Thaum npaj manhole npog ntawm lub lawj, lawv feem ntau yuav tsum tau nyob ze rau ntawm lub hauv paus bulkhead, nrog lub axis ntev ntawm lub manhole npog thaum uas tig mus rau lub compartment, yooj yim rau installation ntawm ib tug ncaj ntaiv hauv qab lub manhole. Txhawm rau kom yooj yim ntawm cov neeg ua haujlwm nkag mus thiab qhov cua, cov kua dej loj dua thiab cov tank khoob yuav tsum muaj tsawg kawg yog ob lub manhole npog qhov sib nrug deb. Cov khoom loj dua nyob rau hauv ob sab hauv qab yuav tsum muaj manhole npog ntawm ob qhov kawg, thiab yog tias tsim nyog, ib qho ntxiv manhole npog yuav tsum tau nruab nrab ntawm nws qhov ntev. Manhole npog nyob rau hauv pem teb sab hauv yuav tsum muaj tsawg kawg yog 800-1000 mm deb ntawm lub ntsiab bulkhead kom tsis txhob muaj zog lub zog ntawm lub puab pem teb nyob ze ntawm lub ntsiab bulkhead.
Txawm hais tias cov npog manhole tau nruab rau ntawm lub lawj, sib npaug, sab hauv pem teb, lossis lub taub hau, cov qauv hull yuav tsum khaws cia kom zoo li qub. Yog tias kev teeb tsa nyuaj thiab tsis tuaj yeem zam dhau los ntawm kev txiav cov qauv hull, qhov kev txhawb nqa tsim nyog yuav tsum tau ua. Manhole npog yuav tsum tsis txhob muab ntsia rau hauv qhov chaw tseem ceeb kom ntseeg tau tias lub cev muaj zog ntawm lub hull, xws li lub lawj ntug, hatch fab, thiab qhov chaw muaj kev ntxhov siab.
Thaum cov npog manhole raug teeb tsa rau ntawm ob sab qis lossis lub platform, lawv txoj haujlwm yuav tsum tau staggered. Yog tias lub hau npog yog nyob rau ntawm lub lawj sab saud lossis lub platform, lub hau npog ntawm lub lawj qis lossis lub rooj sib txoos yuav tsum tsis txhob nyob sab nraum qhov projection ntau ntawm lub hau npog.
