 The functioning of the slipway was essential for the long-term preservation of the restored Underfall Yard as a historic industrial monument, as it provided the Underfall Restoration Trust with funds to maintain the slipway and buildings, and the tenants of those buildings with boats to earn a living.The power house at Underfall Yard was built in 1887 to supply hydraulic power to a network around the floating harbour.It was originally powered by steam (the large chimney remains from this system).