Network Rail installs ten mast-mounted weather stations

Network Rail has installed ten weather stations on existing GSM-R communications masts across Wales and the Borders, creating additional observation points to support railway operations during severe weather. The equipment, developed by Ninehundred Communications Group, measures rainfall, wind speed and direction, temperature, humidity and atmospheric pressure. Network Rail intends to combine the local readings with existing weather forecasts to inform decisions about infrastructure inspections, deployment of response teams and operational restrictions.

The Wales and Borders route is the first within Network Rail to use existing railway communications masts for this purpose. The ten locations were selected to address gaps in weather observations and provide information from sections of railway vulnerable to changing conditions. Installing the equipment on existing structures reduces the need to construct separate masts, although the infrastructure operator has not disclosed the cost of the installations or independently measured construction savings.

Five stations are located at Whitland, Llantwit, Cilmeri, St George’s and Trewyn in south and mid Wales. The remaining installations are at Craven Arms, Gobowen, Glantwymyn, Llanrwst and Buckley, extending the observation network across north Wales and the Borders. Their distribution provides measurements from individual railway locations rather than relying exclusively on observations collected elsewhere in the region.

GSM-R is the railway’s established communications system, using equipment installed along routes to support operational radio services. Its mast infrastructure provides locations with the height required for weather observations. The additional sensors use those structures as mounting positions, although Network Rail has not published the individual mast heights, structural assessments or installation methods adopted at each location.

The monitoring equipment records six weather variables. Rainfall observations can provide information relevant to drainage conditions and the likelihood of surface water accumulating around railway assets. Wind speed and direction are important where exposed structures, trees or debris could affect operations. Temperature, humidity and atmospheric pressure provide further measurements that can help describe developing conditions at each station.

Measurements collected from fixed locations differ from forecasts. A forecast estimates the weather expected across an area and period, while a sensor records conditions at the point where it is installed. Local observations can therefore provide additional evidence when actual conditions differ from those anticipated across a broader forecast region.

Network Rail already works with forecasting specialist MetDesk to monitor weather and prepare for disruption. The new stations are intended to supplement that service, allowing MetDesk and railway operations teams to incorporate measurements collected directly from the network. The announcement does not establish that a new forecasting model has been commissioned or that forecast accuracy has already improved as a result of the installation.

Local topography can influence the conditions experienced along a railway. Exposed sections, valleys and areas close to higher ground may experience different rainfall or wind conditions within the same wider weather event. Observations from additional locations can help describe that variation, but ten stations cannot measure conditions at every cutting, bridge, embankment or drainage asset across the route.

The investment follows a series of storms that have disrupted Wales and Borders services. Network Rail reports that 25 named storms affected the route between February 2023 and January 2026. Where complete performance data was available, the storms caused an average of more than 38 hours of train delays and £179,000 in performance costs per event.

Storm Darragh was the most expensive event identified in that period, with reported performance costs of £1.3m. During the storm on 6 and 7 December 2024, winds reached 93mph at Capel Curig, while fallen trees and debris disrupted services across Wales. These figures describe historical disruption and the conditions motivating the monitoring investment, rather than benefits achieved by the newly installed stations.

Weather information can influence decisions to inspect exposed assets, deploy maintenance personnel or introduce restrictions on railway operations. Strong winds may create risks from falling trees or debris, while heavy rainfall can affect drainage systems and ground conditions. Network Rail intends to use the additional observations to refine the information available when assessing these risks, alongside the organisation’s existing safety procedures.

The stations are also expected to help Network Rail refine operational weather thresholds. These thresholds support decisions about the response required when particular conditions are forecast or observed. A more detailed understanding of local conditions could allow action to be directed towards affected locations, although the infrastructure operator has not published revised numerical thresholds or confirmed a change to any particular operating rule.

Speed restrictions are among the measures that weather information can inform. Such restrictions may reduce exposure to identified risks during severe conditions, but the new weather stations do not independently control train movements or authorise restrictions to be removed. Operational decisions remain subject to the railway’s established processes and the assessment of risks affecting individual routes.

The equipment was developed by Ninehundred Communications Group, which supplies connected communications and monitoring technology. Its weather station products use environmental sensors and remote data transmission to collect information without requiring personnel to read instruments at every location. The supplier describes wireless connectivity and autonomous power options within its product range, although Network Rail has not released a complete specification confirming the configuration installed at each railway mast.

Mounting additional equipment on an operational communications structure also creates installation and maintenance requirements. The sensors need suitable positioning for reliable observations, while their supports must remain secure under the conditions they are intended to measure. Network Rail has not disclosed the maintenance intervals, mounting arrangements or additional structural loads for the ten installations.

Daniel Booth, Head of Operational Weather Strategy at Network Rail Wales and Borders, said the stations would provide more accurate local information and help teams respond earlier to changing conditions. The organisation expects the additional data to support decisions that maintain safe operations while limiting unnecessary disruption. No reduction in delay minutes or storm-related costs has yet been attributed to the installation.

The weather stations form part of wider preparations for autumn and winter. Network Rail has four specialist treatment trains scheduled to cover more than 54,400 miles of track, while teams have undertaken targeted drainage improvements and additional vegetation management. Ten dedicated Autumn Response Teams are also available to respond to changing conditions across the route.

These physical maintenance and response activities remain necessary because weather measurements identify conditions rather than repair infrastructure. A sensor can contribute information about rainfall or wind, but it cannot determine whether every drainage system is functioning correctly or whether a tree is at risk of falling. Inspections, asset records and operational assessments remain important sources of evidence when deciding how to respond.

With all ten stations installed, the next stage will be the use of their observations within forecasting and operational arrangements. Network Rail has not announced a further deployment programme or published measured improvements in weather-related performance. The confirmed development is the establishment of a local monitoring network using existing GSM-R masts, with the intended operational benefits dependent on how its information is subsequently used.