Bob Allison
Paul,
Historically, enlarged rivet heads were used for EM because the holes in the sleepers were punched to suit P4 gauge – the extra meat in the rivet heads meant there was more metal under rails which were 0.3mm offset from the rivet centres. Heaven knows what difficulties that created in the days of cosmetic half chairs glued on once all the rails were in place.
Maybe John W can advise the spacing of holes in the current batch of “EM” sleepers held by the store.
Of course, 2mm heads would be perfectly fine for EM points, where the centres of the rivets are set by the builder.
Bob
Paul Tomlinson
73A
Michael Marshall
Ben Weiner
Lee Davies