Re: kiln mainhole location
At the position of minimum bending stress. This is found at some position fairly close to, but a bit out from, each side of a tyre, with the exact distance out from the tyre depending on the precise shell design through the tyre area.
Re: kiln manhole location
Apart from the kiln load factors, normally near the second tyre a mnahole provided to remove the used bricks and another hole near thr first tyre towards kiln inlet side ,especially when chain zone is available in the kiln. Near the discharge tyre manhole is not necessary as the used bricks/coating can be removed through the hood.