1840.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



73 



IMPROVEMENTS IN THE CONSTRUCTION OF MARINE 

 STEAM ENGINES. 



WHICH ARE PARTICULARLY APPLICABLE TO STEAM ENGINES OF THE 

 LARGEST CLASS. 



With two Engravings, Plates V and VL 



Specification of a Patent granted 7th Maij, 1830, to Joseph Mauds- 

 ley and Joshua Field, of the firm of JMaudsky, Sons and Field, 



Engineers of Lambeth. 



These improvements in the construction of marine steam engines 

 are particularly applicable to those of the larger class, and are designed 

 principally for the purpose of producing and applying a greater 

 amount of steam power, than has heretofore been available within a 

 given space or area on shipboard. This is effected by different con- 

 structions, arrangements, and proportions, of the parts of low pressure 

 engines, allowing a more perfect application of the expansive force of 

 steam without increasing the weight of the whole machinery. 



The first feature of these improvements consists in adapting two steam 

 cylinders to one engine, in such a way that the steam shall act simul- 

 taneously upon both pistons, in order that they may be made to rise 

 or fall together, the piston-rod of each being attached to one hori- 

 zontal cross-head, and thereby the combined action of both pistons 

 applied to one crank, of the paddle-shaft. 



The second feature of these improvements applies more particularly 

 to engines for river navigation, and consists in the adaptation of a 

 piston with two rods, working in a steam cylinder of large area, both 

 piston-rods being connected to one cross-head above, which gives 

 motion to the crank below it, by a single connecting rod. 



The third feature of these improvements consists of a method of ad- 

 justing the expansion valves of combined engines, by which the period 

 for shutting of!" the steam at any part of the stroke may be regulated 

 in both engines at once by a single movement, whilst the engines are 

 working. 



The fourth feature of these improvements is the peculiar construction 

 of the main beams of the framing that carry the plummer blocks of 

 the main crank shaft, to which the paddle-wheels are attached. 

 These beams are formed as hollow trunks, by the combination of 

 wrought iron plates attached to bars of angle iron, in the same way as 

 ordinary boilers are made, and we are enabled by that means to con- 

 struct beams of the largest dimensions of unlimited strength and of 

 comparatively small weight. 



These improvements will be more fully understood by reference to 

 the accompanying engravings and the following description thereof, 

 in which Fig. 1 is an elevation taken longitudinally, representing an 

 engine with two cylinders, constructed upon the plan described as the 

 first feature of the improvement. Fig. 2 is a vertical section of tlie 

 same, taken through the cylinders. Fig. 3 is a horizontal section of 

 a vessel, in which the situation of the engine shown at Fig. 1 is seen 

 as it wouUl appear when looking ujion it from above ; and Fig. 4 is 

 a conesponding engine placed at the other side of the vessel, but 

 represented in section cut liorizontally through the cylinders. Fig. 5 

 is a vertical section taken transversely through a steam vessel, show- 

 ing the positions of two engines, as in Figs. 3 and 4, the one engine 

 being in section, the other an external view seen upon a plane in 

 advance of tlie former. And Fig. 6 is a plan or horizontal view of a 

 portion of the steam-vessel, with the engines and their appendages, 

 and also the framing by which the crank -sliafts of the paddle-wheels 

 are supported, similar letters referring to the same parts of the ma- 

 chinery in all the preceding figures. 



The two connected working cylinders are shewn at a a, their pistons 

 at b b, and the piston rods at c c, the upper ends of which rods are affixed 

 by keys to the cross-head d. Four vertical rods e e e e, afhxed at top 

 to the cross-head d, are connected at bottom to a slidery", which slider 

 is enabled to move up and down on the guide-ribs g g, formed on the 

 outer surfaces of the cylinders. To this slider / one end of a con- 

 necting rod /( is attached, the other end of that rod being attached to 

 the crank i of the propelling shaft. 



From this arrangement it will be perceived that, by the simultaneous 

 ascent and descent of the two pistons b b in their working cylinder a a, 

 the rods c a will cause the cross-head d to move perpendicularly np 

 and down between its guide bars/ ;', and in so doing to raise and de- 

 press the slide/, with the connecting rod /;, which rod will, by that 

 means, be made to give rotary motion to the crank i, and thereby 

 cause the paddle-wheel shaft k to revolve. A rod /,"connected to the 

 slide /, will at the same time work the lever m, to which the rod of 

 the air-pump n is attached. 



The mode of adapting the steam-valve of the combined cylinders 

 a a, is best seen in Figs. 3 and 4. The steam is admitted to, and with- 

 drawn from, these cylinders, by one slide valve common to both, 



No.|30.— Vol. III.— March, 1S40. 



through a pipe n, seen in Fig. 5. From this pipe n the steam pro- 

 ceeds, through a slide valve u of the ordinary construction, and through 

 the curved passages or tubes p p into both cylinders. There is also 

 a narrow passage of communication always open at q, by which the 

 steam is allowed to pass from one cylinder to the other for the pur- 

 pose of keeping the pressure equal at all times in both cylinders. 



The expansion valve is on the steam-pipe n, at the entrance to the 

 slide valve. The slide is moved by an eccentric in the ordinary way; 

 and the expansion valve is regulated by the means described hereafter 

 under the third feature of the invention. 



The advantages proposed by this arrangement are, simplicity of 

 construction, nH)re direct action on the crank, saving of space and 

 weight of material, offering every means of giving larger area of cy- 

 linder, whereby a given amount of steam can be used more expansively 

 than in former arrangements, and consequently yield more power and 

 economize fuel, with the further advantage at sea, that when the 

 engine is reduced in the number of its strokes by deep hnling with 

 coal, as at the commencement of a voyage, or by head winds, more 

 steam may then be given to the cylinders, and, under such circmn- 

 stances, more speed to the vessel, all the steam generated in the Ijuihu' 

 being usefully applied. 



The second feature of this invention, viz. the improved construction 

 of steam engine having two piston rods working in one cylinder, is 

 represented in the accompanying engravings at Figs. 7, 8, and 9. Fig. 

 7 is an elevation of the engine. Fig. 8, a section of the same, taken 

 vertically through the cylinder, with the crank and shaft of the paddle- 

 wheels ; and Fig. ',) is a horizontal view, as seen from above, of the 

 two engines and their appendages, the same letters of reference point- 

 ing out similar parts of the machinery in all the three last mentioned 

 figures. 



The cylinders of large area are shown at a a, and b are their pis- 

 tons; c e are two perpendicular rods inserted into each piston, and 

 working through stuffing boxes in the lid of the cylinder; d is a cross- 

 b.ead, to which the two piston-rods are keyed at top, and e e are the 

 guide-rods, fixed on cast iron supports, upon which rods the cross-head 

 d slides up and down. The connecting rod /is attached above to the 

 cross-head, and below to the crank g g on the paddle shaft. The 

 other parts of the engines will appear so obvious from inspecting the 

 drawings, as not to requiie any further description. 



It will be perceived that by this arrangement of the parts of the 

 engine, motion is given to the crank-shaft below the cross-head, by a 

 single connecting rod. 



The advantages resulting from this improvement are, that a paddle- 

 shaft, placed at a given height from the bottom of the vessel, will be 

 enabled to receive a longer stroke of the piston than by any other 

 arrangements now in use, a more compact and firm connection of the 

 cylinder with the crank-shaft bearings is effected, and a cylinder of 

 much greater diameter may be applied, by which the principle of 

 working steam expansively may be more fully carried out, and a more 

 direct action of the steam power on the crank obtained, with a less 

 weight of materials and a greater economy of space than has hereto- 

 fore been attained, by any of the arrangements of marine engines in 

 use. 



The third feature of the invention, viz. the method of adjusting the 

 expansive valves of combined engines, regulates the flow of the steam 

 into both engines at once, by one simple movement of the spindle and 

 pinion, and without interrupting for a moment the working of the 

 engines, such a means of adjustment being highly important in bring- 

 ing into operation the full effect of steam applied upon the expansive 

 principle, in economizing fuel, and adapting the power of engines to 

 the varying circumstances at sea, between light and heavy lading, and 

 between strong head-wind and scudding before the gale. 



Extensive Use of Slate. — Slates are now applied to purposes unthought 

 of till lately ; and when deposited in drains, ;is the bottoms of tiles, are found 

 as efficacious in keeping the land, as houses, dry. Compared to dressed free- 

 stone, or liat tile, they are at once lighter and less expensive ; ease in hand- 

 ling is a great advantage, and equally, or more so, the alleged property of 

 " lasting for ever." Mr. Laurie, Terregles-town, was foremost in trying the 

 experiment in DumCriesshire.and his expectations have been so fully reahzed 

 that his example will be very generally loUowed wherever drains remain to 

 be cut, and that is secuonally, at least almost everywhere. Of the article in 

 question he has imported from Bangor 200.000 bottoms or pieces, (^nd may 

 have occasion to commission further cargoes. The first imported measured 

 six inches by five : but as these were lovuid a kcnnan too small, the size has 

 been increased an inch each way — that is seven by six. The price put on 

 board is 7s. per thousanil, and, as wares every way so equable jack as beauti- 

 fully as herrings in a barred, we presume, although we do not know the fact, 

 tliat freightage from Wales will not greatly exceed Is. additional. — Glasgow 

 Courier. 



