I've had to use brake on some locos at the club that have a lot of both acceleration and deceleration momentum. After setting the speed control to zero, i'll hit button 6(?) on an NCE cab.
I don't see a brake command listed in S-92. is brake only supported on some decoders?
On the ProtoThrottle, or any type of throttle, is the proper (common sense) way to use brake, first to set the throttle (speed control) to zero and then apply brake?
it's not clear to me what brake will do if the speed control is not zero'd -- does it just cause a slight drop in speed and speed resumes to what it was at before brake was applied.
is this how it works on the ProtoThrottle?
thanks
greg - Philadelphia & Reading / Reading
It has been a while since I have both used and been into the tables/manuals of the two types of decoders I use on my system, but if memory serves me well, only the QSI and Paragon decoders have a brake using a function button. I have a feeling I'm dead wrong on this because it's such a useful feature that it 'should' be on all modern decoders.
In both the QSI and Paragon, it's F7. You press it and the brakes should squeal, and the train should slow IF the throttle is zeroed. I usually zero the throttle and then hit F7 to bring the train to a quick, but nothing like emergency, stop. If my typically long momentum CV4 settings would take a given train about 15 feet to stop from its initial speed, a press of F7 on both decoders mentioned will bring tht train to a screeching stop within about five or six feed instead.
As I said, I'm rusty because I'm just building scenery and haven't done much running except to test the rail geometry.
My first experience with braking was a "trial-by-fire" after I installed a few TCS WOWsound decoders. By default the momentum CVs are exceptionally high (20 up and 60 down) and when I dialed down the throttle... nothing happened other than a reduction of exhaust sounds.
Fortunately I had the function chart handy and saw the note on braking. The F7 button gives a 20% reduction with each press. While this can be a fun feature to have, there's times when I'm running four trains at-a-time, by myself, and having to look for function buttons when I NEED to get a train stopped in a hurry is no picknick. Sometimes I've used the "emergency brake" button on the DT402 throttle to avert disaster.
Some decoders allow for two different momentum settings for mainline or switching (F15 on TCS, F7 on ESU or F 14 on Tsunami [Hyperdrive]).
Soundtraxx uses F11 and they would have you believe they invented momentum:
Loksound is a whole other ballgame with the "Drive Hold" feature, another adaptation where the sound is disconnected from the motor control. THEY use F9 to toggle this on and off and still other functions for dynamic braking, switching mode (which will sometimes place both F & R headlights in dim) on yet another function button (F7). Independent brake is on F10. Dynamic brake is on F4!
Sometimes, I've been stymied by trying to move a train. I dial up the throttle and nothing happens. Somehow I have inadvertently left the dynamic brake engaged. Or the independent brake applied, OR the Full Throttle Drive Hold engaged (or not? I forget) or am I in switching mode? There's an F17 brake apply-release which I haven't even gotten into just yet.
I applaud the Proto Throttle for developing a tactile, if not exactly ergonomic, "control stand" with a throttle, brake, horn and direction lever that has a distinction when you're using them.
Somewhere In Between there should be a throttle where it is easy to hold and a decent, tactile feel for some of the most often used functions.
Yes, the functions can be re-mapped. I have tried to consolodate on a certain manufacturers' decoder in order to keep some of these upper functions, like braking, compatible — which, like Sheldon — I'll get around to doing "someday" .
Even within a manufacturers decoder line, some OEM locomotives come setup to different functions, like some of my Rapido/ESU equipped locomotives.
Admittedly, the Budd RDC and the diesel/electric FL-9 and the Turbotrain each have VERY specific operating modes and it is great that each one can be customized to replicate the prototype — but it can get hairy trying to remember each and every function, even if I did re-map some. The Amtrak F-40s have an HEP mode where the prime mover sound is always in notch 8 but the throttle functions independently. Another feature is "Straight to Eight" which is supposed to imitate fast starts in commuter train operations. Will I ever use it? Maybe, its there if I can ever remember which function THAT is on.
Fortunately the DT throttles will allow you to see if a function (up to F12) is engaged or not. That's a big help.
Again, mimicking prototype, sometimes you would leave the throttle engaged and apply automatic brakes to stretch out the train, or bunch it up with dynamics. The decoder manufacturers are giving us all the options we could ever want to have. It just gets complicated to keep track of them all.
Probably didn't quite answer your question but at least I put in my .
Regards, Ed
That's why the Proto Throttle has profiles for decoders, so you can set up the controls to work the appropriate functions on different brand decoders. Since there is no standard (just like there is no standard as to what function does what - it's just by convention that most models in North America use F1 for the bell and F2 for the horn/whistle - there's no standard that says they have to do this). There are two ways to implement the brake lever action on the PT, one where the maximum travel position of the brake lever is an emergency brake, which might be useful when getting used to operating the loco like the real thing, and one where it is just a maximum applicatioon, not a "stop NOW no matter what"
As for ergonomic, well, the basic design has worked well since the introduction of the diesel-electric locomotive. And people are able to use the PT one-handed. Use of the PT eliminates the confusion over what functions do what, and it's obvious if you left the brake on, or which way you have the lights set, or even what direction you are going.
Some decoders will do much better than others when it comes to trying to make the function actions consistent across brands. Loksound is about the only one that has 100% freedom in mapping functions, most others have 'groups' of functions where any button in the group cna operate any output wire or sound in the same group, but a button in group 1 can't trigger an action in group 3. This distinction seems to throw people - with Loksound there is NOT a set of CVs, for F0, a set for F1, etc. Instead thre is a wide open table where any line can reference any function, any button, any sound, any condition, etc.
You can do the function mapping at the throttle level with WiThrottle/Engine Driver, but that means using a touch screen to operate. You can also do this with ESU's new system, there is a knob and buttons for frequently used functions, the rest are touch screen buttons.
One thing to remember is it's all simulated. It was with DC throttles like the TAT IV and TAT V. You obviously don;t have a train brake, yet depending on how the throttle sends commands to the decoder, it can simulate having a train brake. It usualyl depends on having a high momentum setting, then your train is seldom going the exact speed, it goes above the desired speed so you back off the throttle and/or apply so brake, if drifts below the desired speed, you release some brake, or you add some throttle. Just like the real thing,
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
gregcis the proper (common sense) way to use brake, first to set the throttle (speed control) to zero and then apply brake?
did i hear you can apply brake while the throttle is turned up and the train will stop?
Does brake on a diesel locomotive automatically cause the throttle to be set to zero?
gregcdid i hear you can apply brake while the throttle is turned up and the train will stop?
Yes:
gregcDoes brake on a diesel locomotive automatically cause the throttle to be set to zero?
Idle, actually. I'm only familiar with older (first and second generation) locomotives and as I recall only an emergency application will kick the engines into idle and activate the lead axle sanders.
Newer locomotives have more sophisticated power handling options including "blended braking" where a combination of dynamic and automatic air can be used. In the dynamic braking mode the throttle has to be increased to supply increased deceleration rates, cooling for resistor grids. These systems I'm not that familiar with.
Cheers! Ed
gmpullmanIdle, actually.
so if the throttle was set to a notch other than idle and brake causes the engine to run at idle, what needs to be done so that the engine operates at the throttle setting? ... presumably with the brake released.
i finally watched the video on braking. I thought it demonstrated that the train would come to a stop when brakes were applied f7(?) and resumes speed when brakes are released f6(?).
since this is a steam engine, i can't imagine how the throttle is reduced to idle automatically when brake is applied. Without changing the throttle, I would think chuffs should continue throughout.
wouldn't braking be more effective if the throttle were reduced?
wondering about the differences in braking/throttle on a steam locomotive and a diesel.
gmpullman
I was refering to either a "Penalty" application or "Emergency" application. Again, depending on the type of control used on the locomotive and weather it is equipped with working blended brake system, the prime mover may be set to idle through the governor. There is a reset procedure that has to be followed after the train has come to a complete stop.
The New York Central automatic train stop system the engineer had to go to the back of the tender and open a small box to reset the system to release the brakes.
A penalty application can follow if the engineer doesn't respond to the alerter, or passes a restrictive signal or runs higher than the maximum speed the air brake will go into a "Full service Application" (penalty application) a quick stop, but not emergency. Brake pipe pressure goes to 0. An explanation is due to the dispatcher and road foreman, too. All this is recorded on the event recorder.
This is all handled through the PCS (pneumatic control switch) and the PCR (penalty control relay). Various reset procedures are required after a penalty or emergency application.
You can read more about it here:
https://tinyurl.com/ydeends2
http://local-1405.utu.org/Files/[4889]BNSF-AirBrake-TrainHandle-updated.pdf
(I can't get any of the links to activate! I'll try one more time!)
Depending on era, as I said, I'm not too familiar with the "computer controlled" stuff, the systems can really get complicated and sophisticated.
Hope that helps. I'm sure there are others here more familiar with this stuff than me.
[edit] I was typing while you were posting:
Steam? Whole different ballgame. Other than the ATS system I mentioned earlier. That relies on the engineer to close the throttle manually.
gregcwouldn't braking be more effective if the throttle were reduced?
In your car you take your foot off the throttle (gas pedal) and put your foot on the brake.
Not so simple for train handling. Often, the engineer wants to keep the slack stretched out yet make or control a speed reduction. There's a balancing act between the throttle and brake applications.
Dynamic brakes adds a whole different set of circumstances. PTC (Positive Train Control) a whole new can-of-worms.
(Steam) shoving the throttle closed at the wrong time can have disastrous results.
NYC wreck at Little Falls, NY, April, 1940. The engineer entered Gulf curve at too high of a speed. He made a slight brake pipe reduction (too late) then closed the throttle right at the beginning of the sharp curve.
Gulf_Curve by Edmund, on Flickr
The slack ran in and kicked the engine off the rails. It was a mess. They may have made it through if he hadn't closed the throttle so suddenly. 31 killed, 51 injured.
To answer the question, yes, braking is more effective if the throttle is closed, but for reasons Ed outlined above, this is not always what you want to do. There are differneces depending on if you are pulling a passneger train with tightlock couplers (little slack) or a long freight (lots of slack). And apart from the conductor in the caboose making a brake pipe reduction or some of the newest electronic EOT devices (which are WAY more than just flashing warning lights), a brake application has a travel time, starting with the cars closest to the loco (where the 'hole' is made in the brake pipe) and the cars at the end of the train, so the front cars are going to start braking before the rear cars. That time keeps getting reduced with improved braking systems. THis is also why you will hear aboout the engineer "bailing off" the locomotive brakes - keeps the loco rolling and the slack from bunching up and pushing a LOT of force into the locos. Fictioon and way overblown as it was, that scene in Unstoppable where the one engineer tried to get in front of the runaways and when they crashed into his loco it threw him ahead and off the tracks - certainly that can happen if yoou have say a 100 car train and you jam on the independent and stop the loco without braking the cars - that's a LOT of momentum crashing into the loco. It's also one reason why emergency braking is risky - the modern EOT devices actually open a big hole in the brake pipe from both ends which helps all the cars apply braking faster, but before that, there was still a propogation delay and the whole train pushing forward could easily cause derailments.
Having ridden in the cab a few ties, the engineer is always working the train brake, independent brake, and throttle against one another (this was on a passenger excursion) to give the smooothest ride possibly while maintaining control of the train and respecting various speed limits on different sections of the railroad. Switching cars around after everyone detrained was a real eye opener. I was given the choice to get off with the passengers, or stay in the cab until the switching was completed and the cred got off. Duh. Meant I had less free time at the layover point but it was a great learning experience and worth every penny I paid. Not to mention the standard was to sell 2 tickets for the cab ride in each direction and for the trip I was on, the other ticket was unsold, so it was just me and the engineer, no one else to get in my way or have to trade off sitting in the fireman seat with. Great ride with the most senior engineer on the line (the owner was along in his private car).
gmpullmanHe made a slight brake pipe reduction (too late) then closed the throttle right at the beginning of the sharp curve.
wow
thanks for both your explanations. hadn't appreciated all the dynamics of simply maintaining a train's stability. (assume this is way beyond what a ProtoThrottle can simulate).
I'm not so sure it's beyong what the PT can simulate - but the key word is 'simulate'. Close, but never exact. Watch a few more of the PT videos, the behavior is quite different in independent mode vs train brake mode. Physics doesn't scale, so there will never be a true simulatioon at any common modeling scale, no matter what you do with the car weights and loco drive train/ I've oonly seen positive coomments from professional railroaders over the use of the Proto Throttle, so I'm guessing it's pretty good at what it does.