It seems that MOT type 1 is now known as SHW clause 803
Similarly MOT type 3 is SHW clause 805
But I have a requirement for SHW clause 513
I can't find anyone selling an aggregate described as Cl 513, just lots of specs for road schemes under .gov.uk demanding its use. it's "permeable backfill to earth retaining structures", what is the stuff called in old money?
SHW = specification for highways work