Summary
In Spring 2017, Aeriosense provided its services to Allteck Line Contractors Inc., an industry leader in transmission line maintenance whose expertise ranges from design and installation to maintenance and repair of high-voltage infrastructure. Allteck was looking to achieve more efficient, more cost-effective detailed inspection of high-voltage transmission lines.
Using Aeriosense's automated drone inspection solution on an 18 km, 138kV transmission line section near Dawson Creek, Allteck was able to significantly reduce both the cost and time of inspection, as well as increase safety and reduce disruption to local landowners.
The Challenge
Conventional detailed inspections require up-close visual assessments of a transmission tower's key components. Typically, these inspections are done by either physically climbing the transmission tower or by using a bucket truck, both of which are expensive, time-consuming, and have associated safety risks that need to be mitigated.
Single pole structures can only be climbed part way while energized, giving only marginal advantage over ground-based inspection. While bucket trucks, are costly and subject to limited access in challenging terrain. The transmission line in this project goes through a rural area with farm fields and ranches, so right of way (ROW) access must be coordinated and disturbances must be minimized.
Automated Drone Inspection Tool
Aeriosense's automated drone inspection tool employs a drone equipped with visual and IR cameras, which is automatically guided to and around the structure on a pre-defined flight path. The system was used to inspect 8-12 poles from a single take off location before being taken to the next section of the transmission line.
This system allowed high-quality visual and infrared imagery to be collected and analyzed in detail without the need to climb the poles or drive a bucket truck over the farm fields.
Results
Allteck's experience with Aeriosense's approach was extremely positive. Automated drone inspection significantly reduced project costs and disruption to local landowners and dramatically increased the speed and safety of the detailed inspection of the transmission line, all while producing equivalent quality of inspection compared to conventional methods.
Inspection of the 18km stretch of 138kV line, which previously took 30 days, was completed in under 5 days, with separate inspection flights for detailed visual and thermal imaging. Significant cost savings were achieved compared to conventional inspection methods while avoiding cost overruns due to ROW access issues.
Key Results:
- Inspection time reduced by 85%, inspection cost reduced by 80%.
- Inspection speed of 1km/hr, 10 structures/hr.
- Eliminated safety risks associated with climbing and bucket truck inspections,
- Minimized disturbance to landowners,
- Reduced time spent on project coordination,
- Equivalent inspection quality compared to conventional inspection methods,
- Inspection data logged, to allow future condition trending
"Compared to the bucket truck inspection we are seeing significant cost reduction in the detailed inspection using the Aeriosense tool. It also gets the job done faster, freeing up our bucket truck and personnel for other jobs. The other benefit is we don’t have to worry about rutting out and damaging the farmers’ fields"
- Kevin LaChapelle, Regional Manager, Allteck
Future Plans
Given the strong results achieved during this inspection, Allteck plans to make automated drone inspection part of their routine inspection for the 18km transmission line near Dawson Creek. Allteck is also exploring the possibilities of applying Aeriosense’s automated drone inspection tool to other projects in the future.
Comments
Hi Patrick
I answer your questions below.
I assume this cost reduction is based on aerial inspection exclusively, so you compare a drone inspection team vs bucket truck team on this specific aspect of the inspection process?
This cost reduction is a comparison between bucket truck and Aeriosense Automated drone for this specific project.
Other aspect of the inspection process may or may not evolve the usage of a drone and I cannot figure how we can replace the ''hands on'' tests on some of the requested task below ?
For most of items you mentioned, a detailed visual inspection provides a solid basis for condition assessment. There are certain things however that a drone cannot do, that are sometimes performed during routine inspections, such as hardware tightening, or wood pole drill sampling and treating. This is usually only required on a small percentage of structures though, and can be performed on those few structures selectively during maintenance.
Interesting alternative for aerial inspection, I have few questions:
"Inspection time reduced by 85%, inspection cost reduced by 80%."
I assume this cost reduction is based on aerial inspection exclusively, so you compare a drone inspection team vs bucket truck team on this specific aspect of the inspection process?
Other aspect of the inspection process may or may not evolve the usage of a drone and I cannot figure how we can replace the ''hands on'' tests on some of the requested task below ?
Poles/Supports:
Bent, cracked or broken poles
Excessive surface wear or scaling
Loose, cracked or broken cross arms and brackets
Woodpecker or insect damage, bird nests
Loose or unattached guy wires or stubs
Guy strain insulators pulled apart or broken
Guy guards out of position or missing
Grading changes, or washouts
Indications of burning
Hardware and attachments:
Loose or missing hardware
Insulators unattached from pins
Conductor unattached from insulators
Insulators flashed over or obviously contaminated (difficult to see)
Tie wires unraveled
Ground wire broken or removed
Ground wire guards removed or broken
Equipment Installations (includes transformers)
Contamination/discoloration of bushings
Oil leaks
Rust
Ground lead attachments
Ground wires on arrestors unattached
Bird or animal nests
Vines or brush growth interference
I guess that the other expenses are somehow the same:
I really think that automated drone is an important tool for the inspection patrol when needed to fly by equipment to identify obvious structural problems and hazards.