Railworks America

Some real life engineers will probably know ...

I apply an initial reduction and bail off the independent brakes because power is still applied since I want to make a precise stop in front of the signal.
Subsequently I reduce the brake pipe a few more PSI and notice the brake cylinder pressure rises again, should I bail off again?
What pressure should the locomotive brake cylinders have now, the differential value derived from the subsequent reduction, or the absolute value derived by the triple valve ratio off the brake pipe pressure?

I essentially need to pull the train right under the signal, since that is where the scenario is called complete. In the prototype, is there a regulation as to where the train must come to a halt in front of a STOP aspect, esp. on a down grade? I am talking about Rockwood here, and I mostly fail because I overrun the STOP home signal or come to a halt way off.

I'm no real engineer but generally how I have gotten around that issue in scenarios is bring the train to a crawl (say 5mph or so) and that way it doesn't take much once your right up under the signal to give it one final hard application and stop the little momentum that is left in the consist.

Stretch braking or power braking is what you described. The bailing off answer is YES bail off if you are pulling against the Train brakes. In GCOR (general code of operating rules) I've seen many diagrams that have shown the train to Stop no less than 400ft from a stop signal. I haven't read anything specific to distance but I'm sure it's in the Train Handling book for each railroad. I was always taught to give yourself plenty of room for any errors that could come up.

JohnS wrote:Stretch braking or power braking is what you described. The bailing off answer is YES bail off if you are pulling against the Train brakes. In GCOR (general code of operating rules) I've seen many diagrams that have shown the train to Stop no less than 400ft from a stop signal. I haven't read anything specific to distance but I'm sure it's in the Train Handling book for each railroad. I was always taught to give yourself plenty of room for any errors that could come up.

Thanks.

You don't know the answer to locomotive brake cylinder pressure between intermittent brake pipe reductions and bailing off's? However, it isn't called independent brake for nothing.

I haven't noticed any slack action in TSW:CSX, nor do we have default DPU operation and independent control (yet?), so don't know if my train is stretched or bunched. Run8 definitely has the edge here, and its train handling requires a both a firm and delicate hand at the controls at the same time. I still hope DTG will have TSW match Run8 or even OpenRails in its simulation aspects, since it is only scripting of Newtonian physics that is required for the illusion of handling thousands of horses pulling against thousands of tons ....

It's been a while since I paid attention to the gauges in detail but after you bail off the first application each application afterwards will need to be bailed off. The brake cylinder pressure will apply to the appropriate pressure in regards to the brake pipe. So if you go to full application after you bail off your original application the brake cylinder will only apply the pressure difference not the full application. It's really hard to explain it with out looking at the gauges. sorry I can't be mopre clearer.

JohnS wrote:It's been a while since I paid attention to the gauges in detail but after you bail off the first application each application afterwards will need to be bailed off. The brake cylinder pressure will apply to the appropriate pressure in regards to the brake pipe. So if you go to full application after you bail off your original application the brake cylinder will only apply the pressure difference not the full application. It's really hard to explain it with out looking at the gauges. sorry I can't be mopre clearer.

That's how real locomotive brakes operate? Just as I expected, the locomotive brake cylinder pressure is only relative to the changes in brake pipe pressure between subsequent bail offs.
I thought I saw this behaviour in the TSW:CSX brake cylinder gauge.

_o_OOOO_oo-Kanawha wrote:

JohnS wrote:It's been a while since I paid attention to the gauges in detail but after you bail off the first application each application afterwards will need to be bailed off. The brake cylinder pressure will apply to the appropriate pressure in regards to the brake pipe. So if you go to full application after you bail off your original application the brake cylinder will only apply the pressure difference not the full application. It's really hard to explain it with out looking at the gauges. sorry I can't be mopre clearer.

That's how real locomotive brakes operate? Just as I expected, the locomotive brake cylinder pressure is only relative to the changes in brake pipe pressure between subsequent bail offs.
I thought I saw this behaviour in the TSW:CSX brake cylinder gauge.

yes that's correct from my experiences anyway.

_o_OOOO_oo-Kanawha wrote:I essentially need to pull the train right under the signal, since that is where the scenario is called complete. In the prototype, is there a regulation as to where the train must come to a halt in front of a STOP aspect, esp. on a down grade? I am talking about Rockwood here, and I mostly fail because I overrun the STOP home signal or come to a halt way off.

Well, that surely depends on where the scenario author has decided it stops, doesn't it? In essence, all train/loco drivers are different, it also depends on what locomotive you are driving, in Britain and Europe we may have better visibilty in our cabs, I can pull right up to the signal so it is up at the top of my windscreen and I can see the lens colour, other drivers may stop 15/20 feet from the signal, depending on where you are of course, a main line, a passenger station, a marshalling yard, etc, etc. When I drive an American loco I always give myself plenty of room and pull up short so I can see the signal clearly, that might be 20/30 feet away, but, as you generally have a nose on the vast majority of your diesel locomotives, especially, a Snoot Nose which are very long, rather than a flat front to both our diesel and electric locos we have across the pond, I cannot get right up close to the signal for fear of a SPAD, it all depends on how sensitive the signalling is, if you understand, it's all a bit of trial and error and how our wonderful scenario writers have designed their activities for us all to play with.

Cheerz. Steve.

ex-railwayman wrote:

_o_OOOO_oo-Kanawha wrote:I essentially need to pull the train right under the signal, since that is where the scenario is called complete. In the prototype, is there a regulation as to where the train must come to a halt in front of a STOP aspect, esp. on a down grade? I am talking about Rockwood here, and I mostly fail because I overrun the STOP home signal or come to a halt way off.

Well, that surely depends on where the scenario author has decided it stops, doesn't it? In essence, all train/loco drivers are different, it also depends on what locomotive you are driving, in Britain and Europe we may have better visibilty in our cabs, I can pull right up to the signal so it is up at the top of my windscreen and I can see the lens colour, other drivers may stop 15/20 feet from the signal, depending on where you are of course, a main line, a passenger station, a marshalling yard, etc, etc. When I drive an American loco I always give myself plenty of room and pull up short so I can see the signal clearly, that might be 15 feet away, but, as you generally have a nose on the vast majority of your diesel locomotives, especially, a Snoot Nose which are very long, rather than a flat front to our locos such as a Class 66 like we have across the pond, I cannot get right up close to the signal for fear of a SPAD, it all depends on how sensitive the signalling is, if you understand, it's all a bit of trial and error and how our wonderful scenario writers have designed their activities for us all to play with.

Cheerz. Steve.

It seems the cyan scenario markers you find in the tracks have a certain 'actuation radius', one doesn't necessarily have to stop the locomotive right on top of them. Now, what is that radius?

The fact they have you pull on top of signals is frankly rediculous. They do that in TS2017 as well, and is totally unnecessary and is just asking for SPAD events. 400 feetvis the minimum distance that they should be using, as John said.


Aaaanyways here's how independents work with regards to the automatic.

The locomotives have a control valve much like freight cars, which will communicate changes in air pressure to increases in BC pressure to the J-relay valve. The J-relay will translate said changes to what the locomotives brake cylinder pressures should be, 45 or 72 PSI, prototype depending.

What happens when you actuate is that you're sending 45PSI into the actuate portion of the J relay and it will release pressure on the BC side. Any additional sets of the automatic will have to be re-mitigated via actuation.

By BNSF ABTH, and probably by extension, most other railroads, you are to actuate for 4 seconds, plus two additional seconds for every trailing locomotive en consist (a consist being a group of locomotives, not a full train) before making your brake application and hold it as the BP exhausts. This is for every single application you make. This is to prevent any BC pressure developing on the locomotives and thusly a run in of slack. Some people still carry the habit of actuating after, but it's wrong.

I've been actuating after my application for 13 years. Never knew I was supposed to do it the other way around. I've only had one derailment as an engineer shoving into a yard track. Bad ties and the rail rolled. I guess I never put much thought into the brakes as far as what to do first. I wonder if there is a difference between the electronic brakes and the old air style?

JohnS wrote:I've been actuating after my application for 13 years. Never knew I was supposed to do it the other way around. I've only had one derailment as an engineer shoving into a yard track. Bad ties and the rail rolled. I guess I never put much thought into the brakes as far as what to do first. I wonder if there is a difference between the electronic brakes and the old air style?

Because of the specific need for compatibility between units, no. Though the electronic brakes are much slower to apply independents than say a 26.

The reason for the actuation before taking your set is the presence of air against the j relay in the actuating line means the set will not increase BC pressure at all, whereas when you actuate after you manage to have air set up on the last locomotive in consist will develop BC pressure, even just a little.

Ah now it makes sense. Thanks for explaining

JohnS wrote:Ah now it makes sense. Thanks for explaining

No problem. I think a lot of the rules they make for us are dumb, so I'm the type to look for "why?"

BNSFdude wrote:

JohnS wrote:Ah now it makes sense. Thanks for explaining

No problem. I think a lot of the rules they make for us are dumb, so I'm the type to look for "why?"

I enjoy talking about rules and procedures and how they are interpreted. It was an interesting time switching from NORAC to GCOR. Anytime you wanna talk rules I'm game.