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this new type of furnace was first put into practical use (at Trollhattan), and others have been erected since at different places. In 1920 about 60,000 tons of pig-iron was produced in such furnaces at Domnarvet, Hagfors, Porjus and Trollhattan. The charcoal consumption per ton of pig-iron in electric blast furnaces is only about 35—45 % of that in ordinary blast-furnaces. The saving of chareoal is very considerable, therefore, especially as regards the grades of pig-iron which are rather high in silicon and manganese. This saving is, however, partly balanced by the cost of electric current and electrodes, and the somewhat higher maintenance costs of the furnaces.
Of later years a certain quantity of coke pig-iron has been made in Sweden, and also iron smelted by a mixture of coke and charcoal. The object is to manufacture iron for ordinary purposes to replace imported iron. The output of such iron, however, has shrunk from about 106,000 tons in 1913 to about 16,400 tons in 1921.
The total production of pig-iron in Sweden during the last thirty years is shown in the following table 1.
For production of wrought iron from the pig the most common method in use for a long time was the so-called »German forge», introduced from Germany by ironmakers called in by Gustavus Vasa (before 1540), and also the »Walloon forgo) method brought to Sweden from Belgium about a hundred year later through the efforts of Louis de Geer.
About 1830 a change was brought about by the strong competition abroad and by the growing demand for greater homogeneity in the bar-iron. The method then adopted was the Lancashire process, introduced from England by G. Ekman. It was a more economical and technically perfect forging method that gained a great and growing importance in the Swedish iron industry during the following years of the nineteenth century.
In the nineteenth century also Franche-Comte forging (introduced from France in 1852) was carried on to a rather considerable extent, besides, and some little puddling (the first furnace erected at Klosters Bruk in 1812), and Walloon forging as before, especially at the works which took their ore from Uannemora. At the present day only the Lancashire and Walloon methods survive.
It was not till 1895 that forging in hearths (wrought iron) was surpassed in Sweden by the Bessemer and Martin methods (ingot iron), and still in 1920 more wrought ii'on than Bessemer steel was made in Sweden (see Table X).
The need of a hard malleable iron (steel) was filled in earlier times through heating soft iron in carboniferous substances, through which the iron acquired a more or less thick outside layer of steel. Such a product was designated »blister steel». The first real blister steel furnace, however, was not built in Sweden till 1655. This product is made even now, though to a very small extent.
Crucible steel appears to have been made for the first time in Sweden some time during the latter half of the eighteenth century, but the manufacture was soon discontinued, and did not acquire a permanent domicile in the Swedish steel industry till about 1860.
The Bessemer process made its entry into Sweden in 1858, the Martin process in 1868, and since the year 1900 the electric steel furnace is also used in Sweden for the production of steel.
The Bessemer method was introduced and improved by G. F. Goransson. For the development of the open-hearth process in Sweden much credit should be accorded to Professor E. G:son Odelstierna; F. A. Kjellin being the pioneer for electric steel furnaces.
Of all these processes for making wrought iron and steel the Martin process is by far the most important at the present day. The facilities for great variation in the composition of the charges, the slowness of the process, which offers better opportunities of watching and of taking samples, and, if necessary, making dispositions for obtaining a certain desired product, all these advantages have served to give this process the first place, and distanced the Lancashire and Bessemer processes.
That the Lancashire process should lose ground in competition with the open-hearth process was inevitable, inter alia on account of the growing difficulty of obtaining the chareoal needed for it, and of keeping up the dwindling stock of skillful Lancashire ironworkers. The forging work is heavy and requires physical endurance, but even more, perhaps, special aptitude and judgement. Improvements introduced from time to time have lightened the work and have made the process more economical. This has retarded the retrograde movement but has been unable to arrest it.
The Bessemer process in Sweden has especially good natural conditions in its favour, such as a plentiful supply of water-power, small, well-managed chareoal blast-furnaces, and ore rich in manganese. The drawback is that the pig-iron becomes expensive, owing to the large consumption of fuel. In the competition with the open-hearth process it has in consequence had to give way, but its last positions are defended with notable tenacity and much justification. Just as the Swedish Lancashire iron, the Swedish acid Bessemer steel must be regarded as distinctly superior to the open-hearth product for certain purposes each in theirsown way.
As mentioned above, the Swedish iron and steel industry has advanced with the times in respect to scientific and technical organization, and this has been made possible by the consolidation of the works into large units.
This satisfactory feature in the situation must be ascribed more than anything to the society formed by the ironworks in 1747 on the initiative of A. Baekmansson, afterwards ennobled under the name of Xordencrantz. The society in question is called »Jernkontoret » - The Swedish Iron Masters Association—and still constitutes a pillar of support to the Swedish iron and steel industry. Here it is only necessary to refer to its mighty assistance in developing the Royal College of Mines in Stockholm (until 1869 in Falun) and the Mining Schools at Falun and Filipstad; its work in connection with the creation of the Metallographic Institute in Stockholm; and its many grants for researeh work in mining and metallurgy.
The conditions are at hand, therefore, for ensuring the very best treatment of the renowned old Swedish iron and steel during the production as well as during the following operations up to ready products. They should prove sufficient guarantees that the confidence accorded to it at home and abroad for so long a time will be retained in the future.
./. A. Leffler
The Swedish Machine Industry
The inception of the engineering industry in Sweden coincided with the introduction of modern transportation facilities, and the opening up of new lines of communication in the nineteenth century. Up to that time distance had proved an insurmountable obstacle to disposing of the products of manufacturing on far away markets, but the employment of steam made competition international. In the course of time the competition thus enforeed on the home as well as on the international markets fostered a tendency toward specialisation; i. e., concentration of the manufacture on one or a few articles best suited to the experience, facilities, and materials available. This policy was adopted as a means to attain the largest output, improvement of the quality, and cheapening of the cost of production.
The unceasingly sharpened competition on the part of the large industrial countries, in particular the United States, Great Britain, and Germany, compelled Swedish manufacturers in a certain branch to go in for production on a larger scale than warranted by the domestic consumption, and this in turn made it necessary to look for markets abroad. Many Swedish works or groups of specialized manufacturers had very fair success, too, in this respect, and several Swedish products have even reached a leading position abroad. In general the Swedish manufacturers of machines and appliances have adopted the policy of superior quality rather than low cost as an inducement to purehasers. Swedish products of this order as a consequence are on the whole characterised by exceedingly good workmanship, good materials, serviceable design, and high economy.
The range of the Swedish machine industry is very comprehensive, and really comprises a great many products properly described under different headings, such as tools and implements, appliances and instruments, etc., but the general term current in Sweden has been adopted here. The following brief survey of the chief products or class of products will give an idea of the span of the industry.
Machines and appliances of practically every description for agricultural purposes are made in Sweden. The most prominent place, perhaps, in this sphere is taken by Swedish cream separators, treated in a subsequent article on special industries.
Agricultural machines for tilling the soil and harvesting, etc. stand on a very high level, and comprise most of the appliances used in modern farming: harvesters, selfbinders, mowers, ploughs, cultivators, drills, etc., all of the latest design and construction. Further, threshing machines, hand-presses, steam locomobiles, oil engines, tractors, motorploughs, motor-rollers, and other machines of a similar kind and of the highest class.
Among the first concerns to manufacture machines of the above description may be mentioned Munktells Mek. Verkstads A.-B., founded 1832, J. & C. G. Bolinders Mek. Verkstads A.-B., founded in 1844, A.-B. Joh. Thermenius & Son: and among those that entered the field later are A.-B. J. V. Svenssons Motorfabrik, A.-B. Arvikaverken, Norrahammars Bruks, A.-B. Ofverums Bruk, Ystads Gjuteri & Mek. Verkstads A.-B., A.-B. Wasterasmaskiner, Skandiaverken A.-B.
The works manufacturing the machines and appliances mentioned above are in general equipped for a far greater output than demanded by the domestic market. All of these products have acquired a very large sale in other countries, and normally the greatest portion by far went to the large agricultural countries on the other side of the Baltic. The war and subsequent upheavals naturally placed a barrier in the way of further business there, and since that time there has only been a sporadic resumption of the demand up till the present. The success of the Swedish agricultural machines has been gained in the main by supplying suitable types, specially designed for conditions in those countries, possessing great strength and durability due to good material and first class workmanship.
A particularly prominent place in the Swedish engineering industry is occupied by crude oil engines. In this branch a leading part has been played by Sweden from the first, and Swedish two-cycle crude oil engines have won the highest reputation wherever they have been introduced, which means practically every country in the world. The manufacture of this type of engine was initiated by A.-B. J. V. Svenssons Motorfabrik and J. & C. G. Bolinders Mek. Verkstads A.-B., who commenced building such engines in the first years of this century. The demand soon became very great, and a number of other firms went in for building hot-bulb engines with some little variance in design between the different makes. Among the large makers may be mentioned Skandiaverken, A.-B. Atlas-Diesel, Bergsunds Mek. Verkstads A.-B., Jonkopings Mek. Verkstads A.-B., Svenska Maskinverken A.-B., Munktells Mek. Verkstads A.-B.
The Swedish two-cycle oil engines, which are by now highly perfected, may be regarded as the foremost of their class, and Sweden has well maintained the lead gained in the early years with the types first put on the market. These engines are characterised by great reliability and for requiring little attention, being withal very economical and able to use practically any kind of heavy oil, such as massuth, tar oil, palm oil, etc. The engines are at present made in every style, suited for all purposes; stationary, portable, and marine being the main types, built in sizes from 1—2 HP. to 600 HP.
The building of Diesel engines in Sweden was commenced about the same time as the two-cycle engines. The Swedish type of Diesel engine early attracted attention by the many improvements incorporated in the design. These improvements were indeed of so epoch-making a description that the Swedish Diesel engine could enter the countries who were building Diesel engines in accordance with the original patents. The present types of Diesel engines, made by the A.-B. Atlas-Diesel, occupy a conspicuous position among the world's leading makes of Diesel engines. They are now built both on the four-cycle and two-cycle principle, in sizes up to 1,600 HP. Atlas-Diesel engines are also built by licensees in the United States, Great Britain, Germany and other countries.
Several firms make petrol engines for motor boats. The best known of this class are the Penta motors, built by A.-B. Pentaverken, introduced in a good many places abroad, and the Arehimedes outboard motors.
The extensive building of crude oil engines made it very natural to adapt them to suitable uses in combination with other machines, and in consequence there are a great many Swedish manufacturers of tractors, motor-ploughs, motor winches, motor-compressors, motor-pumps, etc. In general these self-contained equipments are fitted with crude oil engines, contrary to what is the practice abroad, where gasoline or petrol engines are the rule. The advantages of the Swedish machines consist in the first place in their lower operating cost, due inter alia to their use of low-price fuel oils, and in the second place in their simplicity and insensitiveness to rough usage; an important consideration when applied to machines of this kind, which must in nearly every case be entrusted to drivers unskilled in mechanical contrivances. Among the largest concerns manufacturing tractors are Munktells Mek. Verkstads A.-B., Landskrona Nya Mek. Verkstads A.-B., Jonkopings Mek. Verkstads Nya A.-B., A.-B. LindholmenMotala and A.-B. Svenska Motorplogfabriken.
In this connection may be mentioned another class of appliances for which oil engines are often used to supply the power, viz. machines and appliances for street and roadmaking such as motor-rollers, scarifiers, excavators, ditching machines, concrete mixers, stone crushers, road planers and scrapers, etc. The suitability of Swedish iron and steel to the severe service demanded of such machines, in addition to good designs and efficiency, has facilitated the export of such equipment to quite a considerable extent. The principal manufacturers are A.-B. Abjorn Anderson, Nya A.-B. Svenska Maskinverken, Landskrona Nya Mek. Verkstads A.-B., A.-B. Maleus Holmquist, Sala Maskinfabriks A.-B. and Carl Holmbergs Mek. Verkstads A.-B.
Machine tools have been made in Sweden for quite some time, and at present the manufacture stands very high. The Kopings Mek. Verkstads A.-B. commenced manufacturing of machine tools in 1850, and the Munktell works organised a machine tool department in the eighteen-seventies. Several special machine tool makers have since come into being, among them Lidkopings Mek. Verkstads A.-B. The products of the leading Swedish machine tool manufacturers have acquired a very high reputation. During the war years the Swedish machine tool works were considerably enlarged and equipped with special machines, which places them in a position to export a larger surplus than previously of high-class machines of improved design. Before the war the export amounted to 25 % of the total output. Besides general machine tools such as lathes, planers, shapers, drills, milling and grinding machines, presses, etc. might be mentioned, special machines for ball-bearing manufacture and some other industries.
A branc h of machine manufacture of great importance and indeed natural for a woodproducing country is that of lumbering and sawmill machinery. The Swedish manufactures of this kind, including log saw frames, edge-trimmers, transporters and elevators, etc., enjoy a high reputation and are sold extensively abroad. The designs, based as they are on long experience, are very practical and serviceable and the material and workmanship first class. The leading firms in this line are J. & C. G. Bolinders Mek. Verkst. A.-B., A.-B. Atlas-Diesel, E. V. Beronius Mek. Verkstads A.-B., Nya Svenska Maskinverken A.-B., A.-B. Karlstads Mek. Verkstad.
Swedish wood-working machines may be said without exaggeration to be of exceedingly practical designs and strong construction, besides being economical in operation and maintenance. Wood being a very delicate material to work on, the designs must in consequence be founded on very extensive experience, and this has been amply available in Sweden during a very long period. The efficiency and all-round high qualities of these machines is best indicated by their having succeeded in shutting out importation of wood-working machines to Sweden completely, besides gaining a very considerable market in other countries. Among the oldest and largest firms manufacturing woodworking machines are J. & C. G. Bolinders Mek. Verkstads A.-B., E. V. Beronius Mek. Verkstads A.-B., Jonsereds Fabrikers A.-B., Askersunds Mek. Verkstads A.-B., Nya Svenska Maskinverken A.-B.