cab signals in steam locomotives?

An article in the latest issue of Classic Trains mentions Automatic Train Control displays inside a Chicago & North Western class H-1 4-8-4 in 1952. I've never heard of cab signals in steam locomotives before, so I'm wondering how common they were.

http://www.prslhs.com/Steam_Photos/PRR_K4_5495.jpg

The box on the running board just aft of the cylinders is for ATC equipment.

Any engine running on Pennsy's lines between Boston & Washington DC as well as from Newark to pittsburgh would require cab signals.

PRR cabs were installed in the late 1920's I beleive, and considering the above territory, would likely have been on a signifigant fraction of the PRR steam fleet... if not on the entire fleet.

Some others-- CB&Q, New Haven, LIRR, AT&SF.

MBTA3247 wrote:An article in the latest issue of Classic Trains mentions Automatic Train Control displays inside a Chicago & North Western class H-1 4-8-4 in 1952. I've never heard of cab signals in steam locomotives before, so I'm wondering how common they were.

Anything that ran on The Reading's Bethlehem Branch had to be cab signaled. That included steam, diesel and electric.

I believe the UP also had "steam era" cab signals. IIRC, these were two aspect vs. the 3 and 4 aspect type they have today. I'll dig through my pics and see if I have a shot of the "old style" one.

Atlantic Coast Line also had them.

The Santa Fe had (and BNSF still has) an inductive type automatic train
stop which is considerably different than cab signalling.

614 had to have cab signals to run on NJ Transit. Maybe the most modern application-

Rock Island and Milw also had cab signals.

The folks at NJ Transit still have some great stories to tell about how much fun it was installing the cab signals on the 614.

I can imagine some of the fun, putting cab on 614. The air is air, hopefully upgraded to 26, but how do you do power knockdown? Where are the ER and GF relays?

I imagine some sort of break-away link, and an air cylinder, were incorporated into the throttle linkeage?

Wikipedia wrote:Cab signaling in the United States was driven by a 1922 ruling by the Interstate Commerce Commission that trains would be limited to a speed not exceeding 80mph without some form of automatic train stop [system]. Now while several large railroads including the Santa Fe and New York Central decided to fulfill the letter of the requirement by installing intermittent inductive train stop devices, the Pennsylvania Railroad saw an opportunity to improve operational efficiency and installed the first continuous cab signal systems.

In response to the Pennsylvania Railroad lead, the ICC mandated that some of the nation's other large railroads had to equip at least one division with continuous cab signal technology as a test to compare technologies and operating practices.

From what I remember from the history of this, a particularly nasty/deadly accident on the PRR (can't recall exactly where, but I think it was in Maryland or Delaware) was the reason this ruling was made by the ICC and implemented in 1922. Note that this was long before diesel-electric or electric power on the PRR.

Some CNJ power had two types of cab signal, typically mounted on the front of the engine. http://www.northeast.railfan.net/images/tr_cnj832a.jpg

B&M had cab signals too. New haven had two types of cab signals. A few engines had both systems.