Proposed Catenary System - Harlem River Branch

I came across this, which maybe of interest. The New Haven back in 1910 was thinking of using the experimental arched catenary system installed at Glenbrook for the Harlem River Branch. The arched system seemed satisfactory, but by 1912 the railroad decided to use the present tapered leg catenary bridge instead. I don’t know if the change in plan was due to cost, scheduling or engineering concerns. I include a snippet from an article and some pictures as reference.

PROPOSED CATENARY CONSTRUCTION FOR HARLEM RIVER BRANCH OF NEW YORK NEW HAVEN & HARTFORD RAILROAD (Electric Railway Journal 1910)

A 6000 ft experimental section of catenary trolley construction of a novel type was built last fall by the New York New Haven & Hartford Railroad eastward from the end of its electric zone at Stamford Conn The object in erecting this experimental section was to observe the results of electric locomotive operation under an overhead construction much lighter more elastic and less costly to erect and maintain than the catenary construction with double messenger wires and triangular hangers which was used on the initial electric zone between Woodlawn and Stamford The results have been so satisfactory that it has been decided to adopt this new construction with some modifications for the electric equipment of the six track Harlem River branch between New Rochelle and Harlem River 12.13 miles The details of the experimental four track section as built are shown in the accompanying engravings from photographs and the details of the six track construction as modified for the Harlem River branch are shown in the line engravings.

Here is a a sample of the Glenbrook installtion.

This is very interesting and thanks (again) for posting this.

[i]Electric Railway Journal[/i] wrote:The results have been so satisfactory that it has been decided to adopt this new construction with some modifications for the electric equipment of the six track Harlem River branch between New Rochelle and Harlem River 12.13 miles.

Wonder what happened?

I’m not sure what happened, but I think it came down to the difficulty of fabrication and resulting cost. Repetitive member or latticework construction does not lend itself easily to complex shapes. When you think about, fabrication of the existing tapered leg bridge system was not simple either. The cross strapping varies in length from the top to the bottom.
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With 12 miles of track there would have been roughly 213 support locations with 426 arched posts or masts. I am assuming the New Haven engineering staff did a feasibility study and found that a large scale implementation of the Glenbrook system would have been costly and time consuming. I am sure there were also other technical concerns with wire anchoring, signaling, and the NYW&B’s own concern with connections to its particular system.
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Still, the Glenbrook system was ahead of its time and has seemed to survive the past hundred years.

Although the arched catenary supports were not repeated elsewhere, the compound catenary itself is exactly what the New Haven installed on the Harlem River line and from Stamford to New Haven.