I suspect that I’m going to put a cat among pigeons here…
To try to minimise the mayhem…
The track layout and signals are as Dave H sorted me out in my “protecting a diamond” thread.
The date is 1985.
There are two seperate Class 1 RR. - These, and the interchange link between them are not dark territory to each other. (If that matters).
The signals protecting the crossing are absolute controlled from a tower close to the crossing.
Not just being awkward - this was in the original sketched plan - there is at least one road grade crossing of both RR close to the diamond.
As far as I know so far it won’t make any difference if there is more than one crossing.
For now I’m assuming that one (or both) grade crossings are between the protecting signals and the RR/RR.diamond. These crossing(s) are protected by crossbuck with flashing lights (and audible warning) but no barriers.
Feel free to quote just the above and tell me how it would be done on the real RR please…
AND/OR, if I’ve got this anywhere near correct answer the following (possibly miles off target) questions…
AFAIK USA Grade Crossing protection is not linked in with Absolute Signals - ??? - I could be completely wrong on this…???
AFAIK Grade Crossing crossbucks and lights C 1985 could be tripped/set working by either an approach track circuit or an approach treadle… or manually… Is that correct?
If approach TCs or treadles set them off could they be set up so that the speed of the approaching train would trigger a sequence of detection and set the crossbucks off more rapidly for fast train
Grade crossing signals are not connected to the block or interlcoking signals in any fashoin. They are separate circuits and signals.
Crossbucks are twwo pieces of metal wood bolted to a post They are just a sign. They aren’t tripped by anything,
Active warning devices (lights gates) are tripped by a track circuit that is timed based on the speed of the track. No treadles. No manual activation.
You do have a variety of options depending on the type of road that is crossing. Minimum is crossbucks only. Then you can add flasshing lights, then gates, then cantelever lights, and finally double gates (both directions of lanes on both sides of the crossing.)
Crossbucks aren’t set off by anything. The active warning devices (bell, lights and gates) generally fall into two options which depend on when the circuits were installed or last updated. Either the bells, lights, and gate stay on and down until the train moves or in newer systems with motion sensors, after a certain time they they go off and then don’t come on until the circuit senses another train moving in the circuits.
Grade crossing signals are not connected to the block or interlcoking signals in any fashoin. They are separate circuits and signals.
Crossbucks are two pieces of metal wood bolted to a post They are just a sign. They aren’t tripped by anything, Sorry: I was using “crossbucks” sort of generically to mean crossbucks with warning lights - but no barriers.
Active warning devices (lights gates) are tripped by a track circuit that is timed based on the speed of the track. No treadles. No manual activation. Would that be the case in 1985 please?
The big question that I have is the one about trains getting stopped short of the grade crossings by the protecting signals for the diamond. Tripping the warning lights with an approach track circuit would give a false signal in that case. Wouldn’t this cause there to be some sort of interlock between the systems?
The next big issue would be the one of what happens when a train that has been stopped then gets the road… starting to move from right up close to the crossing?
You do have a variety of options depending on the type of road that is crossing. Minimum is crossbucks only. Then you can add flashing lights, then gates, then cantilever lights, and finally double gates (both directions of lanes on both sides of the crossing.)
[quote user=“Dave-the-Train”]
If the crossbucks get s
If there is a crossing close to the diamond, usually the crew will stop short.
Stopped short of a private crossing. The home signal for the diamond is up a ways.
Starting up from a dead stop takes a bit of time, plenty for the lights to get going. If needed, the train would stop a little ways back from the crossing to get the lights going while the train accelerates, about 20 seconds before getting into the crossing.
Very few manually operated grade crossings left in 1985. Might be some in congested areas with many switching moves, but most would be automated well before 1985.
Crossing protection is handled by a separate track circuit, called an island circuit. Stand alone in dark territory or overlaid on the signal circuits. The island circuit is timed for the maximum authorized track speed. Modern motion sensing circuits can vary the activation time based on speed.
When the island circuit is cleared, the crossing protection is deactivated.
As Dave H said, nope. The island circuit never takes a break, works in dark territory, etc. Also the tower operator may bend the rail and clear the signals far in advance of an approaching train. So having the crossing protection active that long, defeats the purpose of it.
With motion sensing circuits, after the train is stopped for a set amount of time, the protection deactivates.
No. Stop thinking that there are any cases where the crossing protection and the railways block or interlocking signals have any influence on each other. They don’t.
If the train has stopped, and the circuit timed out so the crossing signals turned off, then the train would start to pull forward very slowly until it hit the next part of the circuit so the system detects it’s moving and activates the lights/bells/gates again. The train will also ring its own bell and blow the horn as required to let people know it’s moving.
[quote user=“Dave-the-Train”]
This is pretty much the same issue as above… but to give an example… I’m thinking that a train westbound on the 2nd Main could get held in the 2nd Main while one of several things happens:-
A train on 1st Main can pass either way
A train on the other (RRB) track through the diamond can pass in either direction
I don’t believe how fast I seem to be getting the hang of this!
I’ll have to do a sketch for the “track in pavement” concept. Although I think that that may have been covered.
Anyway… I’d forgotten about islands circuits. The holding back makes sense… I’d begun to wonder if that was the solution after all the questions in red. Naturally I don’t want it to be as I want trains to come right up to the protecting signals to wait their turn. So I may have to just shift the grade crossings.
I’ve quoted Nick because it seems to suggest that there can be one clear answer for the main tracks - hold back off the circuit - what do the signs look like please? - and a different one for the switching track.
Would I be right in thinking that the switching track might have a manual over-ride operated by the brakesman or other crew member whenever a switching move might set the lights off incorrectly? Would/could there also be a manual over-ride to cancel the first action and set the lights working?
As it is a switching track I imagine that (A) they wouldn’t want to spend a lot of money on complex track circuits and (B) the movements would be very slow and with plenty of crew - probably riding on the loco steps or car stirrups - to work over-ride switches.
What would over-ride switches look like please? Would they be on the side of lineside equipment boxes or in small phoneboxes on top of posts like they have by some remote electrically released switches?
Hmm… I’m thinking about the manual over-ride… would it reset automatical
While some railroads may have markers for the circuits, I can’t recall ever seeing any markers for the crossing circuits. Just the insulated joints in the rails.
I have never come across a crossing signal with a manual overide. The railroads I have worked for would have a cow over including a manual override.
If the switching lead is “inside” the automatic protection then it has to be included in the circuit.
Where track is in pavement and there is a crossroads would there be crossbucks or crossbucks+ on the cross route? If so I take it that it would be the County or similar who would decide…
As I recall, when there was street running in Erie, PA, streets were protected. The tracks are gone now and with them a lot of the signs. But I remember busier streets having gates and everything. And a few of them, maybe three or four, actually had manned crossings (city law) until the tracks went out of service.
Everybody’s different. Some use a sign that says Hold Back. If you stop for a signal, there may be a “wait light” that illuminates when the signal clears. Some may just give you a mile post to stop at. Some as Dave H stated, may have nothing at all.
I’ve seen and used them in a couple places. Mainly where opening a customer switch triggers the crossing protection. Basically, it’s just a box on the equipment shed.
That’s what I like! [^] Complete, 100%, total standardisation! [:P] Just like we do it! [(-D]
Naturally the next question is… what does a “wait” light look like please?
The other thing I note is that at least one city enforced the crossings being kept manned. I’m pretty sure that I’ve heard of that elsewhere… the question is whether it still happens or when did it finally die out… I guess even the last could vary from state to state.
Yeah, there were literally dozens of cross-streets on 19th in Erie and only a handful were protected by humans. A little nosing around seems to suggest that it was only during the school year too, when buses full of kids would ply the same route as the freight trains.
I can’t quite find which issue, but seems to me a recent issue of Trains or RMC had a picture a guy took of an old CNW crossing tower (for manually activating crossing gates) in Upper Michigan in the mid-eighties. He was very happy to find it still in place, since most had stop being used decades earlier, all but a few had long since been torn down.
BTW crossing shanties/towers were first manned by guys who would come out and manually wave a flag or hold up a stop sign to stop traffic. Later pneumatic crossing gates were developed that they could pump up and down from their tower without having to go down. Electric flashing lights came later, about the time crossing gates became electric. Once electricity was standard (certainly by the fifties) it was easy to rig up an automatic flashing light or crossing gate activating system that didn’t require an employee, so that was done in most all situations.
p.s. Manned crossing shanties in the old days were generally manned by railroaders who had been injured on the job and could no longer work as engineers or brakemen etc. This was long before social security disability or workman’s comp - or the AFLAC duck for that matter !! Once in a while in a train DVD or video you’ll see film taken years back of a crossing shanty guy coming from or going to the shanty…generally walking with a limp.
I think that I have a couple of different ways to go with this:-
I can start thinking about how many crossbucks (minimum 2 - maximum ?) each side of the line - to provide visual warning to traffic aproaching on streets from different directions… or there is a question of how many pairs of lights go on one crossbuck (set at different angles)… so far I’ve seen 2 pairs…
Look at a grade seperation… burrow the street down under the tracks. Not sure about this one. While it can add some interest it raises questions about clearance and angle(s) of approach ramps ??? I know that an underpass can have a restricted height clearance… I just don’t know at what point that would become worthwhile… or maybe the City/County would mandate it???
Thanks again everyone. [:P]
PS 3. Do both??? It sounds crazy but do they ever put in an underpass for cars but leave in a grade crossing for trucks? I know of a couple of places where they’ve put in an overpass but left a grade crossing (normally locked out of use). One is for extremely heavy machinery on special (enormous) trucks to get across the line to a storage facility.
American Family Life Assurance Company of Colombus (“AFLAC”) is a company that specializes in insurance plans that pay you if you’re injured and unable to work. They advertise a lot during sports programs, including often doing a trivia question during the broadcast.
Their commercials feature “the AFLAC duck” whose voice is done by comedian Gilbert Godfreid I believe. Their best known commercial is probably the one with Yogi Berra in a barber shop. “If you get hurt and miss work, it won’t hurt to miss work”…“They give you cash, which is just as good as money” etc.
Not knowing what the intersection looks like its pretty hard to tell.
Normally there is just one pair of crossbucks outside the tracks (with a sign if there are more than one track), just one pair of crossbucks on the mast and one pair of flashing lights on the post.
About the only time you get more than that is if there is an intersection ON the crossing.
Railroads don’t do roads. Cities, counties and states do roads. There is nothing that says you have to put the entire approach ramp on the layout, it can extend to the fascia
Unless you absolutely have to or or going to be driving little model trucks around your layout i wouldn’t devote the real estate to both. KISS.
(I’m sure that it’s a conspiracy [|(]I nootice that this crossing also has barriers… but I’m back-dating to 1985. Even if I’m working a “my world” scenario I like to have some degree of logic in it.
I’ll try to add another link to a multiple headed crossbuck if I can find my way back to what I saw last night.
it shows a train staying off the crossing… with no signal between it and the crossing… which is the thing that I wouldn’t have had a clue about. [sigh]
I can see that some of the heads are actually rail signals in this view… which, to me, is weird - because our authorities would go ape if there was a situation where an Engineer could see both rail signals and any other red signal… even a flashing one. The crossbuck and lights equivalent would be pushed back and/or shrouded so that there would be no way an Engineer could see the road signals.
I guess I am a loss to what this is an exception to. Its a pretty much normal cantilever and gates arrangement. About the only thing different is if the tower manually controls the crossing signals.
I don’t see multiple crossbucks in the picture, but there are multiple flashing lights because its a cantilever signal arrangement. I don’t recall you ever saying you wanted cantilever signals, you just keep talking about “crossbucks” so I am assuming you are talking about a single mast with flashing lights and maybe gates.
And on the vast, vast, vast majority of crossings there won’t be any signage (other than the whistle board about a 1/4 mile away).
