Best Practices For Acceleration And Stopping Distance?

Discussion in 'PC Discussion' started by Jon from Rhode Island, Oct 26, 2021.

  1. Jon from Rhode Island

    Jon from Rhode Island Active Member

    Joined:
    Aug 20, 2021
    Messages:
    64
    Likes Received:
    129
    Do the various carriers (DB, etc) maintain rules and regulations regarding brake settings on approach to station stops, acceleration limits, and other similar passenger comfort/safety best practices? Are these compiled somewhere?
     
  2. lcyrrjp

    lcyrrjp Well-Known Member

    Joined:
    Jan 13, 2019
    Messages:
    181
    Likes Received:
    320
    In the UK it varies from operator to operator, with some being more prescriptive than others. Most of the rules/guidance in place is there to reduce the risk of operational incidents, but in some cases giving a comfortable ride is a factor too.

    Some of the guidance I’m aware of being in place with one or more operators is:

    - no more than 20mph when 200m from a red signal (as a guide, the AWS ramp is normally 183m from the signal). For freight operators this is sometimes 15mph when 200m from a red signal.
    - brake in step 1 when coming to a stand (i.e. just the very final part of the braking, as it gives a more comfortable stop). On a train with a brake without steps (such as the class 101), try to stop on a rising brake - i.e. the vacuum should be rising, not falling, as you come to a stand.
    - when starting, don’t go straight to full power, but advance the power progressively. This varies between trains. With a sprinter (e.g. class 150) for example it is no more than Step 4 at 5mph, and Step 7 (full power) at 10mph. On some trains you can go straight to full power if adhesion is good enough. This normally applies on modern EMUs such as those on the Brighton mainline.
    - some operators have a maximum speed at the platform ramp (when entering a platform). At one operator I’m aware of that being 15mph, but that’s unusually low. If you’re in a modern unit and are going to the end of a 12-car platform, 40mph with the brake in is perfectly possible with good adhesion, but 30mph is more usual.
    - when running on 4 aspect signalling, the speed passing the single yellow must be no more than half the line speed, with the brake in.
     
    • Like Like x 5
  3. Clumsy Pacer

    Clumsy Pacer Well-Known Member

    Joined:
    Dec 10, 2016
    Messages:
    2,927
    Likes Received:
    3,906
    In the UK, don't use full service braking unless absolutely necessary.

    Tell that to drivers on the Durham Coast Line ;)
     
    • Like Like x 2
  4. Lamplight

    Lamplight Well-Known Member

    Joined:
    Aug 20, 2020
    Messages:
    2,443
    Likes Received:
    3,928
    For Germany
    Only things that come to my mind right now are these:
    • General limit for acceleration is 1m/s^2
    • Get a (passenger) train rolling with <20kN per traction motor before increasing force to 40-50kN per traction motor
    • Start a freight train with no more than 40-50kN
    • Release the brakes shortly before stopping so that no more than 0.5 bar brake cylinder pressure is applied at the moment of stopping
    There are probably tons more for specific locos/trains, but these are some general guidelines/rules I know of.
     
    • Like Like x 6
    • Helpful Helpful x 1
  5. FD1003

    FD1003 Well-Known Member

    Joined:
    May 10, 2019
    Messages:
    2,864
    Likes Received:
    4,205
    I would also recommend these videos to have a visual representation (especially of the braking) for operating german trains




    The Br.111 is not a 1:1 representation of the stock we have in game but the braking is still very relevant for a realistic driving style in the sim.

    Also something I've seen quite often with passenger services, to add to the "<20kN departure" is that the train drivers usually set the throttle to ~15/20kN, and check the train as they are departing (they stick out their head from the window), and if everything is fine they then increase the tractive effort.

    Another thing I wanted to add, DB has a yearly limit on energy consumption, and because of that they enforce energy saving driving, this is very hard to achieve because of how the timetables are made in TSW, but basically translating from Wikipedia, the rules for energy efficient driving are as follows:

    -Maximise coasting time (no traction applied):
    Firm Start, drive at top speed and then switch off the power early, coast as long as possible and then firm braking. The switch off time should be as early as possible, but you obviously need to arrive on time. (Lift and coast for any F1 fans)

    -Reduce top speed, in some sections if the timetable allows you don't have to reach max speed, both aerodynamic and rolling resistance increase with speed.

    -If the timetable is tight, firm initial start, followed by a slower acceleration to a lower top speed, short coasting and firm braking is preferable.

    Source: https://de.m.wikipedia.org/wiki/EBuLa

    This also applies to other countries, and is great fun to do on BML, where the timetable is realistic, for example going from London to Gatwick (without intermediate stops), after leaving the London area I usually get off the power extremely early on the uphill part, with the aim of being at ~60/65mph at the "summit" of that short section, so that on the downhill part I can clear the 80mph speed limit without touching the brakes once.
     
    Last edited: Oct 27, 2021
    • Like Like x 5
  6. Blu

    Blu Active Member

    Joined:
    Mar 24, 2021
    Messages:
    148
    Likes Received:
    92
    The British 3 step brake is pretty forgiving in commuter runs. But you need to take into account weather conditions. You can approach a stop at speed and brake down pretty quickly. However here is a vid of the 3 step brake and WSP going wrong with 1B47.
     
    Last edited: Oct 27, 2021
    • Like Like x 1
  7. lcyrrjp

    lcyrrjp Well-Known Member

    Joined:
    Jan 13, 2019
    Messages:
    181
    Likes Received:
    320
    Indeed - as I say, the policies I mention are in place with some UK operators but not all, so there will be variation. I don’t know what Northern’s policy is on this.
     
  8. lcyrrjp

    lcyrrjp Well-Known Member

    Joined:
    Jan 13, 2019
    Messages:
    181
    Likes Received:
    320
    A good point about driving economically (‘Eco-driving’ as it’s referred to where I work). One of the things some operators instruct is that, when maintaining the train at line speed, rather than selecting the power notch which will maintain a steady speed (as you might expect) you should use full power until you reach the line speed, then shut off power completely. Wait until speed drops to about 5mph below line speed, then take full power again up to line speed, and so on. Effectively, use the power controller as an on/off switch. Apparently research shows that this power-and-coast method (known as ‘pulse and glide’ when used by car drivers) actually uses less energy than maintaining a steady, lower level of power.
     
    • Like Like x 2

Share This Page