Cast steel for shipbuilding

Among the almost endless variety of useful purposes to which Bessemer mild cast steel has been applied, there is none more important than its employment in the construction of steam ships for the conveyance of passengers and merchandise, and also of ships of war and fast cruisers. The great strength of this material, as compared with the best brands of iron; its even and homogenous character; its great power of elongation before rupture; and its unequalled amount of elasticity under severe strains; all combine to form a material not only admirably adapted for the plates, beams, and angles of the ship itself, but equally suitable for the construction of her masts and spars, her boilers and her machinery; and for the still more important manufacture of the heavy armour-plates necessary to protect ships of war from the assaults of the enemy.

From a very early period I had become deeply impressed with the importance of the application of my new steel to shipbuilding, and my first impulse was naturally to try and force my own conviction on the British Admiralty, and induce them to employ it in the construction of ships of war. But the remembrance of my treatment at Woolwich came upon me as a warning, for there I had given, at much cost and labour to myself, the most irrefutable proofs of the perfect applicability of my mild steel to the manufacture of ordnance, and all these proofs had been overlooked and thrown aside by the Minister of War in favour of an inferior substitute for steel. This experience determined me not to be foiled a second time by attempting to convince the "How-not-to-do-it" Government official. I therefore preferred to await the more certain and reliable action of mercantile instinct. Private shipbuilders, I had no doubt, would soon find out the merits of steel, and feel a personal interest in its adoption. Boiler-makers, I also felt assured, would recognise its value, and use it instead of iron, many years before the Admiralty officials would wake up and become conscious of the advantages it possessed over the weaker material. Nor did I have long to wait for the verdict of practical men on the value of Bessemer mild cast-steel plates, as applied to the construction of steam boilers; an application which in itself is a sufficient guarantee of their high quality, and their superiority over plates made of the highest brands of British iron. Every person connected with the iron trade is well aware that the articles known to the trade as boiler-plates are superior in quality to those known as ship-plates; in fact, iron ships were never built with the high-class iron used for boilers.

I have already stated that, on the occasion of the Institution of Mechanical Engineers holding one of their annual meetings at Sheffield, in July, 1861, under the presidency of Sir William Armstrong, I read a paper on "The Manufacture of Cast Steel and its Application to Constructive Purposes." I now refer again to that paper, simply to quote a few lines from the speeches made in its discussion, by two eminent practical Lancashire engineers, in order to show what had been done up to that early date in the application of the new steel to the construction of steam boilers. This discussion, be it observed, took place no less than fourteen years prior to the date on which Sir Nathaniel Barnaby, then the Chief Naval Architect at the Admiralty, read his paper before the Institution of Naval Architects, in which he criticised adversely the use of Bessemer steel plates for shipbuilding and boiler-making. Hence it will be interesting to see how far this material had already been employed for boiler-making.

At this meeting of the Institution of Mechanical Engineers above referred to, Mr. Daniel Adamson,*¹ the well-known engineer and manufacturer of steam boilers, whose works were at Hyde, near Manchester, exhibited some beautiful specimens of deep and difficult flanging in some fire-boxes for locomotive boilers. Mr. Adamson said he had already used 200 tons of boiler-plates made from the new steel, and was about to procure a further supply of 70 tons. He found the metal of excellent quality, and of regular character throughout, and it was an admirable material for working. The flanged fire-box plates shown were duplicates of a number that he had used in the manufacture of boilers for very high pressure, with the most satisfactory results. The metal flanged beautifully, and was like copper in this respect,² but with the advantage that it was not so liable as copper to be damaged by overheating. He could fully confirm the statements given as to its strength, having tested it severely. As a precaution every plate had been ordered with a 1-in. margin all round, which was sheared off, and bent double, as a test of the quality of the plate. The