North Yorkshire Moors Railway - Bridge 42 - CML Civil Engineering

Brief Description

Bridge 42 at Grosmont carries every train on the North Yorkshire Moors Railway, supports around 10,000 locomotive movements each year, and has stood proudly over the River Esk since 1846. The original horse-drawn Whitby and Pickering Railway bridge at that location dates from 1836, but the current Grade II listed structure is thought to have been completed around 1845 to 1846, as part of the York and North Midland Railway’s rebuilding of the line. After 180 years of faithful service, this Grade II listed structure now needs urgent repairs to keep trains running safely into the future.

The CML Structures team were appointed to install foundations beneath the bridge in the River Esk, to accommodate a propping system allowing the heritage line to be open and operational. The location of the works and an extremely tight programme made this a very challenging project and required working seven days per week for the entirety of the programme allowing the line to be operational over the bank holiday weekend in late May.

Summary of Work

The CML Structures team were appointed by North Yorkshire Moors Railway (NYMR) to install foundations beneath the bridge in the River Esk, to accommodate a propping system allowing the heritage line to be open and operational. CML have a long standing relationship with NYMR, having worked on Whitby Platform 2 and reconstruction of Bridge 30, Darnholme.

The project commenced with the construction of a temporary access road and crane pad to support a 110-tonne crane positioned on the bridge, enabling the safe transfer of materials and plant to the riverbed below. To facilitate the installation of timber foundations, a temporary dam was constructed extending halfway across the River Esk, creating a controlled working area within the watercourse.

A total of 1000 specialist reclaimed untreated Ekki sleeper (African Azobe) were installed to form the foundation base, which is an extremely dense and strong hardwood, commonly used in marine & civil engineering and designed to resist water absorption. These were lifted into position from the bridge above using crane operations. Following the foundation works, the Mabey Truss arch structure was assembled and installed, with timber packers added between components to complete the propping system and ensure effective load distribution.

Operational logistics required all plant and equipment to be lifted down to the work area at the start of each shift and removed at the end of the day via crane, maintaining safety and minimising environmental impact. Additionally, a temporary scaffold access was installed along the riverbank to provide safe access for operatives between the bridge and the riverside work area.

The works were completed through careful coordination of lifting operations, temporary works installation, and access management, ensuring safe and efficient delivery within a challenging river environment.

Environmental Considerations

A detailed method of work was followed, starting with site surveys and hazard identification, along with the establishment of secure access routes via Grosmont Station. Deliveries were carefully coordinated to minimise disruption to the public and ensure safe movement of vehicles and plant.

Operational logistics required all plant and equipment to be lifted down to the work area at the start of each shift and removed at the end of the day via crane, maintaining safety and minimising environmental impact.

Throughout the project, environmental and access constraints were effectively managed, and contingency arrangements were in place to address delays or operational changes. At the end of each shift, the site was left safe, clean, and secure.

Successes

CML were able to beat their original programme and bring this forward for completion before the Bank Holiday weekend in May, where the line is at it’s busiest.

Passengers will once again be able to travel the full 24-mile heritage route through the stunning North York Moors National Park to the quaint seaside town of Whitby. A full repair programme will take place over the closed season during the winter of 2026/27, which will restore the bridge to its “long-term structural integrity and ensure its preservation for future generations”.

Temporary dam installed successfully within programme timeframe.
Foundations achieved required structural integrity and bearing capacity.
Zero reported incidents, demonstrating strong safety performance.
Effective coordination enabled smooth integration of deliveries and plant operations

“Our heritage railway is at the heart of the local community, and it’s important that we continue to provide a safe and enjoyable experience for all our visitors. The proactive measures for Bridge 42 reflect our commitment to both operational safety and the long-term preservation of this historic line. I want to thank a number of vital suppliers and organisations and the residents of Grosmont, whose help and support during this period has been invaluable – North Yorkshire Council, North York Moors National Park, GGP, Murlac, CML, and Prop Hire.”

Laura Strangeway
CEO at the NYMR