Midtown Cable Upgrade

Evergy is replacing an aging underground power transmission line that is nearing the end of its service life.

Replacing the underground transmission line will increase electric reliability to support the current and future electricity needs of our community.

This project, located at the Roe Terminal, will install new 161kV transmission cable and infrastructure, replacing equipment originally installed in 1959. Related work outside the substation will be located at the intersection of West 47th Street and Mohawk Drive, closing West 47th Street between Mohawk Drive and Reinhardt Drive. Work is expected to begin in late August and be completed by late October.

New cable splicing will occur within the existing manhole at West 47th & Mohawk Drive and will require a temporary building to be constructed to house a freeze pit. The purpose of the freeze pit is to access the transmission line pipe to install liquid nitrogen freeze coils, which freezes the fluid surrounding the cable within the pipe. Liquid nitrogen will be delivered to the site by tanker each night. The temporary structure will be manned while work is underway.

Liquid nitrogen is a colorless, odorless gas, and its extremely low temperature can cause severe frostbite upon contact. You may observe a fog coming off the building when the liquid nitrogen is being used to freeze the pipe. This vapor is similar to fog seen with dry ice and is harmless.

This project is a part of Evergy’s initiative to upgrade utility infrastructure. Evergy is investing in infrastructure upgrades to strengthen the regional power grid and enhance reliability for you and the communities we serve in Kansas. Infrastructure upgrades allow us to continue delivering clean, safe, reliable sources of energy for our customers today, and well into the future.

Evergy plans to begin construction in August 2021 on an underground transmission cable project near the 47th St in Roeland Park, KS.

Project Map

Midtown Cable Map

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We appreciate your understanding as we take precautions to protect you and our workforce.

What work is planned?
This project will install new 161kV transmission cable and new substation terminations, replacing equipment originally installed in 1959.

What is transmission cable?
Transmission cable carries the electricity created at a power plant to area substations. A transmission cable is physically larger than the distribution lines that carry electricity to local homes and businesses.

Why is the work needed?
As central Kansas City continues to grow and redevelop, energy use continues to increase. Replacing the current cables, which are more than 60 years old, will help ensure reliability for years to come.

What is the timeline for the project?
The project will begin in August 2021 and is planned to conclude, excluding weather and other unknown delays, by November 2021.

How will both phases of the project be constructed?
Both phases of this project will remove old cable and install new cable in an existing steel pipe. Workers will be stationed at the Midtown Substation and the remote-end location for the duration of each project phase. At the remote-end locations, a temporary building will be constructed near an existing manhole to house a freeze pit. Cable splicing will be performed in the existing manhole at each remote-end location.

What is a freeze pit and what is its purpose?
A freeze pit is a hole in the ground exposing the transmission line pipe, allowing for liquid nitrogen freeze coils to be installed around the pipe. The liquid nitrogen freeze coils form a plug of frozen oil around the transmission line, allowing it to be worked on. As the liquid nitrogen is used to cool the steel pipe, the warming gas is safely vented off into the atmosphere. This process results in fog coming from the temporary building, similar to dry ice.

What will the temporary building look like?
The temporary building will resemble a small shack with a liquid nitrogen tank attached. The building will contain vents to disperse the liquid nitrogen gas, which looks like fog. There will be security at the site 24/7.

Is liquid nitrogen safe?
Yes. Liquid nitrogen is a colorless, low viscosity liquid that is widely used as a coolant, similar to dry ice. It is non-toxic and safe when used correctly.