The Great Dorset Steam Fair is an annual show featuring steam-powered vehicles and machinery. The fair was founded by Michael Oliver, and has been held in Dorset, England, every summer since 1968, currently at Tarrant Hinton near Blandford Forum. The show is now run by Michael's son, Martin Oliver through Great Dorset Steam Fair Ltd.
It now covers 600 acres and runs for five days from the Wednesday after the UK August bank holiday. It is reputedly the largest outdoor show in the world. The most common exhibits are traction engines, tractors and farm machinery, but also included are preserved railway engines, cars and commercial vehicles, and shire horses. The show also has a market, autojumble, live music and funfair (some of which is powered by the steam engines). The Funfair has traditional rides such as Gallopers and steam boats, as well as modern ones like the "World fair wheel" which was sited in Manchester for the millennium. The funfair this year had an original Wall of Death ride. It is the biggest gathering of Fairground Organs with Showmans engines powering them in the UK.
The show regularly attracts around 200,000 visitors, and there can be 30,000 people on site, making the fair the fourth largest population centre in Dorset, after Bournemouth, Poole, and Weymouth (the population of the historic town of Dorchester being only half that number).
A speciality of the show is the display of traction engines and steam rollers performing the work for which they were designed. Such displays include heavy haulage, threshing, sawing logs, ploughing and road-making. The main arena of the show is purposely sited on the slope of a hill to allow both steam- and internal combustion-powered machinery to demonstrate their capacity for heavy load hauling. One of the main displays is the "Showmans Line up", which is thought to be the largest collection of Showmans engines in the world.
The end of the fair is marked with a Thanksgiving Service on the Sunday, at 12 noon, and takes place on the stage of Dean's Bioscope, the Silver Bell, organised for many years by Chris Edmonds, the Lay Chaplain until his recent death in 2007.
For the 40th anniversary, in 2008, the organisers recreated the very first fair, by tracing all of the exhibits that were displayed at the 1968 show.