The rather secretive nature of the LIRR has always made it somewhat difficult to find information about its signaling infrastructure and interlocking towers. However over the past past 26 years Steven Lynch's decidedly web 1.0 LIRR Archive on trainsarefun.com has ballooned into an absolute juggernaut of quality information. In particular the page devoted to interlocking towers covers not only the current stuff, not only the recently closed stuff, but the towers that were displaced by the modernizations of the 1950's, 60's and 70's as well as the old block stations that were displaced by automa ..read more

On November 6th, 1984 the last train departed the historic Reading Terminal in center city Philadelphia 4 days after the completion of the Center City Commuter Connection tunnel that allowed through running between the former Pennsylvania and Reading electrified commuter rail systems. Immediately after crews began to rip up the tracks as the tunnel had rendered both Reading Terminal and about 2 miles of elevated main line redundant. This also marked the end of RACE STREET as an active interlocking station and its task of signaling trains in and out of the 13 track station complex from the 4-tr ..read more

For years concerns of PTC interoperability drove all manner of decision making at freight and passenger railroads. For example's CSX decision to isolate itself from SEPTA's Regional Rail network, NICTD choosing not using the cab signal codes present on its line because Metra Electric wanted to use the freight-centric ETMS and MARC dumping ACSES for reasons. However one common thread is that when push comes to shove, equipping locomotives with multiple PTC systems is not a big deal (although it certainly isn't free). Case in point are the SD60E locomotives that are always leading certain Norfo ..read more

Since my last update on the status of the former Pennsylvania Railroad Harrisburg Power Director's Office a surprising amount of progress has been made to get the equipment functioning in its 1943 configuration. For those of you who might not be aware, the Harrisburg Power Office used a relay based SCADA system to remote control all of the 1937-39 westward extension of the 12kv 25hz electrification network that first began operation in 1915.  The second phase of the PRR's electrification from New York to Boston had largely relied on tower operators to directly control the substation equip ..read more

METRA recently announced that they were looking to raise speeds on its electric division from the current 65mph to 80 or even 90mph. Typically this is the sort of project that justified a 8 or 9 figure capital spend with concrete ties and brand new signaling. However this announcement explained that management simply looked at the facts on the ground and concluded there wasn't actually anything precluding those faster speeds. Apparently the entire operational management of METRA has assumed that the 65mph figure was a fundamental limitation of the current ABS/CTC block signaling distances that ..read more

In November 2023 an inbound "Skokie Swift" Chicago El train rear-ended an MoW vehicle stopped on the track waiting for signal clearance into the Horward terminal interlocking complex. The impact took place at a speed of 26mph and the NSBT was quick to blame "outdated" signal stopping distances that were last set whenever cab signaling was installed on the line, likely in the 1970's or 80's. The result was a multi-month service suspension and a reduction in maximum authorized speed from 55mph to 35mph, which was achieved by disabling the 55mph cab signal code at ever block location. To the lay ..read more

The Albany Port Road Branch, now under long term lease to Amtrak, has an interesting history. One of the few stretches of non-commuter North American main line track dedicated solely to passenger operation, the Post Road Branch represents the original route of the Boston and Albany before the construction of the Selkirk Cutoff that allowed New York Contrail freight trains to bypass the Albany terminal area in the 1920's. In the 1970's, Penn Central completely ripped up the track on the 12 mile branch as a cost cutting measure before being ordered to restore it by the ICC. Since then it has hos ..read more

For years the western end of the old Boston and Maine main line between the Hoosac Tunnel and Mechanicville, NY has been subjected to a highly inconsistent re-signaling programme by the NS-Guilford joint venture "Pan Am Southern". After a recent visitation and Google Earth survey I believe I have determined the exact disposition of B&M signaling between those two locations.  Starting at the Hoosac Tunnel, both CPF-414 and CPF-415 are retain their B&M signaling with tri-lamp searchlights and pulse-code based block state transmission. Although I have been unable to inspect them per ..read more

While out riding the new MBTA Green Line Extension I noticed a new corporate brand stenciled onto the back of a cheap looking transit type LED signal head. My original assessment that  Velcorp is the company and GEMS is the brand name of their rail signaling equipment turned out to be incorrect as Velcorp was actually Virginia Electronic & Lighting LLC and GEMS was their subsidiary General Electronics Mechanical Services, which I guess does all the rail stuff? Anyway, as you can see below the product looks to be on the low end of the build quality scale with exposed nuts on the front ..read more

 Movable bridge cabins are the invisible step children of the interlocking tower scene, but its easy to forget that they have all the same stuff that regular towers have including the full compliment of electro+mechanical interlocking machines. While poking around YouTube I found this video of someone's 1994 tour of the Souther Pacific's SUISUN BRIDGE movable bridge cabin. This vertical lift drawbridge is a crossing of the Carquinez Strait, which connects Suisun Bay with San Fransisco Bay and hosts Amtrak's Capitol Corridor, Coast Starlight and California Zephyr services. As far as I am ..read more