Looking for replacement (Imperial) manhole cover (S.E.London area)

I went through this process some years ago; a complete waste of time, with hindsight.

There were no standard sizes and the covers seem to have been sand cast in small foundries. Grouting in a new frame isn't a difficult job. Just buy a new pressed steel job and resign yourself to installing a new frame as well.

Unfortunately it's like plumbing (and many other construction disciplines)... Nothing old matches with anything new ;-) You'd probably eventually find a replacement lid but it will be an original and could take you weeks/months to source.

BTW, forgot.

The old ones were made of grey cast iron which had lots of slag inclusions and is very brittle, as you've found. That (grey c.i.) was the only cast iron until the ductile cast iron sort was invented around 1950ish. Most small covers now are made of pressed, welded and galvanized steel, which is much stronger. Ductile cast irom covers are seen in road works but are much more expensive. Get a welded steel tray type. The ones with inset paving are less likely to get pikied.

Can't you cut one in 5mm steel plate and weld a couple of angle irons on the underside as bracing pieces?

I made this one which seems to work quite well. It's a little bit smaller than yours. Cut out of sheet steel, with angle steel welded underneath. Painted with some amazing paint that seems to be unavailable now.

I had one which was cracked.

Bought a pressed steel one to replace it, but I didn't like the way it went poing/ping when you stepped on/off it, so took it back and swapped it for a 7.5 tonne cast iron one, even though it's only a foot passage.

And yes, you have to swap the cover and frame together. You can't buy covers to fit in old frames.

Many thanks to those who took the time to reply to my posting and make useful suggestions. Your contributions are much appreciated.

ATB - Dave.