Just for laughs

[Azervich]

The EMD SW7 Switching Locomotive is rated at 62,000 lbs Starting Tractive effort and a continuous of 36,000 lbs @ 11.0 mph, now, don't miss this, here comes the funny bit, the Auran SW7 which is built-in is rated 296,747 lbs Starting Tractive effort and a continuous of 157,366 lbs @ 12.0 mph, well, if your struggle a hill, why not bank it with a SW7

But seriously... I think there's way too much over powering going on with trainz e-specs on diesel locomotives.

For those people who know locomotives, don't read below here...

Now, Tractive Effort Starting is the amount of force the locomotive produces when they are lifting the load or starting the load and it's based on rail type and adhesion the wheels give to that rail before loosing grip and slipping, most locomotive data sheets are based on 80lb or 94lb rail, Now, Continuous Tractive Effort is the Maximum amount of force the locomotive can produce when the Generator is running at Full Revolutions Per Minute 'RPM' and is rated at a certain speeds which cannot be increased unless you over rev on the engine and generator to produce more AMPS, in reality tractive effort drops as you increase speed, however there are some locomotives that can produce a higher continuous than starting, but they are the very high end powered locos that generate well over 7,000 AMPS of current when engine is at full speed.

Cheers.

 

[Pendolino]

If you look at some built-in enginespecs, you wonder why EMD ever bothered to develop replacements for SD40s and GP38s (or even F7s)

I suppose available data for starting tractive effort represent the maximum tractive effort without slipping. The enginespec tractive values at higher throttle settings, therefore, may have some justification (after all, you don't start slamming the throttle to notch 8). The values for continuous tractive effort at 10-15 MPH (the usual reference speed for US freight locomotives) are far too higher, anyway .

 

[TRam__]

I think there's way too much over powering going on with trainz e-specs on diesel locomotives.

Default wagon's e-specs have excessive friction settings (~2-4 times greater than in real life), so to pull them you have to use a loco with doubled tractive effort.

PS i don't know why N3V hasn't ever checked old e-specs.

 

[frogpipe]

*decided to remove bashing of N3V Auran*

 

[frogpipe]

The EMD SW7 Switching Locomotive is rated at 62,000 lbs Starting Tractive effort and a continuous of 36,000 lbs @ 11.0 mph, now, don't miss this, here comes the funny bit, the Auran SW7 which is built-in is rated 296,747 lbs Starting Tractive effort and a continuous of 157,366 lbs @ 12.0 mph

I'm very interested in this.

Because I have no idea how, can you explain how you were able to get these figures from the e-spec file?

I've always felt the SW7 was crazy overpowered.

 

[TRam__]

these figures from the e-spec file?

they are directly setted in this file, not in lbs but in kiloNewtons.

Contaner throttle-power (also i don't know why it is named as "power", as it sets tractive force. For knotting ?)

 

[frogpipe]

http://www.alkrug.vcn.com/rrfacts/rrfacts.htm - good read


I used the spread sheet at http://forums.auran.com/trainz/showthread.php?74798-Spreadsheet-for-Diesel-Throttle-Power-Container to develop my own SW7 e-spec, though I plugged in the starting tractive effort and not the continuous...

Not sure if I did the right thing or not with that.

 

[Azervich]

The enginespec tractive values at higher throttle settings, therefore, may have some justification (after all, you don't start slamming the throttle to notch 8)

Hi Pendolino,

That's what Vehicle Physics is for, 100% means the locomotive has no slip, 95% means the loco has some slip, I use 85~70% for wet or misty conditions, over powered locos tend to slip in the lower notches, also TS09+ has max-tractive-effort tag in the loco config which helps scale it down when using vehicle physics.

Hi Tram,

Default wagon feels more like rollerbearring for 90~110 ton car, that's why with some of the light weight wagons it feels like there's allot of friction, trainz doesn't quite model loaded wagons so you need to make a physic to get it to handle correct for a fully loaded wagon, I use 0.0317 for 75tons with a drag of 0.0107 which makes the wagon feel rather heavy when loaded while climbing a 1in48, a locomotive that can move 397 tons on a 1in48 will climb the grade with 376tons at 14mph rather easy, but will struggle if you add one extra 75ton car 'loaded weight' .

Cheers.

 

[TRam__]

Check behavior of empty car on plain route. Also, the only tag in config that affects on friction at low velocities - "axis-count".