Topographic Surveys Using UAV:

Mott MacDonald Bentley

Topographic surveys are widely used across the civil engineering and construction industries – on sites where it’s important to get a clear understanding of shape and contour. However, the traditional approach – using teams of surveyors to locate hundreds or thousands of points on a chart – presents a number of challenges that modern UAVs can address.

Site access is a common obstacle to the speedy completion of a survey. Those visiting a site may have to contend with restricted vehicular access, physical barriers such as fencing and hedges, landowner permissions and even hazards such as deep mud or steep slopes. By contrast, a UAV can make repeated passes over a site without obstruction, enabling surveys to be completed many times faster than the usual manual approach.

Modern software can be used in conjunction with high resolution photography to generate a detailed 3D model with accurate contour mapping. Importantly, these contours are based not a few thousand individually measured points but millions. The resulting model delivers far more detail than any conventionally produced drawing and, when the original photos are set as a separate layer beneath it, the result provides engineers and planners with additional visual cues, context and a clearer understanding of any uncharted features.

Typically, the UAV survey process will be in the region of four times faster than a manual survey and will yield corresponding cost savings. However, ground conditions will largely dictate the speed and, in some circumstances, projects may be completed up to ten times more quickly.

However, UAV-based surveys cannot and should not be conducted completely independently from a surveyor. On a middle-sized site, perhaps a dozen control points will need to be located and marked on the ground for reference. Obviously, however, setting just twelve points rather than thousands represents a significant time saving and quickly frees survey staff to move on to other work.

SUAVE has recently undertaken topographic surveys of the terrain surrounding a reservoir and, separately, an area around a broken water main. With subsequent processing, which SUAVE can deliver, the survey data from projects such as these can be plugged into client systems to provide an accurate digital record of the site. For more information about topographic surveys, please contact us.

Building Survey: 24 Mount St., Manchester


City centre building inspections present their own special challenges. Busy roads and pavements, together with the close proximity of other buildings, mean that erecting scaffolding or mast-climbers can be inconvenient and obstructive; sometimes impossible. In such circumstances, the use of UAVs can represent a safe, quick and low cost alternative.

Manchester’s 24 Mount Street (formerly ‘London Scottish House’) is an excellent example. A five-storey structure originally built in 1973, it stands next door to the Grade 2-listed Midland Hotel and across the road from the Manchester Central exhibition centre. In August 2016, its owner, FORE Partnership, was granted planning consent for a partial demolition and refurbishment project that would see the creation of 100,000 sq ft of grade A space, a green wall and a rooftop terrace.

In preparation for the works, the contractor commissioned SUAVE to carry out a detailed aerial inspection of the roof and topmost level. In addition to high resolution photography, the deliverables included a point cloud and a 3D model that architects and engineers could subsequently use in their planning.

Given the restricted access (including one-way streets on two sides) and the building’s unusual L-shape, a UAV-based survey provided to be the ideal solution. On the basis of a single half-day visit, SUAVE  completed the required photographs and telemetry, which it then processed and provided in a variety of forms, including the required point cloud and 3D model.

Construction work on the £13m scheme is due to continue until towards the end of this year. The finished property will have seven storeys with retail units on its two lowest floors. There will be modern office space above, together with a rooftop terrace to be used for meetings and social gatherings. An noteworthy design feature will be a ‘green wall’ on its southern elevation, in which occupants will be encouraged to grow fruit, vegetables and other plants.

For more details of our roof inspection services, please contact us or click on any of the images above. Alternatively, please visit the construction section of our website.

Construction, Progress Photos: Cumbria

Eric Wright Civil Engineering for Cumbria County Council & Mott MacDonald

In December 2015, large parts of the Lake District were badly damaged by flooding, as Storm Desmond followed a succession of other downpours to dump unprecedented volumes of rain into Cumbria’s becks, streams and rivers. Many towns and villages were inundated as centuries-old watercourses burst their banks – releasing floodwaters that did extensive damage to homes and businesses alike.

In the wake of the disaster, Cumbria County Council developed plans for widespread improvements, including bridge repairs, reinforcement works and the installation of new flood defence measures.

Several such projects were undertaken during the winter of 2016/17 by our client, the Lancashire-based Eric Wright Group. One of these took place at Gote Bridge in Cockermouth, and another at Hucks Bridge near Kendal. Flood alleviation measures included re-profiling river beds, reinforcing the bridges themselves, and diverting watercourses with special provision for the passage of wild fish.

Keen to document progress on the sites, the client asked SUAVE to conduct a series of UAV flights to secure both photographs and video. The intention was to show how it was addressing a variety of technical challenges.

The shoots went ahead without incident and the results captured progress very effectively. Indeed, in May 2017, when the Cumbria Infrastructure Recovery Programme was shortlisted in the 2017 British Construction Industry Awards, the main contractor, , asked to use one of the photographs to represent the scheme in marketing materials and at the awards evening itself.

Civil Engineer Joseph Briggs said: “Mott MacDonald and Cumbria County Council are very proud of their shortlisting in the BCIA Awards… SUAVE was responsible for taking some fantastic photographs of the significant repairs of Hucks Bridge and we would very much like to use one on the night of the award ceremony. We believe it excellently captures the collaborative and hard work put into the project to restore and reconnect communities across the whole of Cumbria County.”

Examples of the flood alleviation photographs can be found in our online gallery.

Archaeological Survey: Grimsby

Wessex Archaeology for Murphy

55 miles off the coast of Grimsby, Hornsea Project Two is creating the world’s largest offshore wind-farm. The multibillion-pound scheme will see the installation of 300 turbines over an area five times the size of the city of Hull. Funded by a Danish energy company, the site will eventually deliver clean, sustainable power to around 1.8 million British homes.

Bringing that power ashore, of course, requires a very substantial cable and the route that its 1.5m trench will take across the landscape passes through a number of areas of archaeological interest. Surveying those sites is where SUAVE comes in.

The cable itself will be laid by infrastructure specialist J. Murphy & Sons and as part of the contract, it is working with Wessex Archaeology to identify and evaluate any historically important sites and features. The work so far has required the creation of several very large trenches – some measuring more than 300m by 40m – and Wessex Archaeology asked SUAVE to help produce a detailed photographic record.

We have made two day-long visits to survey the trenches at the point of their completion. The most recent of these was in February 2017. Their aim is to produce detailed survey data before the construction work continues and the archaeology is hidden once again.

The results of our visits to date can be seen in our online gallery.

Construction, Progress Photos: Cheshire

Urban Regen

Winnington is a residential district of Northwich in Cheshire and is perhaps most notable for having been the home of the Brunner Mond chemical works, which was established there in 1874. The facility was set up to produce soda ash (sodium carbonate), which is used in the food industry, as well as in the manufacture of glass, paper and detergents, and in the chemicals industry more generally.

In 1926, Brunner Mond merged with a number of other large chemical companies to form Imperial Chemical Industries (ICI). At around the same time, the company took the decision to expand the site with the construction of five soda ash silos. For the next 90 years, the Wallerscote soda ash works were a major feature on the local skyline, comprising a three-storey structure sitting atop the 50 metre-high silos themselves.

In 2014, the site finally closed and was scheduled for demolition in order to make way for a new residential development. Specialist contractor Urban Regen was appointed to handle the work, which began in September 2016. The company wanted a  high quality visual record of its progress and duly commissioned SUAVE to undertake the required aerial photography and video.

SUAVE was a natural choice for the project. Demolition is a discipline that demands rigorous control of risk, and safety is always a priority. Since its formation in 2010, SUAVE has maintained an excellent safety record and we’ve amassed unparalleled experience of working in and around potentially hazardous construction sites. We understand the challenges of working with large, complex structures and with cranes and similar plant. As a result, our work at Winnington proceeded without a hitch.

The size of the structures made this an impressive demolition project and served as an excellent demonstration of the client’s capabilities. We captured bold and dramatic images of the work in progress, including photos of the long-unseen internal structures of the silos.

The site, once fully cleared, will be transformed for residential use and will ultimately be developed in the final phase of construction of the new Winnington Urban Village.

To see more of the project, please click on any of the image above. For details about our progress photography capabilities, please contact us or visit the construction section of our website.

Structural Survey Video

Video Thumb Structural surveys are becoming an increasingly important part of our work. To showcase our capabilities in this field, we have launched a new video. It shows our work on everything from ancient monuments to football stadiums.