ATLS Slave "Safety" questions

[ctclark1]

I think this question is going to be primarily aimed at stagecoach and boat, but I'm not going to turn down any thoughts

I've used the inverse slave before but never on live tracks. Currently I'm working on a control method for a moving bridge (actually 2 near each other, but that's not important) that stays down until a boat comes along. So far so good on using an inverse to keep it down until triggered by a boat "engine" on the river track - the inverse is connected invisibly to the actual bridge tracks and disappears when triggered, and the real trains travel over completely separate invisible tracks at the bridge, so no interaction at present. That part is no problem.

What I'm trying to figure out is how to control the signals approaching the bridge, my thinking was to use either a slave or an inverse slave on the live tracks for the bridge, but my concern is how to you keep that slave from accidentally appearing when there is a train already on the bridge. The reason I say this is aimed somewhat at stagecoach is because I looked through his ATLS Advanced demo and noticed that he too did this with an inverse slave, but don't completely understand how you would keep this from interfering with a train going over the bridge when the boat triggers it. I can't really test this properly in the demo either because I cannot get the actual boat to download and attempting to replace it with a different one forces me to save a new session, thus resetting all the ATLS controls anyway...



This is a route based on the actual Buffalo Belt Line, these bridges are the bascule bridges that cross the Buffalo River at CSX CP-1 and CSX CP-DRAW, so Sen signals, for example, are not an option. Because the CP-DRAW bridge carries not only the CSX mains but also provides trackage rights to 4 other railroads there are no fewer than 12 signals approaching the bridge separately on as many different lines... so I don't see using a trigger signal rule as a great option either. I had also thought about using invisible tram stoppers but that will just put the 12 signals approaching the line at an approach instead of danger.

 

[stagecoach]

Hi ctclark1 You can put a reverse slave in the middle of the bridge track to control the signals. You need to set them up the same as the one you have controlling the bridge. Assuming that when the bridge slave is visible the bridge opens. You need to set a delay on both track and bridge slaves before it activates to allow any train on the bridge to clear if it is already crossing. Also put a delay on the track slaves after the boat has passed to allow for the closing of the bridge. The slave should then go invisible and let the signals return to automatic. Re demo open the edit session instead of edit route to change the boat and change the boats name to the new one in the drivers schedule.

 

[maruffijd]

I would recomend looking into the ASB Crossover freeware from boat. this allows one line to be stopped while the other line is in use over/under the bridge. the system takes control of the guard signals protecting the bridge for both lines therefore giving you what you are seeking.

 

[ctclark1]

I have used ASB for other crossings in the route, and it is a great item but again I don't think it would work well here.

That being said, One feature I would LOVE to see from boat would be an option to only set the Main signals to red if there was a train approaching on the secondary tracks because by having to wait until the mains trigger to turn green causes a lot of slowdowns. The same issue would occur with this bridge here. I know what you're thinking... "Move the triggers for the mains farther back". This becomes problematic because there are a ginormous number of tracks converging on the bridge from one end, it is literally the only crossing across this river for 5 different railroads in the area and they would all need triggers far enough back to not affect the overall running up to the control point. At this point I might end up just ignoring the boats in the river for now...

BTW the "main at green" option would come in handy for both of the other level rail crossings on this route for similar reasons - I can only put the triggers back so far from the crossing before it becomes burdensome or even impossible because of possible switching moves within the limits.

 

[stagecoach]

Hi ctclark1
Not sure how you are attempting to set up the bridge. I would use the sen city signals with ATLS function (or tram stoppers) as the last signal before the tracks reach the bridge. I would then place ATLS triggers just after the signals. Place ATLS triggers for the boat some distance away with a tram stopper a short way past it with another ATLS trigger just after that. The first boat triggers and the sen city signals would be on one channel while the train triggers and the tram stoppers on the boat track would be on a different channel. This would mean the boat would approach its trigger and set the train signals to red. The tram stopper ahead would be red if a train was already on the bridge so stopping the boat. Other trains would have been stopped by the signals. Once the train is clear the tram stopper would go green and the boat would move on. As it passed the next trigger (on a third channel) it would activate the bridge slave. Once clear of the bridge the bridge will close and train signals revert to auto.

 

[ctclark1]

Hmm, hadn't thought about having separate triggers for stopping the trains and then raising the bridge. I'm trying to keep this close to proto so the Sen City signals are out, being a US route, but that theory with the second set of triggers might be what I'm looking for. I'll keep you posted.

 

[stagecoach]

In the ATLS advanced demo you can change the boat etc by using edit session and not edit route. Don't forget to change the driver information to the new boat. The session contains all the information on the set up of the ATLS. The demo uses 3 channels to control the trains, boats and bridge and traffic. Two slaves are attached to a single traffic stopper on each side of the bridge, one on the train channel and the other on the bridge channel. This allows either the train or the bridge to stop traffic. You can use multiple channels to control situations if you place the triggers and tram stoppers in the correct way. All three channels operate to give the overall effect of one channel controlling it. You can place an inverse slave in the invisible track on the bridge set up to work on the bridge channel. The inverse slave is height adjustable so can be raised to the track height required. You can use the ATLS tram stoppers just before the last signals of each track to control the tracks in relation to the bridge opening.