A phezulu egijima ibhuloho craneingenye yezinhlobo ezivame kakhulu neziguquguqukayo zemishini yokuphakamisa phezulu. Imvamisa ukubizwa ngokuthi i-EOT crane (i-Electric Overhead Travelling crane), iqukethe ujantshi ongashintshi noma isistimu yethrekhi efakwe phezulu komugqa wezindiza ngamunye. Amaloli okugcina ahamba kulawa mzila, ethwele ibhuloho futhi aphakamise kahle phakathi nendawo yonke yendawo yokusebenza. Ngenxa yalo mklamo, i-crane yebhuloho egijima phezulu isebenza kahle kakhulu ezindaweni lapho imithwalo esindayo idinga ukuphathwa ngokuphepha futhi njalo.
Enye yezinzuzo zezinhlelo zokugijima eziphezulu yikhono labo lokuhlanganisa kokubili i-single girder ne-double girder bridge designs. Ibhuloho elilodwa elibamba ibhande livamise ukusebenzisa i-trolley elengayo ngaphansi kanye ne-hoist, kanti ibhuloho elihlanganisa kabili ngokuvamile lisebenzisa i-trolley ehamba phambili kanye nokuphakamisa. Lokhu kuvumelana nezimo kuvumela onjiniyela ukuthi benze ngendlela oyifisayo isistimu ye-crane ukuze ihambisane nezidingo zokuphakamisa ezahlukene. Ngokwesibonelo, i-monorail overhead crane ingase ifaneleke ukunyakaza komugqa endleleni egxilile, kodwa lapho kudingeka amandla amaningi okuphakamisa izinto ezihlukahlukene kanye namakhudlwana, i-EOT crane ekucushweni kokugijima okuphezulu inikeza izinzuzo ezinkulu.
Ngokungafani nama-cranes agijimayo,ama-cranes amabhuloho agijima phezuluakukho mkhawulo kumthamo. Angaklanywa ukuthi aphathe imithwalo esukela kuhlelo lokusebenza oluncane lwe-1/4-ton ukuya kumathani angaphezu kuka-100. Ngenxa yokuthi agibela kumareyili atholakala ngaphezu komugqa wendiza, angakwazi ukusekela ububanzi obubanzi futhi afinyelele ukuphakama okukhulu. Emabhilidini ane-headroom evinjelwe, lokhu kubaluleke kakhulu. Idizayini yebhuloho egijima kabili egibela phezulu ivumela i-hoist netroli ukuthi igijime phezu kwamagida, ingeze amafidi angu-3 kuya kwangu-6 obude behuku. Lesi sici sikhulisa ukuphakama okutholakalayo kokuphakamisa, okuthile ukhrane we-monorail ongaphezulu ongeke ukwazi ukuhlinzeka ngakho.
A phezulu egijima ibhuloho craneifaneleka kahle kuma-workshops, izindawo zokugcina izimpahla, kanye nezindawo ezisindayo zezimboni lapho kudingeka khona ubude obude namandla aphezulu. Uma imithwalo idlula amathani angama-20, isistimu esebenzayo ephezulu iba yinketho efanelekile kakhulu. Esekelwa insimbi yesakhiwo sesakhiwo noma amakholomu asekelayo azimele, lawa ma-cranes adizayinelwe imisebenzi enzima. Ngokuphambene, lapho izimfuneko zokuphakamisa zilula, njengamathani angu-20 noma ngaphansi, i-crane engaphezulu egijimayo noma ye-monorail ingase icatshangelwe ukuguquguquka okukhulu.
Enye inzuzo ebalulekile yamasistimu asebenzayo ukuthi asusa isici somthwalo esimisiwe esivamile ngaphansi kwama-cranes asebenzayo. Ngenxa yokuthi i-crane isekelwa kusukela phezulu, ukufakwa kulula futhi ukugcinwa kwesikhathi esizayo kulula. Ukuhlolwa kwesevisi, okufana nokuhlola ukuqondanisa kukaloliwe noma ukulandelela, kungaqedwa ngokushesha ngokunciphisa isikhathi esincane. Ngesikhathi sokusebenza kwayo, i-EOT crane ekuklanyweni okuhamba phambili inikeza ukuzinza okukhulu nokusebenza kahle uma kuqhathaniswa nezinye izinhlelo ze-crane.
Nakuba amasistimu asebenzayo adinga ukuhlolwa ngezikhathi ezithile komzila wesitimela noma ukuqondisa kwethrekhi, le nqubo iqondile futhi idla isikhathi esincane kunezinye izinhlobo ze-crane. Umklamo oqinile uqinisekisa impilo ende yesevisi ngisho nangaphansi kokusebenza okuqhubekayo. Izinkampani eziningi zikhetha i-crane yebhuloho egijima phezulu hhayi kuphela ngenxa yomthamo wayo ophezulu kodwa futhi ngenxa yokuthembeka kwayo okuqinisekisiwe nokulula kwenkonzo. Ngokufanayo, izinsiza eziqala ukwamukela i-monorail overhead crane ukuze ziphakame kalula zivame ukunwetshwa zibe uhlelo olugcwele lwe-EOT crane njengoba izidingo zabo zokuphatha izinto zikhula.
Kafushane, iphezulu egijima ibhuloho craneiyisixazululo esisebenza kahle kakhulu sokuphakamisa izimboni ezidinga umthamo omkhulu, ubude obude, nokuphakama okuphezulu kokuphakama. Ngokucushwa okutholakala kuzo zombili imiklamo yegirder eyodwa kanye ne-double girder, kanye namandla okuphakamisa asuka kumakhulu ambalwa amakhilogremu kuya ngaphezu kwamathani ayi-100, lolu hlobo lwe-EOT crane luletha amandla, ukuzinza, kanye nenani lesikhathi eside. Emisebenzini lapho ukuguquguquka kanye nemithwalo elula ibaluleke kakhulu, i-monorail overhead crane ingase ifaneleke, kodwa ngokuphakamisa okusindayo nokusebenza kahle okuphezulu, isistimu yokugijima ephezulu ihlala iyisinqumo esikhethwayo.
