"p.k." wrote in message
...
Klara wrote:
In message .com,
writes
Are there Manholes or Inspection holes?
How do you tell the differenence without taking the cover off?
Manholes need to fit one standard working man?? Insepction holes just
need to let you see what is inside?
Des
Manholes to fit a man? Tut tut, that's sexist! People-holes!!! ;-))
Traditionally man-holes are round and inspection covers rectangular.
Why?
Inspection covers are usually the same shape as the inspection chambers they
cover. Older chambers are usually rectangular, brick built affairs, but
circular ones are found, especially modern plastic ones, and they have
'round' lids, so inspection chamber lids are not all rectangular.
Manholes are traditionally for the purpose of allowing workmen to gain
access to whatever lies below the opening, e.g. sewer, culvert, tunnel,
whatever. The cover, obviously, has to match the frame of the opening. A
possible advantage of a circular cover is it is much more difficult to drop
it through the opening than a square one, but the ones I've seen aren't all
circular, either :-)