Greenwood and Batley: Lathes

Note: This is a sub-section of Greenwood and Batley

1889 'THE PARIS EXHIBITION. A WONDERFUL MACHINE TOOL.
Entering from the east by the central avenue, the first striking object that attracts attention, and at which Mr Trueman Wood, the British Commissioner-Delegate who, with MM. Berger and Alphund and other officials, accompanied the President - made a dead stop, was the colossal lathe constructed by Messrs Greenwood & Batley, of Leeds, for the great French engineering establishment Messrs Schneider & Co. at Creusot, which is at last installed after many delays and misfortunes. This machine tool, with the engine to drive and dynamo to accompany it, occupies more than 1000 square feet of floor space, and it weighs upwards of 300 tons. It is quite sui generis, and an outcome of the enormous advance which has been made in the manufacture of ordnance of large calibres. When this lathe gets work at Creusot the great French firm will be able to put the Armstrong 100-ton gun into the shade, and will greatly surpass the power of the great Essen establishment of Krupp. The lathe will turn an ingot of steel more than 60 feet long and more than seven feet in diameter, and will simultaneously bore it out to a 40 inch calibre, if necessary, the energy developed when both processes are going on being absolutely inconceivable. Some idea of this, though an imperfect one, may be gathered from the fact that the steel shavings produced when the two operations are proceeding amount to about 40 lbs. per minute. M. Carnot, himself an engineer, seemed lost in admiration of this wonderful tool, and the profound silence amid which the operation was watched as the huge bits crunched into the steel was strangely impressive. M. Carnot cordially shook hands with Mr. Greenwood, warmly congratulating him on his triumph of constructive skill, and accepting from him an album containing photographs of some of the firm's famous tools for the manufacture of munitions of war — tools well known in France and every country of Europe as they are in England itself.'

1890 Britsh Association Meeting: 'HEAVY LATHES. Mr. ARTHUR GREENWOOD (Leeds) read a paper on this subject. He said that since the general adoption of hydraulic machinery for forging heavy masses of steel, the use of powerful lathes as an adjunct to this system of forging has become a necessity, and it is to this class of lathes in contradistinction to lathes used tor finish turning work that this paper is devoted.

'For the production of tubes, jackets, and hoops for heavy guns, for cranks, marine, and other shafts, ingots of steel are now cast weighing upwards of 100 tons. These lathes are used to prepare such ingots for the forging press. In many cases it is thought desirable to rough turn the entire outside of the ingots to ascertain if the castings are absolutely and sound and free from fissures previous to the operations being commenced upon them. .....

'....As illustrating two types of lathe that have been specially designed for this purpose the diagrams exhibited may be found to be of some interest. The sectional elevation of a fast or driving headstock will give an idea of the power and strength of a big lathe recently constructed by the author's firm for the steel works of Messrs. Schneider, Creusot, France, which was exhibited on its way to the last Paris Exhibition.

'The height of centres is 60 inches. It will admit between the centres of the lathe a steel frging 52ft. 6in. length and 90in. in diameter over the saddles, and is capable of dealing with ingots of upwards of 120 tons in weight. The diameter of the front bearing of the spindle is 20in. by 30in. long. The back bearing of the spindle is 19in.in diameter, and has four collars for resisting the end pressure, similar to the thrust bearings of marine propellor shafts. The face plate is 10ft. in diameter, and is provided with massive gripping jaws for holding the steel ingots. There are four speed cones and four proportions of gearing, giving 16 powers, varying from a proportion of 6 to 1 to 383 to 1,..... The actual weight of this headstock, including gearing, is 40 1/2 tons, the spindle alone weighing 6 tons. The bed of the lathe is made double, and is a little over 14ft. wide, each bed carrying four saddles - two in front of the lathe and two behind. These saddles are provided with two slides, so that in tuning an ingot eight or even sixteen cutting tools would be at work. The heaviest cut that it is found practical to work in this type of lathe is a depth ot 1 3/4in., i.e., at one cut a forging would be reduced in diameter by 3 1/2in. With that depth of cut an advance of about 1.10th of an inch is used. If the depth of cut is decreased quicker advances are made even as coarse as 2 to 3 per inch. The surface speed found most economical for these heavy cuts is about 6ft. per minute, but that, course, largely depends on the hardness of the steel. When eight cutting tools work at this rate, it will not surprising to hear that a ton of cuttings may easily be removed in an hour. The lips on tool slides are all cast solid with the slides and the wear is is taken up with steel slips, made taper end-wise, so that the slide may kept very rigid to stand the jar of heavy cuts. Massive steel tools have generally been found more useful than tool holders carrying loose steel cutting tools. The advance or feed of these four saddles is given by two steel screws, one running near the centre of each of the beds. These screws are driven by gearing direct from the spindle of the lathe. For the quick moving of the saddles longitudinally aiong the beds, and also for the traversing of the tool slides transversely on the saddles, a quick running gear is provided which will move the saddles at a rate of ten feet per minute. The shaft working this quick turning gear is driven by pulleys and friction clutches, so that the saddles may be moved along the bed of the lathe independently when the headstock is at rest. Each of the four saddles is entirely independent and may be sliding transversely in either direction for taper turning. This lathe for the purpose of boring ingots would be provided with a boring bed mounted upon the double bed, this boring bed having a traverse of about 16 feet, and capable of carrying a boring bar with a diameter of 40 inches. Each of the saddles weighs about 23 tons complete, and the weight of the lathe, including the boring bed, is about 350 tons. The third diagram shown represents a cross-section of a similar type lathe to the one just but of more ordinary dimensions, .....'

1889 From the Reports of the United States Commissioners to the Universal Exposition of 1889 at Paris:-

'Not the least remarkable thing in connection with this tool is the shortness of the time taken in its design and construction. A consideration of the following statement conveys some idea of the facilities possessed by this house for turning out large work.

'The lathe was ordered by Messrs. Schneider & Co. July 31, 1888. The design occupied nearly four months, and the actual construction was not begun until the last days of November. At the end of April, 1889, it was shipped to Paris, the whole construction having taken less than six months.

'This lathe is to be used at the Creusot Works in turning and boring large ingots for heavy guns and similar purposes.

'Greenwood & Batley have built during the past five or six years many large lathes, ranging in weight from 50 to over 300 tons, supplying such establishments as, the Woolwich Arsenal; W. G. Armstrong, Mitchell & Co., Newcastle-on-Tyne; John Brown & Co., Sheffield; Thomas Firth & Sons, Sheffield; Taylor Bros. & Co., Leeds; Schneider & Co., Creusot, France; Societe de Forges et Chantiers de la Mediteranee; F. Krupp, Essen; Arsenal of Alexandrowsky, near St. Petersburg; Arsenal of Caeraca, near Cadiz; Arsenal of Keaiuaeg, China, and also many others.'

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