Weather and Physics

[Alpenfreight]

Hey All,

I did a quick search around for this and couldn't find anything. Does weather have any impact on the physics of the game? If it's raining or snowing does wheel slip happen more easily? If it's cold do engines become harder to keep warm?

My guess is no... but i so very hope it's a yes

[_o_OOOO_oo-Kanawha]

Hey All,

I did a quick search around for this and couldn't find anything. Does weather have any impact on the physics of the game? If it's raining or snowing does wheel slip happen more easily? If it's cold do engines become harder to keep warm?

My guess is no... but i so very hope it's a yes

Rain and snow do reduce adhesion. You'll need to sand more often.

The actual adhesion figures vary from engine to engine.
Some engines are unrealistic in their adhesion values.

[Alpenfreight]

Hey All,

I did a quick search around for this and couldn't find anything. Does weather have any impact on the physics of the game? If it's raining or snowing does wheel slip happen more easily? If it's cold do engines become harder to keep warm?

My guess is no... but i so very hope it's a yes

Rain and snow do reduce adhesion. You'll need to sand more often.

The actual adhesion figures vary from engine to engine.
Some engines are unrealistic in their adhesion values.

Do you know what file this is stored in?

[_o_OOOO_oo-Kanawha]

Adhesion values are stored in the engine.bin files.

You'll need RW_Tools to edit them in-situ, or first expand the engine.bin to a corresponding engine.xml file by dropping the .bin file on Serz.exe in the Railworks root folder.

With a good xml editor like Notepad++ you can then edit the values in clear text.

When done, you drop the .xml back onto Serz.exe to re-create the engine.bin with your edit. You might need to remove the read-only flag first in Windows Explorer.

Clear the .pak cache files and restart the game with your edited engines.

I believe the prototype maximum adhesion is .25 in dry conditions.

[buzz456]

Or if you are planning on doing much of this invest in RWTools a nifty editor that does all kinds of things. You can directly open a bin file edit it and when you save it it automatically saves a backup in your engine file or whatever.

[BNSFdude]

.25 adhesion on dry rail is accurate for something with a mon-advanced wheelslip system like a 40-2. Microprocessor units like Dash 8s and up and Radar controlled units like the 50, 60, and 70s are all consistent with getting around 28-30% adhesion with the advancement of truck and wheel slip technology. Advanced AC traction locomotives can get from 33% (EMD) and 38% ( GE with Hi-Ad trucks) utilizing what's called wheel creep where the wheels turn ever-so-slightly faster than the actual ground speed.

[_o_OOOO_oo-Kanawha]

.25 adhesion on dry rail is accurate for something with a mon-advanced wheelslip system like a 40-2. Microprocessor units like Dash 8s and up and Radar controlled units like the 50, 60, and 70s are all consistent with getting around 28-30% adhesion with the advancement of truck and wheel slip technology. Advanced AC traction locomotives can get from 33% (EMD) and 38% ( GE with Hi-Ad trucks) utilizing what's called wheel creep where the wheels turn ever-so-slightly faster than the actual ground speed.

Thanks,

These values I will put into my engines.

What adhesion factor does sanding add?

Can one hear the micro creep? Our AC traction EMU's here makes an awful screeching sound when slipping on wet rail. It even happens at speeds over 60 MpH. Due to the high power to weight ratio the driven axles are always at the adhesion limit in order to achieve the quick acceleration needed to maintain schedule.

Driving trains with prototype locomotive adhesion and car weights is much more challenging and fun than default Railworks stock.
One has to edit many locos and wagons though ...
Especially for use in Quick Drive scenarios where one cannot set cars to 'loaded', but loaded versions of the cars have to be created and put into consist fragments.

[Ericmopar]

I wonder what the wear penalty is for those units and rail lines exposed to that creeping wheel technology. It has to accelerate wear on wheels and rail.
I read a report from one of the big rail outfits once and was surprised how little sand adds to traction. In dry weather the number is pretty much zero and in wet weather it still only added a very small amount of traction.
Some locos in Trainsimulator actually have too little traction worked into the physics. The Dash 9s on Donner will start slipping in notch 2 and even 1 with an incredibly light consist.
Without mods some short trains are impossible to start and require sand all the way to the top.
Even at 20 plus mph, you can't stop sanding and get into notch 6 or higher, and yet I've seen real Dash 9s pulling hard on Tehachapi and Donner Pass without sand at 10mph in notch 7 and 8.
I've also read about and seen small Consolidations pulling 50 car trains on level track with no problem, but Mike's connie is struggling with far fewer cars on level track on the RWA.
At the Nevada Northern Railroad, the head man was telling me about their Connie during it's working days, and it could easily pull (20 something?) large ore cars up to the mine on grades over 2%.

[BNSFdude]

I'm afraid I do not know the number for sand off the top of my head.

There is a distinct singing or groaning locomotives make when right at the adhesion limits or when creeping.

The ES44ACs and like will actually bounce noticeably in the cab while the EMDs will lurch (this breaks trains).

There's also automatic sanding which on GEs actually applies sand briefly while reducing output to slipping motors when the measured torque per traction motor doesn't match the current output levels.

[mrennie]

I wonder what the wear penalty is for those units and rail lines exposed to that creeping wheel technology. It has to accelerate wear on wheels and rail.
I read a report from one of the big rail outfits once and was surprised how little sand adds to traction. In dry weather the number is pretty much zero and in wet weather it still only added a very small amount of traction.
Some locos in Trainsimulator actually have too little traction worked into the physics. The Dash 9s on Donner will start slipping in notch 2 and even 1 with an incredibly light consist.
Without mods some short trains are impossible to start and require sand all the way to the top.
Even at 20 plus mph, you can't stop sanding and get into notch 6 or higher, and yet I've seen real Dash 9s pulling hard on Tehachapi and Donner Pass without sand at 10mph in notch 7 and 8.
I've also read about and seen small Consolidations pulling 50 car trains on level track with no problem, but Mike's connie is struggling with far fewer cars on level track on the RWA.
At the Nevada Northern Railroad, the head man was telling me about their Connie during it's working days, and it could easily pull (20 something?) large ore cars up to the mine on grades over 2%.

It's probably the rolling friction and drag values in the cars that are at fault. Most of the DTG stuff have values that are way off.

For adhesion values and the effect of sand, I always go by what is says in this document: http://www.kth.se/polopoly_fs/1.266907!/Menu/general/column-content/attachment/Zhu_licentiate_thesis.pdf

Rail conditions Adhesion coefficient
-- Dry and clean 0.25–0.3
-- Dry with sand 0.25–0.33
-- Wet and clean 0.18–0.20
-- Wet with sand 0.22–0.25
-- Greasy 0.15–0.18
-- Moisture 0.09–0.15
-- Light snow 0.10
-- Light snow with sand 0.15

[GSkid]

I'm afraid I do not know the number for sand off the top of my head.

There is a distinct singing or groaning locomotives make when right at the adhesion limits or when creeping.

The ES44ACs and like will actually bounce noticeably in the cab while the EMDs will lurch (this breaks trains).

There's also automatic sanding which on GEs actually applies sand briefly while reducing output to slipping motors when the measured torque per traction motor doesn't match the current output levels.

Is the singing you are talking about like this starting at the 1:49 mark of my video?.....

https://youtu.be/Kc370weRITk

That short section is essentially straight, so that clearly sounds like wheel slip/creep singing to my ears. There was a ton of that singing in many of my latest videos from that trip.

I often wonder how much flange grease affects wheel adhesion considering a small amount of it inevitably ends up on the top surface of the rail head. Just run your finger over the top of a mainline rail and you can feel the light grease on your finger.

[BNSFdude]

That sound is it!

It affects it a ton. If you're in throttle or dynamic brakes and hit a greaser you'll slip and the engine will reduce load and apply sand.

[GSkid]

Cool! So I was right in my assumptions of what I kept hearing as these trains climbed the 2+% grade.

I'm not for sure and could be wrong, but anecdotally it kinda seemed like the brand new UP ET44AH locos exhibited more creep ringing than the older locos in the consists. My guess is that's because of it's higher weight and it's newer adhesion package software. I don't recall BNSF's new ET44AC locos exhibiting as much ringing in comparison over the grade.

It may also have to do with UP at times carrying on SP's tradition of sending longer and heavier trains (with a mid-train DPU set) over Tehachapi Pass on average than BNSF does. Maybe the ET44AC would ring just as much as the ET44AH if it was put on the same long and heavy trains.