Browsing Tag: approach

    Reading Canadian Railroad Signals part 2: Single and two headed signals lower music
    Articles, Blog

    Reading Canadian Railroad Signals part 2: Single and two headed signals lower music

    August 24, 2019


    In the first video of this
    series, we laid the foundation for reading railroad
    signals with the basic three-headed railroad
    signal. If you haven’t watched that video yet, you need
    to watch it first to follow along in this video. Now, these signal heads are
    attrociously expensive: some $20,000 or more! So do the
    math: if you’re lighting up 100 miles of track
    with CTC lights, in BOTH directions, with signals
    every two miles? It adds up in a hurry! That track for the most part is
    just straight, high speed track. There are no
    switches or sidings. So to save on costs, the railroad
    will remove 1 or 2 of the heads. Remember how the
    two lower lights were red as placeholders? Well
    the signals are exactly the same, you’ll just
    imagine the placeholders, which I’m going to
    leave in this picture, with the two heads
    faded out to help you remember how to read the signal. This is a clear signal. Proceed
    at track speed. This is a clear to stop signal.
    Proceed at track speed, preparing to stop at next
    signal, which will be a stop signal. A flashing yellow on this light
    is NOT a slow signal. why? Because remember –
    this is the same as a three headed signal, but with
    the two lower heads removed, so this is the high
    speed signal head. Do you remember what a flashing
    yellow on the top head was? Advance clear to stop. We
    can proceed at track speed, next signal will be a
    clear to stop, the second signal will be a stop
    signal. Now – one thing to clarify
    before we get into the reds. When signals are stacked
    above each others like this, or this, that means
    that signal is under direct control of Rail Traffic
    Control. if the heads are staggered, they are
    NOT directly controlled by RTC, they are
    controlled by the automated CTC system itself. The
    lights are controlled by relays reading the
    traffic on the rails. Single head masts are generally
    not controlled by RTC, they are simply controlled
    by the automatic system. The single headed
    signals that are controlled by RTC have an A
    plate on them. Whether right or not, I always likened
    this to an ABSOLUTE signal. So if a single head is red, that
    is a STOP AND PROCEED signal. You stop, then
    proceed at restricted speed. BUT if the
    signal has an A plate, that is an ABSOLUTE stop. You
    stop at that signal and wait until it changes or RTC
    gives you specific, written permission to
    pass that signal. You remember how I talked about
    the system being designed as fail safe? the CTC
    system is tripped by the train making an electrical
    connection across the rails, which are connected
    to an electrical circuit. If that electrical
    circuit is broken in any way – a broken rail or
    broken wire for instance, the CTC lights all
    turn RED. So this can be a real problem if
    your super expensive train has to stop
    every two miles because there’s a problem with the
    system! Time is money, and we get paid to ship cargo,
    not park the cargo on the rails! So, they put an R
    plate on the signal mast. This is a cheap failsafe
    upgrade to the pre-existing system. If the
    signal is red, the R plate upgrades it from a stop
    and proceed signal to a restricting signal – the train
    still has to be on the lookout for other trains,
    broken rails, etc…, but now we don’t have to stop at
    the signal. If the R plate falls off, or is
    covered in snow, then the red signal reverts back
    to the safer “stop and proceed” signal. It’s a fail
    safe upgrade. Now, the R plate is sort of like
    our red lights on multi-headed systems. It’s a
    placeholder – you ignore it EXCEPT when the signal
    is red. Basically, you look for the most permissive
    signal. The only signal the R plate could
    possibly improve would be the stop signal. All other
    signals allow you to go at track speed, which is faster
    than restricting speed. So the R plate would
    upgrade the red signal to a restricting signal. At all
    other times, it is ignored. With two-headed signals, there’s
    a number of combinations you could see, but
    liken it back to our 3-head system. The second
    head represents the second head on the three headed
    signal. so imagine that the third head is there,
    only as a red placeholder which you would
    ignore, and ALL of the signals are exactly the same as
    the three headed signal. So here is your clear signal. This is advance clear to stop signal. This is a clear
    to stop signal. If both heads are red, the
    position of the heads now tells us what to do next: If
    the heads are positioned vertically, this
    signal is controlled by RTC who is instructing you to
    STOP and NOT proceed. If the heads are staggered, that
    is the automatic system indicating there’s
    something going on up ahead – most likely another
    train. You must stop at this signal, then you can
    proceed at restricted speed. Okay, that wraps up this
    segment. you’ve now learned the basics of the
    foundational three headed signal, the two headed and
    single headed CTC railway signals. In the next
    video we’re going to introduce advance speed signals.

    Railroad Signals, part 2: 1 and 2 head systems – reading and meanings
    Articles, Blog

    Railroad Signals, part 2: 1 and 2 head systems – reading and meanings

    August 14, 2019


    In the first video of this
    series, we laid the foundation for reading railroad
    signals with the basic three-headed railroad
    signal. If you haven’t watched that video yet, you need
    to watch it first to follow along in this video. Now, these signal heads are
    attrociously expensive: some $20,000 or more! So do the
    math: if you’re lighting up 100 miles of track
    with CTC lights, in BOTH directions, with signals
    every two miles? It adds up in a hurry! That track for the most part is
    just straight, high speed track. There are no
    switches or sidings. So to save on costs, the railroad
    will remove 1 or 2 of the heads. Remember how the
    two lower lights were red as placeholders? Well
    the signals are exactly the same, you’ll just
    imagine the placeholders, which I’m going to
    leave in this picture, with the two heads
    faded out to help you remember how to read the signal. This is a clear signal. Proceed
    at track speed. This is a clear to stop signal.
    Proceed at track speed, preparing to stop at next
    signal, which will be a stop signal. A flashing yellow on this light
    is NOT a slow signal. why? Because remember –
    this is the same as a three headed signal, but with
    the two lower heads removed, so this is the high
    speed signal head. Do you remember what a flashing
    yellow on the top head was? Advance clear to stop. We
    can proceed at track speed, next signal will be a
    clear to stop, the second signal will be a stop
    signal. Now – one thing to clarify
    before we get into the reds. When signals are stacked
    above each others like this, or this, that means
    that signal is under direct control of Rail Traffic
    Control. if the heads are staggered, they are
    NOT directly controlled by RTC, they are
    controlled by the automated CTC system itself. The
    lights are controlled by relays reading the
    traffic on the rails. Single head masts are generally
    not controlled by RTC, they are simply controlled
    by the automatic system. The single headed
    signals that are controlled by RTC have an A
    plate on them. Whether right or not, I always likened
    this to an ABSOLUTE signal. So if a single head is red, that
    is a STOP AND PROCEED signal. You stop, then
    proceed at restricted speed. BUT if the
    signal has an A plate, that is an ABSOLUTE stop. You
    stop at that signal and wait until it changes or RTC
    gives you specific, written permission to
    pass that signal. You remember how I talked about
    the system being designed as fail safe? the CTC
    system is tripped by the train making an electrical
    connection across the rails, which are connected
    to an electrical circuit. If that electrical
    circuit is broken in any way – a broken rail or
    broken wire for instance, the CTC lights all
    turn RED. So this can be a real problem if
    your super expensive train has to stop
    every two miles because there’s a problem with the
    system! Time is money, and we get paid to ship cargo,
    not park the cargo on the rails! So, they put an R
    plate on the signal mast. This is a cheap failsafe
    upgrade to the pre-existing system. If the
    signal is red, the R plate upgrades it from a stop
    and proceed signal to a restricting signal – the train
    still has to be on the lookout for other trains,
    broken rails, etc…, but now we don’t have to stop at
    the signal. If the R plate falls off, or is
    covered in snow, then the red signal reverts back
    to the safer “stop and proceed” signal. It’s a fail
    safe upgrade. Now, the R plate is sort of like
    our red lights on multi-headed systems. It’s a
    placeholder – you ignore it EXCEPT when the signal
    is red. Basically, you look for the most permissive
    signal. The only signal the R plate could
    possibly improve would be the stop signal. All other
    signals allow you to go at track speed, which is faster
    than restricting speed. So the R plate would
    upgrade the red signal to a restricting signal. At all
    other times, it is ignored. With two-headed signals, there’s
    a number of combinations you could see, but
    liken it back to our 3-head system. The second
    head represents the second head on the three headed
    signal. so imagine that the third head is there,
    only as a red placeholder which you would
    ignore, and ALL of the signals are exactly the same as
    the three headed signal. So here is your clear signal. This is advance clear to stop
    signal. This is a clear
    to stop signal. If both heads are red, the
    position of the heads now tells us what to do next: If
    the heads are positioned vertically, this
    signal is controlled by RTC who is instructing you to
    STOP and NOT proceed. If the heads are staggered, that
    is the automatic system indicating there’s
    something going on up ahead – most likely another
    train. You must stop at this signal, then you can
    proceed at restricted speed. Okay, that wraps up this
    segment. you’ve now learned the basics of the
    foundational three headed signal, the two headed and
    single headed CTC railway signals. In the next
    video we’re going to introduce advance speed signals.

    Railroad Signals, reading and meanings, part 1: The basic three light system
    Articles, Blog

    Railroad Signals, reading and meanings, part 1: The basic three light system

    August 12, 2019


    Being a bit of a railfan before
    I actually became a railroader, I’d always been
    curious about the signals used on the railroads to
    control trains. I actually learned how to read
    them before I became a railway conductor, and I know a
    lot of railfans have always been curious as
    well, and of course, model railroaders wanting to put
    in functioning signals onto their layout. So I thought I’d put together
    this crash course on reading railway signals. Now –
    the signals I’m going to be showing are Canadian
    railway signals. A lot of railways in the US use
    these same signals, or similar, or the same concept
    of signals, but with different methods of
    display. We use coloured lights here in
    Canada, but the Raton subdivision in New Mexico
    still has semaphores. The Pennsylvania railroad, and
    Baltimore and Ohio Railroad use a cross between
    coloured signals and semaphores – the lights are
    coloured, and show the semaphore position of
    horizontal, 45 degrees, or vertical. The most common signals are the
    searchlight signals. These are a single
    light which gets focused through two lenses and
    then the light passes through a coloured glass
    to make it either red, yellow or green. You can
    see the three coloured glasses in this picture
    of the internal workings of a searchlight
    railroad signal. The holder gets pushed to the right
    or to the left by an electromagnet to put the
    yellow or green glass in front of the light. Notice that the middle glass is
    red – this is a fail safe. If the electromagnet
    fails, then the light reverts to red. More and more we are seeing LED
    signals, nicknamed Darth Vader signals because of
    the large sun hood. The principles are the same as
    what I’m going to show you here, only previously,
    a single light could display three different
    colours through the use of different coloured glass
    that would be moved in front of the light. The LED
    signals just have three different coloured LED
    lights under the sun shield, but you just simply read
    the signal as this bank of lights represents one
    signal: it’s either red, yellow or green. The signals use the colours
    you’ve grown accustomed to with traffic signals: Red,
    green and yellow. There are some signals coming
    out that are “lunar” – which is a bluish-white
    colour, mostly seen in the US but is being seen in
    Canada. Trains are slow to accelerate
    and slow to stop. I’d been in one emergency stop
    situation where our train was only seven cars and
    two locomotives, and only going 25 miles an hour. It
    was incredible how much space it took to stop that
    train with the brakes in full emergency –
    probably took about thousand feet to stop. Some heavy freight trains can
    book along at 75 miles an hour – it can take them
    over a mile, or two kilometers, to come to a
    stop in full emergency brake. The reason for this is
    the same reason trains are the second most
    efficient means of transportation. The contact area
    of steel wheels on steel rails is about the size of
    a dime. So literally, an entire train’s
    contact with the rails can be the equivelent surface
    area of a coffee table. That means very little
    friction, very easy and efficient moving of
    incredible amounts of weight. But the downside of very
    little friction and surface area is stopping
    that train. So we need to know what we need
    to do with the train MILES in advance so we can
    take appropriate action to control the train. It
    can take two miles or more to bring a freight train
    to a gentle, controlled stop – what we call a
    “service stop” so we need to know well in advance
    what’s happening up ahead. So there are basically two train
    control systems in Canada: OCS which is the
    Occupational Control System, or CTC which is the
    Centralized Traffic Control System. Up here in
    Northern Alberta where I work, it is all OCS which means
    that, just like air traffic control of aircraft, we
    get clearance from Rail Traffic Control to be on
    the rails. They give us the rails and assure that no
    one else is on OUR track, and we are controlled by
    Rail Traffic Control via the radio. Rail
    Traffic Control is known as RTC. CTC is the most efficient type
    of rail traffic control, and that’s where the
    signals come in. It’s controlled by RTC, but RTC gives
    instructions to the trains via these signals.
    The distance between the signals varies. On the CP
    line behind my house in Ontario, they had signals
    every two miles for instance, but in heavier traffic
    corridors the signals can be closer together. The base CTC signal is three
    lights on a mast. This signal, green over red over red,
    believe it or not, is “clear signal” – it means go
    full bore – whatever your speed limit is,
    you are permitted to go full speed ahead, the track
    is clear ahead of you. You might wonder why on earth do
    they have the red lights then? There are actually multiple
    reasons for this. First of all, understand that is it
    the COMBINATION of lights that communicate what to
    do. The combination of three lights, each of which
    could be either red, yellow or green. Secondly, these
    are mechanical devices – the light bulbs can
    blow out, the mechanics inside that change the
    colour of the light can break. Using three
    lights, we can get an indication of what we need to do
    as much as three signals in advance. So at two
    mile spacings, we could know six miles in advance
    if we have to slow down or stop. But – if the two lower lights
    aren’t lit up, then we’d have to guess what the
    signal combination is! We can’t do that – our lives,
    and the lives of others are on the line here,
    there’s no guessing allowed. So consider the two red
    lights as “placeholders.” They’re lit, so
    we know that they are functioning, but they are
    showing red which effectively means we can ignore
    them as they are below the green signal. The three signal heads each
    represent three different speeds: The top light
    is for high speed – basically whatever the maximum
    speed for that track is. The second head is medium
    speed. The bottom head is for slow speed. Medium
    speed is an actual speed – it is designated as 30
    mph. Slow speed is also an actual speed – 15 mph. So if this signal means track
    speed, then what does this signal mean? You might have
    guessed – it means medium speed. So you should not
    be going any faster than 30 mph when you pass this
    signal. This signal would mean? You guessed it –
    slow speed, or 15 mph. You should not be going any
    faster than 15 mph when you pass this signal. If all three are red, you could
    probably guess what that means. Yup, it means stop. This is slightly simplified for
    instructional purposes, but there you have it:
    your first four signals, and the basics of the
    CTC signal system. But remember – we’re a train,
    and we need to know MILES in advance of what’s ahead
    of us. We need to know long in advance what we’re
    going to need to do. So we’re trucking along at
    track speed, and we come to this signal: Remembering that the uppermost
    non-red light is the one we always want to pay
    attention to, and we ignore the other red lights as
    placeholders. Basically this signal means
    we’re okay to pass this signal at track speed, but it’s
    yellow – warning us that the next signal is going to
    be a stop signal. This signal is called “clear to
    stop,” because we are clear to proceed past this
    signal at track speed, but we need to prepare to
    stop at the next signal. We were just given two
    miles warning of what the next signal is
    displaying, and simultaneously told what we can
    do at THIS signal. Knowing what you now know, you
    might just be able to figure out what this signal
    means. You guessed it: Medium to stop.
    So if you’re driving the train, you must pass
    this signal going no faster than medium speed, or
    30 mph, and expecting the next signal to be
    a stop signal, so you’ll be preparing to stop. Now there is one small catch to
    this next signal: The slow speed light is flashing
    yellow. There’s a reason for that which we’ll get
    to in a minute, but let me just tell you that the
    slow speed head flashing yellow means slow, and
    because it’s yellow, that means the next
    signal will be a stop signal. So this signal is “slow
    to stop.” You can pass this signal going no more
    than 15 miles and hour, preparing to stop at the
    next signal. While we’re on this signal, I’m
    going to explain one of the weird signals. Let’s
    say the yellow light was solid yellow, not
    flashing. This is very similar to the slow signal, but
    with a further RESTRICTION. This signal is
    called restricting signal for restricted speed. You
    cannot go faster than slow speed – 15 mph, but
    the further restriction is that you must be
    on the lookout for a switch lined against you,
    broken rails, and able to stop within half the distance
    of vision. Heres why: If I can only see 1,000
    feet ahead of me, because of a curve with trees on
    the embankment for instance, I have to drive the
    train at a slow enough speed so that when I see
    something on the tracks, I can stop in 500 feet –
    HALF of the distance that I could see. Why
    is this? It’s because that something on the
    tracks may be another train – moving in the other
    direction! So if he is also driving at a speed in which
    he can stop in half the distance he can see,
    then we both stop in half the distance of sight,
    meaning we meet in the middle and don’t collide. Now again, remember – this
    system is built up on a mechanical system. Mechanical
    systems can fail. So let’s take a look at our slow to
    stop signal. It’s a flashing yellow signal on the
    slow speed head. There’s a little relay inside
    the control box that flashes that light. Let’s say
    that relay burns out, and the light no longer flashes.
    It is now a solid yellow. What has just happened?
    It is a fail safe system – we HAD a less
    restricting signal – we were just limited to a maximum of 15
    miles an hour. But now because it’s a solid yellow,
    it’s now a restricting signal which is more
    restrictive than a slow signal: we have to slow
    down to whatever speed the terrain demands. We need to
    be extra cautious and be able to stop within half
    the distance of vision. So those are the two
    reasons why the flashing yellow light means slow
    speed. you’ll notice this very
    carefully thought out trend as we start to get into flashing
    lights on the signals: If the flashing fails,
    the signal simply reverts to a more restrictive
    signal. A flashing yellow light on the
    top now tells us what’s going on TWO signals
    ahead of us. It’s yellow and on the top head,
    meaning we can blow by this signal at full speed ahead
    – but it’s yellow, warning us that up ahead is a
    stop signal. It’s flashing, telling us that the
    stop signal is TWO signals ahead. So this signal
    will be a flashing yellow, meaning advance clear to
    stop. We have now been given advance warning that
    in FOUR miles we’re going to have to stop. The next
    signal will be solid yellow on the high speed
    head, meaning clear to stop. We can blow by that
    signal at track speed if we want, preparing to stop at
    the next signal. Now let’s say that the flashing
    relay melts down in the control box again, and our
    light now stays a solid yellow. What has happened? It’s a fail safe system: It’s
    the wrong signal, because we would read it as
    clear to stop – we would pass this light thinking
    we had to stop in two miles, not four miles. We
    would get to the next signal, expecting it to be a
    stop signal, but it would turn out to be a clear to
    stop signal as well. No bigee – we carry on at
    track speed to the next signal, prepared to stop. So now that we’ve seen how the
    signals can indicate both what to do NOW, and what to
    expect at the next signal, let’s go back to our
    first three signals again: This one is a clear signal.
    Proceed at track speed. This one as we discussed is a
    medium signal, but it is green – indicating that the
    next signal is a clear signal. We must slow down
    and pass our ENTIRE train by this signal going no
    faster than medium speed, then we can speed up to
    track speed. The reason for the medium speed
    will no doubt be because at that signal, the
    train will pass through a switch. You can’t just go
    blazing through those switches at high speed! You’ll
    take the train right off the rails because it can’t
    take the corner at high speed. But this switch is
    designed to be transited at 30 mph or less. So,
    you pass this signal at medium speed,
    indicated by the medium speed head. The light is green
    which tells us that the next signal we encounter
    will be a clear signal. It’s the same thing if we
    encounter a green light on the slow speed head. The
    switch will have an even harsher curve to it,
    designed for a train going 15 mph or slower. However,
    the light is green, telling us that the next
    signal will be a clear signal. So once our entire
    train has gone through the switch, we can now
    accelerate to track speed, knowing that the next
    signal is a clear signal. This three head signal system is
    the foundation for all of the other signals I’m
    going to show you in this series of videos. Just keep
    this three head system in mind as you learn the
    other indications – high speed on the top, medium
    speed in the middle, slow speed on the bottom. In the next video, we’ll discuss
    two headed and single headed signals, the
    reasoning behind them and how to read them.