Client POWER Engineers
Location Northern Minnesota
Scope 225-mile, 500 kV transmission line and two substations in Northern Minnesota

Great Northern Transmission Line

Project Details

Westwood’s Role

  • Surveying
  • Easement Exhibit Preparation
  • Construction Staking
  • Aerial Mapping/LiDAR
  • Existing Road/Infrastructure Studies
  • UAS/Drone Services

Overview

Westwood was hired to conduct various surveying tasks on this 225-mile transmission line from the Minnesota-Manitoba border to the Iron Range Substation near Grand Rapids, MN. Westwood’s surveying team has overcome a number of challenges already, and more challenges can certainly arise before the project is to be completed in 2020. This 500 kV line will bring hydropower from a new dam being constructed by Manitoba Power to Minnesota’s Iron Range region.

Swamp Surveying and Traversing with ATVs

Over 65% of the land to be crossed by the line is swampland, much of it practically untraversed since the original survey in the late 1800’s. Westwood’s surveyors are making use of amphibious all-terrain vehicles to travel onsite and conduct their surveying activities. These vehicles are approved by the DNR for being less impactful on the area and are an absolute requirement for getting the work done. Outfitted with additional safety features, the surveying team has extended their transportation services to the client and other consultants because of their knowledge of the land and the vehicles.

GPS and Mobile Tracking for Safety

The remote and difficult environment this project traverses has provided a unique set of challenges for the field personnel. Very limited access to the route has been a significant burden, along with deep snow, dense swamps, never-ending deadfall, extreme cold, lack of cell coverage, and wolf and moose encounters to name a few. The crews are equipped with GPS trackers that create maps, showing how a surveyor got to a location so that they can find their way back out or leave an electronic trail in the case they need to return to that area. These crews are also making use of tablets for their maps, survey notes, and geo-referenced photos. The surveyors find it handy to have all of the information they may need at their fingertips, neatly organized. It saves time sorting through paper folders, books, and maps, and helps ensure that details are not missed during the survey.

Public LiDAR Data and Advantageous Aerial Mapping

The client wanted to make use of public LiDAR data for preliminary design, so Westwood’s aerial mapping team reformatted the data to be usable in PLS-CADD. Ground truthing was conducted in several areas along the route to verify the accuracy of the public data and confirm it was suitable for design.

To aid in the planning process for the transmission line and access roads, Westwood provided aerial photography for the entire proposed route so the client had an up-to-date image of the planned corridor. This was advantageous due to the ever-active logging industry that dominates the area. Because of the logging, new areas are being cleared and new temporary roads are being constructed on a regular basis. After the flight was conducted, the aerial team was able to extract the location of existing transmission and distribution lines for design purposes.