First of all I do not presume and claim to know more than the Engineer or Conductor. I never drove a locomotive. I was in the Car Department, and inspected/welded/repaired just about everything on railcars.
While working for the RR I witnessed the most negligent acts committed by my fellow employees. I saw a man start up a P&H wreck crane, climb off to adjust the motor, and the crane slipped into gear and careened towards us workers that had a jacked up loaded steel coil car that had its one truck rolled out from under it. Not to mention it was also careening towards a cushman repair cart equiped with oxy/acetelene compressed gas tanks.
I saw the same coil car (which we repaired), which was clearly labeled "DO NOT HUMP", go over he hump, and tear though the classification turnouts, while its lead air hose caught up in the switch, which ripped the entire airbrake trainline out from under the car, causing it to derail.
I saw a crew push 17 TOFC railcars, and never mind the conductors scream over the radio to "STOP STOP STOP", they kept on shoving, till the cars and trackage was sticking up in the air 15' twisted like a pretzel.
I saw them shove 125 Iron Ore Gennies back, derailing almost all of them into a twisted massive derailment.
I saw switch crews shoving CR coal hoppers with the handbrakes still not released (because they were too lazy to climb and release handbrakes). The cars skidded along the rails with sparks shooting out from the railhead, so hot that steam was emitted from the rail (as the rail was wet). I questioned them why not release the handbrakes ? Their reply: Why ... do you care ? I replied: Yes, because I have to shop them for flat spots on the wheels. One car had such bad wide flat spots ... it wouldn't even roll right after the traincrew destroyed the wheels.
I saw what happens when another car inspector purposely neglected to inspect, even bother to walk the train, and neglected to oil even one of the journal boxes. By the time the train reached Valley Forge almost all of the 1000 journals on the 125 car train of Gennies were smoking. We were all called out that day, everyone on the our division, to oil that train, and inspect it on the main.
Almost no radios existed, and if they did, it was one of the big black box transcievers, that had absolutely no get out wattage, and was conversation was totally unreadable.
I was informed that 2 car inspectors that had no radios, crossed over couplers without radio permission, and were quickly mowed down by a passing freight in Oak Island yard.
After another car inspector was run over and killed, and after the tagging, bagging, and FRA was finished, workers were instructed to respond to the scene and throw lime over the aftermath.
I have seen dozens of lifetime RR employees avoid work throughout their long career. Obviosly you didn't work for Penn Central & Conrail. One guy I worked with hadn't changed a brake shoe in 10 years, but he filled out thousands of false billing for well over 30 years showing that he had done 5-10 per day.
On the job training was usually sticking the new hire with the 35 year veteran, who inturn showed th new guy the ropes, as the veteran was shown 35 years prior. There was no schooling, class's, tests ... it was all hands on training. Sure I was shown exactly how to give a Initial Terminal Air Brake Test, and performed many, many Air Tests on the main. There even was one actual single video tape, (that was every so often handed around), for the employee to take home and view at his lesure.
I was quized by the veteran employee on all the hundereds of railcar nomenclature, and could tell a AB from an ABD, and repair them all. Through hands on training I was shown that the cut lever pushed up on the toggle, and that moved lock lifter up, forcing the thrower to push out on the knuckle. I was sick and tired of fixing busted knuckes and pins that you guys continually break by rough switching. One engineers flat switching "smooth move" sent a loaded tank car crashing at 35 mph into a consist, breaking the pressure dome ceramic disk, spraying chemical into the air and all over the railcar.
Corporate once sent a bigwig down to test his dimwitted brainstorm of how to patch a busted airhose with a entire roll of 3M electrical tape ... which quickly expanded like a balloon, and finally blew up with an earshattering Ka-BLAM-O !
Radio Telemetries were a complete rairity to snag off of incomming trains. Most were broken and malfunctioning, and the 100+ NiCad batteries in the terminal had so much memory that they would not even hold a charge. Flashing yellow Star Makers were the norm, and these made crews furious that manned trains bound for the NEC. Oftentimes no markers were available at all, asside from a waving red linen flag in a stick.
Engine crews that came aboard a new fangled electronic equiped loco, frequently had to call out a CR tech to unlock the computer controls. DPU was new fangled and experimental.
Several Conrail high ranking executives came up with a scheme to steal couplers, air brake rigging, and entire freight railcar trucks. By falsifying and then submitting fictacious billing of foriegn roads freightcar maintenance records. One example: showing that a UP freightcar recieved 2 new replacement trucks and couplers. But when alas: UP inspectors went out in Baily, and found that the original 1976 trucks and couplers were still in place, they found that no actual repairs had ever made in any Conrail shop. Hundereds of computer records were altered to show that work was done, when in fact no work had ever been done at all.
This swindle caused the closing of the huge Enola Freight Classification Yard. Enola may have been reopened in receint years, I don't railfan that much. I haven't ever "Foamed" trackside with my foot up my rear ... and my $99 camera hardly is comparable to a $500 railfans equipment.
US railroads had fallen complete neglect, akin to Ralph Naders-Corvair "unsafe at any speed", and it is no wonder why the US is (was) a classic setting for rail disaster movies. Recient decades there have been many more safety and training programs enacted. Thank goodness that railroads of today are much safer than years ago, and they actually have classroom training programs nowdays.
In responce to your Emergency braking question: I really am unsure, I was the guy who repaired the railcars, so that they would brake properly. Possibly a kicker in the consist ? I was informed that a train, that came in on my shift, had 16 cutout valves turned, by a car inspector trying to isolate the problem car near Reading, as it kept going into emergency. We had to watch that kids didn't see what position we reset the air retainers to ... as they would purposely sabotage the train by setting them all upwards, to screw up the train. Their other hobby (besides opening plug door boxcars and robbing the consist) was rolling derilict spare tires down an embankment, in between couplers, to bust open the airhoses.
Pbbbbbbbt ! http://www.youtube.com/watch?annotation_id=annotation_257253&v=RWZyJukAWBk&feature=iv