Why level crossings limit the acceptable train frequency

 
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
I have noted elsewhere before that eliminating a level crossing allow more frequent trains if there are not other factors limiting the train frequency. The problem is more nuanced than vehicles and pedestrians not being able through if they barriers were down and the pedestrian gates closed.
It also has to do with equipment. For one, the way that the bells and yodel alarms are programmed means that they would sound the whole time if the roads and footpaths were blocked by too frequent trains. Additionally, each barrier only covers half the road, this is intentional. The boom barriers and pedestrians gates automatically close starting seven seconds after the beginning of activation, and so leaving the other side completely open means that vehicles still on the crossing after the barriers go down can still get off it. Pedestrian gates have emergency exits for the same reason.
If a level crossing were to be closed to road traffic (including pedestrians) for an extended period of time, the gates or barriers would need to cover the full road width, or the road barricaded in some other way. And emergency exists, if they are any, would also need to be locked. The warning bell would also need to be disconnected.
Back when level crossings had wooden gates, it was a different matter. The main gates at a level crossing with a quiet road could simply be kept in the clear position for trains, and the wicket gates locked, for an extended period of time if there was a suitable alternative grade separated crossing for all road traffic during these times.

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  gordon_s1942 Chief Commissioner

Location: Central Tablelands of NSW
I think you will find in automatic signaling areas, its the distance the signals are set apart that has more to do with the frequency of trains than level crossings do.
Many years ago when speaking to a Signal Branch employee about the then new colour signals over the Blue Mountains of NSW, he said the the minimum 'Time gap' between trains was about 8 minutes.
This however varied where there was a steep rising grade with the 'section' between the signals being longer to allow a goods train to have an uninterrupted run up the grade.
Half Boom gates are the norm because they allow any vehicles to move off the crossing should they there but the LAW says that vehicles are to STOP when the warning lights flash which they always do before the boom begins to descend.
Today the Boom appears to be made of a plastic (Carbon Fibre?) which would perhaps bend more than the previous wood booms would and not break.
Since the introduction of Half Booms, there have been a number modifications made in relation to their placement and operation so its possible to see one set of Road and pedestrian booms operate differently to another set but the principle is the same.

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I need to add this is as  basically what I have posted above is for one line with trains going in one direction.
What throws a spanner in the works is double or multiple lines.

At some crossings I have seen the warning for people to wait until the booms (where in use rise) and the lights to go out and the bells stop ringing as there might be a train on the other line approaching.
I was a signalman where both manual and auto  lights were in operation, Block Telegraph, T.B.A and ES. sections.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
I think you will find in automatic signaling areas, its the distance the signals are set apart that has more to do with the frequency of trains than level crossings do.
gordon_s1942
I know the distance between signals also limits train frequency. But regardless of the distance between signals, there is a limit to the acceptable train frequency for reasons given above, which exist regardless of the spacing between signals.

No comment on the situation in the Blue Mountains.

Half Boom gates are the norm because they allow any vehicles to move off the crossing should they there but the LAW says that vehicles are to STOP when the warning lights flash which they always do before the boom begins to descend.
gordon_s1942
I already noted this above.

I don't have anything to say on most of the rest but:
At some crossings I have seen the warning for people to wait until the booms (where in use rise) and the lights to go out and the bells stop ringing as there might be a train on the other line approaching.
gordon_s1942
In many European countries, including the U.K and Germany, some level crossings have full-skirted barriers. These are not automatic but remotely operated. The person operating it can see the crossing and checks the crossing is clear. On these crossings the bell (mainland Europe) or yodel alarm (British Isles) stops once all the barriers are closed. The British Isles also has some automatic half-barrier crossings and on most of these, the yodel alarm does keep sounding throughout the activation period.
  gordon_s1942 Chief Commissioner

Location: Central Tablelands of NSW
The only connection I know of between Type F barrier crossings was on Single Line and if the crossing equipment failed, so did the Staff Instrument.

I would suggest you dont try to use a level crossing in NSW where there is a double line as you will find that after a train passes one way, another can be approaching from the opposite direction on the other line so the booms could begin to rise only to be brought back down by the other train.
With ONE exception, when Goods were hauled by Electric Engines up the Blue Mountains, due to the power limitations,  a following train was to wait until the first train passed a location, this was done by the Signalman using the clock.
  justapassenger Chief Commissioner

It really doesn't need to be hard.

Run as many trains as you need to, let the motorists work out how to deal with it. Pay for a bridge if there are not enough other options capable of handling the traffic.

Simples.
  gordon_s1942 Chief Commissioner

Location: Central Tablelands of NSW
The Railways (NSW) has the Right of Way at level crossings and they dont set maximum speed for a Train to approach or cross a Level crossing unless its related to the condition of the Track.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
Run as many trains as you need to, let the motorists work out how to deal with it. Pay for a bridge if there are not enough other options capable of handling the traffic.
justapassenger
But as I noted above, too many trains per hour would mean no one is able to get across, and on many automatic crossings, the bell or alarm would sound the whole time too.
  steve_w_1990 Junior Train Controller

Location: Trying to fix something on the PTA Network
"If a level crossing were to be closed to road traffic (including pedestrians) for an extended period of time, the gates or barriers would need to cover the full road width, or the road barricaded in some other way. And emergency exists, if they are any, would also need to be locked. The warning bell would also need to be disconnected." - Myrtone

What Standard says this? What is defined as "an extended period of time"? Why do they need to cover the full road width? If the crossing is active no traffic should be able to enter it, and all traffic that was on it at the time of the activation should have cleared.  

If you are talking about a crossing being closed for a special event, (such as track work) then traffic controllers would have to be called to place signage and cones around the crossing on both sides. Once traffic control was in place, a signal technician could then deactivate the crossing, at which point, the boom gates should fall to the horizontal position (unless secured upright) with no lights or alarms sounding until the crossing was reactivated.

Sometimes booms get held down because of equipment failures, train breakdowns, and incidents on trains. We had one occasion where a train had to be held at Gosnells station (WA) because a passenger was unwell and needed an ambulance. The crossing would have been active for at least 20 mins before the ambulance arrived and took the person to hospital, and the train was able to clear the crossing.

If a crossing is near a residential area and noise from the alarm is a concern, then timers can be set up so the alarm doesn't sound at certain times of the night. I believe this is the case on a few boom gate crossings between Berry and Bomaderry on the NSW South coast as the crossings are next to farm houses, and the booms were only recently installed (well recent being within the last 10 years) replacing passive crossing protection methods (Stop, Look for Trains signage)

Crossings can also be set up so that the bell only rings from activation to boom down. (Pitt Street crossing on the Midland Line in WA is an example of this).

"Today the Boom appears to be made of a plastic (Carbon Fibre?) which would perhaps bend more than the previous wood booms would and not break." - gordon_s1942

Although a failure for every scenario would be difficult to simulate, having the booms break if they are struck is sometimes the best thing that can happen, especially in the electrified area, as a bent boom could rise up and come into contact with the overhead.

On all crossings on the PTA network in WA, they all still have wooden booms, and, when crossing equipment is being renewed (2018) they still are being installed with wooden booms. I have seen the boom gates you are talking about outside the PTA territory

"I would suggest you dont try to use a level crossing in NSW where there is a double line as you will find that after a train passes one way, another can be approaching from the opposite direction on the other line so the booms could begin to rise only to be brought back down by the other train." - gordon_s1942

Can't comment on NSW practice, but in WA they have "approach" circuits on crossings with more than one track so the booms stay down, if they can't clear before another train arrives.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
What Standard says this? What is defined as "an extended period of time"? Why do they need to cover the full road width? If the crossing is active no traffic should be able to enter it, and all traffic that was on it at the time of the activation should have cleared.

I mean a long enough time that all road traffic (including pedestrians) needs to take another route.  

If you are talking about a crossing being closed for a special event, (such as track work) then traffic controllers would have to be called to place signage and cones around the crossing on both sides. Once traffic control was in place, a signal technician could then deactivate the crossing, at which point, the boom gates should fall to the horizontal position (unless secured upright) with no lights or alarms sounding until the crossing was reactivated.
steve_w_1990
This is an example of the sort of thing I mean. Another example is a level crossing otherwise being activated continuously throughout a very busy time.

Crossings can also be set up so that the bell only rings from activation to boom down. (Pitt Street crossing on the Midland Line in WA is an example of this).
steve_w_1990
This is like what is done in the British Isles on (remotely operated) full-barrier crossings, not generally on automatic half-barrier crossings. If you can see why that is, that's sort of why the gates or barriers would need to cover the full road width for extended closure periods.
  justapassenger Chief Commissioner

But as I noted above, too many trains per hour would mean no one is able to get across…
Myrtone
This would have to rank among the finest pieces of road transport advocacy I have ever seen on this website. Enjoy your fully lit burnout or whatever you guys do to congratulate yourself for a job well done.

The problem with a level crossing where too few drivers can cross the railway is nothing to do with the number of trains and everything to do with too many motorists trying to use a road where there is not the capacity to do so.

The solution is not to decrease the number of trains running, but for any motorists displeased with the situation to take one of the following actions available to them:
- drive at a different time of the day when there is less traffic
- drive via a different route
- switch to a different mode of transport
- relocate to an area with a shorter commute
- lobby for the government to spend money to improve the roads, like drivers did with Dodgy Dan for the LXRA project and the Westgate tunnel.

It is not within a railway's powers to direct which roads drivers may use in order to manage traffic congestion. It is the railway's gift to run trains, so the best thing a railway can do to help mitigate the issues is to increase the number of train services they run so as to allow capacity for more people to switch from driving cars to riding trains.

"Today the Boom appears to be made of a plastic (Carbon Fibre?) which would perhaps bend more than the previous wood booms would and not break." - gordon_s1942

Although a failure for every scenario would be difficult to simulate, having the booms break if they are struck is sometimes the best thing that can happen, especially in the electrified area, as a bent boom could rise up and come into contact with the overhead.

On all crossings on the PTA network in WA, they all still have wooden booms, and, when crossing equipment is being renewed (2018) they still are being installed with wooden booms. I have seen the boom gates you are talking about outside the PTA territory.
steve_w_1990
I would be extremely surprised if they are carbon fibre, which does flex a little (provided the correct layup is used) but once pushed too far will shatter into a great number of shards which are sharp enough to puncture car tyres.

There are other cheaper plastics (i.e. a handful of plastic booms for the price of one carbon fibre boom) which could do just as good a job at taking a very light impact but break off more cleanly in the event of a heavy impact.

You want the boom to break off cleanly and stay intact as it is thrown around, to protect the moving parts of the mechanism from damage and avoid having shards of carbon fibre strewn around which would lengthen the cleanup/recovery effort and delay the return of the crossing to normal use.

Plastic booms are installed in South Australia these days. The great things about them are that the wiring is internal, and a telescoping design is used which allows all manner of different road widths to be catered for with just two different size booms carried in inventory.
  gordon_s1942 Chief Commissioner

Location: Central Tablelands of NSW
I will have to have a better look at the Booms here to see if the wiring is now enclosed or external.
I just suggested Carbon Fibre for their construction but I know their not timber anymore.
The level crossing here was over a previous double line which is why we have Booms and not just the lights and Bells as you would expect over a single line.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
This would have to rank among the finest pieces of road transport advocacy I have ever seen on this website. Enjoy your fully lit burnout or whatever you guys do to congratulate yourself for a job well done.
justapassenger
What about pedestrians? Also, bicycles come under road vehicles too.

Also, you surely cannot argue against what I said would happen with too many trains over a crossing too frequently. That's not road transport advocacy, that's a fact. No pedestrians or road vehicles would be able get across.

The problem with a level crossing where too few drivers can cross the railway is nothing to do with the number of trains and everything to do with too many motorists trying to use a road where there is not the capacity to do so.
justapassenger
I don't really get this. And it's hard to see what that solution you mention means.

I know that trains have priority at level crossings, what I explained right at the start is why there needs to be a limit to the scheduled train frequency over a level crossing.
  justapassenger Chief Commissioner

No, the railway should just run as many trains as they need to and let the motorists work out how to find other ways around level crossings if waiting for a couple of trains in a row is too painful.

Only the most rabid of all the rootin tootin V8 driving petrolheads would suggest that train services be arbitrarily restricted to give drivers a better run, because even most motoring enthusiasts can easily recognise that cancelling a peak hour train will put hundreds of cars back on the roads. People want more train services running, not fewer.

Are you a Ford man or a Holden man Myrtone?
  steve_w_1990 Junior Train Controller

Location: Trying to fix something on the PTA Network
If a crossing is causing too many traffic issues, because of long, frequent activation times, then, in theory this should push forward a business case to close the crossing and put in an alternative route such as a bridge or an underpass.

Some crossings would require very major re engineering at considerable cost to be able to eliminate, however the economic benefits of getting rid of another choke point cannot be ignored. There has been some amazing engineering undertaken over the years to be able to eliminate just one crossing.

Crossings can also be eliminated as part of a major road upgrade, and the cost of a bridge or underpass simply factored into the cost of the project. This is usually the best time to push for crossing removal, so the new road can be fully utilized without bottlenecks.

Four Crossings on the PTA network have been selected for elimination, those being Denny Ave, Kelmscott, Caledonian Ave, Maylands, Oats Street Carlisle, and Wharf Street, Cannington.

Whist the removal of these crossings will be of great value to the people of WA, there are other crossings such as Welshpool Road that are extremely busy having to cope with one Armadale, and one Thornlie Train (as well as ther respective returning services back to Perth) every 15 mins for most of the day (and that doesn't count the time that the Perth bound ex Thornlie serivce holds the Boom gates down whilst loading and unloading passengers at Welshpool Station) that have "been on the cards for removal since the 70's" and still no word has been mentioned on its removal
  Rodo Chief Commissioner

Location: Southern Riverina
This post should be re-named "Why Train Frequency Limits Level Crossings".
Of course that simply raises a rather obvious point.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
No, the railway should just run as many trains as they need to and let the motorists work out how to find other ways around level crossings if waiting for a couple of trains in a row is too painful.
justapassenger
The problem wouldn't be just waiting for a couple of trains, but the whole lot that traverse, say, during the busiest hours of the day.

If a crossing is causing too many traffic issues, because of long, frequent activation times, then, in theory this should push forward a business case to close the crossing and put in an alternative route such as a bridge or an underpass.
steve_w_1990
Exactly, high enough train frequency over a level crossing justifies eliminating the crossings. We have a case here in Melbourne where a long stretch of line in the southeast was grade separated to allow an increase in train frequency.

No comments on the rest.
  justapassenger Chief Commissioner

The problem wouldn't be just waiting for a couple of trains, but the whole lot that traverse, say, during the busiest hours of the day.
Myrtone
Drive at a less busy time of the day or take another route.

It's really quite easy, because cars don't have timetables or routes set by signallers.
  awsgc24 Minister for Railways

Location: Sydney
I would suggest you don't try to use a level crossing in NSW where there is a double line as you will find that after a train passes one way, another can be approaching from the opposite direction on the other line so the booms could begin to rise only to be brought back down by the other train.
gordon_s1942
In NSW at least, on double lines, there are TWO approach track circuits on each line. These are arranged so that if a second train arrives too closely, the booms rise after the first train only if they can be up for at least (IIRC) 15 seconds, before the booms lower again for the second train. Otherwise, the booms stay down continuously for BOTH trains. Similarly if there are several trains.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
Drive at a less busy time of the day or take another route.

It's really quite easy, because cars don't have timetables or routes set by signallers.
justapassenger
Surely 20 trains over the crossing, each passing another within the activation zone would be ridiculous. True or false? Otherwise ridiculously high train frequencies over a level crossing during the busiest hours of the day would mean putting up barricades on both sides and detour signs during these times.

I have stationed myself in Macauley road, Kensington before and seen just how bad it can get when the train frequency is close to the limit to the acceptable train frequency. Has anyone else here done the same with a memory of what it looks like and how it sounds?
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
I have a question in the post above but no response so far. Surely a need to run very very frequent trains over a level crossing would justify a level crossing removal, even if only during the busiest hours of the day.

I realise that trains have priority at level crossing, in the sense of not needing to stop or slow down to avoid any road traffic, but obviously there has to be a limit to how many trains can acceptably be scheduled over a level crossing.
  BrentonGolding Chief Commissioner

Location: Maldon Junction
I have a question in the post above but no response so far. Surely a need to run very very frequent trains over a level crossing would justify a level crossing removal, even if only during the busiest hours of the day.
Myrtone
So you want to remove level crossings only during the busiest hours of the day? Might be a difficult to achieve!

They do have people and formulas to calculate this stuff, it has been the justification for many of the LXRA removals.

BG
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
No I explained right at the beginning why level crossing limit the acceptable train frequency. What I mean is that running trains any more frequently than that will justify a removal of all level crossings, even if only during the busiest hours of the day.
  BrentonGolding Chief Commissioner

Location: Maldon Junction
No I explained right at the beginning why level crossing limit the acceptable train frequency. What I mean is that running trains any more frequently than that will justify a removal of all level crossings, even if only during the busiest hours of the day.
Myrtone
  justapassenger Chief Commissioner

No I explained right at the beginning why level crossing limit the acceptable train frequency.
Myrtone
There's no such thing as an "acceptable train frequency" which is limited by road traffic needs. You made that up.

Maximum train frequency is always determined by the configuration of the rail network and its signalling.

What I mean is that running trains any more frequently than that will justify a removal of all level crossings, even if only during the busiest hours of the day.
Myrtone
I think you'll find it's actually the road usage which determines whether there is a good case for a grade separation, not the number of trains.

A busy main road with a quiet railway would need a grade separated crossing far more than a quiet local access road with a busy railway.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
There's no such thing as an "acceptable train frequency" which is limited by road traffic needs. You made that up.
justapassenger
The reason for acceptable is because level crossings aren't exactly a hard limit the way that flat junctions or single track sections are. Also, as far as I know, there isn't always a hard and fast rule but...

Maximum train frequency is always determined by the configuration of the rail network and its signalling.
I think you'll find it's actually the road usage which determines whether there is a good case for a grade separation, not the number of trains.
justapassenger
...but in my city, running more frequent trains has in fact justified grade separations, especially of nine in the southeast.

A busy main road with a quiet railway would need a grade separated crossing far more than a quiet local access road with a busy railway.
justapassenger
Okay, this comment is likely valid for grade separations, but what I said is "running trains any more frequently than that will justify a removal of all level crossings"[emphasis added]. Level crossing removals include closure of less busy level crossing. A quiet local access road crossing a busy railway on the same level is sure to simply be sealed at the railway if the railway gets that busy.

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