It will man versus machine when volunteers attempt to pull a 40 ton steam train at least half a mile.
The team were inspired by Tillilngham teenager Ellalouise Middleton, who has the incurable neurological condition dystonia.
Lloyd Claydon from the Blackwater Preservation Group, based in Bradwell, came up with the idea for the locomotive pull.
Her dad Paul and members of the preservation group will be attempting the challenge on September 21 at the Colne Valley Railway in Castle Hedingham.
Ellalouise hopes they will raise £9,000.
Donate at justgiving.com/Ellalouise-Middleton
She is also holding a fundraising tea and cake day at the open gardens day in Mill End, Bradwell, on July 13 from 10am-6pm.
It costs £4 adults, free for children.