The Merryweathers worked with the engineer Edward Field to fit his design of a vertical boiler onto a horse-drawn platform. They successfully applied it for use in their steam fire engine, thus improving water pressure and making easier to use once steam had been got up. It was reckoned that an engine could get up enough pressure to pump within ten minutes of a call out; the fire could be started before leaving the fire station so there would be enough pressure by the time they arrived at the scene of the fire.