Arriva Rail North’s modernisation is gathering speed, with over £500 million being spent on 98 new state-of-the-art trains, the first due to be in service at the end of the year. They will be capable of travelling at 100mph, will have Wi-Fi, plug sockets at every seat, be air-conditioned and fully accessible.

The modernisation plans also include providing more than 2,000 additional weekly services by 2020 with faster connections, better stations and improved customer service.

To support this investment, Arriva Rail North is developing Newton Heath TMD (traction maintenance depot) in Manchester to include a new maintenance facility and a wheel lathe installation. Arriva will use Newton Heath to house and maintain its 55 new Class 195 trains that are being built in Spain by CAF, as reported in issue 162 (April 2018).

Arriva has recently awarded the design and build principal contract to Stobart Rail & Civils, a division of Stobart Group and a business that understands logistics and customer service. The Group owns and operates airports, an airline and a railway station, its Energy division is the largest biomass supplier in the UK and it provides national emergency logistics support for major clients including EDF Energy and the Environment Agency. Its heritage features the UK’s best-known road haulier, Eddie Stobart Logistics.

With this background, it’s only natural that the company’s core engineering capability should capitalise on a wealth of expertise to deliver challenging transport infrastructure projects using a client-focused approach that embeds operational priorities throughout its delivery solutions.

Managing director Kirk Taylor outlined the approach that led to Stobart’s successful bid: “This project is ideally suited to our capabilities and we knew we could offer something special for Arriva. With our rail and civil engineering experience, backed up by our operational knowledge of rail depots, we inherently understand the pressures and constraints that Arriva face every day, and this let us develop a great solution.”

Challenging construction

To accommodate the new trains, Stobart Rail & Civils will provide a steel portal framed building that’s approximately 135 metres x 24 metres on plan and includes four maintenance roads, alongside a 113 metre long and six metre wide side annexe to house stores, offices, toilets and kitchen facilities for the depot team.

A vehicle lifting road will fit up to a four-car unit, and a floor designed with jacking points for sixteen 15-tonne synchronised lifting jacks.

Two examination and maintenance roads will have swimming-pool-style inspection pits – large concrete-lined pits with access steps at the end of the track crossing it on stilts – and fixed roof-level access platforms that will enable the safe and effective maintenance of roof mounted HVAC units, helped by two 10-tonne overhead cranes.

With two roads mounted above pits and two on steel plinths, the concrete base of the shed includes some complex formwork and construction sequencing to deliver the varying finished floor levels. During design development, an optimised solution was formulated to use thickened ground beams that will also act as permanent earthworks support during reduced-level excavations. This will minimise any temporary support requirements and provide a robust foundation of edge protection for the site team.

Integrated solution

Externally, Stobart’s in-house track capability will come into play during construction of the new sidings layout which will serve the maintenance shed and connect to the existing rail network.

This provides an ideal opportunity to deploy the company’s specialist road-rail fleet, which includes laser dozers to grade the bottom ballast, Colmar heavy lifters to position the S&C components and the unique Jack & Tamper unit (issue 160, February 2018) to deliver a perfect track alignment.

This latest piece of kit was developed after a gap in the market for a small format fully remote-controlled S&C and plain-line tamping machine was identified. It provides high quality track alignment during small renewals, re-ballasting or maintenance activities and removes the need to jack and pack the track using manual labour, reducing risk and the chance of manual fatigue, and saving time and cost.

For maximum flexibility, the Jack & Tamper unit was designed for road delivery and lifting onto track either by RRV or a small mobile crane, then either towed to the worksite using an RRV or operating entirely under its own power. Twin Kinghoffer four-tool tamping banks allow independent lateral movement around the many obstructions encountered within S&C, making it ideal for completing the tamping work in the new sidings at Newton Heath.

Finishing off

To complete the external work, Stobart Rail & Civils will construct a road-rail transfer point and a new site access route that includes a widened and upgraded connection to the public highway. This route will also provide a link to Network Rail’s nearby track-access point and the depot’s fuel stores – both of which will remain open and unobstructed throughout the construction programme.

A new surface water drainage system will include attenuation situated beneath the new access road – just one of the design’s numerous features that contributes towards the building qualifying for a BREEAM Good rating.

The right team

To deliver this project, Stobart Rail & Civils has assembled a team including Craddys, which is providing civils and structural design, Border Steelwork Structures (building superstructure) and Novus Rail for the track design.

Kirk Taylor commented: “Between them, this team has contributed to major projects in the past including roof strengthening at St Pancras Station, Bombardier’s V-Shop that manufactures trains for Crossrail, and TfL’s New Cross Gate Depot in London. I believe that, with this expertise and the way that our team has integrated with Arriva’s team to develop a solution which guarantees unhindered depot operations throughout the delivery phase, we have given this exciting project the best possible start.”

Wheel lathe

Separate from the maintenance building, Stobart Rail & Civils is also converting the depot’s redundant paint shed to create a new wheel lathe facility. This will re-use a double-headed wheel lathe that is being refurbished and relocated from Old Oak Common Depot by Richardson Machine Tool Services.

To receive the wheel lathe, the paint shed requires some major modification, not least forming the three-metre-deep pit that it will eventually sit inside. Excavating this pit within the confines of the existing shed poses a major challenge that is further complicated by the high water table found on the site.

Stobart’s innovative solution to this challenge uses secant piles to form a contiguous wall to a depth well below the pit’s formation level. As well as preventing water ingress during the pit’s construction, this removes the need for separate temporary earthwork support using sheet piles.

This is particularly welcome because the limited roof height within the shed won’t allow use of a piling rig of sufficient size to install full length sheet piles, meaning that shorter piles would need to be used and welded together sequentially as they are driven into place, greatly increasing cost and the programme duration.

The wheel lathe will be complemented by new electrical supplies, a swarf removal conveyor system, a jib crane and, to ensure a perfect interface between the trains and the wheel lathe, the alignment of the existing siding will be altered – which will also neccessitate modifications to the shed’s gable ends to ensure adequate clearance for the trains.

Collaboration

Within a depot environment, the major challenge is invariably delivering the works programme alongside normal depot operations without causing disruption that might affect vital maintenance work. At Newton Heath, this is a particular challenge owing to the extensive earthworks that are needed for the new shed – with 30,000 tonnes of spoil to remove before more than five hundred piles can be installed.

Additionally, the works for the wheel lathe take place in an existing building at the very centre of the depot. The solution here is to use the siding that will eventually connect to the wheel lathe for road-rail plant carrying materials and spoil between the workface and a remote staging point far away from daily activity. Only then is minor modification needed to a depot walking-route to enable Stobart Rail & Civils to totally segregate its site.

Kirk Taylor further commented: “Ensuring depot operations continue unhindered throughout the works is a key project objective. We regularly work within a rail depot environment and we own and operate logistics sites throughout the UK that include a rail interface, so we understand how important it is to minimise disruption. Working together with the depot team we have planned our works to ensure full segregation of our activities from depot operations, and our daily coordination meetings will ensure that all stakeholders stay fully informed of upcoming works.”

Diverse capability

This project is another in an impressive portfolio of civil engineering and construction solutions that enhance the UK’s infrastructure. Previous projects include road and rail freight depots for some of the country’s most prominent businesses as well as developing Stobart’s own airports at London Southend and Carlisle Lake District, where runway construction and the new terminal building for the latter were completed in June 2018 for the first commercial flights since 1993.

With the site works at Newton Heath planned for commencement in July, Stobart Rail & Civils is busy concluding the design development phase and finalising the delivery plans.