380 



THE CIVIL ENGLXEER AND ARCHITECT'S JOURNAL. 



[Dec. 



be dispenseJ with, and snuR knees of hackmatack be applied externally, 

 at proper intervals, where the projection of the guards will permit. 



llh. There should be a very light hurricane-deck over the central por- 

 tions of the hull, and extending to a length eijual to two or three diameters 

 of the vessel. AH the constructions above deck should be of the very 

 lightest description, and be comprised, if possible, within the same limit. 

 Thus the forward and after ends, each to the extent of about three diame- 

 ters of the vessel, would be left free of incumbrances ; excepting the gun- 

 fixtures and other indispensable attachments. 



5th. The engine should be so placed below deck as to act directly upon 

 the cranks, as in the steam frigate Missouri, if the midship body of the 

 vessel will allow of this arrangement ; otherwise, a half beam arrange- 

 ment may be resorted to. The paddle-wheels should spread less on the 

 shaft than is common in American steamers, and the paddle be extended 

 to a point at its centre in a trapezoidal or triangular form. This form will 

 admit of a greater immersion, and thus obtain a better resistance, than the 

 common paddles, especially in a sea-way. The crank and chimney open- 

 ings in the deck should be comprised in a narrow enclosure, with upright 

 sides, extending fore-and-aft-wise to a point, so as to present an acute 

 angle of deflection, for the proteciion of the crank and lower part of the 

 Ctiimney from shot when end on with an enemy. The main shafts, which 

 must be above the deck, should also be protected by deflecting planes, 

 covered with iron and slightly inclined from horizontal. 



iNluch apprehension has been sometimes manifested for the safety of the 

 wheels and paddles when under fire ; but those who have employed 

 steamers day after day, for successive seasons, in encountering ice from 

 four to fourteen inches in thickness, and who have witnessed the speed of 

 a steam vessel when one half or more of the wheel arms and paddles have 

 been disabled in this service, will think more lightly of this hazard; to 

 avoid which, almost every quality valuable for a war steamer has some- 

 times been sacrificed. 



0th. To sustain the guns, the scantlings beneath them should be some- 

 \vliat enlarged in thickness, and securely stanchioned and screw bolted. 

 The gnn pivots should be of strong timber, adequately secured to the 

 deck-frame, and extending to the keelsons. The ileck, where exposed to 

 the action of the guns, shonhl be strongly sheathed, and the whole be 

 secured, if needful, by transverse bars, strongly bolted or clamped to the 

 deck-frame; and, if necessary, connected by vertical bolts and stanchions 

 with the floor-timber. M'hen about to engage, sand bags, or other equiva- 

 lent weights, may also be used for coveting that portion of the deck ex- 

 posed to injury from the explosion of the guns. 



To illustrate my views of the proper form of construction of these ves- 

 sels, I annex an approximate sketch of the Jeck plan and guards. This 

 outline has, for its base, the elongated rhomb a it, h 6, (fig. 1, Plate XIX.) 

 and presents at the deck a guard line of the bow and stern, a a, the maxi- 

 mum semi-angle of fourteen degrees; which is only equal to that which 

 has been already adopted in some well-proportioned steamers for coast 

 service. It also contemplates a length which is equal to nine diameters of 

 the vessel ; each of these diameters being visibly set olf on the plan, fig. 

 It will be found, practically, that this proportion of length is sufficiently 

 limited ; for the engine, if placed as proposed, will require much length, 

 and the necessary weight must, also, for a light draft, be extensively dis- 

 tributed. IMoreover, the first diameter at each extremity, the flotation of 

 which can properly support little more thau itself, may be viewed as sub- 

 stituted for the cutwater, bowsprit and other fixture, wlilch is coramouly 

 attached to heavy steamers and sailing vessels ; while the second diameter 

 thus set oil', answers practically to the usual bow and stern in other ves- 

 sels ; thus leaving five diameters for the proper body of the vessel and the 

 necessary machinery and storage. 



7th. The armament of each steamer, I apprehend, should consist of six 

 ttai'trsing guns. Two of these, of ten inciies calibre, should be worked 

 each ou a strong pivot, placed on the line of the keel, at the distance se- 

 verally of about one and a half or two diameters of the vessel from the stem 

 and stern post. The four remaining guns, each of eight inches calibre, may 

 be worked on like pivots, placed near the sides of tlie vessel, and as much 

 nearer to the main shafts as will avoid interference with the two larger 

 guns. When engaged with an enemy, the line vf fire shuuUi alivai/s, iihcn 

 praclicniile, be in the line oj Ike keel. The above mentioned ordnance con- 

 stitutes the armament of the recently constructed war steamers of Eng- 

 land ; and, so far as I can perceive, is the most appropriate and ell'eclive 

 for a steam vessel : the peculiar vocation and advantages of which ouglit 

 to be rapid motion and eli'ective fire. 



l'erha|)S some persons may entertain apprehensions of the inability of 

 these light steam vessels to carry and sustain the action of the guns above 

 mcntioneil. lint these apprehensions are without any just foundations, as 

 will appear from the following facts and considerations: — (1.) The points 

 at which the guns are placed, require an access of weight equal to this 

 armament, in order properly to equalise the load throughout the body of 

 the vessel. (2.) The weight merely of these guns is uo more formidable 

 or destructive to a vessel than a like concentrated weight of other heavy 

 articles, of which vastly greater amounts are safely carried in all weathers 

 on lighter decks than I propose for these vessels. (3.) Owing to their 

 large capacity, and their great superficial bearing upon the water, these 

 vessels are better able to bear the addition of the above weight than any 

 vessels now iji the naval service. 



This may appear from the following facts ; First, tho average load-line 

 area, or bearing superficies, of class is nearly three-fljihs of that 

 o! the lirandyvvine frigate ; while, if we allow 50,t)001b.for the guns and 



carriages of the steam vessel, and 48,0001b. for the ammunition and other 

 accessaries, it will then equal but one-fifth of the weight of the armament 

 and its accessories of the lirandyvvine ; and will require to sustain it only 

 a draft of IJ inches from the light load-line. Again, this average super- 

 ficial bearing of the steam vessels is more titun four-ninths that of the Ohio 

 ship of the line : while the above weight of guns, ammunition, &c., is less 

 than nne-eleienth the weight of the military outfit of the Ohio. Once 

 more, the average height of the decks of these steamers above the water at 

 midships, exceeds six feet, with an average bearing surface of near 74 

 feet per ton of the vessel and its contents; while the height of tile port- 

 sills of the liruidywine and Ohio are but 5J feet above water, with an 

 average b«--ai'ing superficies of nearly 2J feet per ton. This shows an im- 

 mense proportiim iu favour of these steamers, in the ability to carry acces- 

 sory weight. Hence, this class of steamers may not only carry this arma- 

 ment, but, in addition, may also transport, when occasion requires, from 

 five to eight hundred troops. 



It may be well to notice here the apparent chances of this class of 

 steam vessels when opposed to heavy war ships of the rates above men- 

 tioned. 



1. The choice of action and position will always belong to the steamers. 

 This is important when opposed to any force whatever; for the most fa- 

 vorable time and circumstances for combat may thus be commanded, or, if 

 it should be proper and advantageous, tlie action may for the time be 

 easily avoided. Mliile, on the other band, an equal or inferior force need 

 not be allowed to escape. 



2. The target surfuce presented by the Ohio when in chase, below the 

 hammock rads, is probably equal to 1450 square feet ; and in broadside 

 about 5CU0 square feet. The cross area of the Brandywine presented la 

 chase is probably equal to 940 feet, and that of her broadside area near 

 3800 feel; while the average cross area of tlie hulls of the steamers of 

 class C exposed above water, to a height of seven feet above the deck, is 

 only 340 feet. Now, as the steamers will probably engage chiefly at long 

 shot, and end on, we may here perceive how great will be the advantage 

 for the steamers, with equal skill in gunnery, whether or not a sufficient 

 number of steamers to match the broadsides in weight, be taken into the 

 account, 



I say nothing here of the extraneous exposure of the wheels and smoke- 

 pipes on one hand, nor of the spars and rigging of the ships on the other : 

 believing that these chances, with proper precautious, are not unfavour- 

 able to the steamers. 



From the great stability and superior steadiness of these steamers when 

 in motion, particularly on the line of the keel, and from the accuracy with 

 which they may be made to head on or off' an object, by means of a mark- 

 ing point subtended above the bow, to guide the helmsman, they will afl'ord 

 to skilful gunners greater accuracy of fire than is usually obtained in ships, 

 unless the latter be lying in smooth water. 



In comparing the weight of metal opposed, if we reckon to the steamers 

 the full weight which is due to the increased calibre of their guns (and 

 considering the greater destrucliveuess of shells to a ship, this appears 

 not improper), we shall find that four of these steamers, each with three 

 guns engaged, will exceed, at each round, the weight of shot thrown by 

 the broadside of the 15raudywine; and that the fire of seven steamers will 

 equal, in like manner, the broadside of the (Jhio. While, iu chase, there 

 would be an overwhelming advantage in favour of the steamers. In these 

 estimates the weight of shoi thrown by the broadside of the Ohio is taken 

 at 11)00 lb., and that of the Braudy wine at 8G4 lb., as by advisement ; and 

 the shot of the eight and ten inch guns at 68 lb. and 98 lb., respectively. 



As regards the relative power of endurance, if shells are used, as they 

 doubtless will be, this power in a vessel cannot be in [>roportion to the 

 weight and massiveness of the structure ; and may proie quite the con- 

 trary. Hut, if the form of model and position in action, which is here re- 

 commended, can be made efficacious in some degree for the protection of 

 the engine and byilers below deck, which seems practicable, the steamers, 

 with equal gunnery, must clearly have greater advantages for the endur- 

 ance of fire in the aggregate thau will belong to the ships. Besides, if we 

 may estimate the aggre^^ate power of endurance to be in proportion to the 

 bearing area or superficial extent of the vessels, as appears not wholly im- 

 proper, this advantage will be proportionally in favour of the steamers. 

 Moreover, in shell-firing a single shot may prove fatal to a ship ; while 

 even a like result to one or more of its alert antugouisls need not cause a 

 discontinuance of the combat. 



However import.int it may be to maintain a powerful and well ordered 

 navy, consisting of ships of the established classes, it can hardly be in our 

 power, or within the scope of our policy, to maiutaln a numerical superior- 

 iiy as against England, even on our own coasts. And without such supe- 

 riority, or at least a near equality, ellectual blockades may not hereafter 

 be prevented; to say nothing here of the chances of losing our ships and 

 naval arsenals, by the onset of a powerful and well appointed expedition, 

 supported by a numerous fleet of ships and war steamers. 



With the aid of her numerous and heavy armed steam ships, England 

 might ell'ectually blockade not only our ships, but our war steamers of the 

 heavy and medium classes. For our steamers of these classes could hardly 

 put to sea, or return to port, in the face of a superior force of the same 

 cliaracter; and it would be quite iu vain to attempt gaining a superiority 

 of this force by new constructions of like klad, for the present means of 

 England, both mechanical and financial, are suflicient to outdo us in this 

 etl'ort, more than three to one. It is therefore indispensable tu our supe- 

 riority, that we should be prepared with fuster steamers, of lighter druft. 



