Born in London, Simms suffered from ill-health in his younger years (as his obituary put it, he was "of delicate constitution",[1] and some difficulty was encountered in finding him suitable employment until via the influence of his brother he was despatched to Ireland as an assistant to the Ordnance Survey.

After leaving Ireland Simms became an astronomical assistant at the Royal Observatory, Greenwich, under John Pond.

[7] Simms' own efforts included writing a pamphlet promoting the use of Seyssel asphalt, based on an 1836 paper by geologist M.

[10] In 1836 Simms joined the South Eastern Railway Company as a resident engineer and undertook a considerable number of works, including the construction of the Bletchingley and Saltwood tunnels.

His health suffered from the climate and he spend some time in Mauritius before returning to duty where, among other work, he supervised a complete survey and mapping of the city of Calcutta which was principally carried out by local assistants.