Special Steels for Heavy Vehicles.
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A Noted Hallamshire Firm Enters the Motor Industry.
One result of the rapid increase in the number of heavy motor vehicles is the realisation, on the part of chassis manufacturers, and, in fact, all those practically interested in the motor movement, of the necessity for using steel of a certain standard for the several parts of the machinery. The conditions under which public-service vehicles have to run make it essential that only the highest grades of steel should be used in their construction, because, unless this is done, the vehicle will be unduly heavy, or will, if built to conform with the legal tare, be unaEle to accomplish the work which it will be called upon to do. Steel manufacturers now realise the necessity of being able to supply a first order, and an unlimited supply of subsequent ones, to exactly the same analysis required by the purchasers. William Jessop and Sons, Limited, of Brightsidc Works, Sheffield, is making a speciality of different types of steel used in the construction of motorbus chassis and heavy vehicles generally. For over one hundred and thirty years, or, to be precise, since the year 1774, these works have been manufacturing steel of all descriptions for both home and foreign markets. The laboratories are an important department, and the staff of chemists is, generally, working upon some new mixture of steel for special purposes. The Brightside works have made no less than 600 different brands of steel for various purposes. The present works cover almost 45 acres of ground, and so great is the necessity for additional shops that larger and more commodious buildings are, in one or two cases, actually being erected around the original ones, which will, eventually, be demolished. This method has been adopted to obviate the necessity for stopping operations while the new buildings are being built. About 1,500 men are regularly employed at Brightside, and five miles of
railway connect up the different shops, whilst three locomotives and a number of steam travelling cranes are, during working hours, constantly at work transporting heavy ingots and castings from one part of the works to another.
A vast supply of the best Swedish bar iron is always in stock, and this forms the basis from which the various types of steel are manufactured. The bar iron is, in the first instance, laid in underfed furnaces, each layer being separated from its neighbours by a stratum of charcoal. 'Ilse top layer of charcoal is then covered over with a thickness of clay, and a fire is, subsequently, lit beneath each furnace. The fire, in each case, is kept f7t the correct heat for ten days, during which time the iron absorbs a percentage of carbon from the charcoal. On an average, the iron bars, or now, snore correctly, " blister " steel, are allowed a further period of so days to cool down before being taken from the furnaces. It is found that the carbon penetrates the iron, on an average, about A inch for every 24 hours that it is in the furnace. After being converted in the furnaces, the " blister " steel undergoes two different processes, and is used as a basis for the manufacture of crucible and SiemensMartin steels. The furnaces wherein the latter material is manufactured have each a capacity of from 30 to 40 tons. Steel forgings of any size are made, and the writer arrived at .one.of the numerous forging shops at the time when a portion of a large shaft, weighing over 12 tons, was being manipulated under. a 55-ton steam hammer.. Throughout the works, there are no less .than 30 steam hammers' of various sizes, starting from a small pattern used for the manufacture of rods of tool steel to the large hammer mentioned above. To the foregoing number must be added the numerous old-style tilt hammers, which are driven by water power.
Among the smaller work done in the rolling mills is the making of band saws for the American timber trade. These saws are rolled from a solid billet of steel until they eventually become about 6o feet long and ss inches in width. although the sizes, naturally, differ. The machine-tool shod is fitted with lathes suitable for dealing with the heaviest castings made at the works, and the usual radial drill's, and planers, circular saws for cutting off lengths from steel billets, and a number of special tools, are also to be seen. The pattern-making shop is a commodious one, and is excellently lighted; all the wood-working machinery is driven
by electricity, generated in the works. The roof is fitted with a complete installation of tire sprinklers, and the entire department is heated by steam. The new section for the manufacture of motor parts is being built as fast as possible, and new plant is already being delivered. The Company will produce every portion of the machinery appertaining to a chassis, and the best mixtures of steel for each part have only been arrived at after long tests and experiments. Plant for the production of pressed-steel frames for chassis will be shortly laid down. Drop forgings will be made a speciality, and any pattern can be made to a purchaser's requirements.
Nickel steel is one of the most suitable materials for use in i)arts of a chassis subjected to sudden jars and excessive vibration. We give a table which clearly demonstrates the valuable effects of a certain proportion of nickel incorporated with ordinary mild steel. It will be seen that, with only the addition of 3 per cent. of nickel steel, the elastic limit is more than doubled, whilst the tensile strength is also enormously increased.
The Company makes a speciality of chrome-nic el steel, which, although more expensive to produce than ordinary nickel steel, is eminently suited for employment in such parts as crankshafts or others which are subject to torsional strain. The table given herewith shows the result of a test made recently at the Brif.thtside Works :—
Manufacturers who cannot obtain delivery of chassis parts will do well to remember that Jessops, Limited, will very shortly be in a position to supply special castings, forgings, and machined parts in any quantity ordered. The many years of practical experience which back the efforts of this company in the endeavour to produce a perfect steel for use in the construction of mechanisms upon which will be thrown the strain of heavy work and road shocks should go far to create a feeling of confidence in those who have to depend upon an outside source for these parts.