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New Haven Catenary Replacement Project Update (May 2017)


Work on replacing the New Haven Line's catenary system is in the last stretch, with final completion expected in mid-2018. This project is being funded and managed by the Connecticut Department of Transportation.

What is catenary and why do we need it? The State of Connecticut does not allow third rail operations, so our trains are powered by overhead wire called catenary, like the kind once seen on trolley cars. (Trains on the Danbury and Waterbury branch lines use diesel locomotives.)

When we started this phase of the project in 2014, we broke down the 10.1 mile distance into two segments, from East Norwalk to Green's Farms, and from Bridgeport to Milford, in addition to working on our Bridgeport Yard. Here's the progress: By May, all of the overhead wire and the systems that support them above tracks 3 and 1 along both segments, will have been completed.

June will mark the beginning of the last phase of this project in which we replace all the old wires with the new system above tracks 2 and 4. That final portion of work will start first with the Bridgeport to Milford segment, and both segments should be completed by mid-2018. While we are working, only one track will be taken out of service continuously during daytime, non-rush hours and at night, without impacting train service and virtually invisible to our customers.


The catenary that we are replacing was originally installed in 1907-110 years ago! When this Connecticut-side catenary work is completed, we will have replaced the original "fixed termination" catenary (which can sag or contract due to temperature changes) with a state-of-the-art constant tension system that better accommodates temperature extremes. (The New York State portion of the line was completed in 1995.)

That requires special weights of 4,176 lbs. each placed approximately every mile along the catenary that act as dynamic balancers, making wires tighter when it's hot outside (because the wires are sagging from the heat), or looser when it's freezing cold outside. And don't worry about safety, all of the weights are protected with a special cage below so that no one can get accidentally "weighed upon!"

In addition to making our operation safer and more reliable, the new catenary will reduce wear and tear on the pantograph itself because of flexible registration arms that come out and float the catenary back and forth within a six-inch tolerance above the track, ---so it doesn't get worn down in one spot.


The work will include the installation of drop tubes that hold the wires in the correct position.

Work on the catenary replacement for this section was started in 2007. In 2014, we completed catenary work in the seven-mile stretch between Southport and Bridgeport, allowing us to route peak-period trains on all four tracks in this area for the first time in four years. We also replaced open deck railway bridges in Bridgeport and Fairfield, and complicated wire work at the Southport and Bridgeport interlockings - sections of track, signals and switches allowing trains to cross from one track to another.

Photos: Catenary replacement on the New Haven Line.

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