Tag Archives: railroad crossing

Call board safety video

From the “I forgot I had this” files (sometimes I have the memory of a goldfish). This is a short TriMet safety video about call boards and their use to protect workers in the right of way. Safety at rail is not a joke and it’s never taken lightly because of how severe the consequences of a lapse in safety can be. I think it’s a good thing for the public to see things like this because ordinarily they don’t get the opportunity to watch how much effort goes on “behind the scenes” to keep things running smoothly and safely.

Manual blocks and reverse traffic

I recently was asked some questions about

Manual blocks

(and this post got long… you might want to go make a nice sandwich or something for yourself before settling in to this one)

When train movement on one track is not available, a manual block is used to move trains on the adjacent track. This could happen because of planned maintenance, or it could be done in the event of an accident/emergency situation. In a manual block, Control directs train movement in both directions on the track that is in service. Manual blocks will have associated train orders.

You’ve done the equivalent of a manual block in your car before if you’ve gone through road construction where only one lane is open. For cars in that setting, there’s a flagger at each end of the construction area that lets a number of cars through and holds oncoming traffic from entering the single lane, and then they switch to let cars from the other direction go through. A manual block for trains is essentially the same idea – Controllers and supervisors coordinate to govern train movement into a manual block, alternating between trains running normal traffic (e.g. east in the eastbound) and others running reverse traffic (west in the eastbound).

Reverse traffic

Borrowed photo. This is not a manual block, but it shows a train running reverse (here east in the westbound at Willow Creek)

Running reverse traffic is not the same thing as backing a train up. An operator backing a train up (such as in the case of uncoupling a train car) can’t see in the direction that the train is moving – this is why backing a train up is almost never done. When an operator is running reverse traffic, they face in the same direction as the train’s movement, but that movement is in the opposite direction of what the track they’re on is typically used for.

There are a number of rules that govern running reverse traffic. First, it’s always done at restricted speed (the lesser of 20mph or the posted speed and always at a speed that the operator can stop in half their sight distance) whether or not it’s part of a manual block, unless you’re in the tunnel. Because the tunnel is signalized in both directions, trains running reverse can operate at the posted speed limits which are about the same as normal speed limits, though trains going west in the eastbound bore will exit the tunnel much slower than normal traffic because they will be diverging into the west portal pocket track. Other areas of the alignment that are signalized in both directions are already single track, e.g. the “fishhook” for the Red Line at Gateway, so travel in both directions is normal.

While running reverse, operators will also have to stop and observe every set of switch points to ensure they are properly aligned. In ABS territory, running reverse traffic is where dwarf signals come into play – they protect mainline power switches while running reverse traffic. In other words, the ATS magnets associated with the dwarf signals are active for trains going the “wrong way”. Operators will have to key-by these signals (this is done from the operating console in the train cab) after calling Control. This gives the operator 23 seconds to move the train past the ATS magnet without tripping.

On Burnside, operators running reverse traffic will have to SOP the intersections since the mass detectors are only for normal traffic. If the reverse running on Burnside is part of a manual block, the train orders associated with the manual block will include instructions to SOP intersections within the block. So operators will not need to call Control for permission at those intersections, but otherwise the process to SOP them is the same – stop, wait for fresh parallel green and walk signal and red left turn signal, sound horn warning, and proceed when safe.

You may have seen these stop signs at gated intersections or in places where the view is obstructed by a substation building – these are for trains running reverse traffic since people are not likely to expect a train from that direction on that track.

Gated intersections are also handled differently when running reverse traffic. When running normal traffic, the gates are lowered either by a call loop if the platform is right near the intersection (such as the above picture of Elmonica/170th) or when the train enters the approach circuit as it approaches the crossing gate for gates that are not near a platform. There is another circuit that extends 10 feet on either side of and through a gated crossing called the island circuit. When the island circuit is shunted, it will lower the crossing gates if they weren’t already lowered – you won’t notice this running normal traffic since under normal operations the gates will be lowered by the time the train gets there, but when a train is running reverse traffic, it uses island circuits to lower the crossing gates. The operator will wait until the gates have been fully lowered for 10 seconds before proceeding through the intersection.

Manual Block

In a manual block, most of the rules that apply to trains running reverse traffic will also apply to those running normal traffic. For one thing, travel in both directions of a manual block will be done at restricted speed, unless otherwise instructed by Control.

Borrowed picture – Both of these trains are running normal traffic, but it shows switch points as the operator sees them. Here it is a trailing move since the points are facing away from our oncoming train

If there are switches in the manual block, operators in both directions will be required to stop and observe every set of switch points before proceeding, regardless of whether the switch points are facing toward the train or away from the train (as seen in the above picture).

A planned manual block will have a written train order, but operators about to enter a manual block, whether planned or unplanned, will still call Control before they enter to receive specific instructions. The instructions will have to be repeated back word for word, which ensures that there is no misunderstanding of the instructions, since manual blocks have the potential to be extremely dangerous. Even at 20mph, a train splitting a switch (making a trailing move over a power or t-rail switch that isn’t set for you) or hitting another train can cause serious damage. The specific details of the instructions may vary depending on where the manual block is and why a manual block is in effect – for example, a planned manual block may have pullback operators to pull the train through crossover switches so that the operator of the train doesn’t have to change cabs.

Previously, a “medallion” system had been used for manual blocks. A medallion was an object such as a stuffed animal (like the rabbit) that would be passed off to a train as it was about to enter the block. If you didn’t have the medallion in your possession, you would not enter the block. Nowadays that system isn’t used. Instead, a clearance sheet is used to record all train movement in manual blocks. This written record details the movement of all trains into, through, and out of the block, ensuring that only one train is in the block at a time.

Once an operator is clear of the block, he or she will call Control. Their train will be recorded on the clearance sheet, and the operator will then be able to resume normal operation. The next train will then be cleared to enter the manual block. This process continues for the duration that the block is needed. At that point, Controllers and supervisors will ensure that all trains are clear of the manual block and that all switches are aligned normal and locked. The first train through the track that had been out of service may be asked to sweep that section of the alignment, especially if the manual block was due to an emergency, and then following trains can operate as normal.

Decision Point Markers

Okay, back to train stuff.  Here’s a neat safety feature built into the alignment on Burnside (Blue Line) and Interstate (Yellow Line) – the decision point marker.

Decision Point Marker BurnsideDecision Point Marker on Burnside

Decision point marker InterstateDecision Point Marker on Interstate – since the rail is embedded in pavement here they look a little different, but the function is the same.

As you may recall, both Burnside and Interstate are in pre-empt territory, meaning intersections with auto traffic are protected by pre-empt signals, not crossing gates.

Recall that the permissive pre-empt signal aspect is a white vertical:

White Vertical

A rail operator traveling down Burnside or Interstate cannot enter a pre-empted intersection unless their signal is displaying that white vertical. But unlike the pre-empted intersections downtown where the speed limit is 15mph or below (a relatively slow speed to stop from if a white vertical is not yet displayed), the speed limits on Burnside (35mph) and Interstate (30mph) are much higher, and not as easy to stop a train from.  The intersections are also farther apart on Burnside and Interstate than they are in other pre-empted areas such as Holladay and Washington – both of which still run slower than Interstate and Burnside.

So, someone did the math to figure out if a train is going 30 (or 35) miles per hour, and then applies the strongest braking mode permissible to use in normal service (called the Maximum Service Brake, or MSB), how many feet does the train take to stop? It’s about 400 feet at 35 mph under ideal conditions. The decision point markers were then placed between the rails that many feet prior to each pre-empted intersection – orange tents on Burnside; orange reflectors on Interstate.  If an operator reaches the decision point marker and their pre-empt signal is still displaying a yellow horizontal (which indicates stop and does not permit them to enter the intersection), they must immediately apply the MSB braking in order to smoothly and safely stop the train before entering the intersection.

Decision Point Marker on InterstateAnother Interstate picture

One of many safety features built in that commuters never need to think about, but it’s a very good thing that they’re there – they take the guesswork out of how to best stop the train if the white vertical does not come up.

Failed crossing gate

I had mentioned in an earlier post that one use of call boards is if a crossing gate fails.  I didn’t have any pictures of failed gates at the time, but thanks to today’s windstorm, I do now:

Failed crossing gateSW Hall, failed crossing gate – it bent backwards on itself

An eastbound operator told me that Hall failed, so I was able to get a picture as the train I was riding westbound went through. I heard the gate at 185th before Willow Creek failed too, but I got off my train at Elmonica and by the time I went through Willow Creek later in the evening it had been repaired (as was the gate at Hall).

So if you experienced a delay in your MAX commute on the westside today, this is part of the reason why – each westbound train had to call Control at Beaverton Transit Center, each eastbound train had to call Control from Beaverton Central, and then in both directions trains had to come to a full stop and sound warning before proceeding through the intersection – and if the gate at 185th was down as well, that was another stop & delay.

All in the name of safety though!

Call boards

I had been working on a draft of this topic, then I saw a video of Al’s asking about these, so here it is:

Ever see one of these before?

call board

You probably have even if you never gave it conscious attention since track work is done almost daily… they’re called “Call boards” (the logic behind that naming convention is pretty obvious!)

They’re one of the many safety features built into the system.  When a call board is up, an operator MUST call Rail Control over the radio before doing anything at that platform aside from opening their doors.  They cannot leave that platform or select their signal (at platforms where that’s applicable) until they get permission over the air from Control.

There are a number of reasons why a call board might be up.  Two that I’ve seen most frequently are for track personnel and crossing gate failure.

Authorized Maintenance of Way (MOW) Personnel in Track

The most common use of call boards is for authorized personnel in the track – this can be anything from people doing maintenance on the switches, cleaning litter, or doing a walking inspection of the rails and overhead lines.

So for example, if personnel are going to be walking down the tracks along I-84, it’ll be typical for call boards to be up at Lloyd Center for eastbound trains and Gateway for westbound trains.  When an operator calls Rail Control at either of those locations, Control will contact the personnel doing the inspection to confirm their location and ensure that the train operator knows where they will be.  The train will then operate at reduced speed away from the platform, giving audible warning to the personnel, and then resuming normal speed once they’re clear of the area.

Obviously this is a HUGE safety issue – normal operating speed in some areas of the alignment is 55mph.  Consider what could happen if there were personnel in the tracks and the operator, not knowing they were there, went down the tracks at full speed. Requiring operators to contact Control when they see a call board ensures that they know where to expect people in the tracks and can proceed at a slower rate of speed until clear of the area. No TriMet employee has ever been killed by TriMet light rail, and using a setup like mandatory calls like this is a big part of the reason why.

The reason why an operator can’t select their signal at a platform without permission if a call board is up is that at many platforms, selecting a signal will also throw switches on the alignment, in locations not always visible from the platform.  If a worker has their hand or a tool in the switches and the switch suddenly moves, serious damage can occur.

Crossing Gate Failure

The second use of call boards that I’ve seen has been when crossing gates fail.

Crossing GatesI have no pictures of a broken gate, so here is a crossing gate that is working properly - the slightly long exposure shows that all of the mast lights and arm lights are working – normally they are flashing lights.  EDIT – on April 5, 2010 I got a picture of a failed gate arm.

First, a gate has malfunctioned if one of the mast lights are dark or if one of the gate arm lights are dark.  In these situations, the gate will be reported to Control so it can be fixed, but movement through it can proceed as normal.  A gate is considered failed if more than one of the mast lights is dark, or if more than one of the arm lights is dark, if a mast light AND an arm light are both dark, or if the gate is obviously broken (gate arm on the ground or stuck in the upright position, car crashed into it, etc). Federal regulations come into play when this happens. So when a gate has failed, a train is required to call Control from the platform prior to the broken gate. At the crossing with the failed gate, the operator must come to a complete stop, sound horn warning, and proceed when safe – even if there is a supervisor or police officer directing traffic at the intersection.

Once again, you can see the importance of the call boards – they are a reminder ensuring that the train operator knows that they will have to come to a complete stop at the next gated intersection because gate protecting it has failed.