After getting concrete dug up, the original sized opening for an inspection chamber has been revealed - its rectangular and larger than normal. over 60cm wide and over 90 cm long. How could this be reduced to fit a normal sized rectangular cover?
How much room (height) do you have to play with? What does the chamber lid look like presently? Piccies would help especially a look at the interior of the chamber (it may be concrete ring biggie).So would the lintels go width ways to reduce the length down to less than 500 say? And if so, if the width (which the long side of the cover would straddle) of the remaining hole is lets say a little less than 600 (I need to check the width) how can you reduce that part, given the lintels would stop you laying another lintel length ways on one side. i.e. how to reduce the manhole on two perpendiular sides - length and width. It needs to take the weight of a car.
You can buy deeper pre-stressed concrete lintels to suit your needs.