Britain’s railways have always inspired great innovation from engineers; whether the numerous firsts in structures designs, the world’s first steam-powered passenger railway or even the first-ever commercial maglev system.
Although bridges, viaducts and locomotives perhaps provide the most visible examples, this innovation also plays a vital role in maintaining and enhancing our railways too – helping to deliver safety and efficiency while providing value for money against ever more challenging budgetary constraints.
At any engineering planning meeting today, there is often enthusiastic talk about remote condition monitoring, aerial surveys, new track materials, exciting ways of improving structural integrity, enhanced coastal and flood defences, in-cab signalling, ‘smart’ personal protective equipment, and a host of other innovative ideas that were barely dreamt of just a few years ago.
Enthused by reports of great things happening in Carlisle, a senior team from Network Rail London North Eastern (LNE) recently visited Stobart Rail & Civils to see a few of its new developments. They were welcomed by Stobart Rail & Civils’ plant maintenance and innovation manager Richard Errington, who hosted the day and provided a fascinating insight into the latest innovations.
Stobart Rail & Civils first encountered ballast undercutters as far back as 2006, when an opportunity arose to acquire an existing machine. Stobart soon put this to work on a range of sites and, while it did a decent job, Stobart’s engineers and site teams quickly identified numerous potential improvements.
After several visits to Stobart’s workshop, and with a wealth of learning gathered on many projects, it was clear that there was still further room for improvement in both performance and reliability, but realistically Stobart’s engineers were facing a ‘Trigger’s broom’ situation, where the desired changes would have left little remaining of the original plant.
Inspired by the potential performance enhancements, Stobart committed the investment for a complete re-build to a much higher specification – and what became known as the MK1 ballast undercutter was born. This included major improvements to its hydraulic performance and changes to the digging wheel design based on feedback gleaned from the site teams. Major safety enhancements were also incorporated to protect workers from the undercutter’s many moving parts.
These upgrades had an immediate impact, with both productivity and quality of work greatly improved. The revised machine now offered real potential for a new cost-effective solution to carrying out track re-ballasting, track lowering, wet-beds removal, and S&C refurbishment.
To support the growing workload, and to incorporate the lessons learned from many successful deployments of the MK1 machine, Stobart decided to press ahead with development of a second generation ballast undercutter – inevitably soon to be labelled MK2.
This iteration included improved hydraulic design to deliver a more powerful performance, a new conveyor design, a modern air-conditioned cab, and a driver console that could be operated from the comfort of the cab seating. The new design also included additional safety devices including split screen cameras that provide the operator with all around visibility.
To provide operational resilience, Stobart developed a comprehensive support infrastructure, including an on-site maintenance cabin stocked with critical spares and hydraulic hose-making facilities. Together with the engineering improvements inherent in the machine, this has significantly reduced downtime and increased the production rates and reliability figures. According to Network Rail’s Rail Plant Performance System (RailPPS), in 2017 the MK2 Ballast Undercutter achieved an impressive reliability figure of 99.57 per cent, up from the MK1’s 2014 reliability figure of 86.7 per cent.
Never standing still, Stobart’s engineers soon saw opportunities to further refine the capability of the undercutter and this has led to the development of 2017’s new MK3 version.
This incorporates a rubber-tracked undercarriage to increase the machine’s on and off-tracking capabilities – it can now move under its own power from a lineside position and onto the track using only a temporary RRAP, rather than previously needing a mobile crane lift. It also has both front and rear tilting axles, which allow the cross-fall of the cutter bar to be set from the safety of the cab. The machine can also be connected to TMDs (track measuring devices), if required, to provide valuable engineering assurance data.
Stobart Rail & Civils’ bespoke integrated operating system, with a 12-inch touchscreen in the cab, is connected to head office using a GPS/GSM modem with CAN (Controller Area Network) interface. This provides a continuous live data feed of the machine’s operating parameters, from pre-start checks through to completion of operations, to allow the engineering team to access the system remotely for performance monitoring and to aid in diagnostics.
This approach has proved so valuable in predictive monitoring to support maintenance regimes that the operating system is now fitted to all RRVs when the machine is upgraded through Stobart’s plant engineering workshops.
Adjacent line open system
When plant is required to work on one track of a two-track railway, while the other track remains open for traffic, it is essential that nothing – no parts of the machine and no trackside operatives – are ever in a position to come in contact with an adjacent train. This is known as working Adjacent Line Open (ALO).
To accomplish this, Stobart Rail & Civils developed an ALO system that uses 3D cameras and illumination units to measure and continually plot position in relation to the track. Visual and audible warnings are then triggered whenever an object – person, plant, equipment, or anything else on the worksite – approaches the predefined limits. This is linked to all plant items’ operating systems so that, as the limit is reached, the machines’ movements are automatically ceased, making it impossible for any part of the plant to leave the safe zone.
Full data logs are recorded and can be used to support training and mentoring sessions.
During the development of this system, another innovative application became apparent. When working within a possession, using road-rail vehicles or on-track machines alongside track personnel, it is vital that the two are effectively segregated. By setting up the ALO system and programming it to recognise workers’ high-visibility clothing, it is possible to continuously monitor distances between every plant item and worker on site. If a worker is detected within the exclusion zone, the system’s connection to the plant item’s RCI (rated capacity indicator) instructs the motion-cut solenoids to instantly stop the machine and protect the worker.
This system will deliver a step-change in safety whenever there is an interface between plant and personnel. Stobart Rail & Civils is progressing towards approval of this system so that it can soon be deployed on worksites.
Stobart’s vacuum machine is an RRV attachment designed to clean all areas of tunnel linings that are contaminated with soot build-up.
This provides a valuable solution that exposes long-hidden brickwork for inspection, for preparation before brickwork repairs or for any other work such as the installation of overhead electrification. It removes potentially harmful contaminants before personnel enter the worksite, and ensures that engineers are able to inspect structural elements properly in order to determine best construction solutions, minimising the risk of later delays or abortive works through incomplete information.
The unit has an inbuilt tilt and rotation system, allowing placement of the unit at any angle to sweep tunnel walls and roof areas, and also to clean vertical walls and station platforms. It is entirely self-contained and incorporates an industrial vacuum so that all soot is collected for safe disposal in accordance with Environment Agency guidelines, ensuring nothing is left behind to contaminate ballast.
The unit can also be fitted with a variety of brushes to suit various applications such as graffiti removal and platform cleaning.
Jack & Tamper
Stobart Rail & Civils identified a gap in the market for a small-format fully remote-controlled S&C and plain-line tamping machine.
In collaboration with GOS Engineering, Stobart developed the Jack & Tamper Unit. This 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.
The lift frame is fitted with clamps to lift and slew the track – up to 300mm lift and 100mm slew – and is fitted with compaction feet, which aid compaction between the sleepers. Twin Kinghoffer four-tool tamping banks allow independent lateral movement for complete flexibility around the many obstructions encountered within S&C and plain line sites.
The machine is compliant in accordance with Rail Industry Standard for Engineering Acceptance of On-Track Plant and Associated Equipment RIS-1530-PLT.
The next development is to incorporate direct communication with TMDs, so it can be used for auto alignment.
The Network Rail LNE team certainly saw some interesting innovations during an enlightening visit to Stobart Rail & Civil’s Carlisle facility. All these solutions were developed to approach challenges in maintaining and enhancing the railway and are sure to prove essential tools for years to come.
Steve Pinkney, LNE & EM Route programme manager North, commented: “Stobart Rail & Civils clearly recognise the importance of investing in its people and machinery to drive excellence in maintaining and enhancing our railways. The innovation we have seen today is exactly what we need when facing the challenges within the growing rail industry. Keep up the good work.”
The only question left on everyone’s mind was – what comes next?
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