DIESEL’S IMPORTANT ROLE

Cue (NZERS), Issue 7, 15 September 1944, Page 6

DIESEL’S IMPORTANT ROLE

DIESEL power has played a great part during the present war and particularly in the recent invasions of France. The bulk of the great fleet of 101 newly developed types of landing craft were propelled by diesel engines. Its role has been a most important one.

Engineers have used diesel power very consistently during the last 15 years. Its application in every day life may be seen in gritless trains, heavy duty trucks, ships, submarines, dirigibles, planes, power plants and agricultural equipment. But its rise to commercial importance is little known and its telling provides an interesting story. The inventor, Rudolph Diesel, was born in Paris of German parents , in 1858 — the era of the storage - battery, balloon, gas engine, electric lights, dry-plate

photography' and many chemical novelties. In his youth he spent a great deal of his time in one of the earliest industrial museums, the Conservatoire des Arts, at Metiers, near his home. At school he showed himself to be mechanically gifted. On the outbreak of the Franco-Prussian War of 1870 the family moved to London. . Later, he attended the Technical High School at Munich where his brilliance was soon noticed by the. celebrated Professor Carl Von Linde, pioneer of mechanical

refrigeration. Diesel was soon convinced from Linde’s lectures of the low efficiency of the steam engine and he was impressed by such engines and machines which transmit power — the windmill and the water wheel. / Following Diesel’s * graduation, Linde sent him to work at his factory in Paris where his first job was the assembly and installation of refrigerators. Soon he was in charge of the whole plant. He had not been idle. He patented methods for making « clear ice » and for producing ice in a water bottle at the dinner table. This work, the extraction of heat-from water, proved invaluable in his later experiments of turning heat into work. Diesel realised that high temperatures can be produced by compressing gas. An apt illustration of this is the heat felt at the nozzle of an ordinary bicycle pump. Using this basic principle; Diesel evolved his motor. It differs from the petrol internalcombustion engine in that it has no electric ignition. Air is drawn into a cylinder and compressed by a piston until its temperature rises to about 1000 degrees F. Fuel is sprayed into the cylinder and ignited by the heat. The .resultant explosion drives the piston. Details of the action of a fourstroke diesel cycle can be explained as follows: — (1) Suction — Piston moves down from cylinder head drawing air only into the cylinder through an inlet valve. Exhaust and fuel - injection valves are closed. (Illustration 1).

(2) Compression — Piston moves back toward cylinder head compressing air in cylinder to? pressure of 400-5001bs to* square . inch, raising its temperature to about 1000 degrees F. The valves are still closed. (Illustration 2). (3) Power-stroke — Near-- end of , compression stroke, the fuel valve opens and atomised fuel is shot into the cylinder. Theheat ignites it and the fuel valve closes, while the expansion of heated gases drives the piston downwards. (Illustration 3). (4) Exhaust-stroke —.Near finish of power-stroke the exhaust

valve opens and the piston returning upwards drives the gases through the exhaust valve into the exhaust pipe. The air' inlet valve and fuel injection valve are closed during this operation. (Illustration 4). Thus, .it can be seen that the diesel is almost identical with the petrol engine. The main differences in the diesel are: — <{l) Compression and temperature — before entrance of fuel — are higher. <2) Air only is drawn into the . cylinder during suction. <3) Fuel is sprayed into cylinder at high pressure. <4) ; No electrical or mechanical action is required to produce ignition; and 45) Combustion temperature and . compression are higher. The two-stroke engine is less ■complicated. There is only one power-stroke for every complete revolution of the crankshaft. Suction and exhaust strokes are ’eliminated as simple strokes. In 1892, Diesel took out a patent and his first engine, a 13 horsepower unit, had its trial the following year. To Diesel’s satisfaction the engine blew up, as it proved his theory that sufficient heat was in the cylinder to ignite the fuel. Countless modifications were made during the next four years, but in 1897 his machine was ready for commercial production. - » *

Diesel became a millionaire, ‘contracts were sold to manufacturers in Germany, Austria, *Great Britain, Russia, America, Switzerland, France and Belgium However, the difficult period of development still lay ahead. Although the trials had proved a success, the selection of a suitable -fuel still formed a difficult problem.

An oil company finally saved his engine from the world of « Won’twork » inventions by producing a crude lubricant which assured that the engine would work efficiently and economically, in the meantime, it had created tremendous interest at the Munich, Paris, Brussels and St. Louis Exhibitions. . \

The year 1910 marked the development of .the small diesel engine with the introduction at the Brussels exposition of an automobile powered by a fourcylinder diesel. ’Following this, Amundsen used a diesel marine engine in the «Fram» for his Antarctic Expedition, while the Selandia, built in Copenhagen and fitted with a diesel engine, completed a voyage to Bangkok and back. The last years of Diesel’s life were hardly a fitting reward for this genius. He had invested his money. foolishly and most of his capital disappeared. In a book published in 1913, he expressed a realistic philosophy" for inventors:— «An invention consists of two parts: the idea and its execution. « An invention is never a purely intellectual product, but it is the result of a battle between the idea and the material world. « The birth of an idea is the happy moment in which it appears possible and reality has not yet entered into the problem. « The inventor must be an optimist, since the full driving power of an idea is to be found only in the mind of the originator. He alone has the sacred fire to push it . through.» The summer of 1930 was to end in tragic circumstances for

Rudolph Diesel. It is reported that he left Munich for the purpose of attending the opening of a Diesel factory at Ipswich, England. During the Channel crossing in the hours of darkness he disappeared and to this day no clue or trace of his body has ever been found. . Although Diesel’s loss was greatly -felt in the world of science, nevertheless his ideas are today being applied with maximum success. To the farmer the diesel unit has proved an economic means of bringing under the plough thousands of acres of formerly waste land. In all branches of farming it has proved a great boon and has proved undoubtedly a most suitable engine for heavy work. . In New Zealand diesel power is being put to an ever increasing

use on the railways, particularly with regard to rail-cars,\ in the larger omnibus services, - and on coastal shipping routes, while in the factory it is playing a great

part in the expansion of the Dominion’s industries. Rudolph Diesel had many hopes: one was that his engine would, one day be given preference'over steam. Perhaps this will some day become a reality.