steve-in-kvilleHere's another: How close to the W sign are the sensors to drop the crossbucks?
Most of our whistle posts are about 1200 ft from the crossing. There are a few leftover from when they ran passenger trains 90mph. The circuits are a lot farther out then that.
We have a rule, as I suppose others do too, that when starting movement within 3000 ft of a crossing speed must not be increased over 5 mph until it's seen the crossing signals have activated and gates (if equipped) are fully lowered.
Jeff
Good References:
Introduction to Railroad Signaling and Grade Crossing Operations
http://shrp2.transportation.org/Documents/Renewal/Webinar-Rail-Signaling%20and%20Grade%20Crossings%2010.18.18.pdf
There was a great site with a lot of info that I cannot find ..will keep looking
Semper VaporoWhat triggers the circuit to turn on the lights and lower the gates is how fast that current increases as a train approaches. The faster the train the faster the current goes up and the sooner the gates will come down. When the current flow returns to the previous state the gates are raised and the lights turned off. Or if the current stops changing (the trains stops before reaching the crossing) the same thing can happen. But, it can also sense when the train is in the crossing so that it will not release the gates and shut off the lights if the train stops but is still blocking the crossing.
That describes the "predictive" circuits.
With a fixed circuit, it's a matter of whether a train is shunting the circuit. A train standing still on the "approach" circuit will cause the gates to stay down.
The gates will only rise if the activation is over-ridden (a button, usually in a locked box on the signal shelter) or it the circuit is jumpered out, OR, the train goes through the logic of the crossing properly. If that's the case, the gates will rise once the train clears the island circuit (the crossing itself).
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
It is not always a matter of a “sensor” some distance from the crossing.
If it were just a sensor at some distance a fast train would arrive that the crossing sooner than a slow one. Motorists don’t really know how fast the train is moving and so they would be frustrated with gates that drop too long before a skow train gets there or might get killed if the gates didn’t drop soon enough before a fast train got there.
The crossing lights/gates are controlled by a circuit in the little bungalow near the crossing. It is measuring the current flow between the rails. Sometimes there will be a “shunt” across the rails at some distance from the crossing and it can be at various distances from the crossing, depending on what other sensor circuits are in the vicinity; other crossings, crossovers, switches to spurs and other tracks, diamonds (crossings with other RRs), etc. The shunt might be up to or beyond a mile away, or there may be no shunt specific for that circuit.
The circuitry is measuring the current flow from one rail to the other. This current depends on the resistive value of the rails, the shunt (if present) and the leakage of current through the ground, which will vary with humidity and other factors of nature. It also varies as to any trains in the area and how many axles it has shorting out the rails, and how dirty (leaves, mud, rust, etc.) the rails and or wheels are.
What triggers the circuit to turn on the lights and lower the gates is how fast that current increases as a train approaches. The faster the train the faster the current goes up and the sooner the gates will come down. When the current flow returns to the previous state the gates are raised and the lights turned off. Or if the current stops changing (the trains stops before reaching the crossing) the same thing can happen. But, it can also sense when the train is in the crossing so that it will not release the gates and shut off the lights if the train stops but is still blocking the crossing.
Semper Vaporo
Pkgs.
The gates are supposed to be activated 15-20 seconds before the train arrives at the crossing. How far out the train is for that to happen is dependent on track speed.
For hard-wired crossings, that's where the gap will be. The W sign may not be at the same point for high-speed crossings, as the horn is only to be sounded at a quarter mile from the crossing in those cases.
Predictive circuits use doppler via the rails to determine the approach speed and activate the lights and gates at the appropriate distance/time. In this case, the W sign will again be set based on maximum track speed.
In either case, it's up to the engineer to ensure proper horn warning.
CSSHEGEWISCH When you consider that the consignee is usually a lumber yard, I'm surprised that tipping doesn't occur more frequently. I've rarely seen lumber yards with a lot of open space on each side of the track.
When you consider that the consignee is usually a lumber yard, I'm surprised that tipping doesn't occur more frequently. I've rarely seen lumber yards with a lot of open space on each side of the track.
Thanks to Chris / CopCarSS for my avatar.
Regards - Steve
SD70DudeEven those with all-steel wheels and axles do not always reliably activate the signal system, I suspect due to some combination of the smaller number of axles and lighter weight compared to a locomotive or railcar.
Since we don't run in the winter, we start out each season with instructions to approach each signalled crossing prepared to stop, account rusty rails.
Hi-railers generally stop at every crossing, and have exclusive occupancy of a block by warrant/EC1/Form D, or whatever mechanism that railroad uses. You may find hi-railers following a train, but you'll virtually never see on preceeding a train.
steve-in-kvilleI had seen a hi-rail maintenance truck on the main line yesterday. But for some reason it did not trigger the block lights or the crossbucks? Any idea why?
How Hi-Rail Pickup Trucks Work | The Daily Drive ...
Hi-Rails and other maintenance equipment may have insulated wheels, so do not activate track circuits. Even those with all-steel wheels and axles do not always reliably activate the signal system, I suspect due to some combination of the smaller number of axles and lighter weight compared to a locomotive or railcar.
Here's a incident report from a crash involving a train and a hi-rail. The hi-rail had proceeded outside its working limits, and the train crew was proceeding on permissive signal indications:
https://tsb.gc.ca/eng/rapports-reports/rail/2016/r16h0024/r16h0024.html
Greetings from Alberta
-an Articulate Malcontent
The wheels are insulated.
tree68I'm pretty sure I've mentioned seeing, years ago, lumber being unloaded from a boxcar, board by board, running down a roller tray into the lumber shed...
That second one is for 'Olympic/Paralympic wheelchair race route crossing'.
Before the advent of the ADA, I think the 'usual' meaning of the sign would have been to indicate wheelchair-accessible restrooms. Not too much else was provided free then...
More active? My first thought was that he was falling out of the wheelchair. Come to think of it, that is more active than sitting.
When I first saw that wheelchair figure on highway signs ( the original one), I thought it indicated restrooms.
_____________
"A stranger's just a friend you ain't met yet." --- Dave Gardner
I'm pretty sure I've mentioned seeing, years ago, lumber being unloaded from a boxcar, board by board, running down a roller tray into the lumber shed... Talk about manpower intensive.
Re: Pictograms. There are now two handicapped pictograms in circulation. The one with the individual seated upright is still the officially recognized version. The second depicts a more active individual. Only two states have made that one official. The international version is still the first version.
DeggestyQuite interesting, Paul. The only warning I have read indicated that no more than two layers should loaded or unloaded before moving to the other side and, again, moving no more than two layers past leaving/adding and then moving to the other side. That is, no more than a two layer imbalance...
That's a practical interpretation of what Paul's warning says.
If we were to 'literally' follow what that warning calls for, we'd need coordinated lifts from both sides of the car at once, I might add starting alternately from the ends toward the middle in a coherent pattern, so that the added weight is 'exactly' balanced side-to-side at any point. My opinion is that this is lawyer CYA; you can't argue in court with what the 'manufacturer' or 'owner' has said about keeping the balance exact, exact, exact even if in 'practice' that's functionally ignored...
I'd note that with palleted loads the 'two-layer' weight might be greatly exceeded modularly, to the point where you well might want to alternate 'sides' even piece by piece. Especially if the side-bearing clearance is excessive, or the truck springing compromised, or the track 'soft' or inclining to one side...
Quite interesting, Paul. The only warning I have read indicated that no more than two layers should loaded or unloaded before moving to the other side and, again, moving no more than two layers past leaving/adding and then moving to the other side. That is, no more than a two layer imbalance..
Johnny
Link to one of the center beam warnings (3rd photo):
http://www.trainweb.org/mccloudrails/Equipment/Centerbeams.html
I did find some others - one had some profane graffiti added - but I can't locate them now.
- PDN.
Add the Volkswagen Fahrvergnügen ( promo stick-guy) and the Nine-Inch Nails logo w...and then
Overmod MikeInPlano Not sure I get the reason for this link... It's humor. If the flat, outline plug-door guy is related to the flat, outline guy running away from tipover, why can't they also be related to the flat, outline mudflap girl? Note I didn't bring up their urban relatives from Haring and Harald.
MikeInPlano Not sure I get the reason for this link...
It's humor. If the flat, outline plug-door guy is related to the flat, outline guy running away from tipover, why can't they also be related to the flat, outline mudflap girl?
Note I didn't bring up their urban relatives from Haring and Harald.
MikeInPlanoNot sure I get the reason for this link...
Overmod Not sure I get the reason for this link... zugmann He's related to the guy that always has the plug door falling on his head. I like their far more attractive second cousin much more: https://www.youtube.com/watch?v=wObd5GI-qGk
zugmann He's related to the guy that always has the plug door falling on his head.
I like their far more attractive second cousin much more:
https://www.youtube.com/watch?v=wObd5GI-qGk
zugmannHe's related to the guy that always has the plug door falling on his head.
jeffhergertLove the stencil of the little stick figure running from a turning over center beam on the inside of the end bulkhead. Some even have added "speed indicating" lines behind the running figure.
He's related to the guy that always has the plug door falling on his head.
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
jeffhergertLove the stencil of the little stick figure running from a turning over center beam on the inside of the end bulkhead. Some even have added "speed indicating" lines behind the running figure. Jeff
tree68 Deggesty I wonder how often the load/unloading instructions are ignored. Probably only once by any given person/crew... I wonder, though, if anyone has come up with the expedient of placing jacks under the corners of the cars to reduce/eliminate the tipping.
Deggesty I wonder how often the load/unloading instructions are ignored.
I wonder how often the load/unloading instructions are ignored.
Probably only once by any given person/crew...
I wonder, though, if anyone has come up with the expedient of placing jacks under the corners of the cars to reduce/eliminate the tipping.
Deggesty CShaveRR The Centerbeam flat cars are notoriously top-heavy--they don't have thick underframes down below floor level. I nearly had a passed-drawbar incident while working that would have fipped about a half-dozen of them on the yard lead...fortunately, I could grab the loads in the retarder, let the centerbeams right themselves and roll, then it could be fixed the right way with a locomotive making the joints. I have not seen many centerbram cars up slose, but I am sure that if you examine one carefully, you will see instructions for loading and unloading--you do not fill one side and then fill the other; you balance the overall load as much as is possible--some on one side, as much on the other side plus as much, back to the first side and add more, back to the second side.... Unloading is done in reverse--some off, change sides....
CShaveRR The Centerbeam flat cars are notoriously top-heavy--they don't have thick underframes down below floor level. I nearly had a passed-drawbar incident while working that would have fipped about a half-dozen of them on the yard lead...fortunately, I could grab the loads in the retarder, let the centerbeams right themselves and roll, then it could be fixed the right way with a locomotive making the joints.
The Centerbeam flat cars are notoriously top-heavy--they don't have thick underframes down below floor level. I nearly had a passed-drawbar incident while working that would have fipped about a half-dozen of them on the yard lead...fortunately, I could grab the loads in the retarder, let the centerbeams right themselves and roll, then it could be fixed the right way with a locomotive making the joints.
I have not seen many centerbram cars up slose, but I am sure that if you examine one carefully, you will see instructions for loading and unloading--you do not fill one side and then fill the other; you balance the overall load as much as is possible--some on one side, as much on the other side plus as much, back to the first side and add more, back to the second side.... Unloading is done in reverse--some off, change sides....
Love the stencil of the little stick figure running from a turning over center beam on the inside of the end bulkhead. Some even have added "speed indicating" lines behind the running figure.
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