MHB Client - CPMS – Principal Contractor
Ultimate Client – Network Rail
On behalf of CPMS, MHB undertook Topo Surveys of 11 no. station footbridges to support structural and condition assessments. The drawings were delivered in 3D AutoCAD.dwg format.
The topo survey of the footbridges required a mix of working during daytime in normal high street conditions and at night under track possession (times when there are no train movements). The client CPMS arranged possession times with Network Rail and provided a schedule from which MHB could plan additional day shift visits to allow efficient completion of the onsite survey works. Tracks, platform edges, track furniture and sections of the footbridge not accessible form the platform were surveyed under possession. During normal operating train times when survey work was being carried out no equipment was placed within 1.25m of the platform edge in accordance with Network Rail PTS.
The key challenge of the footbridge surveys was the intricacies of the structure and the requirement of multiple total station set ups to capture all aspects of the bridge. The works were undertaken using a Trimble S8 High Precision 1” total station. Angular Accuracy is accurate to 1” (0.0003°) with electronic distance measurement accurate to ± 1mm + 1ppm in prism mode and ± 3mm +2ppm in direct reading (reflector-less) mode. This is above the minimum standards for total station accuracy as outlined in section 5.9 of Network Rail Document NR_L3_TRK_3101 which states a minimum angular accuracy of ±2” and EDM accuracy of ±2 mm + 2 ppm. All observations on rails were taken with prism on a rail foot adaptor to get the inside running line which is 14mm below the head of the rail.
Before commencement on each site a reconnaissance was carried out to plan the optimum total station locations. These were positioned in areas which allowed large sections of the survey to be completed to minimise total number of set ups required, and thus possible introduction of error. Lines of sight were taken into consideration as well as safety of location and ensuring not to block or hinder public access during station operational hours.
The total station was set up over a survey nail and levelled to gravity. The instrument was levelled using electronic bubble until 3” or below in both pitch and roll was indicated. The compensator was switched on in case of any minor vibration from passing trains etc. All required survey control was set in from the initial set up. A base line longer than the extents of the site was selected from which GPS coordinates were observed using Trimble R6 dual frequency GNSS receiver with choke ring antenna. The completed survey could then be transformed to OS National Grid coordinates in Trimble Business Centre post-processing software.
Levels were taken on inside running line of rail track, platform edge, platform extents footpath edges and centres. On roads, top and bottom of kerb lines were taken along with road centre to ascertain camber. Building footprints were observed with levels taken either side of door openings. Soffit and cill levels were taken by reflectorless measurement on buildings and underside of bridges. Stairs were taken at front edge of each riser with levels on centre of walkways and landings. Ample points were observed to show the position and orientation of all service covers and street furniture. On completion of each set up observations were made back to the reference object to ensure that no drift greater than ± 0.1m in 100.00m had occurred within instrument position.
A MHB method statement for topographical survey and risk assessment was carried out for all sites and a tool box talk was conducted by staff immediately before commencement on site. A COSS briefing was attended in addition for nightshift works to highlight any other activities which may be going on along the line and when to be clear of tracks.
As the survey was carried out to the specifications detailed in Network Rail document NR/L3/TRK/3101 Topographic, engineering, land and measured building surveying guidelines the 3D CAD drawing is compliant to BIM level 3.
We are really pleased to have Scott Kennedy here with us as our Summer student for 2018.
Scott has already completed 4 years at Strathclyde University studying Civil and Environmental Engineering. During his time at MHB Consultants he hopes to gain valuable industry insights and get some hands-on site experience, and even an occasional nightshift with our senior engineers! We are lucky to have a flexible working environment, so we can ensure that Scott gets involved across a wide variety of projects.
After his summer placement has finished, Scott plans to further his studies at Glasgow University, taking on a Masters degree in Civil Engineering or Sustainable Energy.
Photo – Scott (second from the right) pictured with fellow students during their Constructionarium project in 2015, a week long program involving planning and building a scaled down version of the Barcelona tower. Scott and the team took charge of setting out, health and safety, finance, scheduling and the actual construction of the tower.
MHB carried out the design of a series of temporary works to facilitate the removal and replacement of the existing bridge (UB 280/129) over Baberton Road in Edinburgh.
The temporary works included the analysis of the abutments when the existing deck had been removed, abutment saw cuts, abutment edge protection, crane outrigger foundation design, S&T cable support system and precast concrete unit lifting anchor checks.
We also carried out the design of temporary steel frames to ensure the stability of the proposed concrete cill units during transport on the Self Propelled Modular Transporter (SPMT) and a check of the stability of the existing deck when it has been removed on the SPMT. The job was successfully completed in June 2018.
Photos below taken onsite by AMCO.
As part of Network Rail’s 2017/18 programme to carry out repairs and refurbishment of existing structures, MHB Consultants Ltd. was appointed as designer by Taziker Industrial to undertake the engineering design of the works on UB 162/051 River Ayr Viaduct, which crosses River Ayr in Ayr town centre.
The works included undertaking condition surveys of the existing cast iron walkway and masonry before developing repairs to both. To assist in determining repairs for the walkway, MHB Consultants undertook 3D finite element analysis to determine extents of metalwork repairs, designed the replacement concrete deck units and assisted Taziker Industrial in developing a safe construction methodology to implement the repairs.
All works were carried out without the need for disruption to rail traffic.
Read more information about the project from Network Rail:
MHB Consultants were recently commissioned by ABLE UK to carry out the design of three culverts at their Marine Energy Park at Killinghome, South Humberside. The park will provide a port facility for the Renewable Energy Sector, particularly Offshore Wind and covers an area of around 900 acres and features over 1,300m of new deep-water quays. The culverts are necessary to convey two watercourses across the site as part of the overall development plan which involves upfilling the site with rockfill and installing various new access roadways.
The culverts comprise of precast reinforced concrete boxes of up to 4m span. Twin box culverts were used for the largest drainage channels. The structural design accommodates full railway and highway loadings as well as loads from self propelled modular transporters used to transport wind turbine components across the site.
MHB services included topographical surveys, site investigation design/ interpretation and full structural design of the culverts and wing walls. MHB are also responsible for preparation of railway design documentation and provision of Principal Designer Services.
Construction of the first culvert was recently been completed with some photographs of the structure below.
Photos courtesy of ABLE UK
The Edinburgh Glasgow Improvement Programme (EGIP) is a comprehensive package of improvements to Scotland's railway infrastructure. A Scottish Government priority, the EGIP is being delivered by Network Rail and includes modernisation and upgrades to key junctions and infrastructure as well as widespread electrification of the Scottish rail network, including the main line between Edinburgh and Glasgow and to Stirling and Dunblane.
As part of the Stirling/Dunblane/Alloa Electrification Works, Kerse Road over the Scottish Central Mainline is to be replaced. MHB have been involved in the temporary works designs to facilitate the removal of the existing bridge and the installation of the proposed bridge.
We have designed the following;
With more designs being carried out over the next few months as part of the on-going improvement project.
We were recently commissioned by George Leslie to carry out internal and external surveys of water towers in and around the Glasgow area. The towers are owned and operated by Scottish Water and located at;
The towers are circular reinforced concrete structures and a mix of visual, topographical and laser scanning surveys were carried out. The project is ongoing, however preliminary output from the laser scanning at Bearyard is shown below. The internal and external surfaces of the towers were scanned to provide a full 3D model of the structure and any defects noted. More to follow……..
Congratulations to Lucie Killen on her promotion from Graduate Engineer to Engineer.
Lucie started with MHB in April 2016 and in the last two years has grown her technical ability and commercial awareness. Lucie's duties broadly comprises of technical work on Civil and Geotechnical projects, and also undertaking topographical surveys and site visits.
She has managed her projects technically and financially and latterly developed good relationships with clients, who now come to her directly. Lucie has also managed the work of others including our summer placement students.
Well done Lucie!
We are delighted to announce that we have been shortlisted as a finalist for the 2018 Ground Engineering Awards in the " UK Project with a Geotechnical Value of up to £1M category". This is for our work on the Aberdeen Western Peripheral Route - Sheet Pile Retaining Wall for Bridge on A90 at Stonehaven.
Thanks to the teams at AWPR, Albion Drilling, LB Piling and Hewson for your contribution to a great job !
Full details of the job can be found here .
We are currently receiving graduate applications for bridges, civil and geotechnical engineering positions.
Please apply with CV and cover letter to firstname.lastname@example.org before 31/05/2018.