Colas Rail
Colas Rail is a railway infrastructure and rail freight company owned through Colas Group by Bouygues.
Last updated August 27, 2026
Overview
Colas Rail is a railway engineering, infrastructure and freight-transport business operating under the Colas Group, which is controlled by the French construction and industrial conglomerate Bouygues. The company developed from Seco Rail, a railway engineering business established by SECO (Société d'Études et de Construction d'Outillage). Its historical activities included the construction and maintenance of railway lines, track renewal, electrification, railway systems and urban-transport infrastructure. The business expanded significantly in the United Kingdom. Before adopting the Colas Rail name, Seco Rail participated in the first phase of High Speed 1, supplying and installing substantial sections of track, overhead electrification and related railway systems. In 2006 it entered the British rail freight market, initially moving aggregates with leased rolling stock. Its first regular freight contract followed in 2007, when it took over timber services for Kronospan between Carlisle and Chirk. The company also acquired locomotives and began operating railhead-treatment trains for Network Rail. A major organizational change took place in 2008. After Colas Group acquired Carillion Rail's plant division and had also acquired AMEC-Spie's relevant rail activities, Seco Rail and the acquired operations were combined under the Colas Rail brand. The enlarged company possessed a large fleet of on-track plant and broadened its capabilities in track construction, maintenance, renewal and rail systems. In Britain it subsequently expanded into steel, coal, timber and infrastructure-train traffic, acquiring or leasing locomotives including Classes 47, 56, 60, 66, 70 and 37 at different stages of its development. Colas Rail's business is not limited to freight operations. Its infrastructure work covers railway construction, maintenance, renewal, electrification, signaling-related systems, depot and station works, and specialized on-track plant. The company has participated in major projects in France, the United Kingdom and overseas markets. In Morocco, it acted as the primary infrastructure contractor for the Al Boraq high-speed railway project. In France, it was involved in the Contournement Nîmes–Montpellier high-speed line. In Britain, its projects included improvement work at London Waterloo, enhancements to the West Midlands Metro and substantial contracting activity for Network Rail. The company also explored adjacent transport opportunities. In 2013, Colas Rail formed a joint venture with Go-Ahead Group to bid for the Docklands Light Railway operating concession; the bid was later withdrawn. Its British rolling-stock maintenance business, Pullman Rail, was sold to Transport for Wales in 2021. Colas Rail nevertheless continued to operate as a rail infrastructure contractor and freight operator, including a 2022 timber-haulage trial between Devon and Monmouthshire. Colas Rail is positioned primarily as a technical railway infrastructure partner rather than as a passenger-facing consumer brand. Its activities combine civil and railway engineering, specialist plant, maintenance capability and freight operations. The company has advocated for improved long-term capacity planning for rail freight in the United Kingdom and has expressed interest in major infrastructure programs such as High Speed 2.
History
Colas Rail traces its origins to Seco Rail, which was founded by the French railway engineering company SECO. During the twentieth century, the business concentrated mainly on railway construction, track maintenance and urban-transport work. Its expertise was later incorporated into the wider Colas Group after SECO was acquired by Colas in 2000. Although its historical base was in France, the business also developed operations in the United Kingdom and Belgium. In Britain, one of the early significant assignments was participation in the first phase of High Speed 1. The company supplied and installed track, overhead electrification and associated systems across a substantial section of the project. This work established the business as a railway infrastructure contractor in the British market before it became a freight operator. Seco Rail entered rail freight operations in 2006, initially moving aggregates with hired locomotives and other rolling stock. In 2007 it took responsibility for Kronospan timber trains between Carlisle and Chirk, its first regular freight contract. It also acquired three Class 47 locomotives from EWS, which were overhauled for Network Rail railhead-treatment duties. The business subsequently added steel, coal and further timber traffic, while developing a larger owned and leased locomotive fleet. Colas Group expanded the British rail operation in January 2008 by acquiring Carillion Rail's plant division. The acquired assets included tampers, regulators, a locomotive, a Kirow crane, switch-handling units and the Mill Lane Plant Depot in Rugby. Colas then combined Seco Rail with the acquired Carillion Rail plant activities and AMEC-Spie's rail subsidiary. The resulting organization operated as Colas Rail and had substantially broader infrastructure and plant capabilities. During the late 2000s and 2010s, Colas Rail diversified its British freight portfolio. It began steel services in 2008 and 2009, added coal haulage from 2011, and introduced another Kronospan timber service in 2011. Its fleet included Classes 47, 56, 60, 66, 70 and 37, acquired or leased at different times for freight, infrastructure and maintenance work. The company also bought Pullman Rail, a Cardiff-based rolling-stock maintenance business, in 2012. In 2013 it ordered ten Class 70 locomotives from GE Transportation and purchased additional Class 37 locomotives for main-line use. It later acquired ten Class 60 locomotives from DB Schenker, although these were sold to GB Railfreight in 2018; its Class 47 locomotives were sold to the same operator in 2017. Colas Rail also pursued passenger-transport and international infrastructure opportunities. In 2013 it formed a joint venture with Go-Ahead Group to bid for the Docklands Light Railway operating concession, but the bid was withdrawn. Internationally, it acted as the primary infrastructure contractor for Morocco's Al Boraq high-speed line. In France it participated in construction of the Contournement Nîmes–Montpellier high-speed line. In the United Kingdom it worked on London Waterloo improvements, the West Midlands Metro and Network Rail infrastructure programs. By late 2016 it was among Network Rail's five largest contractors and employed approximately 1,500 people in the United Kingdom, according to the cited reference material. The company continued to advocate for rail freight development, including clearer guarantees for future freight paths. In 2021 it sold Pullman Rail to Transport for Wales. In 2022 it tested a timber service for Euroforest between Devon and Monmouthshire. Colas Rail remains an active infrastructure and freight business within the Colas Group and Bouygues group, with operations centered on railway construction, maintenance, specialist plant, electrification and freight services.
- 2022Timber-haulage trial
Colas Rail conducted a trial timber service between Devon and Monmouthshire for Euroforest.
- 2021Pullman Rail divestment
The Pullman Rail engineering operation was sold to Transport for Wales.
- 2018Class 60 fleet disposal
Colas Rail sold all ten of its Class 60 locomotives to GB Railfreight.
- 2017Class 47 fleet disposal
Colas Rail sold its three Class 47 locomotives to GB Railfreight.
- 2016Major Network Rail contractor
By late 2016, Colas Rail was described as one of Network Rail's five largest contractors and had approximately 1,500 UK employees.
- 2013Class 70 locomotive order
Colas Rail ordered ten Class 70 diesel locomotives from GE Transportation and separately acquired preserved Class 37 locomotives for main-line operations.
- 2012Pullman Rail acquisition
Colas Rail acquired Pullman Rail, a rolling-stock maintenance business based in Cardiff.
- 2011Expansion into coal haulage
Colas Rail entered the British coal-haulage market while continuing to expand its timber, steel and infrastructure freight work.
- 2008Formation of Colas Rail
Seco Rail, AMEC-Spie's rail activities and Carillion Rail's former plant division were reorganized under the Colas Rail name.
- 2007First regular freight contract
The company took over Kronospan timber trains between Carlisle and Chirk and acquired its first locomotives for British operations.
- 2006Entry into British rail freight
Seco Rail began operating rail freight services in the United Kingdom, initially transporting aggregates using leased rolling stock.
- 2000SECO is acquired by Colas
Colas Group acquired SECO, bringing the railway engineering activities that formed the basis of Seco Rail into the Colas organization.
Products and positioning
A technically focused railway infrastructure and freight specialist combining construction, maintenance, electrification, on-track plant and rail logistics capabilities within the Colas and Bouygues groups.
Railway infrastructure constructionRail infrastructure
Colas Rail delivers construction and renewal work for conventional, high-speed and urban railway systems. Its scope can include track installation, line construction, electrification and associated railway systems. The company has participated in major projects such as High Speed 1 in the United Kingdom, the Al Boraq high-speed line in Morocco and the Contournement Nîmes–Montpellier line in France.
Track maintenance and on-track plantRail maintenance
The company operates specialist railway plant used for maintenance, renewal and infrastructure delivery. Its British assets have included tampers, regulators, cranes, switch-handling equipment and locomotives. This capability supports work for infrastructure owners and contractors, including Network Rail.
Rail freight servicesRail freight2006
Colas Rail operates or has operated freight services for industrial customers and logistics partners. British traffic has included aggregates, timber, steel and coal. Its fleet strategy has combined owned and leased diesel and electric locomotives, with different locomotive classes assigned to freight and infrastructure duties over time.
Rolling-stock maintenanceRail engineering2012
Through Pullman Rail, Colas Rail operated a rolling-stock engineering and maintenance business based in Cardiff. The operation was sold to Transport for Wales in 2021, so it is no longer presented as a current Colas Rail business line.
Urban and metro rail systemsUrban rail infrastructure
Colas Rail participates in urban and metro railway infrastructure projects, including work associated with the West Midlands Metro and other urban-transport systems. Its capabilities are focused on infrastructure delivery and engineering rather than consumer-facing passenger services.
Flagship businesses
- Rail infrastructure delivery for high-speed, conventional and urban railways
- Network Rail maintenance and infrastructure-train services
- Bulk and industrial freight haulage, including aggregates, timber, steel and coal
- Specialist on-track plant operations
Brand decisions
- 2021Sell Pullman Rail to Transport for WalesM&A
Pullman Rail was Colas Rail's rolling-stock engineering and maintenance operation in Cardiff.
What changed. Colas announced the sale of Pullman Rail to Transport for Wales.
Aftermath. The divestment removed Pullman Rail from Colas Rail's portfolio while transferring the operation to a government-owned not-for-profit organization.
- 2018Advocate for protected rail freight capacityStrategy
Colas Rail argued that uncertainty over future freight paths could discourage investment in new rail freight services, including potential parcel traffic.
What changed. The company publicly called on Network Rail to provide greater certainty about future freight capacity and paths.
Aftermath. The position highlighted the company's interest in expanding rail freight and in securing predictable access to the national rail network.
- 2013Withdraw from the Docklands Light Railway concession bidOther
Colas Rail and Go-Ahead Group formed a joint venture and were shortlisted in the competition to operate the Docklands Light Railway.
What changed. The joint venture withdrew its bid in August 2013.
Aftermath. Colas Rail did not become the Docklands Light Railway concession operator.
- 2008Combine rail activities under the Colas Rail brandStrategy
Colas Group had acquired or assembled several railway and plant businesses, including Seco Rail, AMEC-Spie's rail activities and Carillion Rail's former plant division.
What changed. The businesses were reorganized into a single rail organization operating under the Colas Rail name.
Aftermath. The combination created a broader railway contractor with a larger on-track plant fleet and capabilities spanning infrastructure, maintenance and freight.
Recent events
- 2022Colas Rail conducts Devon–Monmouthshire timber trial
The company operated a trial timber service for Euroforest between Devon and Monmouthshire.
Product launchOther - 2021Pullman Rail sold to Transport for Wales
Colas announced the sale of its Pullman Rail engineering operation to Transport for Wales, a government-owned not-for-profit organization.
M&A - 2018Colas Rail calls for greater certainty over British freight capacity
The company argued that Network Rail should provide greater certainty on future freight paths, saying uncertainty could discourage investment in new services such as rail-based parcel traffic.
RegulationOther - 2008Colas combines rail subsidiaries under the Colas Rail brand
Colas Group reorganized Seco Rail, AMEC-Spie's rail activities and Carillion Rail's former plant division into the Colas Rail business.
M&ALeadership change - 2006Seco Rail enters the United Kingdom rail freight market
Seco Rail began operating as a British rail freight operator, initially transporting aggregates with leased rolling stock.
Other
Sources
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