5.5mm scale narrow gauge model railways were developed by GEM in 1963, using gauge track, which was the smallest commercially available gauge at the time (TT gauge).Why 1/55th scale? GEM produced kits for locomotives and rolling stock from the Ffestiniog and Talyllyn railways. Following the development of N gauge, using gauge track, the popularity of 5.5 mm scale declined as modellers adopted OO9 which could combine N gauge track and mechanisms with the widely supported 4 mm scale.
