Here is a couple of pictures of how a sewer manhole is put together for those of you who have not seen it done. Normally it is done in a trench but the soil here was very unstable so we had to do what is called a V-ditch so that it could not cave in on us.
After this we toss on the ring and cover and bury it, alot simpler than people would think.
Do you hand form the base, or do you have some sort of template for that concrete pour???
Didn't know it was that simple.
We have a steel ring that makes the outer circle and everything else is done by hand. We have trowels that are the channel size and from there just normal concrete tools and some manual labor, it is pretty simple. The tough part is when you are in a 20 foot deep trench trying to do this with shoring all around you and the trench is only a foot or two wider than the manhole.