[cjakeman]

steamer_ctn, on 06 January 2022 - 04:57 PM, said:

My personal preference would be to see this option removed, and then applied on a car by car basis as it would most likely be in a real world situation.

Mine too.

Although I've suggested ways to notify and prompt users, I can't think up a way to notify/prompt users that this is a feature they could benefit from. Unlike some other extra WAG file parameters, the absence of the parameter does not indicate a missed opportunity.


The next control on the General Tab is:




and the Manual reads:



The Manual also states "This option should be unchecked, except for compatibility problems with old MSTS stock."

It would be much better if Open Rails could detect automatically that the user's content is "old MSTS stock". Does anyone know what might be different about "old MSTS stock" in this instance?

[Weter]

Tag ORTS-Ready, for instance.
This is better example to remove, than retainers.

[cesarbl]

cjakeman, on 07 January 2022 - 12:25 PM, said:

It would be much better if Open Rails could detect automatically that the user's content is "old MSTS stock". Does anyone know what might be different about "old MSTS stock" in this instance?

I believe this option can be removed. It is no longer required, as graduated release can be configured with appropriate .eng and .wag parameters. This option could be used for passenger cars with badly configured braking parameters (which lead to unrealistic release times), but I don't think there is a way to detect it, as the same configuration could be valid for a freight wagon, for example.

[steamer_ctn]

cjakeman, on 07 January 2022 - 12:25 PM, said:

Although I've suggested ways to notify and prompt users, I can't think up a way to notify/prompt users that this is a feature they could benefit from. Unlike some other extra WAG file parameters, the absence of the parameter does not indicate a missed opportunity.

I am not 100% sure what you mean by this? Are you suggesting that OR should advise users if they are not using a possible feature?

cjakeman, on 07 January 2022 - 12:25 PM, said:

It would be much better if Open Rails could detect automatically that the user's content is "old MSTS stock". Does anyone know what might be different about "old MSTS stock" in this instance?

I would suggest that a check of all cars is done at startup, and if the train has a mix of retained and non-retained cars then a message is displayed in the log file indicating this. This message should be able to be turned on/off with the "Verbose Message" option. Cars with retainers fitted will be able to be identified because they will have "Retainer_4_Position" or "Retainer_3_Position" in the BrakeEquipmentType statement. Thus it is possible to differentiate between cars with and without it the retainer.

Once notified, the user can then make appropriate adjustments if required to their stock.

cjakeman, on 07 January 2022 - 12:25 PM, said:

Graduated Brakes - It would be much better if Open Rails could detect automatically that the user's content is "old MSTS stock". Does anyone know what might be different about "old MSTS stock" in this instance?

This could be be set up with a similar notification system as above, ie where the train has a mix of graduated and non graduated cars then it could make a notification. It uses the "graduated_release_triple_valve" token so this could be used to check for cars with/without it.

For this feature, given that there are also a number of brake control tokens, such as "TrainBrakesControllerGraduatedSelfLapLimitedHoldingStart", possibly an information message could be provided to the user if they are running a locomotive with this type of token, and no cars with graduation triple valves fitted.

[darwins]

The odd one out is triple_valve - this is the one out without graduated release when using air_single_pipe or air_twin_pipe systems.

Anything else such as graduated_release_triple_valve or distributor, and any other brake system such as EP, SMEE, vacuum, and straight_vacuum has graduated release.

A message is a good idea where there is a mixture of stock. For goods trains in Europe it is not unusual for there to be a mixture in real life, and depending on the country the loco may well have a graduated release brake valve. So a message should be all that is needed.

[Genma Saotome]

re retainers

Quote

“Retainers were stop-cocks in the brake cylinder piping (exhausting to the atmosphere). By closing the retainer valves (on a few of the cars), it closed off the escape path of the brake cylinder air on those cars. Thus, the brakes stayed applied to the wheels of the cars where the retainer valves were closed.

In order to release the brakes from the wheels, engineer moves the brake handle to recharge the train line pressure—- the restored pressure in the train line moves the control valve to permit air flow to recharge the auxiliary reservoirs on each car.”

So, setting some of the retainers keeps the brakes on those cars applied. The brakes are not completely applied on those cars, more like “riding the brakes” in a car on a downhill grade. When the train comes to a steeper section of track, the engineer applies the brakes and all of the car brakes slow the train down. When the brakes are released when the train gets to less-steep grade, the air pressure will start increasing in the system but those cars with the retainers set will continue to hold the train in check. The engineer needs the brake line pressure to move back up to normal to be able to apply the brakes on the next steep grade.

They were certainly in use in the mid 1950's, perhaps later. If I hear any more I will pass it on to you.

[cjakeman]

The next control on the General Tab is closely linked with the one above:





and the Manual reads:




I have doubts about this control. It seems strange to be asking the user to play with the speed of a pressure change. We already have an in-game feature to initialise brakes for those who don't want to wait for the brakes to be released at realistic rates. Perhaps this is just my ignorance. I've also little idea what a "self-lapping notch" is but I did find this useful article.


By the way, this tour through all the options is quite revealing. I hadn't realised just how much detailed behaviour has been stashed away in the corners of Open Rails.

[Weter]

Yes, this was for compatibility issues with workaround-coded *.wag-files. EP didn't work right in MSTS.

Quote

"self-lapping notch"

Where did Yiu see it?

[Genma Saotome]

More on retainers:

Quote

Retainers are still in use and are still sold.

There are 3 settings:
D or EX: Direct Exhaust (this would be the setting when they are not in use)
SD: Slow Direct (through air orifice)
H: High Pressure (retains approximately 20 psi in brake cylinder)

As for when they they originated I would think it was not too long after the air brake itself was developed. The 1888 edition of the Car-Builder's Dictionary can be found on-line at: https://library.si.e...ldersdict00forn and the "Pressure Retaining Valve" is described on page 133. I did not have time to thoroughly search for a figure illustrating the valve, but there may be one farther back in that edition. There are figures in the 1906 edition and possibly some of the intermediate editions.

[Weter]

So, as I said, this function was later integrated to more sophisticated designs of some freight air bistributors.