Aqueduct reconstruction
Miller Argent (South Wales) Ltd has organised and paid for the reconstruction of a Grade II Listed aqueduct (Plate 1) which is located within the Ffos-y-fran Land Reclamation Scheme.
The aqueduct is a Grade II Listed wooden structure built in circa 1876 and was part of a complex water management system (Dowlais Free Drainage System), which would have fed water to the Dowlais Ironworks. The aqueduct was one of two similar structures that carried water across the Great Western and Rhymney Joint Valley Railway to the Sarn Howell reservoir. The Dowlais Free Drainage System was developed on the Cwmbargoed Mountain from circa 1818 and the Sarn Howell Watercourse was in operation by 1839. At this time, the Dowlais Ironworks was the largest in the world, and needed vast amounts of water for powering the ironworks steam engines, as coolant and also for use in water balance winding gears in the mines. The watercourses and reservoirs evolved into a uniquely large and densely developed industrial water control system. The Dowlais Free Drainage System was in use until mining works ceased on the mountain. Timber aqueducts similar to the two aqueducts at Ffos-y-fran were common spanning railways in the nineteenth century, but are now quite rare.
In January 2007, the Grade II Listed aqueduct collapsed, as a result of bad weather in the form of exceptionally strong winds (Plate 2). Prior to this, the aqueduct was already in poor structural condition. The aqueduct collapsed into the former Great Western Railway cutting on the Cwmbargoed line that it was spanning. It is thought that the collapse started at the southern end where the bridge fabric had eroded away from the abutment structure and therefore was not securely anchored. The tie rods, nuts and washers were too decayed for structural reinstatement and many components are bent/damaged as a result of the collapse. A significant proportion of the now collapsed structure is in an advanced state of decay and as a result of which cannot be reinstated in its current condition.
The aqueduct is about 32 meters long and constructed from pine, using traditional techniques of joists and planks. Its has three spans, from masonry and brick abutments across timber trestle piers. The plank sides of the aqueduct are held in place by complex timber tie struts above and below them, tied vertically by wrought iron rods. Major repair work was carried out on the aqueduct in the 1960's, however, the repairs are thought to have been inadequate and may possibly be a cause for the aqueduct's weakened state.The aqueduct was recorded insitu by the Glamorgan Gwent Archaeological Trust and lifted by crane onto specially made wooden pallets.
The aqueduct was lifted from the railway cutting on the 22nd October. It was then stored in a safe area on site until it was transported to the conservation company on the 26th November. The conservation company that is reconstructing the aqueduct is David Michelmore Consultancy and Conservation for Historic Buildings. We hope to errect the aqueduct back on Ffos-y-fran in 2010.