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SUMO Utility Survey

Updated: Jan 31

SUMO Successfully Complete An As-Laid Services Contract On One Of Their Biggest And Most Complex Sites To Date.


SUMO recently completed a highly complex utility survey at an airfield in advance of a major restructuring project to redevelop the area as a world class training facility. The airfield was closed prior to the works, which included the site-wide upgrade of the existing utilities infrastructure across a 1,200-acre area within a tight 18-month programme.


Following the detailed utility survey, the final deliverables were presented on 117 sheets at a scale suitable for legibility of detail.


Detailed utility survey

As-laid contract


With respect to the upgrade of the existing utilities network, SUMO were commissioned to carry-out an as-laid survey of the newly installed services over an 18-month contract. The services comprised of HV and LV cables, Fire mains, Potable water mains and Gas mains. The total length of these services was approximately 27km.


In addition to the pipeline routes (Water, Gas & Fire), all associated fittings comprising of washouts, air and scour valves, stop vales, metres, hydrants, and pressure reducing valves, plus electric cables, transformers, feeder pillars and sub-stations were all detailed for inclusion in the final deliverables. To carry this out, SUMO’s surveyors visited the site on a weekly basis over the 18 months, to record the position of the installed services on a rolling program.


With up to 12 working crews installing services across the site at any one time, this created a significant logistical challenge to not only locate the working crews and record their latest works, but also the access to and parking of vehicles on site was severely restricted for security reasons, making the task even more difficult.


To deal with these complications, a GPS Rover unit was used to accurately record the as-laid services. This equipment uses the Trimble VRS solution for corrections referenced to the Ordnance Survey Grid, meaning that the GPS could be used anywhere on the site, with the added advantage of being easily portable and carried by the surveyors, walking the many kilometres required on each visit.


A huge number of photographs were also taken as a visible record of the site, to assist in piecing together the jigsaw puzzle of pipes and cables.




Due to the number of site photographs taken, this also necessitated creating a digital database. Using the CAD model, camera icons were then inserted in the actual positions that the photographs were taken and the camera icons included a photo reference number, date of capture and a hyperlink which accessed the photograph when clicked.


SUMO Utility Survey images

Deliverables:


The end user client stipulated that the minimum number of drawing sheets absolutely necessary for ease of reference and practical use on site were required. In addition, individual drawing sets were needed of each of the 4 utilities: fire mains, water mains, potable water mains and electric cable routes. Accordingly, in order to meet this requirement, a compromise had to be reached with relation to the scale of detail.


It was therefore decided that 7 sheets of A0 drawing sheets at a scale of 1:500 would be created for each of the utility sets to cover the site.


Digital data model

The compromise reached was to create a ‘hybrid’ of accurate digital data (model) and schematics, where the representation of fittings such as valves etc., would not be to scale, but shown at a size and relative positon only, for ease of visualisation. Accurate details, when required, could then be interrogated from the digital model.


Example of Potable water schematic

Above: Example of Potable water schematic with valve identifiers (similar for Fire and Gas) and symbols (right).


Symbols were then created as blocks to represent the fittings as a simple visual reference and for ease of insertion into the drawings. Similar blocks were created for Fire main and Gas main drawings.


Electric Cable routes (HV & LV)


Although there was an attempt to survey the individual electric cables within the defined routes (trenches), this could not always be achieved due to the large number of cables in certain areas, crossing over, partially buried or too bunched together. However, in consultation with the senior electrical engineer, we were able to identify the routes of individual cables from the transformers / feeder pillars to the supply side where they entered the buildings and these were shown as schematic layouts.


Example distribution of cables

Above: Example distribution of cables from sub-station and enlargement of sub-station showing individual cable routes, ring main unit (RMU), transformers (TX1), feeder pillars (FP) and earth rods.


The same approach was then applied to the gas mains.


Example extract schematic showing gas pipes

Above: (Left) Example extract schematic showing gas pipes, pipe sizes, valves. (Right) Gas pipes installation.


Through constant communication and collaboration with the client, plus SUMO’s flexibility in organising multiple survey teams working throughout the base, as and when needed, the project was undertaken within the necessary deadlines. Furthermore, the ability to send data back to our Central CAD office electronically, enabled SUMO to provide preliminary results within hours of each site visit, meaning that the client could have a timely overview of the contractor’s ongoing progress over the entire site and identify any problem areas at an early stage.

The enormity of the site meant that the sheer volume of deliverables would normally be unworkable in this type of dynamic environment, however regular consultation with the client allowed us to devise and provide a practical solution. As a result, we were able to provide unique working drawings at a suitable scale which tied in with a bespoke digital model with supporting photographic evidence, thereby enabling the client and their contractors to complete the project on time and with minimal disruption. All in all, it was a complex and at times stressful project, but one in which everyone was delighted and proud of the end result.


 

So, no matter how big (or small) your project, why not give SUMO the opportunity to find the solution that best meets your needs?


Contact us now on 0845 456 1104…

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