1846. J 



THE CIVIL ENGINEER AND ARCHITECrS JOURNAL. 



193 



THE ENGINES OF H. M. STEAM FRIGATE, 

 "GLADIATOR." 



( With Two Engravinf(s, Plates IX. and X. ) 

 The gradual improvement of direct action engines, and the general 

 adoption of them in the place of beam engines in steam navigation are sub- 

 jects of the greatest importance to the mechanical engineer. On the first 

 introduction of direct action engines it was imagined that they could never 

 be made to work so steadily as those of the original form, and that conse- 

 quently the application of the principle must be extremely limited in ex- 

 tent. It was confidently predicled that in large engines, the great mass of 

 metal put in motion must cause such a vibration, if the beam were dis- 

 pensed with, as would speedily cause >he pistons, slides, &c., to work un- 

 truly. 



It has been found, however, by actual experience, that the evil in ques- 

 tion may be entirely removed by accuracy of workmanship, and by skill 

 in the arrangement of the working parts. And on the other hand the dimi- 

 nution of the weight of the engines and of the space occupied by it, are ad- 

 Tantages of so great importance in navigation, that they far outweigh the 

 supposed disadvantage of removing the beam. 



The Gladiator, one of the vessels forming the " Squadron of Evolution," 

 is a beautiful example of the perfection of workmanship exhibited in the 

 construction of British marine engines. 



Before, however, describing those peculiarities in the engines of the 

 Gladiator, which are illustrated in the accompanying plates, we wish to 

 remark willi respect (o the observations which have been made on the per- 

 formances of the steam vessels of the Squadron of Evolution, that those 

 remarks apply exclusively to the powers of the steam vessels as sailers 

 when deprived of the assistance of their engines. To compare the powers 

 of a steam vessel as a sailer with those of a ship built to be propelled i)y 

 its sails exclusively, seems to us as absurd as to compare the speed of two 

 animals possessing altogether dilferent organs of locomotion. It can be no 

 matter of wonder ihat a vessel containing the enormous weight of marine 

 engines, and built of a form suitable for containing them, should not sail 

 so fast as one which does not contain this load, and is built of the form best 

 adapted for sailing. Between steam-ships and sail ships no correct com- 

 parison can be drawn. Not only are iheir means of propulsion entirely 

 dilferent, but tlie circumstances under which each acts most usefully, are 

 altogether dissimilar, so that for the purposes of war each in its turn would 

 be invaluable, where the other would be inefiicient. The most rational 

 method therefore seems to be to keep the individual characteristics of the 

 two classes of vessels perfectly distinct, — to render each as perfect as pos- 

 sible in those qualities which consiitute its peculiar advantages — in other 

 words, to speak to those whom we have the most interest in addressing, to 

 render the war-steamer as perfect as possible us a stemner, and not to injure 

 her powers by injudicious attempts of combining with them the peculiar 

 qualities of sailing vessels. 



The engines of the Gladiator were constructed by the well-known firm 

 of Miller, Ravcnhill, and Co., of Blackwall. The principal feature of 

 these engines is their compactness, the cranks, and consequently the cylin- 

 ders being brought close to each other, to give deck room for moving the 

 cannons fore and aft. The air pumps are constructed on a principle pa- 

 tented by Mr. INIiller, being inclined towards each other, and worked by a 

 crank common to botli, on the same shaft with the cylinder cranks. 



The following are the references, I'lales IX and X. 



A A, Cylinders 7b^ inches in dia(i:eter, 5 feet *J iuch stroke. 



B B, Piston rods. 



C C, Conoecting rods. 



D D, Cranks ou working sliaft. 



E, tJprigbt sleatn.pipe. At its lower end are bracketfl e €» cast on ttie slide-valve 

 casing, to support tlie steam-pipe. 



F, Expansion valve box. 



G, Beam working the refrigerator pump of Howard's patent condensing apparatus. 

 Ttie beam, of which the bearings are supported by the upright steam-pipe, forms part of 

 the parallel motion. 



H, Slide valve casing, h h k> Openings from the steam. pipes on wtiicb the expansion 

 TBlves work, 



I I, Cross-bar, and K K, Eccentric rods, for working the slide valves. 



I,, Opening between slide valve casing and condenser. 



M M, Condensers. 



N N, Air-pumps, n n. Delivering valve openings. 



O, Crank for working air pumps. 



P P, Hot water cisterns. Q Q, Feed pumps. R R, Bllgs pnmps. 



The annexed <l lagrani represents a section of one of the air-pumps and con- 

 denser of the Gladiator. 



No, 106.— Vol, IX, July, 1846, 



Fig. 1.— Section of one of the Air Pumpa and CoiuleaBcr of tbe Gladiator. 



A, Air-pump. — B, Pflrt of condenser— C, Foot-valve.— D, Delivering valve. — E, Hot 

 water cistern-— F, Bracket for suppor.ing guide-rods for air-pump cross-bar. 



The following extract from the specification of a Patent, granted March 

 22, 1842, to Mr. Joseph Miller, will further explain the construction of 

 the air-pumps and condenser. 



The engraving fig. 2, show a vertical section of the condensers B B, and 

 air-pumps C C, dispo.sed wilhin the condensers, and between the steam cy- 

 linders, in a ditlerent manner lo that hereinbefore described, one pump being 

 before the other, instead of the two pumps being side by side. The pumps 

 C (J are inclined from the vertical, in contrary directions, so that the di- 

 rection of the centre line of each pump will point to the centre of the ro 

 tative axis G, and both pumps are workea by the same crank A, on that 

 axis, by means of two crank rods k k, of which only the centre lines are 

 shown dotled. and the upper ends whereof may be applied side by side on 

 the pin of that crank /i, one of those crank-rods k being for working one 

 pump C, and tlie other of those crauk-rods A: for working the olher pumn 

 C. In case of the two crank rods being so applied, side by side on ihe 

 said pin of the crank, then the two air pumps (when viewed frmn the 

 front) cannot stand exactly in the same vertical plane one with the other 

 but the centre line of one pump will be as much at one side of the centre' 

 line of the other pump as is lequlsite to suit the crank-rods fc k, in case 

 they are one at the side of the olher, in order that they may both work 

 upon ihe same crank-pin A, as already mentioned ; or one of the crank, 

 rods kk may be made forked at the upper end, when it is applied uuon" 

 the crank-pin, with twojolnlson that pin, side by side, and including the 

 joint of the other crank-rod between them, and in such case the centre 

 lines of both air pumps may be in the same vertical plane. In such an 

 arrnngement of ibe air-pumps, the steam cylinders will stand nearer 

 together, and the middle portion G of the rotative axis will be very short 

 and there will be only one crank A on that middle portion. The condens' 

 ers will be narrower in ihe direction between the cylinders, but longer in 

 the opposite direction. The vertical partition b, by which the condenser 

 IS divided inlo two compartments or distinct condensers, may stand in the 

 direction from the centie of one steam cylinder to the centre of the other 

 provided that, by means of another partition or a branch of one partition 

 suitably disposed within the condenser, one of the eduction passages G of 

 one of the cylinders cut only one of those passages, is prolonged and con- 

 tinued withiuside the condenser beyond or through the partition b so as to 

 communicate very freely from that said cylinder to that condenser or 

 compartment of Ihe condenser which is most remote from the siidiuo- valves 

 and Ihe eduction passages G. The manner of fixing the air-pums C C into 

 apertures through partitions m and n, and the manner of placing the foot, 

 valves o, is much the same as aire -dy described, except that instead of Uie 



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