The line was converted to use steam locomotives in 1848, partly because wear on the rope proved greater than anticipated (a steel-wire replacement had been tried but this twisted and kinked ferociously) and partly in consequence of the intended 1849 extensions. A light roof over the line was provided where it passed near to timber stores or shipping, because of the anticipated fire risk from locomotive sparks. It then became possible to travel directly between intermediate stations, without a detour by way of a terminus.