Peter.
5 Inf Div landed at Reggio di Calabria on 3 Sep 43 as part of Operation BAYTOWN. Their task, with 1 Cdn Inf Div, was to push north and meet up with the US Fifth Army who, on 9 Sep 43 landed at Salerno as part of Operation AVALANCHE.
The US 36 Inf Div had responsibility for the right flank of the Salerno landings and it was they who met up with 5 Inf Div when they reached the beachhead on 17-18 Sep 43 or thereabouts.
As a Royal Engineer in 5 Inf Div, he would have been in either 38 Fd Coy, 245 Fd Coy, 252 Fd Coy, 254 Fd Park Coy or 18 Bridging Platoon.
Regards
Frank