Similar in scope to a topographic survey, an overhead line survey focuses on creating an accurate and detailed ground profile.
This survey is crucial for determining the exact undulation of a parcel of land, knowledge that is in turn, critical in the design of new or refurbished/rebuilt power lines.
Accuracy must be a key feature of overhead line surveying, as power lines need to comply with statutory clearance requirements. Line Design Technology Limited employs a range of methods, including survey-grade receivers, to produce precise survey results.
The finalised overhead line survey can then be used to create compliant route plans.
Below are details of some of the projects we've worked on over the years
Jacobs Engineering UK engaged our services to undertake an overhead line survey of the existing XG & XQ 275kV overhead lines located near Neilston in Scotland.
As part of a design study to facilitate the reconductoring of the existing lines a topographic survey was undertaken to locate all the ground and vertical features of the circuits.
The attachment points on each tower were located using a total station and RTK GNSS.
At the same time detailed measurements were made on the towers to check for verticality.
A series of photographs of each tower were captured including details of the foundations.
A 3D CAD model was produced and handed over to the client along with a verticality report and photographs of each structure.
The field work took three weeks to complete the full 22km survey.
Weston Power were seeking to increase the capacity on its 66kV network in South Wales.
LDT were engaged by Jacobs Engineering UK to undertake a catenary survey to determine the feasibility of increasing the capacity on the Grange to Llynfi circuit.
In order to determine conductor sag, a detailed topographic survey was needed.
Each span of the line was surveyed as well as the attachment points of each structure. To accurately determine the circuit load, climatic conditions needed to be recorded at the time of the survey.
This included wind speed and direction, ambient temperature, solar radiation and atmospheric pressure.
We used a combination of RTK GNSS, Total Station and 3D laser scanner to conduct the survey. As part of the line was on the Port Talbot Steel Works, enhanced risk assessments and method statements were required to ensure the safety of all involved in the project.
Deliverables included a 3D CAD model of the line, weather report, and a classified 3D point cloud.