Message Areas - "Physics & general questions?"

Train-Sim.Com Message Areas

"Physics & general questions?"

Email this topic to a friend
Printer-friendly version of this topic
Bookmark this topic (Registered users only)
Previous Topic | Next Topic Conferences MSTS Locomotive Design (Protected) Original message
mra1968 (27 posts)
Mar-29-02, 11:01 PM (EST) "Physics & general questions?" I have downloaded and utilized many physics updates ie: eng files created, for mainly diesel locos with many thanks to the talented authors who have made the sim such a realism treat. thanks gents.just a couple of (possibly dumb?) questions though?Regarding the 'locos' consist, should the wag files match the locos physics too, like max app, max rel, chrg rate, rel rate, max BForce, aux pressures etc for realism?, as most of my numerous wagon files are all differential in this regard, and in the 'real' world do various wagons all differ in specs for braking etc?.And if so what would be the said ''optimum'' wag file overall brake settings (compromise) to use for realism in msts?, so as to change all to the same settings?Lastly has anyone done any physics for the Default passenger locos and rolling stock (acela,hhp, cars etc), in msts or should i stop now. LOLthanks in advance all and sorry if should have posted into general forum, but the brains are in here! markus
aust.
Alert Edit | Reply | Reply With Quote | Top
Table of Contents

Subject Author Message Date ID RE: Physics & general questions? jtr1962 Mar-30-02 1 RE: Physics & general questions? plainsman Mar-30-02 2 RE: Physics & general questions? mra1968 Mar-30-02 3 RE: Physics & general questions? mra1968 Mar-30-02 4 RE: Physics & general questions? kevarc Mar-30-02 5 RE: Physics & general questions? RickCan Mar-31-02 6 RE: Physics & general questions? plainsman Mar-31-02 7 RE: Physics & general questions? RickCan Mar-31-02 8 RE: Physics & general questions? plainsman Apr-01-02 9 RE: Physics & general questions? jtr1962 Apr-01-02 10

Lobby | Topics | Previous Topic | Next Topic
Messages in this topic
jtr1962 (82 posts)
Mar-30-02, 00:44 AM (EST) 1. "RE: Physics & general questions?" I updated the friction values for all of the default MSTS engines and cars. It is in the file library under fcalc_10.zip in the miscellaneous section. Some others have done extensive work with both the regular and dynamic brakes, and their work is in the file library also. To my knowledge, no one has done a comprehensive update of all the MSTS rolling stock which includes all the fixes thus far.I was recently trying to see if I could get a better representation of curvature resistance the same as I did for straight line friction, but I discovered that even when I set the curvature friction parameters to ridiculously high values, the trains behaved the same in curves. Apparently, MSTS doesn't even bother to calculate curvature friction at all even though there is a place for it in the .eng and .wag files. There are some other parameters, such as MaxInLowAcceleration and MaxInHiAcceleration, which are also documented but have no effect on the actual behavior of the trains. Remove | Alert Edit | Reply | Reply With Quote | Top
plainsman (793 posts)
Mar-30-02, 01:03 AM (EST) 2. "RE: Physics & general questions?" LAST EDITED ON Mar-30-02 AT 01:07 AM (EST)Hi,
Alright, .wag physics. The first thing I do with all my rolling stock is use a variation of Joe Realmuto's friction analysis to update the cars. I also check to make sure the derail force values agree with the weight for that car.
I try to reset the values in the brake section as below. This is much better than the default values, but still not quite realistic. I general, I find people don't want to spend their sim time waiting 35 minutes for brakes to release. With these settings, you will still need to conserve air, but you won't just sit and wait as long if you do dump too much air.
TripleValveRatio( 2.5 )
MaxReleaseRate( 6 )
MaxApplicationRate( 4 )
MaxAuxilaryChargingRate( 1.2 )
EmergencyResCapacity( 8 )
EmergencyResChargingRate( 1.7 )
I adjust the max brake force based somewhat on the car weight. In general, I lower the value to a range between 18 and 30 kN, the lighter force on empties, the heavier on heavy loads. I also adjust this range slightly with car period.
I think Chris Lee and Chuck Schneider may have done some of the passenger locomotive physics. I don't run anything except the GE E60CP (Metroliner), which Chuck redid, and I run a modification of that occasionally. I usually use the Alco PA and PB and FM CPA-20-5 for passenger consists.
Hope this helps some.
BobHi Joe,
You got in before I got posted, I was not trying to step on your post. I really appreciate the work you did. It is a big improvement in the sim. Thanks again.
Remove | Alert Edit | Reply | Reply With Quote | Top
mra1968 (27 posts)
Mar-30-02, 07:00 PM (EST) 3. "RE: Physics & general questions?" Thanks for replies joseph and bob.
joe, have been using your mods since released and must say what a great improvement over default settings , shame about the curvature attempts though. quick question , how do i add your mods to downloaded rolling stock, as opposed to the default cars. also bob, thanks for your excellent eng files which are being run in all my locos and the engineers are very impressed with the results. will certainly try the wag brake settings youve suggested , just a quick question, with max brake force can you suggest a ratio ie: mass x .15 or similar? would this be a good starting point etc?do you both think the acela , hhp, passenger cars etc eng & wag setting are close out of the box or should i try some mods?

so thanks again gents and with your input, shall have settings hopefully as close to realism as possible.cheers
marcus
aust. Remove | Alert Edit | Reply | Reply With Quote | Top
mra1968 (27 posts)
Mar-30-02, 07:22 PM (EST) 4. "RE: Physics & general questions?" re: default setting question out of box for acela,hhp, pass cars etc, joe, i am using your friction calc settings, should have said was questioning the brake settings.marcus
aust
Remove | Alert Edit | Reply | Reply With Quote | Top
kevarc (566 posts)
Mar-30-02, 09:57 PM (EST) 5. "RE: Physics & general questions?" First, open the wag physics file you want to copy the brake data from and highlight and copy the lines. Then open the wag file in wordpad and highlight the lines to be changed and right click and paste. Cole the file and save your changes.Kevin Arceneaux Remove | Alert Edit | Reply | Reply With Quote | Top
RickCan (205 posts)
Mar-31-02, 01:30 PM (EST) 6. "RE: Physics & general questions?" Wouldn't it be proper to use the MaxBrakeForce on a loaded version of the car for an empty car?
Theoretically a freight or passsenger car brake force does not change as a mass load is added to the car. The braking efficiency is designed for the car at maximum mass.
For MSTS I find a MaxBrakeForce value of 26% of loaded weight for a four axle car equipped with shoes (standard freight car) to be a good starting point for realistic train brakes at nominal grades.
Disk brake equipped passenger cars with a mass of at least 60 metrec tons appear to work best for me at 34% of loaded weight.Richard Remove | Alert Edit | Reply | Reply With Quote | Top
plainsman (793 posts)
Mar-31-02, 05:24 PM (EST) 7. "RE: Physics & general questions?" "Wouldn't it be proper to use the MaxBrakeForce on a loaded version of the car for an empty car?"
No
In modern braking systems, there is a load sensing pressure limiting valve which adjusts the amount of maximum force allowable depending on the car being empty or loaded.
Bob
Remove | Alert Edit | Reply | Reply With Quote | Top
RickCan (205 posts)
Mar-31-02, 10:59 PM (EST) 8. "RE: Physics & general questions?" Thanks for the info on this one also Bob. Do these modern systems also apply the the standard freight car?
Would you have an idea when this technology became available?Richard Remove | Alert Edit | Reply | Reply With Quote | Top
plainsman (793 posts)
Apr-01-02, 00:13 AM (EST) 9. "RE: Physics & general questions?" Here is a good article with brake info. It also has some useful links.
http://www.trainweb.org/railwaytechnical/brake2.html
Hope this helps,
Bob Remove | Alert Edit | Reply | Reply With Quote | Top
jtr1962 (82 posts)
Apr-01-02, 08:08 AM (EST) 10. "RE: Physics & general questions?" >Thanks for replies joseph and bob.
>
>joe, have been using your mods
>since released and must say
>what a great improvement over
>default settings , shame about
>the curvature attempts though. quick
>question , how do i
>add your mods to downloaded
>rolling stock, as opposed to
>the default cars.Just use the included program, fcalc_10.exe, and input the parameters it asks for. The program will output a line that you copy into the .eng or .wag file under the friction parameter. There are two sets of five values for this prameter, my program deals with the first set.
>do you both think the acela
>, hhp, passenger cars etc
>eng & wag setting are
>close out of the box
>or should i try some
>mods? I changed a few of the other values in my download. For example, the power of the Acela power car was double what it should hae been.>so thanks again gents and with
>your input, shall have settings
>hopefully as close to realism
>as possible. You're welcome. Remove | Alert Edit | Reply | Reply With Quote | Top

Lock | Archive | Remove

Lobby | Topics | Previous Topic | Next Topic