Casgliadau Arlein

03/2010 - PM - This machine consists of two horizontally opposed engines; one would be running whilst the other was in reserve. During planned maintenance or if a ‘breakdown’ occurred, components like the connecting rod could be transferred to the other engine, thus allowing the fan to be brought back into use with the minimum of ‘downtime’. This engine originally drove a fan 42 feet (12801mm) in diameter. It was the Colliery stand-bye fan until 1967

Ventilation fan steam engine.