DEEP-SEA CABLES.

New Zealand Herald, Volume XLIX, Issue 15169, 7 December 1912, Page 4

DEEP-SEA CABLES.

DIFFICULTIES OF UYli«fifjfa|. WORK ON A CABLE SHIP, ' ijfc The bilking up of Auckland and | by a. new- submarine cable aSoid'ji t?V| \ public an opportunity of learning (~»« ;-. i thing of the wonderful -wait of deep**'.! cable lading. Th* Silvern, which was engage fa ■' the laying of the new Auckland to Bj*|i,ct : cables, is essentially a cable-laying dftaZ while the Iris, which is a well-known A|,»:'; in Auckland Harbour, is' a cable-repair, ? ing boat. The Silveriown baa a 350 ft/ -with a net tonnage of 3735 %,£ | When she -Bias built a. good many ijjjj ■? j ago, it was not intended that s&e sbigjj be a cable boat. But extensive altera?**..' ■were made in her structure, and shp|| jj, t i .on© of the moct efficient cable boat* ajw ; I W. Some idea, of her immense capacity can. I. 'If; ganged from the fact tint lie ; 'JR tanks'.en board bare a .oial capadt? a : '■' 171,4315 : cubic feet Tie § greatest load -was on tbo occasion of«« ft recent laying of a cable in the Afissut She then had on board no less than 256 '1 nautical miles of cable, weighing 48§1 toiii ! ■ In. addition there were 111 taxi of baovi' ' I chains, sad cable gear. Two ■ thesauri H ' tens of coal can alao be carrid, Hfe [ enabling her to keep at sea Ijngey , J any other cable ship. When fulh/ii^j 1 ";| < ! her crew numbers about 150. Liv* ' in the way of bullocks, £,««, and supply her bands with fresh meat. j^' ". wireless apparatus with a rang* if 325 miles is fitted en board. K.';. v . ' '- " .' .!'••'„ ,' ■ SorTsyisg a ■ Cable EcaJt ! ( Preparatory to laying a submarine egjft Tery extensive and accurate ' synvftai'.' bare to be taken all thewSS . I bare to be taken all along the j*wKfi- ; route. This, in the ease of a : long iJgg-:';% jto be bid, is often carried oat by a'ea&tr " I j vesseL ..-.The Iris,'' for instance, JW"&M'' ''.-I jths Tasmaa Sea, and prepared .'<&m% 4* ; 'j . the benefit of tie SUra-towa. nrrtiato to 1 I tie latter ship laying 'ike tfnrVab&Pbosi I ] Sydney to'Moiana The Sfrntoira «r- /Vf J ties aboard a usteam sowll aaaaiatsj, : /fi I which she often bas occasion to, age." Tha';|M i mounding wire used is what is known as 'la .3 steel pianoforte -Brine, jdwl^:^ ''1 J thick. Hub is manufactured m lengths of | j from 1A: to miles, -and bas a tcdafebrtajdug M i strain of 23C0b&. - A spherical w*9jj!is«?aia '' I sinker, is attached to end. ''' $/s&},ss. 3. sounding wire is let out. its areiigs tste" ■;'" ; of descent » 103 fathoms lit */mh«Bya«<t§! : it is pulled up at the rate of 70 il4oaa ; , a minute. . Once, in , tbe%ibuiU^4]iepti l .'j, I of 3233 fathoms, or nearly Q\mls-%uik : iwacbed. On this occasion the lead took I] 23 minutes 50 jjeconds to xeack lbs 4*.!- & torn, 45 minutes being sptmt : it ig> again, There are many tfpes j cinkers used; some bring up iampks ti.* ocean's bed, while otibeas, ngatertby test ' pexateres met with at diSereat y'-, Some of the mOa^ti^^^S Bering the actual laying of a salnitni>:' : cable, after an end has been eeetttd w ashore, toere are numerous difficultiei 'vi-yM conntered, which would never tMsil»t»iv. j of by the reinitiated. The cabia, litat i coiled in the tank, is eased oat, aW$ , cumber of men being engaged on ita " work. "When the paying-out gear is set it motion many 'mechanics are m attojiM ' ', on the csEbie--drams and brakes;- wi3s -, others keep a perpetual stream cf vstat ' playing on ike running cable 10 plena! / cnrer-heatiiig from friction. Supposisg&|t a cable as being run out into 2ESQ faiboms of water, order to <K j from going oat too fast,' a bat,'.' force of. no jess than two tons is lapnl This is obtained by means of brah£alijap on the dram shaft. ■ Bach «|a^j^^^| ; circled by■ a stoat, iron -.stxafi, m j are hard wooden blocks bearzug"*wilsi] j the ' smooth face 'of ' the wboeL tiiaE& far showing the strain on the cabin hiv -1 also to be closely -watched. Evßr/{a i engaged must, he oh the alert in caeeK < untoward incident demands an inriiiinßm I stoppage Operations, when once blip ' arc carried right through, the men i sm ' % , ing. on •'"''shifts.':' :.: At ;r night, the She-,- ■ town's ff»a electric plant . makes a t^ ! i that .can be seen at a distance «3 151 ft' '.' 20 miles. In fair weather, nba A goes well, a speed of six knots m Vf,\Ci may be maintained when p>yis£ », J J ;.', . deep-sea cable. In the ease «f cnafag; ■ : '- or intentional cutting^the ends'are nan by large buoys. When it is deanei regain the ends, .the tedious wodr . grappling begins. In deep water aad laif.,:'. weather it may be weeks hefeea-A severed end is finally retrieved and nofilf' : /-. up again, 4 1, ;»| ~. Testia.e the Cable. T . ;^|||j As it is essential that -a : cable «Jtft.,' is, being laid .should be perfect ia «;?, ,!'' derail. extensive tests are made betew' after the cable is broastt ta b»«t . ■During the whole time .that a cwb, * ' being paid oat commnnicatioa; is j through it between the ship and w«» | at the shore end, in order that any wa may be at once discovered and i«!wP»; One of the faults that has to Iw'jgpwg against is. air bubbl«s in fJbe grtMfafferiß covering. At a diipth of 809 afitaspiw^. pressure on the cable eo^als ; <b» *"*?*;''. * ; tbe square inch. ' Any air haWaii tafflf this pressure' is burst and rasd» «5 cable. Overbeatajsg is another »SOT*« ~ : trouble, destroying the. inadla&|TPW3«j,'';* " ties.of the gutta-percha. sa*W, f ": deep-sea . and *' W * V action of the ocean, mud, law*, '*8!j^ i '- known to destroy a. cable, lb ®U*"f! carry on- the i-eouisiie testing and spa*. t ■ ing during cable laving, a f^WlS®!''' 1 ' of electrical apparatus is r«9ls|B»a» *r [ fl \ than 309 battery cells being ia «a»'**t* D l !S:-. • SilvertOTs-n. , r ;' <|v;/-, - ■;,',, Safely in Ike De*y;»«-' ~'- "^ Tbe types of cable used «V;*J according to the locality it is mm m in. - The ordinarv deejHss*!£^'?M", ,:; thicker than one's "thumb. tjHWW" ,fi pressure of hundreds of faih«W»,« *** will beep the cable resting : ocean bed. where it is uJikebj l *Vj* any disturbing influences. In &**&%, > and. shallow, "roclrsr waters,'- ; .":'.' thicker' type is nsed. ■". Seldffln:|fe^T"(3 : ajjes occur in the deep-sea cables?.'• all the trouble met with takes f** m the thickest cables in exposed pl*«*-.' ;::- ■ _ .>ss% v'vS; "-■■: