United Illuminating to rebuild transmission lines along rail corridor between Milford and New Haven

Photo of Luther Turmelle
Passengers prepare to board a New York bound Metro North train at the Milford Train Station in Milford. UI will rebuild its transmission lines and separate them from the Metro North power lines starting in 2023.

Passengers prepare to board a New York bound Metro North train at the Milford Train Station in Milford. UI will rebuild its transmission lines and separate them from the Metro North power lines starting in 2023.

Brian A. Pounds / Hearst Connecticut Media

The United Illuminating Co. is preparing for a multi-year, $300 million transmission line upgrade along a 9.5-mile stretch of the railroad corridor between Milford and New Haven, officials with the Orange-based electric utility said.

The project, which will begin in late 2023 and run until late 2028, will serve two purposes, company officials said in announcing the plan.

One is to rebuild 115-kilovolt lines to conform to current utility industry standards. The other is to separate those transmission lines from their current spot along railroad catenary structures which power electrified Metro North commuter trains.

Because UI’s transmission lines are part of a regional network and the work is being done to improve reliability of the delivery of electricity, the project will be funded by ISO-New England, the operator of the grid, company spokesman Gage Frank said.

Frank Reynolds, UI’s president and chief executive officer, said the so-called Milvon to West River Transmission Line Rebuild Project will “improve the resiliency of our electric grid.” The railroad line is controlled by the state Department of Transportation.

“This project will also ensure we can provide safe and reliable power to help meet the growing energy demands of our customers,” Reynolds said.

The project takes its name from electric substations that UI has in Milford’s Devon section and New Haven’s West River neighborhood. Substations take the very high voltages at which electricity travels on transmission networks and convert it to a lower voltage for use by residential and business customers.

As part of the project, UI’s rebuilt transmission lines be placed on their own dedicated, double-circuit monopole utility towers. The rebuilt transmission lines will be able to withstand extreme weather conditions, such as Category 3 hurricane winds, UI said.

Milford to New Haven project is part of a larger effort by UI to separate the company’s transmission lines from the railroad’s electrification network, where some of towers and poles were installed over 100 years ago. The project is designed to have a service life of about 40 years.

During this project, UI will install approximately 160 galvanized steel transmission poles rising from a single footing. The poles will vary in height from 70 feet to 170 feet, depending on their location and the existing environment.

The typical span length between the poles ranges from approximately 300 to 400 feet. But UI officials said that in some locations, spans as long as 800 feet will be needed to minimize impacts to the environment as well because of nearby land uses like parking lots, roadways and railroad spurs.

The final segment is expected to be completed by the fall of 2028, but final restoration activities along the transmission line are expected to extend into 2029. UI customers should not experience any power outages as a result of this construction, Reynolds said

“We are meeting the community’s growing energy demands while working closely with town officials, local tree wardens and with residents and customers,” he said, to avoid or minimize disruptions to the environment or Metro-North rail service.

UI officials anticipate that the majority of construction will be scheduled for daytime hours. But in certain instances, nighttime work or around-the-clock construction may be necessary to accommodate the construction schedule and the needs of the railroad.

The project will require that UI acquire new permanent easements from adjacent landowners. Officials with the utility will also need new temporary easements during construction to install work pads and access roads that will be needed to safely remove the existing transmission network infrastructure replace it with newer equipment.

The Milvon to West River rebuild project is the second in a series of transmission line projects UI is announcing this year. The company announced an upgrade of transmission lines in Derby, Shelton and Ansonia in mid-March and a project in the city of Bridgeport will be announced later this year, according to Frank, the UI spokesman.

Residents and business owners seeking more information on the project should call (888) 848-3697 during regular business hours. The utility serves 341,000 customers in 17 communities in the New Haven and Bridgeport areas.