CD Surveys were instructed to carry out a topographical survey of a large site in West Sussex. The site was around 370 acres in total and consisted of around 2km of roads surrounding the site, approximately 250 acres of farming fields with the remaining balance of areas used as offices, warehousing, Treatment plants etc.
The deadline given for the work was quite tight so it would involve multiply crews working simultaneously across the site. The first action to be taken on site was to set out a control network around the site. The site was surrounded on three sides by roads and down the southern boundary was formed with crop fields. A network of permanent control stations were put in around the road creating three sides of the traverse loop. To ‘brace’ the loop we put in three sets of earth anchors through the crop fields – making sure that these were positioned clear of where the farming machinery would work to ensure no damage would result. Once the loop was formed we then placed a further six control stations through the site forming further braces across the internal part of the site.
Once the control network had been processed and the accuracies within the acceptable tolerances for this type of work and plot scale we then used these stations to start our survey work and observe and collect the details and levels
During the first week we split the site into different areas for our surveyors to work within. We had two surveyors completing the road, one surveyor working around the boundary in the southern section and the fourth and final surveyor was working in the built-up area. Luckily the site was naturally split into sections so it was quite simple to hand over the areas to each surveyor to ensure sufficient checks were applied but not the duplication of information. It was also convenient that the crops were not fully grown by the time we started our surveys
In the next few weeks each area was swiftly being completed
with the added fifth surveyor working his way through the farming fields. Around 4 weeks the site was nearing
completion but we still needed to piece the separate job files together and
ensure all of the boundaries between the areas were surveyed, ie. no holes,
overlapping detail or gaps in the information.
Piecing the surveys together proved an easy task due to the extensive
control network that was put in prior to the survey work. With the site linked together and processed
into AutoCAD we could visually see how much of the site had been surveyed and
if there were any areas that overlapped or areas that did not quite meet. It was obvious that three areas we had been
instructed to get as much detail as possible had proved difficult for the
surveyors to obtain data in – mainly due to the 3 meter high security fence
around each of these areas.
The next stage of our site survey was to fly the site with
our in-house Drone. This would provide
an accurate, highly detailed aerial photo of the complete site. This will enable us to verify the surfaces,
roof details on buildings and more importantly accurately enable us to provide
4 dimensional tree spreads to the lone trees scattered about the site. This also proved highly effective in enabling
us to draw in the buildings and surface detail for the ‘No or restricted Access’
areas which was an added bonus for our client. The client did ask for as much
detail as possible in these areas.
The last part of the site work was to complete a site verification to ensure all data had been collected and to survey in any areas needing a little more detail. This finished the job off within our desired deadline and gave the office staff the required detail to enable them to draw the survey and provide the client with the final drawings.
All in all, it was a large task for CD Surveys to complete
the work as the job came to us during a busy period and also a period where we
had just employed two new staff members.
The surveyors worked extremely well as a team and together produced a
great final product well within our client’s time frame.
8th February 2017
East Lothian council have asked us to create a 3D, high density point cloud, topographical survey, elevations, cross sections and drone survey. This…Find out more