[steamer_ctn]

NickonWheels, on 20 December 2019 - 01:53 AM, said:

But the real problem for many complainig users out here is being able to start a given train, at least not realisticly.

I don't believe that it is appropriate to do any more code changes until fuller research is done on appropriate starting friction values, and especially how they vary with temperature, load, etc. So far with all my code changes I have tried to base them on solid research information that I have found, and realistic test results rather then using my "gut feelings".

I would also want to see realistic test scenarios established to confirm whether or not we are meeting realistic performance expectations and standards.

For example, based upon appropriate tonnage ratings for a section of track, is OR performing realistically or not? You have quoted a couple of examples (Timken and Big Boy, etc), if these are set correctly, what load would we expect to be able to start? Can we start these published loads?

If you are interested in assisting in the above tasks (under my direction - it will take some effort on your part), I would be happy to consider reviewing the starting resistance model.

Thanks

[steamer_ctn]

NickonWheels, on 20 December 2019 - 05:16 AM, said:

I´m indeed interested in helping you as ORTS needs all help it can get, but I´m little more than an ordinary user, having only complated writing an assisting program (calculating diesel engine power, fuel consumption, traction curves etc.) with massive outside help;

I am not interested in somebody to assist with coding.

I am more interested in somebody to help to do research, set up tests, perform tests and feedback the results, etc.

NickonWheels, on 20 December 2019 - 05:16 AM, said:

otherwise I can only express myself by words and drawings.

You have expressed a view as to what you think the starting resistance values should be. What research information are you using to form your view in terms of the appropriate values for points A and B?

I have done some reasonably extensive research to form a view on the starting resistance, and any new information would be beneficial to me to confirm or challenge the model currently in place.

This is but one of the areas that I am interested in getting some assistance.

If you are still interested, then contact me through the Coals to Newcastle contact page so that we can establish an email dialogue.

[ATW]

It’s not only the bearings that heat up from resistance but wheels heat up too by brake resistance forces, brake rubbing based on distance/speeds etc. Handbrakes left on a wagon dragging high speeds or wagon brakes not releasing would intentionally heat up the wheels.

[ATW]

For satisfaction to reach goals on what's mentioned here about bearings I think a special parameter like Brake Shoe friction or even the traction/dynamic curve should be made from scratch just for Bearings or/and frictions. Does that make sense? So you can plant various weather adhesion a like curves in addition to Davis equation totaling to more friction resistance. ORTS is the way to go when making variables an new features for the laws of physics and intentional errors due to poor bad ordered builds or just reaching goals for cars?

[scottb613]

Hi Folks,

RE: Friction - https://archive.org/...wyuoft/page/n99

I'm not sure if anyone has read the article I posted - but it's an interesting discussion on friction from 1922...

I've noted that that the starting forces seemed a bit hard at times while working on my locomotive physics files...

One thing I found interesting in the article - is starting friction is decreased by using draft gear with slack - so the locomotive doesn't have to overcome the starting forces of the entire train just those of each car in turn... It appears from the F5 display that ORTS totals the forces for the entire train ?

Regards,
Scott

[steamer_ctn]

scottb613, on 29 December 2019 - 03:12 PM, said:

I'm not sure if anyone has read the article I posted - but it's an interesting discussion on friction from 1922...

Whilst I have seen this type of information before, it is of interest, in particular the concept of tonnage ratings is the very interesting and this type of information was published by railway companies, and ideally the OR community should use the info to set realistic tonnage trains.

It looks like there is a Part 2 article as well, have you come across it?

scottb613, on 29 December 2019 - 03:12 PM, said:

One thing I found interesting in the article - is starting friction is decreased by using draft gear with slack - so the locomotive doesn't have to overcome the starting forces of the entire train just those of each car in turn... It appears from the F5 display that ORTS totals the forces for the entire train ?

As suggested in some other threads, this is correct, as there is no significant allowance for coupler slack, so in effect the whole train load needs to start at once.

[scottb613]

steamer_ctn, on 30 December 2019 - 12:40 AM, said:

It looks like there is a Part 2 article as well, have you come across it?

Hi Peter,

No - sorry - it appears to be an annual publication and 1922 (which I posted) is the newest one I've ever seen...

Regards,
Scott

[steamer_ctn]

Hi Scott,

scottb613, on 30 December 2019 - 04:43 AM, said:

No - sorry - it appears to be an annual publication and 1922 (which I posted) is the newest one I've ever seen...

No problems, I suspect that a lot of the information came out of this test report anyway.

I was mainly interested to see how the information was shared with the reader, as this sometimes gives slightly different explanations, and makes it easier to get your head around the technical aspects.

For your interest, I have previously found this document on the Internet as well. It demonstrates in real life how the tonnage rating methodology described in the test report was used.

These are the types of figures (as adjusted to the period being modeled) needed to ensure accurate modeling of train consists which will provide the most realistic performance in OR.

[scottb613]

steamer_ctn, on 30 December 2019 - 12:40 AM, said:

It looks like there is a Part 2 article as well, have you come across it?

Hi Peter,

I came across Part 2 (just realized each volume is made up of monthly periodicals):

https://archive.org/...ge/146/mode/2up

Regards,
Scott

[scottb613]

Hi Folks,

The info in the aforementioned link contains some hard data on resistance at 5 and 10 MPH - albeit it's for friction bearings - this seems to sum it up nicely.





It mentions the actual starting "Starting Friction" of train IS NOT the controlling factor of how much tonnage a locomotive can move - - - while "Starting Friction" IS most definitely the controlling factor in ORTS as it stands today...

Steam Locomotives - Low Piston Speed generates more power ? I don't think this is something we take into account for ORTS...

I believe Peter is working on advanced couplers again - I'm not sure if this will address the actual slack and how it relates to starting friction - but - my fingers are crossed...

Regards,
Scott