Trenchless Solutions Ltd, the Barnsley, UK-based trenchless installation contractor was recently subcontracted by main contractor Sirius Civil Engineering Ltd to complete the trenchless installation of an under-track crossing at South Drive, Hebburn, which lies about 7 mile east of Newcastle-upon-Tyne in Tyne & Wear in the northeast of England.
Property developer, Miller Homes Ltd was undertaking a substantially sized new build housing development project which as a consequence required the local sewerage system to be upgraded to allow for the increase in sewerage volume from the development. Since the housing development was adjacent to an existing railway line there was a requirement for a trenchless installation of a 650 mm diameter sewer pipeline to pass underneath
the railway tracks. The sewer would then be diverted some 250 metres down a public footpath into the existing sewer network adjacent to the River Tyne.
Sirius Civil Engineering Ltd was responsible for the design of the sewer route, with its ability to design and deliver efficient and cost effective solutions. Ground conditions for the crossing comprised stiff clay so it was decided that a Guided Auger Boring solution would provide the ability to install the 650 mm diameter GRP pipes to the required line, level and gradient. The route ran over some 38 linear meters with DA650 GRP Hobas Jacking Pipe being the pipe material of choice. Having been awarded the subcontract to complete the installation Trenchless Solutions Ltd selected its Perforator PBA85V auger boring machine along with a Perforator HS90 hydraulic Powerpack, Bentonite Pump and tank, and OEN navigation unit (which uses a camera system to ensure accuracy of the pilot bore installation of the multi-stage installation process). Trenchless Solutions Ltd operates what is believed to be the largest fleet of Perforator auger boring machines in the UK.
A view along the route alignment for the Hebburn under-track crossing
Ground investigation works were completed prior to work commencing both for the planning stage and practical contracting purposes. Bore logs completed were by other operators The project had been planned over the course of approximately 18 months due to the railway line being a live track, and the need to ensure public safety. Sirius was required to consult with Network Rail, Nexus, the track monitoring company Seprail Ltd, Miller Homes Ltd and Trenchless Solutions Ltd to ensure this project could be delivered within a narrow 72 hour access window starting at 4 pm on Friday 20 November, 2020, with a completion target of not later than 4 pm on Monday 23 November.
Round the clock working was requested by Sirius Civils in order to make the most of the time available for project completion. Trenchless Solutions arrived onsite the morning of Friday 20 November, set up site, started the installation works with the pilot bore at 4.30 pm. The whole process was completed by 8 am Sunday 22 Nov and the trenchless installation equipment was removed from the site first thing on the Monday morning. This meant the whole rail crossing project from arrival at site to completing demobilisation was achieved in just 40 working hours! No problems were encountered during the trenchless installation due to the very detailed advanced planning and meticulous investigative works undertaken. Furthermore, the construction of the works was planned so that residents would have access to the public footpath at all times over the period of the railway crossing operation. This was vital as the path is a very popular route for dog walkers and
cyclists. The local residents were kept informed of the project progress from the planning stage to completion and were quite polite and welcoming considering the operation was working through the night over a weekend!
Commenting on the project for main contractor Sirius Civils, a company director said: “I would like to take this opportunity to thank the whole team at Trenchless Solutions for their expert assistance throughout the protracted process of obtaining approvals and the planning of the works. Without this support we would not have been in a position to complete the works. www.trenchlessgroup.co.uk