The yellow markers, flagship of the NaTran gas transmission network
They are installed along roadsides and fields, often unnoticed. And yet these yellow markers, in the colours of the NaTran brand, mark the 32,000 kilometres of pipelines in our gas transmission network. Their mission is essential: to point out what is invisible - a buried network - to prevent any incident.
Until the 1990s, several colours could be used to identify the gas transmission network in France. This patchwork, a source of confusion, has been replaced by national standardisation. A turning point came in the early 2000s, before being enshrined in a decree in 2018 and a standard: from now on, gas will be indicated in yellow throughout France. Electricity in red, water in blue, sewerage in brown... each network has its own official colour.
This emblematic yellow will become the colour of NaTran in 2025. More than a safety marker, it is the symbol of our identity and our presence in the territories.
"Yellow catches the eye and indicates a potential hazard in safety pictograms. It was logical to choose this colour for the gas,"Olivier Le Touzic
Operations Support Engineer at NaTran and technical leader in boundary marking and beaconing
The choice of yellow: visibility and safety
Visible from a distance, even in low light or in dense vegetation, yellow drastically reduces the risk of accidental damage to pipelines by site machinery. In rural areas, where the markers are mainly located, this colour catches the eye. In urban environments, where bollards are used, the same colour ensures consistency and immediate recognition. "Yellow catches the eye and indicates a potential hazard in safety pictograms. It was logical to choose this colour for the gas," explains Olivier Le Touzic, Operations Support Engineer at NaTran and technical leader in boundary marking and beaconing.
NaTran's yellow markers and bollards enable private individuals, local authorities and businesses to identify the boundaries, of rights of way, and allow NaTran to react in the event of unforeseen circumstances, such as undeclared works. Today, NaTran combines ground inspections with monthly overflights by plane to identify undeclared building sites. Penalties for breaches of this kind can go up to several thousand euros.
Scheduled maintenance
Markers are placed at road crossings, railway crossings, river crossings, plot boundaries and at each change of direction of the pipeline. A marker is always visible on a pipeline when looking ahead or behind.
Maintenance follows a precise cycle, with the right of way cleared of undergrowth every two years and the boundary markers and bollards completely renewed every four years.
A social and local dimension
Markers also have a social value. NaTran entrusts their manufacture and maintenance to committed service providers. Among them is Sicomen, an adapted company that employs disabled people to design hats and plates in plastic or aluminium. Other local organisations, such as ESATCO (formerly Les Ateliers Briochins), are involved in clearing the undergrowth and boundary marking.
A new identity as replacements are made
The old GRTgaz plates will be replaced by new plates engraved with NaTran's name as bollards or markers are replaced or damaged. Each plate also has a unique identifier and a toll-free number, linked 24 hours a day to the Regional Surveillance Centre. "Local residents can call directly if they notice an anomaly," stresses Olivier Le Touzic. This visibility project will be phased over four years, in line with renewal and maintenance work.
