i've been reading about the early use of manual signals, the tedious bookkeeping the operators had to do and protocols for recognizing that a train has cleared a block and that the block can be cleared for the next train.
i'm wondering how successful the use of manual signals was in reducing the number of train accidents -- both head-on and trailing collision, or if human error still resulted in many accidents.
i would assume the cost of operating and training people for manual signal operation was expensive but necessary.
greg - Philadelphia & Reading / Reading
Head-on and rear-end collisions involving passenger trains killed several thousand passengers in the early days of manual signals due to engineers failing to abide by the signals, misreading their train orders, or just plain carelessness and drunkeness.
Some modern signal systems automatically apply the brakes if the engineer ignores a signal telling him to slow down or stop.
Greg,
I assume you are talking about manual block or Train Order type Signals? Human intervention(or lack of) is usually the reason for train collisions. If the train order operator does not set the manual bock signal to restrictive after a train passes, the 'protection' is gone.
Automatic Block signals reduced this work, but the train crew needs to see the signals and react to a restrictive indication. Railroad went to ABS or APB signals quite fast on busy lines as soon as the technology was developed. The current trend to implementing PTC will allow a computer system to stop a train if the train crew fgails to react to a restrictive signal indication.
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
Yes and no. Ball signals if used correctly would have been fine for early railway operations. Human error is always the determining factor on succes of a system. Even with 3 position semaphors and position light signals later on there were still accidents due to human error.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
Early signals were adequate about informing train crews whether the track ahead was free of an opposing train. They couldn't force compliance, and they couldn't warn of other problems (washout, landslide, fire damage...) Also, some systems allowed a following train to proceed before the train ahead had cleared the block (which usually extended from one passing place to the next.)
The bottom line - it was still incumbent on the engineer to avoid actions that would result in wrecks. Eyeballs forward were the first, last, and, frequently, only line of defense. (Does, "Hand on throttle, eyes on rails," sound familiar?)
Chuck (Modeling Central Japan in September, 1964 - with working staff-and-ticket signaling)
On a darker note the early signals also weeded out engineers that was near color blind..
Even today compliance of a signal is in the hands of the engineer.
Larry
Conductor.
Summerset Ry.
"Stay Alert, Don't get hurt Safety First!"
so what features of signals significantly improved safety? or is it a combination of signaling and training?
in the club i operate on, there are short blocks that detect when a train has run thru a stop signal, and disables it by shuting off power. i doubt there's a comparable prototype.
gregc so what features of signals significantly improved safety? or is it a combination of signaling and training? in the club i operate on, there are short blocks that detect when a train has run thru a stop signal, and disables it by shuting off power. i doubt there's a comparable prototype.
The difference between cars and trains is stopping distance. Signals, especially automatic block signals give indications that allow trains to prepare for a more restrictive signal. As train sizes and speeds increased the stopping distance exceeded sight distance. By the time an engineer saw a stop signal it was too late to stop before passing it. That's why the distant/approach signals were so important.
Another advantage was the signals were visual indicators. Visual indicators are a "modern" management tool that was applied 100 years ago.
Signals allowed information to be passed to the train without stopping or slowing the train or writing down information.
By the 1920's various systems were invented that applied the brakes if a train failed to acknowledge a restrictive signal or passed a stop signal. Most of those systems are still in use.
Dave H. Painted side goes up. My website : wnbranch.com
dehusmanBy the 1920's various systems were invented that applied the brakes if a train failed to acknowledge a restrictive signal or passed a stop signal. Most of those systems are still in use
And still trains manage to plow into each other by the crew disregarding a restricting signal.
cacole Head-on and rear-end collisions involving passenger trains killed several thousand passengers in the early days of manual signals due to engineers failing to abide by the signals, misreading their train orders, or just plain carelessness and drunkeness.
Fatigue was probably a bigger factor. In the 19th century, there were no laws or regulations about required rest periods, so in a busy time (like a fall grain rush) an engineer might work several days straight with no sleep. I recall an old RR employee writing that when he started in the 1880's-90's it wasn't uncommon to go trackside to 'hoop up' orders to an engineer, only to see the train roll by with the engineer and fireman sound asleep, even half falling out of the cab window. He said all he could do was wire ahead to the next station to let them know to clear the line for the runaway, and hope the crew woke up in time to prevent an accident.
A good example: at the time of his famous fatal accident in 1900, Casey Jones had been 'on the clock' for something like 20 straight hours.
p.s. Early signal systems, just like modern systems, couldn't prevent accidents from happening - people will always find ways to mess things up. It would probably be very accurate to say early signal systems reduced the number of accidents significantly enough to prove signalling worked, and to warrant folks spending the time and effort to find new and better safety systems.
As we all know the rulebook is written in blood. From all that I have learned about early railway operations the real breakthrough in safety was a combination of automated signaling and train dispatching by telegraph. Consider this, in the 1850s some operating rules stated that when two trains scheduled for a meet were both late, the conductors had to telegraph each other and arrange a new meeting place and time. This of course assumes that they were both stopped at stations with a telegraph connection.
There were frequent human errors leading the tragedies in the era of manual sinalling. In one instance a New York and Greenwood Lake passenger train went through an open drawbridge into the Hackensack River. The bridge tender made a point of showing everyone the "bridge open" aspect on the signal although no one else remembered seeing it.
In another case on the same line, a station agent mistook a special train for the regular train. He thought that there would be plenty of time to set the manual block signal before the next regualry scheduled train. But the next train was only a few minutes behind the special. The subsequent rear end collision casused the last car to be telescoped by the locomtive with a large loss of life.
Yes, train crews did disregard signals but there were also a lot of failures on the part of station agents and others responsible for operating manual signals
Glad to be living in an historical period where a guy can die of old age,
Kevin