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Additional remarks on the stowage of ships
* SCIn a
modern 14 guu ship, fitted f’m sea, the length being 12% feet,
breadth 473, the forces are thus distributed. AftcfmM 49 feet Weight 699 ~‘ressure G27 I)ifference 12 toll& xcxt 20 4.0s 297 108 50 121G 1098 I18 20 290 409 - 119 37 4,98 4Gl 37 .-176 ::CJOO ;000 ooo
tl:c
BenwG
on the rStowage of
S~i~i,
937 By the above calcul$on, it will appear that there is & $xc*.of weight at both extremltzes, and that In the adjoining sections&e pressure greatly preponderates. Cqnsequently, these forces a’re oppo~et to each other, a$ in a directlon very prejudicial to tlj$ ship; as it IS not only the ev11 of weight preponderatingat the extremitiesi the pour of wh_ich $11 be increased by the action of the ship, but from the formatlon ot the body at those parts they cnn atford but a
feeble resistance to s~grcnt a force. Perhaps the followmg figures will best explain where the weights and pressure now preponderate, what particular weights may be su posed to cause an excess, and such as may be most convenient Py and advantageously transferred.
Figure tbc 1st represents the length of a 74 gun ship, divided into five sections, and the excess of weight or pressure in each. Figure the 2nd also. represents the lengtl!, divided inti sectiqne and the positions of the masts, b ‘which it wltl be. seen that they are and that situ&d in those parts where t g e weights preponderate; they greatly contribute to it is a very natupa ’conclurrioa~ In the foremost section there is, unavoidably, not only the weight and anchors also; of the foremast and its rigging, but the bowsprit the latter stowed at the extremity of the sectton, and the Fowsprit beyond it; which, on the lever prmcl le, asprojecting considerabl sisted by the action oz the ship and the escess of weight, an 8 being sif,uatctl in a part which, froin its formation, affords but little re&,tanCe, and which is frequently left unsupported, must considerablyl aug,nlent the pitching motion, and contribute to the tendency to arch or hog. In the aftermost section, the mizen-mast may he considered as contributing to the excess o( weight; but it is not 6f Such ~$litudC as the fore or main-mast; and its position is WUCh more fav6urable ‘rhe strain aIs0 011 the a&r part iS for the ship than the fore-mast. as it is seldom lelt so entircJy utlSupp6rt~d not so great as tkvnrtl, 4a_ L-MAY, 18:,0. Tot. V .--No.
338
I2ewuwks aft the S’lowage of Ships.
by ihe passing of a sea, and the sending motion is not so sudden OF pitching. In the extreme sections, and from the formation of those parts below the surface of the water, the upper works may also be considered as contributing to the excess of weight. In the middle section, the main-mast, from its magnitudt, may be consitlered as materially contributing to the excess of weight; and that, according to the ordinary distribution of the weights in *he main hold, a large proportion of it may be supposed to fall in the vicinity of the mast. If this conclusion be admitted, it must appear prejudicial, and the more so, in consequence of the pressure preponderating so much at both estremities of the section. Among other weights concentrated about the mast is the shot locker, and which must considerably add to the unavoidable and too great weight of the mast alone acting on so small a space. I shall now encleavour to explain how far the alterations proposed in my former remarks would be likely to remedy the inequality of the distribution of the weight and pressure specified in the calculation. In the foremost section, No. 5, where there is at present an excess of weight, arc placed the bower anchors, and the gunners’, boatswains’, and carpenters’ sea stores, which I proposed transferring; the anchors furLher aft, by removing the cat heads to the fore parts of the channels, which, although by the removal still situated in the same sectior, would considerably lessen the power of their we@t on the ship rn a sea ; and the sea stores to the after cock-pit, which will be found situated in section No. 2, where the pressure now preponderates. In the after section, No. 1, where there is also an excess of wri@t, the bread is stowed at the extremity; a part of which, together rvith beds, slops, marine clothing, kc., (at present stowed in the after cock-pit) 1 proposed should occupy theprescntplace of the sea stores in section No. 5; which would reduce the excess of wcightjat present in ,the after estremity, and place less wei$t, more lively, and more speedily consumed than the sea stores, In the place now occupied by them. Such arrnngements would also be likely to contribute to a mire equal distribution of the weights and pressure in sections 3 and 4; as it would most probably admit of weight being removed froln the one where there is at present an cxccss, to that where pressure pre. ponderates,and, in fact, to a much more equal distribution through. out the whole body. The following alterations would also contribute to a’better distri. bution than the present. Let the bower and sheet cables be stowed further aft; the stream cable and hawsers abaft them, in the space now occupied by cat>ina, slop-room, &c.; and the stores, at present stowed in the foremost section, No. 5, removed aft to the fore part of the cable tiers; a part of the bread, slops, beds, marine clothing, kc., as in the former pro. posal, to occupy the’present place of the sea stores in section No, 5, By such arrangements the weight of the stream cable and hawsers, violent as the
IhART 0% the %%anomena attending E&.,&
&ids.
339
and part of the bower cables, wouid be removed to section No. 2; the sea stows to. NO, 4; and the weights reduced at both extre&&. The excess 01 weight would not only be considerably ryduced in the fore extremity, by the proposed alterations, but at sea, if desirathis part as speedily as possible, a regular decre;\se, ble to b&en in a 74.gun ship, of two tons per week, my be culcul:;t& C_I~I,tiii the expiration of half the cruise, when the fore bread ro0n1 ~ot11d be cleared. By a minute inspection and measurement of the tlilkrent arts, and a correct calculation of the direrent weights and their bumK., the. distribution may be made with great exactness. Removing the anchors where they will stow p~fectly clear 0f tljc ports, and similar to the sheet and s~xwe anchors, u itI ais,, t~;wc tile round of the bow perfectly clear, and remove every impcdilnerrt to its being better fortitied. 1 G)11wtr,ly .l010t1ul.
E3pYimcnts
ard
the ,swlden EWAILT,
O~serurttions
cxpmsioa
on some
oJ the Ph:~nnmcnn
of’conpxssc~ltImtic
fii’ttitis.
ctltczztli~t~ _f~t~ P ~~TI’X
Esq.*
HAVING
occasion, about seven years ago, io make so~ne erpcriments on a high pressure steam engine of the estimated po~cr ofninc horses, in the boiler of which the elasticity of the steam was equal to sixty on the square inch, and, consepounds (includin g the atmosphere) quently, the interior temperature about 290” of l?ahrcnheit, I applied the bulb of a thermometer close to the opening of the sal’cty-valve, while the steam issued from it in great quan,tity, and it stood steadily The engine being in motion, and the stcani, after having at 160’. by a perpassed through the cylinder, escapin, lr to the atmosphere pendicular pipe four inches in diameter, and five fixt in height, K applied a thermometer to the steam as it issued from the top of that pipe, and found the temperature to be 212O. Finding the temperature of the issuing steam only 160” at thC safety valve, close to the boiler, an d 21&O after it had passed to the distance of five feet from the boiler, 1 constructed an apparatus (fig. 1.) for the purpose of ascertaining whether, under certain cijxumstances, the temperature of the steam increases after It has Issued from the boiler. I had an opportunity (in iMarc\! 1823) of applying this apparatus to the high pressure steam boiler of bf r. Pi+ ‘I’aJ-ior, near London. A is an iron pipe of three quarters of an at &omlcy, in& bore, contrected with the boiler, and tet’n~illa~ed by a st(jp-COCk B, tile area of the opening of which was the same a~ that of the pipe. The end of a copper tube (2, two inches diameter, and sixteen inches long, was screjved to the cock U, SO its to bc sk!:itrl tigltt. ‘I’0 this tube was adapted ;I thermometer I), SO tllot the bulb stW(i tltRCtly opposite t]je centre of tllc q)Cnitig of tile cock l<, antI at thC diSlil~lCt~ of an inch and a half from it. ‘V]lC openiiig in tilt: side of the cc~pljcr ??
Tiiis arti& consists trf extracts {rorn I\%‘0pgpW5 I C’:iilI)CfiWC t!lC I.itCl’iU~
and PhilosophiCal
Society
of h~~c~ctlcite~j-cornnlunic:\tet~
tly t1lC 4UtliU1’.
modern 14 guu ship, fitted f’m sea, the length being 12% feet,
breadth 473, the forces are thus distributed. AftcfmM 49 feet Weight 699 ~‘ressure G27 I)ifference 12 toll& xcxt 20 4.0s 297 108 50 121G 1098 I18 20 290 409 - 119 37 4,98 4Gl 37 .-176 ::CJOO ;000 ooo
tl:c
BenwG
on the rStowage of
S~i~i,
937 By the above calcul$on, it will appear that there is & $xc*.of weight at both extremltzes, and that In the adjoining sections&e pressure greatly preponderates. Cqnsequently, these forces a’re oppo~et to each other, a$ in a directlon very prejudicial to tlj$ ship; as it IS not only the ev11 of weight preponderatingat the extremitiesi the pour of wh_ich $11 be increased by the action of the ship, but from the formatlon ot the body at those parts they cnn atford but a
feeble resistance to s~grcnt a force. Perhaps the followmg figures will best explain where the weights and pressure now preponderate, what particular weights may be su posed to cause an excess, and such as may be most convenient Py and advantageously transferred.
Figure tbc 1st represents the length of a 74 gun ship, divided into five sections, and the excess of weight or pressure in each. Figure the 2nd also. represents the lengtl!, divided inti sectiqne and the positions of the masts, b ‘which it wltl be. seen that they are and that situ&d in those parts where t g e weights preponderate; they greatly contribute to it is a very natupa ’conclurrioa~ In the foremost section there is, unavoidably, not only the weight and anchors also; of the foremast and its rigging, but the bowsprit the latter stowed at the extremity of the sectton, and the Fowsprit beyond it; which, on the lever prmcl le, asprojecting considerabl sisted by the action oz the ship and the escess of weight, an 8 being sif,uatctl in a part which, froin its formation, affords but little re&,tanCe, and which is frequently left unsupported, must considerablyl aug,nlent the pitching motion, and contribute to the tendency to arch or hog. In the aftermost section, the mizen-mast may he considered as contributing to the excess o( weight; but it is not 6f Such ~$litudC as the fore or main-mast; and its position is WUCh more fav6urable ‘rhe strain aIs0 011 the a&r part iS for the ship than the fore-mast. as it is seldom lelt so entircJy utlSupp6rt~d not so great as tkvnrtl, 4a_ L-MAY, 18:,0. Tot. V .--No.
338
I2ewuwks aft the S’lowage of Ships.
by ihe passing of a sea, and the sending motion is not so sudden OF pitching. In the extreme sections, and from the formation of those parts below the surface of the water, the upper works may also be considered as contributing to the excess of weight. In the middle section, the main-mast, from its magnitudt, may be consitlered as materially contributing to the excess of weight; and that, according to the ordinary distribution of the weights in *he main hold, a large proportion of it may be supposed to fall in the vicinity of the mast. If this conclusion be admitted, it must appear prejudicial, and the more so, in consequence of the pressure preponderating so much at both estremities of the section. Among other weights concentrated about the mast is the shot locker, and which must considerably add to the unavoidable and too great weight of the mast alone acting on so small a space. I shall now encleavour to explain how far the alterations proposed in my former remarks would be likely to remedy the inequality of the distribution of the weight and pressure specified in the calculation. In the foremost section, No. 5, where there is at present an excess of weight, arc placed the bower anchors, and the gunners’, boatswains’, and carpenters’ sea stores, which I proposed transferring; the anchors furLher aft, by removing the cat heads to the fore parts of the channels, which, although by the removal still situated in the same sectior, would considerably lessen the power of their we@t on the ship rn a sea ; and the sea stores to the after cock-pit, which will be found situated in section No. 2, where the pressure now preponderates. In the after section, No. 1, where there is also an excess of wri@t, the bread is stowed at the extremity; a part of which, together rvith beds, slops, marine clothing, kc., (at present stowed in the after cock-pit) 1 proposed should occupy theprescntplace of the sea stores in section No. 5; which would reduce the excess of wcightjat present in ,the after estremity, and place less wei$t, more lively, and more speedily consumed than the sea stores, In the place now occupied by them. Such arrnngements would also be likely to contribute to a mire equal distribution of the weights and pressure in sections 3 and 4; as it would most probably admit of weight being removed froln the one where there is at present an cxccss, to that where pressure pre. ponderates,and, in fact, to a much more equal distribution through. out the whole body. The following alterations would also contribute to a’better distri. bution than the present. Let the bower and sheet cables be stowed further aft; the stream cable and hawsers abaft them, in the space now occupied by cat>ina, slop-room, &c.; and the stores, at present stowed in the foremost section, No. 5, removed aft to the fore part of the cable tiers; a part of the bread, slops, beds, marine clothing, kc., as in the former pro. posal, to occupy the’present place of the sea stores in section No, 5, By such arrangements the weight of the stream cable and hawsers, violent as the
IhART 0% the %%anomena attending E&.,&
&ids.
339
and part of the bower cables, wouid be removed to section No. 2; the sea stows to. NO, 4; and the weights reduced at both extre&&. The excess 01 weight would not only be considerably ryduced in the fore extremity, by the proposed alterations, but at sea, if desirathis part as speedily as possible, a regular decre;\se, ble to b&en in a 74.gun ship, of two tons per week, my be culcul:;t& C_I~I,tiii the expiration of half the cruise, when the fore bread ro0n1 ~ot11d be cleared. By a minute inspection and measurement of the tlilkrent arts, and a correct calculation of the direrent weights and their bumK., the. distribution may be made with great exactness. Removing the anchors where they will stow p~fectly clear 0f tljc ports, and similar to the sheet and s~xwe anchors, u itI ais,, t~;wc tile round of the bow perfectly clear, and remove every impcdilnerrt to its being better fortitied. 1 G)11wtr,ly .l010t1ul.
E3pYimcnts
ard
the ,swlden EWAILT,
O~serurttions
cxpmsioa
on some
oJ the Ph:~nnmcnn
of’conpxssc~ltImtic
fii’ttitis.
ctltczztli~t~ _f~t~ P ~~TI’X
Esq.*
HAVING
occasion, about seven years ago, io make so~ne erpcriments on a high pressure steam engine of the estimated po~cr ofninc horses, in the boiler of which the elasticity of the steam was equal to sixty on the square inch, and, consepounds (includin g the atmosphere) quently, the interior temperature about 290” of l?ahrcnheit, I applied the bulb of a thermometer close to the opening of the sal’cty-valve, while the steam issued from it in great quan,tity, and it stood steadily The engine being in motion, and the stcani, after having at 160’. by a perpassed through the cylinder, escapin, lr to the atmosphere pendicular pipe four inches in diameter, and five fixt in height, K applied a thermometer to the steam as it issued from the top of that pipe, and found the temperature to be 212O. Finding the temperature of the issuing steam only 160” at thC safety valve, close to the boiler, an d 21&O after it had passed to the distance of five feet from the boiler, 1 constructed an apparatus (fig. 1.) for the purpose of ascertaining whether, under certain cijxumstances, the temperature of the steam increases after It has Issued from the boiler. I had an opportunity (in iMarc\! 1823) of applying this apparatus to the high pressure steam boiler of bf r. Pi+ ‘I’aJ-ior, near London. A is an iron pipe of three quarters of an at &omlcy, in& bore, contrected with the boiler, and tet’n~illa~ed by a st(jp-COCk B, tile area of the opening of which was the same a~ that of the pipe. The end of a copper tube (2, two inches diameter, and sixteen inches long, was screjved to the cock U, SO its to bc sk!:itrl tigltt. ‘I’0 this tube was adapted ;I thermometer I), SO tllot the bulb stW(i tltRCtly opposite t]je centre of tllc q)Cnitig of tile cock l<, antI at thC diSlil~lCt~ of an inch and a half from it. ‘V]lC openiiig in tilt: side of the cc~pljcr ??
Tiiis arti& consists trf extracts {rorn I\%‘0pgpW5 I C’:iilI)CfiWC t!lC I.itCl’iU~
and PhilosophiCal
Society
of h~~c~ctlcite~j-cornnlunic:\tet~
tly t1lC 4UtliU1’.