1862-06-20 Mechanics Magazine - Ferrabee Vertical Steam Engine

FERRABEE'S VERTICAL DIRECT ACTION HIGH PRESSURE STEAM ENGINE. THE above illustration represents the engine which drives the wood cutting and printing machinery in the Western Annex of the International Exhibition. It was manufactured by James Ferrabee & Co., of Phoenix Iron Works, Stroud, and 75 High Holborn, London, W.C., and is an engine of a simple, compact, and substantial character, with peculiar mechanical arrangements to ensure its working steadily, effectively, and economically, whether the amount of duty it has to perform be either constant or subject to sudden variations. The frame-work consists of a massive iron base, on which are fixed two strong iron standards braced together by cross-brackets. The cylinder with its slide-valve and a cut-off valve, rest on the base, to which they are bolted, in such a way as to admit of their being easily removed. The feed-pump is fixed on one side of the base. The piston-rod is connected by a cross-head con- meeting-rod and crank to the crank-shaft, whose bearings are on the tops of the standards, and the fly-wheel is keyed on between them. The governor and its appendages are supported by brackets attached to the standards. The slide-valve, the cut-off valve, the feed-pump, and the governor, are all driven from the crank-shaft. The circumference of the fly-wheel is turned and the crank- shaft is extended beyond one of its bearings to take a pulley or a cog-wheel, so that motion may be transmitted from the engine by means of a strap on either the fly-wheel or a pulley, or by means of gearing, the frame-work being well adapted for the latter. The cylinder has a steam- jacket cast around it, and is fitted with metallic piston and steel piston rod. The crank-shaft, crank, connecting-rod, and cross-head being fitted with adjustable nuts, by which the wear of the guides can readily be taken up. 

A cistern is formed in the base into which the steam from the cylinder is discharged to heat water for the boiler; this heated water is supplied to the boiler by a feed pump, made so as to be unfailing in action, | and fitted with a safety escape valve. But the most novel and important feature in the engine, is the simple and effective method of regulating the quantity of steam to be admitted to act on the piston, An ordinary slide-valve, with lap, worked by an eccentric on the crank shaft, gives the steam ingress to and egress from the cylinder in the usual way. Immediately behind the slide-valve, and in connection with the chamber thereof, is placed the improved cut-off" valve, which is actuated by an ingenious application of the link motion worked by eccentrics, driven from the crank shaft. This cut-off valve is connected to and controlled by the governor, and by their combined action the proper quantity of steam at its full pressure is supplied to the | cylinder at exactly the right moment. The steam is cut off instantaneously at any part of the stroke of the piston, according to any variation that may occur in the resistance to be overcome. By this prompt and perfect self-control, unvarying steadiness in the working of the engine is gained, no matter how sudden or frequent may be the changes in the duty required of it; hence the fall benefits of expansion are realized, and great economy in the consumption of fuel is attained. The nominal power of the engine at the Exhibition is 14 horse; but as it is constructed of extraordinary strength, with all the moving parts adapted to a high velocity, it may safely be worked with steam at a pressure of 70 lbs. to the inch, and thus give off double the power nominally ascribed it. The circumstances under which it is working certainly constitute a severe test of its capabilities; placed at the extreme end of the steam pipes, it has to | contend with an irregular supply and an imperfect exhaust, while the variations in the power re- quired by the machinery driven are unceasing and frequently very sudden. That the engine performs its duty with great steadiness under such conditions must be very gratifying to the makers, and cannot fail to attract the attention of those interested in steam power.