FILENAMES: greenwood3.jpg DESCRIPTION: This is a picture of an old, huge lathe as scanned from an engraving. Posted by Brian Drummond Brian provided the following description: =============================================================== Description of the lathe shown in "greenwood3.jpg" "The Plate gives a view of one of the monster lathes introduced of late years for the turning of steel ingots and large steel forgings. The height of the centres above the upper surface of the bed is 5 feet, and it will take work over the saddle 7 feet 6 inches in diameter, and 52 fet 6 inches long.It was made for the Creusot works, in France, by Messrs. Greenwood & Batley, of Leeds. It carries a 10 foot face-plate, and is powerful enough to cut steel shavings 1 3/4 inches deep, by 1/16 inch traverse feed. This cutting is done at the rate of 6 feet per minute; and as there are four saddles, two in front and two behind, carrying eight tools, it can remove over a ton of steel turnings per hour. Each saddle weighs 23 tons; the fast headstock weighs 40 1/2 tons; the main spindle 6 tons; and the whole lathe weighs no less than 350 tons. It is quadruple geared; and as there are four steps on the driving pulley and two sizes of counter-shaft pulley, there are altogether 32 different speeds possible for the lathe, ranging from 28 turns per minute down to 6 minutes per turn. The maximum ratio of cone pulley speed to that of main spindle is 383 to 1, while the minimum is 6 to 1. The main spindle is 20 inches in diameter, and its front bearing is 30 inches long, while at its back end the end pressure is taken by four collars turned on the spindle after the manner of a marine propeller- shaft thrust-block bearing. The bed is double, the whole width being 14 feet. Down the centre of each bed lies a traversing screw, each screw being geared to two saddles. A quick rack-and-pinion traverse motion is provided, and each of the four saddles can be traversed independently of each other, and of the main spindle; that is, the fast traverse motion can be applied while the main spindle is motionless. (A few points; Fast headstock = Headstock; in contrast to: Loose headstock = Poppet = Tailstock. Quadruple geared: in a triple geared lathe, even the backgear has backgear. Presumably this lathe has another backgear stage beyond that... That wasn't the biggest lathe in the book. :-)