Abergwynfi Culvert Repairs

Client: Neath Port Talbot County Borough Council
Location: Blaengwynfi, Port Talbot
Services: Confined Space | Culvert Rehabilitation | Concrete Repairs | Temporary Works | Environmental Protection

Project Overview

Kaymac Marine & Civil Engineering was commissioned by Neath Port Talbot County Borough Council to undertake specialist repairs to the Abergwynfi Culvert in Blaengwynfi, Port Talbot.

The works involved repairing a series of scour-damaged areas within the culvert, requiring Kaymac’s confined-space capabilities alongside carefully planned temporary works, concrete pumping and water-management measures. Access to the culvert was established through the grounds of a nearby primary school, adding further logistical and public-interface considerations to the project.

Scope of Works

The project included mobilisation and establishment of a safe working area, creation of access through the school grounds, installation of fixed steel concrete pumping lines, concrete repairs incorporating steel mesh where required, and full reinstatement and demobilisation following completion.

Ground protection was installed across the school grounds to facilitate the movement of plant and materials while minimising disturbance. A dedicated working platform accommodated the crane and concrete pump, with the crane also providing emergency access and egress arrangements for the confined-space operation.

The Challenge

Ten areas of scour repair had been identified within the culvert, with the first approximately 45 metres from the entrance. The works therefore required concrete to be transported considerable distances into a restricted confined-space environment while maintaining control of the live watercourse.

The project also required careful management of the interface between the works, the school grounds and the surrounding environment. Key considerations included confined-space working, potential changes in water flow, safe movement of vehicles and plant, and preventing concrete or other contaminants from entering the watercourse.

Kaymac’s Solution

Kaymac installed fixed steel pumping lines along the culvert, temporarily securing them to the walls before testing the system for leaks. Concrete could then be pumped from the working platform at surface level through the fixed lines and into the individual repair areas.

The repair programme progressed from the downstream end towards the upstream end of the culvert. Temporary fluming was installed around each repair location to divert water and create a semi-dry working area, allowing concrete to be placed into the scour voids. Once each pour had sufficiently set, the team progressed upstream to the next repair location.

Communication between the surface team and operatives within the culvert was maintained by radio, enabling the team underground to control the concrete flow and minimise the potential for overspill.

Protecting the Watercourse

Environmental protection was integral to the methodology. Sedimats and other environmental protection measures were positioned upstream and downstream of the repair works, including multiple layers of protection downstream. Plant was located on hardstanding with appropriate containment measures, while discharge points were protected to minimise the potential for contamination, discolouration or localised scour.

Concrete used for the works incorporated an underwater anti-washout admixture, with formwork monitored before and during pours to further reduce the risk of contamination.

Specialist Capabilities Demonstrated

This project demonstrates Kaymac’s ability to combine confined-space expertise, specialist civil engineering and temporary works to deliver complex repairs within difficult-to-access water infrastructure.

The works brought together confined-space trained personnel, water management and fluming, long-distance concrete pumping, scour repair, environmental controls, lifting operations and careful site reinstatement within a sensitive operational environment.

A strong example of Kaymac providing a practical, self-delivered solution to extend the service life and integrity of critical culvert infrastructure.