SEPTA Sours on Unilens Dwarfs

In yet another chapter of the rail industry's love-hate relationship with the Safetran Unilens signal, over the last few years SEPTA has been systemically replacing its Unilens signals with L&W LED searchlights similar to those being employed by Amtrak in the Chicago, New Orleans and Albany terminal areas. Although I am in the Philly area and perform various SEPTA excursions I only just noticed the change since they were limited to the former Reading Company lines I haven't ridden lately. Below is an example of a compact Unilens "high" mast at JENKIN interlocking since 2006 that was converted from Unilens to LED searchlight at some point over the last 2 years.

Track 2 LED searchlight high dwarf at JENKIN in 2003

Track 2 LED searchlight high dwarf at JENKIN in 2010

Combing through some SEPTA territory railfan window videos I can confirm that the majority of Unilens signals have now been replaced by LED searchlights. including those at NEWTOWN JCT, TABOR JCT, the Fox Chase sidings and Norristown Elm St. Because of SEPTA's use of reduced aspect signals, new searchlights won't get much opportunity to demonstrate their full rage of colors and the clipped flashing might be a little irritating while displaying "cab speed" indications.

LED Searchlights at Albany Union Station

For those of you who might be encountering the Unilens saga for the first time, the Unilens was created as a solid state replacement for the traditional electro-mechanical searchlight. It makes use of plastic light pipes (think big fiber optics) to deliver light from up to 4 lamps to a single lens assembly. While this might sound like a great solution, apparently the product suffers from expensive propritary incandescent bulbs and degradation of the light pipe that reduces output over time as well as giving green indications a yellow cast.  While some of SEPTA's Unilens dwarfs were approaching 20 years in service, some, like those at Norristown, had been installed less than 10 years ago. It's entirely possible that the long term costs of operating the type became just too much. It will be interesting to see if LED searchlight technology migrates to the Class 1's, which still seem wedded to the Unilens for restricted clearance applications.