Project Overview

This project was an ECI Contract to demolish an existing arched aqueduct and construct a new 32m clear span plate girder aqueduct, on piled abutments, to carry the Neath canal over the River Neath at Resolven. 

The aqueduct is the longest single span aqueduct constructed in the UK; it is 1.3m deep and 7m wide and incorporates foot/cycle paths on both sides. The abutments were supported by sixteen 900mm tubular steel piles bored to depths between 28 and 40 metres. 

The original design for the bankseat piling on this scheme was based on using 900mm diameter bored concrete piles installed to a depth of 28 metres in the river bank(s). Following meetings with the Environment Agency who expressed concerns in respect of concrete spillage, and further geotechnical investigation, we proposed a system that incorporated 900mm diameter tubular steel piles that were driven to depths up to 40 metres. 

Our alternative design eliminated the risk of concrete spillage and other pollution into the River Neath, reduced the construction programme, enhanced skin friction and end bearing of the piles, and reduced cost. 

Throughout the contract we conducted our operations to ensure that marine and wild life including otters were not affected by our works, much of which was delivered in the water. Bat boxes were also installed on the aqueduct. 

Adjacent to the aqueduct is the A465 dual carriageway and significant traffic management was implemented on the carriageway to allow for deliveries of the outsized girders. 

The Ynysbwllog Aqueduct project was shortlisted in the 2010 Waterways Renaissance Awards and the 2010 ICE Wales Project Awards in both cases being highly commended by the judges.

Project Gallery


Neath Canal Navigation



Project Value


Contract Period

48 weeks