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Article Tribil and Mechanical Engineer's Society. ← Page 3 of 4 →
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Tribil And Mechanical Engineer's Society.
was buried . The water Avas very shallow for a considerable distance out , aud its bed was of rock covered with a fine sand , so that to dredge or excavate a channel for a vessel to come alongside the quaywall and take the obelisk on board , would involve an outlay of , £ 50000 or more . It
, would also be impossible to make a mole on which to convey the obelisk out to a vessel lying in deep Avater , simply because there was no material available , and even Avere there material , the length of mole required would necessitate an outlay of at least
, 630 , 000 . Neither of these plans was available . What was proposed to be done was simply to excavate about the obelisk , and to build around it a huge iron cylinder or boiler , so to speak , 95 feet long and 15 feet in diameter . In the first
instance there would be constructed around the obelisk , 10 ft . apart , about seven diajihragms , discs , or collars , so to call them , circular on plan , and with square apertures in the centre through which the obelisk passed ancl Avould be held iu position by wedges ancl other appliances so disposed ancl arranged as to prevent any excess of strain being brought to bear on the monolith under auv
circumstances , wnether the cylinder containing it were held up in the centre on the crest of a Avave or at each end by two Avaves without any support in the centre . To these diaphragms or collars would be built longitudinal girders and framing , which Avould in their turn carry concentric ribs of iron to receive the external skin of
plate iron . The obelisk will be disposed as nearly as possible in the centre of this cylinder , which will have both its ends pinched up , so to speak , in wedge-form , to serve as bow and stern . On the side of the cylinder Avhich is intended to remain uppermostmanholes will be left for
, taking in ballast . Tho weight of the obelisk is about 183 tons . The cylinder , Avhen completed , will be rolled out in the shallow water until it floats , being previously covered with a stout jacketing of timber-workin order to prevent the
, possibility of its being damaged by any sharp pieces of rock which it may roll over . When the cylinder is in deep water it will be towed into the Khedive ' s dry dock at Alexandria , where the wooden jacketing ^ ill be stripped off ; one of the
wedgeshaped ends will be provided with a rudder , and the cylinder will be fitted with two bilge keels and a small platform or deck , thus becoming a cylinder ship . It will be named the Cleopatra . Ballast will be taken on board to g ive the whole greater
stability , which would have been secured , if the obelisk could have been taken on board an ordinary vessel , by placing the load nearer to the bottom than in the present case , where , in order to facilitate the rolling of the cylinder , the obelisk is
to be placed in the centre . All being ready and the weather favourable , the cylinder and its contents would be towed to England . Mr . Dixon went into details to show the stability of the vessel , as to which every care had been takenseeing
, that not only was the safety of the obelisk involved , but the credit of English engineering was at stake . The plans of the vessel had been approved by Mr . Fronde and other authorities on the subject of naval architecture . Having reached the
Thames it would be towed to that part of tho embankment wall nearest to the site which might be selected , and at high tide wo uld be floated on to a staging or
gridiron of timber constructed to receive it . When the tide receded the cylinder would be left high and dry , and would theu be raised by hydraulic power until the level of the Embankment was reached . The keels , deck , and other excrescences having been removedand the ballast taken out
, , the cylinder Avould be rolled across the Embankment to the site the obelisk was intended to occupy , Avhere the cylinder Avould be broken up and removed to the scrap-heap . Then came the question of raising the
obelisk into au upright position ou its pedestals . The Romans , and , later , the French , had pulled their obelisks up by ropes , but that plan necessitated a large number of capstans and other appliances . Mr . Dixon proposed to raise Cleopatra ' s
Needle in the following manner : Having brought the centre of the obelisk over the exact site it was to stand upon , he should put round the central 4 ft . or 5 ft . an iron jacket , or , more properly speaking , a , pair of iron st ; i \ 'S capable of being so ti ghtly laced or screwed up as to prevent the stout ; from slipping . Ou the centres of two of its sides this jacket Avould have projecting
Note: This text has been automatically extracted via Optical Character Recognition (OCR) software.
Tribil And Mechanical Engineer's Society.
was buried . The water Avas very shallow for a considerable distance out , aud its bed was of rock covered with a fine sand , so that to dredge or excavate a channel for a vessel to come alongside the quaywall and take the obelisk on board , would involve an outlay of , £ 50000 or more . It
, would also be impossible to make a mole on which to convey the obelisk out to a vessel lying in deep Avater , simply because there was no material available , and even Avere there material , the length of mole required would necessitate an outlay of at least
, 630 , 000 . Neither of these plans was available . What was proposed to be done was simply to excavate about the obelisk , and to build around it a huge iron cylinder or boiler , so to speak , 95 feet long and 15 feet in diameter . In the first
instance there would be constructed around the obelisk , 10 ft . apart , about seven diajihragms , discs , or collars , so to call them , circular on plan , and with square apertures in the centre through which the obelisk passed ancl Avould be held iu position by wedges ancl other appliances so disposed ancl arranged as to prevent any excess of strain being brought to bear on the monolith under auv
circumstances , wnether the cylinder containing it were held up in the centre on the crest of a Avave or at each end by two Avaves without any support in the centre . To these diaphragms or collars would be built longitudinal girders and framing , which Avould in their turn carry concentric ribs of iron to receive the external skin of
plate iron . The obelisk will be disposed as nearly as possible in the centre of this cylinder , which will have both its ends pinched up , so to speak , in wedge-form , to serve as bow and stern . On the side of the cylinder Avhich is intended to remain uppermostmanholes will be left for
, taking in ballast . Tho weight of the obelisk is about 183 tons . The cylinder , Avhen completed , will be rolled out in the shallow water until it floats , being previously covered with a stout jacketing of timber-workin order to prevent the
, possibility of its being damaged by any sharp pieces of rock which it may roll over . When the cylinder is in deep water it will be towed into the Khedive ' s dry dock at Alexandria , where the wooden jacketing ^ ill be stripped off ; one of the
wedgeshaped ends will be provided with a rudder , and the cylinder will be fitted with two bilge keels and a small platform or deck , thus becoming a cylinder ship . It will be named the Cleopatra . Ballast will be taken on board to g ive the whole greater
stability , which would have been secured , if the obelisk could have been taken on board an ordinary vessel , by placing the load nearer to the bottom than in the present case , where , in order to facilitate the rolling of the cylinder , the obelisk is
to be placed in the centre . All being ready and the weather favourable , the cylinder and its contents would be towed to England . Mr . Dixon went into details to show the stability of the vessel , as to which every care had been takenseeing
, that not only was the safety of the obelisk involved , but the credit of English engineering was at stake . The plans of the vessel had been approved by Mr . Fronde and other authorities on the subject of naval architecture . Having reached the
Thames it would be towed to that part of tho embankment wall nearest to the site which might be selected , and at high tide wo uld be floated on to a staging or
gridiron of timber constructed to receive it . When the tide receded the cylinder would be left high and dry , and would theu be raised by hydraulic power until the level of the Embankment was reached . The keels , deck , and other excrescences having been removedand the ballast taken out
, , the cylinder Avould be rolled across the Embankment to the site the obelisk was intended to occupy , Avhere the cylinder Avould be broken up and removed to the scrap-heap . Then came the question of raising the
obelisk into au upright position ou its pedestals . The Romans , and , later , the French , had pulled their obelisks up by ropes , but that plan necessitated a large number of capstans and other appliances . Mr . Dixon proposed to raise Cleopatra ' s
Needle in the following manner : Having brought the centre of the obelisk over the exact site it was to stand upon , he should put round the central 4 ft . or 5 ft . an iron jacket , or , more properly speaking , a , pair of iron st ; i \ 'S capable of being so ti ghtly laced or screwed up as to prevent the stout ; from slipping . Ou the centres of two of its sides this jacket Avould have projecting