Also, as revealed on the programme, during the latter part of the race approaching the Berwick stop, Tornado's speed had to be temporarily reduced to 50 mph due to one of the steam injectors (which is a device which uses the boiler's own steam to transfer water from the tender into the boiler, over-coming the high pressure within the boiler) failing to operate for 10 minutes, risking the boiler running dry which would have necessitated dropping the fire to prevent major damage.