I've been running single lever trains up to recently, and now trying to understand the proper methods of braking on Amtrak and MBTA.. or any train using dynamic braking, automatic brake, and independent. There is a suppression setting on the automatic brake at different levels on different trains, which suppresses a penalty from the ATC or ACSES. On the Amtrak dynamic is on the power lever, and is effective at high speeds, but it can also activate by activating the automatic brake, and not even touching the power lever, since the traction motor is disabled at that point, so it allows a slow down, and then release and back to power. On MBTA the F40, the dynamic brake comes on only with automatic brake, so not much an issue.. When getting a speed limit change, and a slow down required, what the proper braking method.. just going right into suppression with the automatic brake? On the Amtrak, leaving the power lever or going into dynamic only or in combination? What about stopping from the last 5mph at station.. automatic brake is a bit overpowered at minimum, so it's possible to do the last few mph with independent brake. But does that stress the loco brakes too much? The ACSES on the Boston Sprinter trains, doesn't seem to give much time for smooth slowdowns, since it just pops in without warning. ATC is anticipated more with track signaling. Best way to deal with ACSES? Finally, the OpenRails speed limits seemed correct for the LIRR at least, but for the NEC, the ACSES tends to be slower. I guess that's a per train type speed. Are the ACSES fixed on sections, or dynamic. In other words can the ACSES be charted by distances to anticipate better? Thanks
If you get an ATC/ACSES alert, acknowledge. You then have 8 seconds to either A) get below the new speed, or B) place the auto brake in suppression and hold it there until you reach the new speed. The throttle handle is irrelevant here. On Amtrak, applying the air brake will cut the power if in a power setting and you have to neutral it before applying power again once the brake handle is returned to release. If you're in DB, I think that will override anything the computer applies automatically with the autobrake, but you want to brake anyway so it doesn't really matter. On the F40, you'll have to cut the power manually. Personally, I leave a couple notches on just to make sure I don't slow down too much as the brakes are releasing once I get to the new speed. In game, no - TSW doesn't simulate to that extent. In the real world, probably not as much as you'd think. Passenger trains are relatively light and that's such a low speed. Often switching freight cars is done using just the loco brake as the train line isn't hooked up This came up a lot when Boston released, with 'route knowledge' as the answer. Technically, you can avoid needing suppression braking if you learn where the reduction is and stay ahead of the braking curve for it - then just acknowledge the beep. Otherwise, just throw it into suppression and acknowledge. As long as you don't take the brakes off too early, ACSES stays happy.
Indeed, this is correct, as in real life there are sections where speeds of 150 MPH are allowed, however the only train in North America that's even capable of achieving that speed is the Acela Express. The typical ACS-64 consist with Amfleet cars have a maximum allowed speed of around 125 MPH, with the MBTA trains being slower and restricted to about 80 MPH. As far as I'm aware, ACSES is mostly there to enforce the track speed limit instead of warning you for it. (ATC in contrast enforces a speed limit based on the signals.) It's up to the driver to already know where the changes are based on their route knowledge, and take action accordingly. The actual problem with ACSES and ATC on Boston Sprinter is that they're too overly cautious, and often restrict you to coasting at a much slower speed when in reality, you can actually go a bit faster and still remain safe. There might also be instances of stuck red aspect signals, when they should be clear. This seems to happen near Canton Junction, from my experience. In general for all trains, what you want to do is ensure comfortable changes in velocity in the sake of passenger comfort. Therefore if the change in upcoming speed limit is small, say maybe 10 or 15 mph, using the dynamic brake and adjusting it accordingly might be a good idea. However if you're coming to a stop or need to slow down substantially, using the automatic brake is better. If you're being beeped at by ACSES, then set the automatic brake lever to suppression and leave it there until you're safely below the speed limit. There is a brake curve that ACSES calculates, and by setting it to suppression it knows you'll be able to safely follow that brake curve. If you're coming to a stop at a station, ideally you want as few changes to the amount of brake force as possible. It should be smooth and consistent, thus you should be able to set the automatic brake to a certain setting and keep it there without having to move it or 'fan the brakes.' Regardless, if you are indeed coming up to a stop at 5 MPH, you should let the train coast (or if you deem it safe enough, perhaps apply a bit of power and bring the speed up a bit more), and at a certain point, typically at the last second possible, just apply a minimum set and bring the train to a stop. Its all up to the engineers judgement in this case.
Thanks for the info. Upon running the route some more, and thinking about it, kind of started to understand it as noted here. Good to get confirmation so as not to miss something. Yea, I can certainly vouch for the max speeds on the NEC. Monitored both Acela and NE Regionals between DC and NYC a couple times with a GPS app. Acela hit 150mph at just a couple sections, with the Regional never getting above 120 mph. So can't really rely on the max track speed from maps for lower speed trains, as you say. openrailwaymap doesn't show any max higher than 201 kph (120mph) for NEC between NY and DC, so not always correct on the max either. As a side note, I had the opportunity to ride the TGV between Munich and Paris, initially not being too impressed with the speeds as it felt normal. After entering France, at some point felt a particular acceleration around a very wide curve, realizing this was the start of proper high speed section. Accelerated to 300 and maintained around 300-315 kph for the next 1.5 hours into Paris. Have never seen scenery pass by so quickly. And it was notably very smooth and quiet with an occasional rocking at most. That route is 320 kph track max and very straight with wide right of way on sides and elevated on a berm. Too bad we can't buy out enough land to make a dedicated track on the NEC. Acela is actually quite nice considering the tracks it has to run on. As noted, leaving a couple notches on the power while braking is a good idea on the F40, to keep the revs, as the accel is slower than the decel. Now another thing about ACSES speeds. Simply, is it fixed by distances (per train type)? For the LIRR, I ran the whole route and every 0.1 miles noted the distance from/to station, track speed and slope. Then from the spreadsheet made 2D elevation, speed and distance charts for the whole route. Printed out this reference to anticipate the route like a map. I plan on doing this for the NEC Boston-Providence. A bit of a pain initially but then having these makes it more enjoyable. openrailsmap is practically accurate for LIRR. Also found a good track guide from CSX to include the Sand Patch sections and speeds and distances, just no slopes. If I do this, will this ACSES speed be fixed and repeatable? If I run the route with just a loco, will I expect the same ACSES indications at the same distances? Thanks again.
