Runcorn East Cutting - Halton

The Scope

Runcorn East Cutting is formed of a mixture of soil and weak heavily weathered rock cuttings, it runs from Runcorn East Station to Halton Tunnel [ Sutton ] tunnel. The height varies from 20 metres at the tunnel portal to 8 metres towards the station. Occasional creep and seepage lines are present with small blocks in the cess.

A re-signalling scheme was programmed to commence on site in September 2020. The condition of the geotechnical assets could adversely affect the installation and long-term maintenance of the assets and the location required rectification prior to this. The site works were undertaken immediately following the re-signalling works undertaken by Story & Volker Rail.

The Challenge

As a specialist Tier 2 supplier to the railway the company was awarded the contract by the Tier 1 Principal Contractor Murphy to undertake the slope stabilisation of Runcorn Cutting at Halton Tunnel in Cheshire.

In order that the works could be undertaken the access to the Upside & Downside site crests through forest managed by the Woodland Trust. Great care had to be taken to develop and deliver a joint strategy with Murphy to allow plant, equipment, materials & personnel to access and operate safely on both sides of the cutting whilst ensuring the woods were protected.

Collaborative working between all the parties was essential on this project as the design had to evolve as the site clearance works revealed the true extent of the issues that affected the long-term stability of the cutting. The efficient use of the limited blockades was a key part of the planning process and involved significant management by Vertical Access to ensure a successful outcome.

The works required:

• Engagement and management of VA sub-contractor Gunform for the application of spray concrete

• Supply and operation of Road Rail Vehicles including RRV MEWP’s by VA sub-contractor Pod Trak  

• Clearance of 6,500m2 of cutting face vegetation, the majority of which occurred on possessions and blockades in conjunction with Podtrak RRV’s and trailers.

• Felling of substantial trees including on the crest that required climbing and sectional dismantling during blockades & possessions

• Identification of sandstone overhangs that required spray concrete dentitions or heavy scaling

• Installation of 111 base grouted anchors installed using RRV mounted drill rigs

• Installation of 109 top grouted anchors using excavator mounted drill rigs

• Installation of 135 profile resin anchors using RRV mounted drill rigs or handheld rock drills

• Installation of dentition resin anchors and weldmesh in preparation for spraycrete application

• Application of spray concrete by Gunform Ltd to dentitions using RRV MEWP’s

• Installation of 7300m2 of Maccaferri rockfall netting working behind magnetic safety fencing to separate the work area from the railway  

• Replacement of palisade & wooden boundary fences

‍

The Vertical Approach: Safety, Quality, Innovation & Agility

Safety

The works were delivered without any incidents or accidents due to the constant focus by both Murphy & Vertical Access and their sub-contractors on working together in a planned and structured manner that was at the centre of the culture that the Principal Contractor & Employer had set out as their vision for site works operation.

The project personnel also had to work in conformity with Covid Regulations as the pandemic was at its height and controls were strictly observed and carefully monitored by third party checks.    

Quality

The Inspection & Test Plan for the project set out the quality requirements for each section of work and ensured that objective criteria would be used to confirm delivery to the required NR standards.

Innovation

The project could have significantly affected the safe operation of the railway without the temporary works design and installation of a rock anchor & Maccaferri mesh catch fence. This allowed the majority of the meshing works to be undertaken during normal hours and freed up time in the rail blockades and possessions for the heavy scaling anchor, dowel drilling and spraycreting.    

Agility

To plan the blockades & possessions with multiple contractors’ operations and RRV’s & an RRV MEWP was an opportunity for Vertical Access to demonstrate our capacity to schedule and deliver this type of complex planning.

The company developed Contract Trackers which could be easily updated to show progress to milestones and practical completion, this worked alongside detailed shift plans to successfully to allow prediction of progress in the blockades and the required planning for the following week.

‍

Outcome & Feedback:

A very successful contract the works commenced in late November 2021 in preparation for the main delivery on 4no. 29 hour blockades in January 2022, completion occurred in late April 2022.

‍