The International Simutrans Forum

 

Author Topic: Need a primer on Tractive Force and Braking  (Read 1305 times)

0 Members and 1 Guest are viewing this topic.

Offline zook2

  • *
  • Posts: 321
Need a primer on Tractive Force and Braking
« on: January 13, 2014, 02:11:21 AM »
It's 1875 and I'm beginning to feel the strain on my rail networks. Up to now I have chosen my locomotives by top speed/running costs alone. That was easy enough - engines having running costs of 3c/km make money, those with 15c/km lose it. But there are lots of choices by now and I'd like to better understand the effect of Tractive Force and Braking values. Unfortunately, it's difficult to directly compare two trains running on the same line, especially when interspersed with trains from different lines. The topic hasn't been discussed much either, it seems, so can anyone point me in the right direction?

For example, there are two locomotives with a top speed of 105 km/h and similar braking values:
D1 - 117 kW / 60 kN
Midland 1866 - 146 kW / 53 kN

And then there's the
Precedent - 178 kW / 44 kN
with a top speed of 125 km/h but requiring en extra braking car. Running costs are astronomical.

What would be a good engine for passenger or freight transport? Which one is better at climbing hills? How important is braking?

Offline ӔO

  • Devotees (Inactive)
  • *
  • Posts: 2345
  • Hopefully helpful
  • Languages: en, jp
Re: Need a primer on Tractive Force and Braking
« Reply #1 on: January 13, 2014, 09:54:29 AM »
Tractive effort is for acceleration
Power is for how much the train can pull.

Generally, you want to use the slower, high power, high tractive effort locomotives for freight or passengers with frequent stops, while using fast, high power, low tractive effort locomotives for express duty.

D1 is good for lighter freight and frequent stop passenger
Midland 1866 is good for medium freight or heavier frequent stop passenger
Precedent is an express passenger locomotive.


Not that these are absolute rules, so use what you want for your various services.

Offline jamespetts gb

  • Simutrans-Extended project coordinator
  • Moderator
  • *
  • Posts: 18617
  • Cake baker
    • Bridgewater-Brunel
  • Languages: EN
Re: Need a primer on Tractive Force and Braking
« Reply #2 on: January 13, 2014, 10:07:54 AM »
I should add to this that the various purchase/running costs have yet to be balanced (that is a very great task), and some of these figures may well make more sense when the costs are balanced.

Offline zook2

  • *
  • Posts: 321
Re: Need a primer on Tractive Force and Braking
« Reply #3 on: January 14, 2014, 05:56:42 PM »
I should add to this that the various purchase/running costs have yet to be balanced (that is a very great task), and some of these figures may well make more sense when the costs are balanced.
I could provide some feedback on this, from my ongoing 1860 game, if that''s any help. I'd title it "EFC - Everything Feeds the Clippers".

Offline jamespetts gb

  • Simutrans-Extended project coordinator
  • Moderator
  • *
  • Posts: 18617
  • Cake baker
    • Bridgewater-Brunel
  • Languages: EN
Re: Need a primer on Tractive Force and Braking
« Reply #4 on: January 14, 2014, 11:25:32 PM »
Feedback is helpful, thank you; although the balancing of running costs and purchase prices will be more starting from scratch than adjusting, so bear this in mind if you are thinking of posting at great length about the current prices.