A phezulu ibhulorho crane ebalekayoyenye yezona ntlobo zixhaphakileyo kunye neziguquguqukayo zezixhobo zokuphakamisa phezulu. Idla ngokubizwa ngokuba yi-EOT crane (i-Electric Overhead Travelling crane), iqulathe isiporo esisisigxina okanye isixokelelwano somzila esifakwe kumphezulu womgaqo weenqwelo-moya ngamnye. Iilori zokugqibela zihamba ngala mzila, zithwele ibhulorho kwaye zinyuswe ngokutyibilikayo kuyo yonke indawo ekusetyenzwa kuyo. Ngenxa yolu yilo, i-crane yebhulorho ehamba phezulu isebenza kakuhle kakhulu kwiindawo apho imithwalo enzima kufuneka iphathwe ngokukhuselekileyo kwaye rhoqo.
Enye yeenzuzo zeenkqubo ezisebenzayo eziphezulu kukukwazi kwabo ukuhlalisa zombini i-girder enye kunye ne-double girder bridge designs. Ibhulorho yebhanti enye ihlala isebenzisa itroli ejingayo ngaphantsi kunye ne-hoist, ngelixa ibhulorho edibanisa kabini iqhele ukusebenzisa itroli ehamba phezulu kunye ne-hoist. Oku bhetyebhetye kuvumela iinjineli ukuba zenze inkqubo yecrane ukuze ihambelane neemfuno ezahlukeneyo zokuphakamisa. Umzekelo, i-crane engaphezulu kwe-monorail inokulungela intshukumo yomgca ecaleni kwendlela emiselweyo, kodwa xa kufuneka izinto ezininzi ezahlukeneyo kunye namandla okuphakamisa amakhulu, i-crane ye-EOT kuqwalaselo olusebenzayo oluphezulu lubonelela ngeenzuzo ezinkulu.
Ngokungafaniyo phantsi kweekhreyini ezibalekayo,iikhreyini zebhulorho ezihamba phezuluazinasithintelo kumthamo. Ziyakwazi ukuyilwa ukuphatha imithwalo ukusuka kwisicelo esincinci se-1/4-toni ukuya kwiitoni ezingaphezu kwe-100. Ngenxa yokuba bakhwela kwiireyile ezibekwe ngaphezulu komgaqo weenqwelomoya, banokuxhasa iindawo ezibanzi kwaye bafikelele kwiindawo eziphakamileyo zokuphakamisa. Kwizakhiwo ezine-headroom ethintelweyo, oku kubaluleke kakhulu. Uyilo oluphezulu lwebhulorho ebambekayo kabini luvumela i-hoist kunye netroli ukuba ibaleke phezu kweebhanti, yongeza i-3 eyongezelelweyo ye-6 yeenyawo zokuphakama kwe-hook. Eli nqaku linyusa ukuphakama okukhoyo kokuphakanyiswa, into enokuthi ibonelelwe yi-monorail ngaphezulu kwecrane.
A phezulu ibhulorho crane ebalekayoifaneleke ngokufanelekileyo iindibano zocweyo, iindawo zokugcina iimpahla, kunye nemeko-bume yemizi-mveliso enzima apho kufuneka izithuba ezinde kunye nezakhono eziphezulu. Xa imithwalo idlula iitoni ezingama-20, inkqubo yokusebenza ephezulu iba yeyona ndlela ifanelekileyo yokukhetha. Ukuxhaswa yintsimbi yesakhiwo sesakhiwo okanye ngeekholomu zokuxhasa ezizimeleyo, ezi cranes zenzelwe imisebenzi enzima. Ngokwahlukileyo, xa iimfuno zokuphakamisa zikhaphukhaphu, ezinje ngeetoni ezingama-20 okanye ngaphantsi, i-crane ephantsi kokubaleka okanye i-monorail overhead crane inokuthathelwa ingqalelo ukuguquguquka okukhulu.
Olunye uncedo oluphambili lweenkqubo eziphezulu ezisebenzayo kukuba zisusa umthwalo omisiweyo oqhelekileyo phantsi kweekhreyini ezibalekayo. Ngenxa yokuba i-crane ixhaswa ukusuka phezulu, ukufakela kulula kwaye ukugcinwa kwexesha elizayo kulula. Ukuhlolwa kwenkonzo, njengokujonga ukulungelelaniswa koololiwe okanye ukulandelela umkhondo, kunokugqitywa ngokukhawuleza kunye nexesha elincinci lokunciphisa. Ngaphezulu kobomi bayo bokusebenza, i-crane ye-EOT kuyilo oluphezulu olusebenzayo inika uzinzo olukhulu kunye nokusebenza kakuhle xa kuthelekiswa nezinye iinkqubo zecrane.
Ngelixa iinkqubo ezisebenzayo zifuna ukuhlolwa ngamaxesha athile kumzila kaloliwe okanye ulungelelwaniso lwengoma, le nkqubo ithe ngqo kwaye ayidli xesha lininzi kunezinye iintlobo zecrane. Uyilo oluqinileyo luqinisekisa ubomi obude benkonzo naphantsi kokusebenza okuqhubekayo. Iinkampani ezininzi zikhetha i-crane ephezulu yebhulorho hayi kuphela ngenxa yomthamo wayo ophezulu kodwa kunye nokuthembeka kwayo okuqinisekisiweyo kunye nokulula kwenkonzo. Ngokukwanjalo, amaziko aqala ukwamkela i-monorail ngaphezulu kwekhreyini yokunyuselwa kancinci ihlala isanda ibe yinkqubo yecrane epheleleyo ye-EOT njengoko iimfuno zabo zokuphatha izinto zikhula.
Ngamafutshane, iphezulu ibhulorho crane ebalekayosesona sisombululo sisebenzayo sokuphakamisa kumashishini afuna umthamo ophezulu, ubude obude, kunye nobude obuphezulu bokuphakamisa. Ngolungelelwaniso olukhoyo kuzo zombini igirder kunye noyilo oluphindwe kabini, kunye nokuphakamisa amandla ukusuka kumakhulu ambalwa eekhilogram ukuya ngaphezulu kweetoni ezili-100, olu hlobo lwe-crane ye-EOT lunikezela amandla, uzinzo, kunye nexabiso lexesha elide. Ukusebenza apho ukuguquguquka kunye nemithwalo elula ibaluleke kakhulu, i-monorail overhead crane inokufaneleka, kodwa ukuphakamisa okunzima kunye nokusebenza kakuhle, inkqubo ephezulu yokuqhuba ihlala ikhethiweyo.
