inside the air receivers
between the stages and cause a possible explosion in the
coils. To counteract partially this drawback there was a
drain provided at the lowest point of the intermediate cooling
coil, which, combined with the downward path of air in the
cooler, was supposed to clean the air enough to obviate the
likelihood of an explosion. However, such an explosion occurred
in service, and therefore new compressors were fitted
to all these engines, having L.P. suction valves connected
direct with the atmosphere and the air cooling coils were removed
from the compressor jackets into a separate box fixed
at the side of the engine.
The copper jackets also proved to be slightly leaky in service,
and the last three engines were built with thin cast iron
jackets cast integral with cylinder block in the usual motor
car style. Gradually all engines of that type had their copper
jacketed cylinders replaced by those of new design. The fuel
consumption at full load of these engines was 215 gram (0-475
lbs.) per b.h.p. hour at normal speed. Beside submarine use
four of such engines were fitted as auxiliary sets into the Russian steam driven transport Xenia (mother-ship for submarines
of Ssom class), the reason for this being to have identical
engines in the whole of the flotilla, so as to facilitate replacement
of spare parts.
The submarines of the Makrel class had four-cylinder non-
reversible Diesel engines of' 120 b.h.p. installed to replace
the old petrol engines. The short length of engine room prevented
the installation of the six-cylinder engines of 160 b.h.p.,
in order to give a higher speed and therefore the old h.p. was
retained, giving the boat a speed of 6|-7 knots on surface.
These 120 b.h.p. engines were of a slightly different and
heavier design than the six-cylinder engines described above.
The cylinders were cast in pairs, the heads and water jackets
forming an integral part of them. Large inspection doors on
both sides of the jackets were provided to facilitate cleaning of
water spaces. The two blocks of cylinders were fastened by
studs to a light cast iron crankcase having detachable aluminium
covers to prevent oil splashing. The bedplate was also
of cast iron with three cross members containing the water-
cooled main bearings (Figs. 23 and 24.) The crankcase was relieved of tensile stresses in a manner similar to the
160 b.h.p. type, and also had a light sheet steel undershield.
The lubrication of the cylinders and air compressor was by
means of the usual mechanical lubricator, whereas that of the
main bearings and crank pin was similar to the engines of the
Ssom class boats; the circulating oil was cooled bv a cooler
placed alongside the bedplate of the engine.
The cooling water was circulated through the main bearings and cylinder water jackets by means of a gear driven from the forward end of camshaft.
The camshaft was enclosed in the
crankcase and was driven from the crankshaft by spur gearing
at the rear end of the engine. The cylinder diameter of these
engines was 250 m/m. (9 |in.) and stroke 300 m/m.
(11 13/16th ins.), the full power of 120 b.h.p. being developed
at 450 r.p.m. The two-stage air compressor was similar in design and method of drive to the improved type of' 160 b.h.p.
compressor. The two air coolers were separate and bolted to
the off side of the engine. The four valves were on the top
part of the cylinder, the inlet and exhaust opening vertically
downwards, whereas the starting and fuel valves were inclined
at 45° to the vertical. All these valves were actuated from
the camshaft by means of the usual motor car type tappets
and push rods. Auxiliary exhaust ports were also provided
with an exhaust manifold similar to that of the Ssom class
engines. The two eccentric shafts controlling the throwing
in and out of action of the starting and fuel valves were on
top of the cylinder, and each shaft controlled two cylinders by
means of a small hand lever, seen near the top between the
cylinder blocks. In order to assist the ventilation of the
crankcase, part of the cylinder suction working air was taken
from the crankcase, suitable baffle plates having been provided
to prevent lubricating oil being- sucked into the cylinders.
For this purpose three copper pipes having a number of slots,
connected the inlet valve chambers with the crankcase. A
similar arrangement was also provided in the 160 b.li.p.
engines of the Ssovi type. The four fuel pumps were grouped
together between the two cylinder blocks above the camshaft
from which they were driven. A band lever at the rear end
of the engine controlled through suitable gearing the amount
of fuel delivered by the fuel pumps to the cylinders. To prevent
racing of the engine a centrifugal governor of the Jahns’
type was driven from the rear end of the engine. In the case
of both types of engines (120 b.h.p. and 160 b.h.p.) the uncooled
pistons were of cast iron, having five piston rings and
no scraper rings at the lower end of the piston skirt. The connecting
rods of I. section were forgings of nickel steel,
machined all over, while the chrome-nickel steel crankshafts
were machined from the solid. The fuel consumption of that
120 b.h.p. ennine was 215 gram (0-475 lbs.) per b.h.p. and
the weight of the complete engine 3,220 kg. (7,100 lbs.) or
26-8 kg. (59 lbs.) per b.h.p. Besides submarines, this size of
engine was put in several small minelayers, tugs and in the
revenue cruiser Control of the Baku Custom House. The
overall dimensions of that ship were: length B.P. 72ft. Oins,
breadth md. 14ft., depth md. 6ft. 6ins., and loaded draught
3ft. 3ins. The engine of the submarine Delphin was a combination
of designs of the 160 b.h.p. and 120 b.h.p. types. It
was a six cylinder noil-reversible set of the same cylinder
dimensions as the 120 b.h.p. type (D = 250 m/m. (9|ins.) x S =
300 (11 13/ 16th ins.) but of slightly higher piston speed, the
r.p.m. being 500, which gave it a power output of 220 b.h.p.
(Figs. 25 and 26). The cylinder design as well as that of the
bedplate, crankshaft, connecting rods, piston and compressor
was similar to the 120 b.h.p. type, but the valves, though in
arrangement similar to the above-mentioned type, were actuated by rockers from an overhead camshaft driven from an inclined shaft at the rear of the engine. This camshaft was not of the hinged type, but was supported on ball bearings by four brackets bolted to the cylinder tops, the cams working in an oil bath. The eccentric shaft was in one piece actuated from a hand lever at the front end of the engine, thus putting all six cylinders on fuel at once during the starting operation. A centrifugal governor was mounted on the inclined shaft and the fuel lever, placed near by, controlled the fuel pumps, six in number, grouped together at the rear of the crankcase and driven by bevel gearing from the inclined shaft. The crankcase was of very light scantlings and of cast iron with large aluminium inspection doors, which were easily detachable. The weight of the engine'was 4,275 kg. (9,440 lbs.) or 19,4 kg per b.h.p. The duty of the governor was to prevent excessive racing' of the engine when the clutch was released or when the dynamo was running' at no load. During tests of instantaneous throwing off the load from full to no load, the engine speed increased momentarily to 565 r.p.m. and then settled down to 545 r.p.m., which was the speed for no load running of the engine. In table II. are given the principal results of the official 12 hoiirs non-stop trials of that engine made in 1912.
Owing to the shallow and undulating coast line of Russia
in the Baltic Sea, it was necessary to have small size submarines,
which could navigate those waters, and that explains
the reason why the submarines of the Ssom and Makrel class
were retained during the war when most other nations built
only quite large sea-going submarines. The Russian Navy
had a good number of large submarines also, fitted mostly with, two-stroke engines, but even the small submarines were
often operating near the coast of Germany, as could be instanced
by the case of submarine Oltun (Makrel class) which
sank a German battleship off Danzig in 1916. The abovedescribed
Diesel engines were not the smallest type submarine
engines built by Nobels. In 1914-three 50 b.h.p. four-cylinder
non-reversible Diesel engines were made, running at 500 r.p.m.
These engines were fitted in three 35-ton submarines, giving
them a speed of 6j knots. These submarines were designed
for the defence of the approaches to Cronstadt, and, if necessary,
could be taken on board ship for transportation. The crew of
these submarines consisted of five men all told, and the headroom
available was so small that a tall man had to move inside
the boat in a bent position. The cylinder dimensions of
these small engines were : diameter 170 m/m. (6 11/16tli ins.)
and stroke 220 m/m. (8 11 / 16th ins.) In general design they
were a copy of the 120 b.h.p. type on a smaller scale. The
weight of these engines was 910 kg. (2,000 lbs.) or 18-2 kg.
(40-2 lbs.) per b.h.p. A slightly modified type of such engines
using six cylinders in three blocks of two, the cylinder diameter
being 180 m/m. (7 l/16th ins.) and stroke 230 m/m.
(9 1 16th ins.) and developing 80 b.h.p. at 450 r.p.m., was
fitted into several minelayers during the war (Fig. 27). Reverse gears were provided for astern motion. A very important
point in connection with the design of these small and
medium size high speed Diesel engines was that of crankcase
ventilation. During the working of the engine, inside the
crankcase an oil vapour accumulates, and if it is not expelled
from the crankcase, an explosion may occur due to the ignition
of that oil vapour when coming in contact with the underside
of the hot uncooled piston head. To overcome this defect,
part of the necessary suction air for the cylinders is drawn
through the crankcase, thus sucking that vapour into the
cylinders, and incidentally cooling the pistons by air. But
this again has its disadvantages, because inside the crankcase,
especially in forced feed lubricated engines, oil splashes all
over the place and particles of such oil are drawn into the air
suction pipe. The engine in such a case runs partially on
fuel oil and partially 011 lubricating oil, with the result that
the fuel oil consumption is considerably reduced, while the
lubricating oil consumption is correspondingly increased. Besides
the financial drawback, such running entails considerable
risks, as, when there would be too much lubricating oil sucked
into the cylinder, the engine might get out of control and race
away, with consequent disastrous results. A system of carefully
designed baffle plates should be fitted into the suction
pipe, so as to arrest the particles of oil 011 their way up that
pipe.
A purely Diesel electric drive for warship propulsion was
also made by Nobels in the case of the small converted cruiser
liynda. The reason for the adoption of the purely electric
drive was that at the time the order was placed (1910) the
Admiralty had many doubts as to the advisability of having
reversible engines of 1,000 b.h.p. per shaft, considering that
for a six-cylinder engine the cylinder dimensions would be
prohibitive. This was contrary to Nobels ideas, who urged
the Admiralty to adopt one reversible engine of 1,000 b.h.p.,
as the ship was single screw. This, however, would have
meant too many alterations in the engine room, which was
very short, as a compound steam engine was there previously,
and the boiler space could not be allotted for the Diesel installation,
as it was to be used for other purposes. Eventually it
was decided to put two high speed Diesel engines of 600 b.h.p.
each direct coupled to 400 kw. D.C. generators, these generators supplying current to one slow speed electro-motor on the propeller shaft. In cylinder dimensions, D=450 m/m. and and S = 510 m/m. and general appearance the
engines were similar to those of motor ship Robert Nobel, hut
in order to get the necessary power output their piston speed
was increased to 5-45 m./sec. (1,070 ft./min.) or 320 r.p.m.
and the engines were of course not reversible. Owing to the
adoption of the electric drive the weight of the engine had to
be kept as low as possible, so as to come within reasonable
total weight figures, and the main cast parts of the engines were
steel castings with the exception of cylinder liners and
pistons, which were of cast iron (Fig. 28). No flywheels were fitted, as the armature of the dynamo, weighing 4,850 kg. (4|
tons) served as such. The weight of each engine proper was
23,750 kg. (23} tons) or 39-G kg. (87-5 lbs.) per b.h.p. Owing
to the high power output per cylinder (150 b.h.p.) piston cooling
had to be resorted to, and this was effected by circulating
the forced feed oil in the piston heads via hollow connecting
rods, the returning oil having been cooled in special separate
coolers provided for the purpose below the engine room floor.
The exhaust valves were water-cooled, as well as the exhaust
pipe and main bearings. Two plunger circulating water
pumps were driven from the forward end of the crankshaft, from which also was driven a two-stage tandem air compressor.
The dimensions of that compressor were D-HP 9U m/m.
(3 9/16th ins.) D-LP = 290 m/m. (11 7/ 16th ins.) and stroke
280 m/m. (llins.) and the air cooler was separate and bolted
to the side of the crankcase. Considerable trouble due to overheating
of air was experienced with that type of compressor,
so that it was replaced by a three-stage double tandem air compressor
of the following dimensions: D-HP 55 m/m. (2 3/16tli
ins.); D-IP 125 m/m. (4 15/ 16th ins.); D-LP 290 m/m.
(11 T/ 16th ins.) and a common stroke of 280 m/m. (llins.).
After that alteration the compressor troubles disappeared. It
was the first time, in Russia at least, that a double tandem
three-stage air compressor was applied to Diesel engines, but
since then all Nobel Diesel marine engines, having compressors
driven direct from the crankshaft, are fitted with such
double tandem three-stage compressors. In table III. are
given results of non-stop 100 hours duration official trials of
these Rynda type engines.
In 1912-1913 great extensions were made in the Naval Port
of Sebastopol, on the Black Sea, including the building of a
large dry dock to accommodate the new Russian battleships,
then under construction. A pumping station of considerable
power was built at the Dockyard. To prevent any damage to
machinery by enemv fire, the plant was placed underground
in casemates, protected by ferro-concrete and armour plates.
Owing to this the space was limited, of course, and the power
station of the plant was designed to have high speed Diesel
engines, driving the various pumps by electricity. The
Russian Admiralty expected war in the Black Sea, and therefore
was anxious to have the pumping station in working order
as soon as possible. As no firm could give quick enough delivery
of a high speed Diesel electric plant of about 750 kw.
aggregate output, the Admiralty sacrificed for the purpose
the Rynda engines, which were put into that power station in
1914, with all their electric gear, without any alteration.
The cruiser Rynda was broken up just before the war.
When the foiir Russian battleships of the Gangout class were
designed it was decided to provide some Diesel generating sets,
which could run in parallel with the steam turbine driven sets
and supply current to various parts of the ship, including the
electromotors for turning the gun turrets. The steam auxiliary
plant consisted of four 320 KW. DC. dynamos fitted with A.C. stop rings and driven by De Laval steam turbines. The
Diesel plant was of two sizes : the lighting plant and the power
plant. The lighting plant consisted of three sets of 180 b.h.p.
six-cylinder, four-stroke Diesel engines built by Felser Works
of Riga. These engines were direct coupled to 120 I(W. DC.
generators. The power plant consisted of two 320 KW. DC.
generators, with A.C. slip rings, direct driven through a
Voigt elastic coupling by a 480 b.h.p. Nobel Diesel engine
(Fig. 29). The reason for the adoption of Voigt coupling was that the engine and dynamo bedplates were separate castings,
not bolted together. These engines were placed in one engine
room just in front of the rear gun turret and under the main
protected deck. The cylinder dimensions were: diameter
375 m/m. (14fins.) and stroke 430 m/m. (16 15/16th ins.) and
the normal output of 480 b.h.p. was obtained in six cylinders
at 320 r.p.m. The fuel consumption of the engines at full
load w'as 195 grams (0-43 lbs.) per b.h.p. hour. The engines
were non-reversible and in general outline followed the usual
Nobel Diesel high speed medium power practice. A double
tandem air compressor of equal dimensions to that of Rynda
engines, but of slightly shorter stroke (270 m/m.—lOfins.) was
direct driven from the forward end of the crankshaft. The
pistons were water-cooled bv means of a telescoping gear and
the exhaust valves and exhaust pipes, silencers, and bearings 'were also water-cooled. The telescoping- gear consisted of a
tubular bridge piece bolted to the piston skirt by the middle
and having at the ends two vertical steel pipes well polished
externally.
These steel pipes moved up and down in gunmetal water
receivers, the leakage of water was prevented by a gland.
During navigation in the Baltic Sea, ordinary seawater was
used for piston cooling, as the salt contents in the water was
small, but during ocean voyages, the pistons were to be freshwater
cooled, while the cylinder jackets, etc., had seawater
cooling. The above-mentioned telescopic gear proved to be
troublesome in services, as the tightness of the gland depended
upon the perfectly vertical motion of the piston, i.e., without
any side play whatever. In practice this was impossible of
achievement as the piston had to have some small play inside
the cylinder, and that small play was large enough to loosen
the glands, so that water used to spout past these glands into
the bedplate. This was very undesirable, as the water was
mixing with the circulating oil at the bottom of the bed plate
and the emulsion was taken by the oil transfer pump to the day circulating oil tank and hence sent through the oil circulating system, with results which can easily be guessed. The author remembers such a case, while he was in charge of these
auxiliary sets on board the battleship Sebastopol in 1S14 in
the Baltic. The engines were supplying current for the turning
of 12in. gun turrets, and after some time it was observed
that emulsion got into the drip feeds. The situation was
rather an unpleasant one, as the engines could not be stopped
on any account. To continue the running of the engines on
emulsion for some considerable time was also out of the question,
therefore the only possible solution at that moment was to
stop the circulating principle of lubrication and lubricate the
bearings with fresh oil all the time, using the oil transfer
pump to convey the emulsified oil from the bottom of the bedplate
to an empty reserve oil tank near by, to which a suitable
connection was improvised 011 the spot. After the emulsified
oil had settled in that tank it was filtered, transferred to the
day oil tank and used over again.
After this experience it was decided to change over from the
telescopic principle to the grasshopper type, which was later
fitted to ail the eight engines and proved to be practically
immune from trouble. After this reconstruction the ordinary
circulating lubrication of bearings was again resorted to.
The author had another interesting experience with these
engines on hoard of all the four ships, and that was the effect
of resonnance or vibrations of foundations due to minor unbalanced
forces in the engines. It was found that when the
two engines were running together at the same speed, vibrations
of certain amplitude were set up in their foundations,
and when the two amplitudes synchronised, the vibrations became
so pronounced that it was quite unpleasant to stand on
the engine room floor. The remedy for it was found in the
running of engines at different speeds (one at 323 r.p.m. and
the other at 318 r.p.m.), when these vibrations disappeared.
With the description of this type of engine closes the chapter
of the four-stroke Nobel Diesel engines, as no more new types
of four-stroke engines were built by Nobels after those, all the
new types being of the two-stroke cycle; to the description of
which engines the author will proceed at next meeting, as it
is considered more desirable to do so and invite discussion on
each.
The C h a ir m a n : The paper to-night is historical. Some of
those present will probably find points for discussion, particularly
those who are opposed to the! four-stroke type of engine.
I notice that in the last paragraph the author states that Messrs.
Nobel have given up the manufacture of the four-stroke engine
in favour of the two-stroke.
Mr. W. H amilton Martin : Mr. Steinheil’s paper lias given
us some interesting historical facts about the early achievements
of the Nobel firm on the Diesel engine. What the
author tells us does not readily invite discussion, but it certainly
leads one back to the days when the marine Diesel engine was
in its infancy. Many were the difficulties met and overcome,
and great was the prejudice encountered by Dr. Rudolf Diesel
and his assistants while devoting untiring energy and capital to
the perfecting of his engine for both land and marine use.
Thanks to the wide circle of friends which my father had, and
the way in which I was always taken by him to join in the discussions
on matters of future interest, I had the privilege of
meeting the late Dr. Diesel several times. My father was one
of the engineers who took out an early licence for building the
two-cycle marine Diesel engines at the Flushing Royal Dockyard,
Holland, of which lie was the Engineering Manager from
its foundation in 1875.
We had many very interesting conversations with Dr. Diesel before deciding to take up the building of his engines, now nearly 15 years ago, and I recollect how even then Dr. Diesel repeatedly referred to the fine results obtained by the Nobel firm in Russia.
If I may make a slight digression, I would like to mention
here that three 1,000 K.W. dynamos, driven by six-cylinder
Diesel engines, were some time after installed at the Flushing
Dockyard by my father instead of the old steam plant for driving
the entire yard. This was just prior to the war, and when
soon after we had the coal famine in Holland, our yard with
its plentiful oil supply, thanks to foresight, could carry on
where others had to slow down on close altogether. This power
house has proved a great success. I may add that my father
made several suggestions, which were gratefully accepted, for
converting tlie inherently somewhat stationary type of Diesel
engine into a more suitable marine job. He very soon substituted
solid drawn steel tubing and conical unions for copper
piping with brazed joints for the fuel injection line, which was
always giving out, not being able to stand the vibration. He
also did away with silencers altogether, and substituted a light
water-cooled valve which has since been adopted as standard
in a certain Continental Navy’s Submarine Service; he devised
a. simple fuel injection pump which allowed of close speed regulation
and assured equal fuel supply to all working cylinders,
and made various other practical improvements.
In consequence of our relations with Dr. Diesel I had the
privilege of working for some time at the M.A.N. Works at
Nurnberg, as assistant in their testing department for highspeed
marine Diesels, which were then mostly fitted in submarines
or gunboats in sizes from 200 to 1,200 B.H.P., of three,
four, or six cylinders, all two-cycle. These people were continually
carrying out costly experiments for Dr. Diesel on
cylinder and piston head formations, scavenge, exhaust, and
fuel valves, cast iron mixtures for cylinders, etc.
I went through many of their marine engine “ teething ”
troubles with them, and gradually saw most of these cured on
severe endurance tests. Later on I saw several of these engines
giving satisfactory service, also during war service.
The Nobel people had by then, however, already passedi
through most of their troubles, and had actually been successfully
running reversible units in Russian tugs and submarines.
Speaking of tugs, we arranged with the makers to have a
300 h.p. six-cylinder two-cycle engined tug boat, the .Xirrn-
berg, in use some time in the dockyard at Mushing. She had
110 magnetic clutch as the Nobel’s fitted in theirs, and consequently,
when picking up a string of barges on a river or tidal
basin with current, this job often proved a more profitable one
for the tow-rope suppliers than for the tug owners.
The cushioning effect of steam when taking up the tow-strain will take a lot of beating, but the idea of fitting a magnetic or friction clutch ought to solve the question of gradually picking up the load. Without a clutch one could best compare the flexibility at starting of oil and steam power with a horse which jerks, when starting a loaded cart, and a span of oxen which slowly but steadily lean, as it were, against their yoke when commencing to move.
This tug was eventually sold to the German Navy at Kiel for instruction purposes of their submarine engineers, for which it has no doubt proved eminently suitable.
While at Numberg I met an engineer officer of the Russian Navy who was taking delivery there of some 1,100 B.H.P. two-cycle Diesel engines made presumably for Russian gunboats. Through the outbreak of war, however, these went into German submarines. His wonderful experience in the running of Diesel engines in those early days I have always envied. The inevitable result was, however, that this officer proved a relentless inspector. I remember his examining all finished cylinders and piston heads minutely with a strong lens, for hair-cracks or small flaws, after which they had to be kept for 24 hours under hydraulic preassure twice the working preassure.
I understood these were the Russian Admiralty’s test standards. Batches of a dozen or so fully finished cylinders or piston heads were rejected by him at a time, many of which would probably have been good enough for an appreciable amount of running. I did not envy the builders having that inspector!
These requirements no doubt led to the fact that the M.A.N. people soon made the finest cylinder head castings, and many of their later licencees preferred to order these parts from them. Their foundrymen were at the time earning as much as 90 to 100 marks a week, then £5, which in those days was very high pay indeed for such work. If Messrs. Nobel have had to contend with similar rigorous inspections in Russia and still managed to get such success in those days, it speaks all the more for their pluck and determination to have achieved all the work which has just been shown to us so ably by Mr. Steinheil.
Before ending, the following observation may be of interest; I just happened to notice in the Motorship year book of this year that from 1904 to 1911, out of the existing twenty-one motorships of the world, nineteen were Nobel and Kolomna engined.
The other two were—one in 1910, the tugboat "Nurnberg", which I mentioned, fitted with M.A.N. engines, and the other the "Vulcanus", fitted with Werkspoor engines.