[steamer_ctn]

To allow simple operation of some of the vacuum brake configurations, a simple control mode has been implemented. This will allow operation of the vacuum brakes without the need for the user to use all the ejector valves.

[darwins]

It is now possible to have a separate large ejector on steam locomotives.

It is also now possible to have functional independent "steam brakes" on vacuum braked steam locos.
There is an example activity on the Coals to Newcastle website: https://www.coalstonewcastle.com.au/physics/demo-activity/#act7
The example is based on the Gresham & Craven type SSJ brake controller used on BR standard locos.

Thanks Peter for adding this to the OpenRails code.

This will allow more realistic braking control for BR, GWR, LMS and MR locos.

In the near future I will be releasing, via UKTS, some OpenRails updates to some of the excellent MSTS cab views by Hans Nooyen and Lew Price to include a large ejector control and high resolution gauges.

The details for this required in the eng section of the file are:
Comment ( ************************** Brake System *********************************************
Included in this section - Compressor, Reservoir, Application rates, etc
************************************************************************************* )

Comment (*** Braking systems ***)
BrakesTrainBrakeType( vacuum_single_pipe )
TrainPipeLeakRate ( 0.05inHg/s )

Comment (*** Ejectors ***)
Comment (* Estimate for Gresham & Craven SSJ type P ejector *)
VacuumBrakesHasVacuumPump ( 0 )
ORTSBrakePipeChargingRate ( 0.38inHg/s )
VacuumBrakesLargeEjectorUsageRate ( 690lb/hr )
VacuumBrakesSmallEjectorUsageRate ( 210lb/hr )
VacuumBrakesMinBoilerPressureMaxVacuum ( 110psi )

Comment (*** Brake Valve ***)
TrainBrakesControllerMaxSystemPressure ( 21InHg )
ORTSBrakePipeTimeFactor ( 0.02s )
ORTSBrakeServiceTimeFactor ( 10.0s )

Comment ( == Independent Brake valve - Engine & Tender == )
EngineBrakesControllerMaxReleaseRate ( 2.0inHg/s )
EngineBrakesControllerMaxApplicationRate ( 2.0inHg/s )
and in the EngineControllers section:
Comment ( Locomotive brake based upon Gresham & Craven MkIV Steam Brake Valve )
Brake_Engine ( 0 1 0.25 0.0
NumNotches( 5
Notch( 0 0 EngineBrakesControllerBrakeNotchStart )
Notch( 0.25 0 EngineBrakesControllerBrakeNotchStart )
Notch( 0.5 0 EngineBrakesControllerBrakeNotchStart )
Notch( 0.75 0 EngineBrakesControllerBrakeNotchStart )
Notch( 1 0 EngineBrakesControllerBrakeNotchStart ) ) )

Comment ( Based upon Gresham & Craven SSJ Ejector and control valve )
Brake_Train ( 0 1 0.1 0.1
NumNotches( 1
Notch( 0 1 TrainBrakesControllerVacuumContinuousServiceStart ) ) )

ORTSLargeEjector ( 0 1 0.1 0.0 NumNotches ( 0 ) )

ORTSSmallEjector ( 0 1 0.1 1.0 NumNotches ( 0 ) )

[darwins]

There is now a second tutorial on the Coals to Newcastle website. This one uses a locomotive (LNER V2) with a combination ejector of the type that was common on the LNER, SR and many of the pre-grouping companies.

https://www.coalston...-activity/#act8

Another example will shortly be provided as a tutorial for GWR brakes.

The latest round of developments mean that brake valves in Open Rails now behave in a much more appropriate way for vacuum brakes.

These changes do not automatically work with old MSTS files, but a simple cut and paste can significantly improve the functionality of vacuum brakes in old MSTS steam locomotive models.

If you still wish to use MSTS as well as OR you will need to make a copy of the MSTS eng file and put it into an OpenRails sub folder.

Open the copy in the OpenRails sub folder and find the train brake part in the file - this is from the default Flying Scotsman

Brake_Train ( 0 1 0.01 0.65
NumNotches( 3
Notch(0 1 TrainBrakesControllerReleaseStart )
Notch(0.4 1 TrainBrakesControllerRunningStart )
Notch(0.5 1 TrainBrakesControllerApplyStart )
)
)

Replace the entire of the section with:

Brake_Train ( 0 1 0.2 0.2
NumNotches( 3
Notch( 0.0 0 TrainBrakesControllerReleaseStart )
Notch( 0.2 0 TrainBrakesControllerRunningStart )
Notch( 0.4 1 TrainBrakesControllerVacuumApplyContinuousServiceStart ) ) )

and you should find that vacuum brakes on your steam loco work in a similar way to how they used to work with MSTS and probably even better!

Any feedback on progress so far would be welcomed.

[darwins]

The GWR demonstration is now available:

https://www.coalston...-activity/#act9

The demonstration uses a Hall class locomotive, with both large and small ejector controls as well as the driver's brake valve.

For those who like the GWR there it is now possible to include the brake controls as well as the vacuum pump for most types of GWR locos.

The same features will also allow improved brake models for MR/LMS and LNWR/LYR vacuum brake systems.

Together with the models above this gives fairly comprehensive coverage of vacuum brake systems for steam locomotives.

[Traindude]

darwins, on 21 January 2020 - 12:22 AM, said:

Open the copy in the OpenRails sub folder and find the train brake part in the file - this is from the default Flying Scotsman

Brake_Train ( 0 1 0.01 0.65
NumNotches( 3
Notch(0 1 TrainBrakesControllerReleaseStart )
Notch(0.4 1 TrainBrakesControllerRunningStart )
Notch(0.5 1 TrainBrakesControllerApplyStart )
)
)

Replace the entire of the section with:

Brake_Train ( 0 1 0.2 0.2
NumNotches( 3
Notch( 0.0 0 TrainBrakesControllerReleaseStart )
Notch( 0.2 0 TrainBrakesControllerRunningStart )
Notch( 0.4 1 TrainBrakesControllerVacuumApplyContinuousServiceStart ) ) )

and you should find that vacuum brakes on your steam loco work in a similar way to how they used to work with MSTS and probably even better!

Any feedback on progress so far would be welcomed.

I've been having trouble with the CTN test locos (such as the B1) with this brake script--even when I move the handle to the apply position, the brake pipe pressure doesn't decrease like it's supposed to, unless I open the end angle cocks from the F9 window. What am I doing wrong?

[darwins]

Thanks. Will look again and report back. Does it work on MSTS locos at all (as opposed to CTN locos that may be set up with other OR values that conflict with this)?

[Traindude]

darwins, on 22 March 2020 - 11:53 PM, said:

Thanks. Will look again and report back. Does it work on MSTS locos at all (as opposed to CTN locos that may be set up with other OR values that conflict with this)?

I modified the default Scotsman to use the V2 brake script and it didn't work.

[darwins]

Taking the case of the CTN B1 first of all - I can not reproduce the problem.
Firstly I downloaded the and installed the loco from the CTN website.
Secondly replaced the train brake part of the engine controller section with the one above.
This worked perfectly using OpenRails U2020.03.21-0706

Which version of OpenRails are you using?
You must be using a recent unstable version of OpenRails (released on or after the date of my post) for this controller to work.


Similarly I downloaded the latest version of the V2 from CTN website
Copied
Comment ( Based upon Davies & Metcalfe type VB ejector )
Brake_Train ( 0 1 0.2 0.2
NumNotches( 3
Notch( 0.0 0 TrainBrakesControllerReleaseStart )
Notch( 0.2 0 TrainBrakesControllerRunningStart )
Notch( 0.4 1 TrainBrakesControllerVacuumApplyContinuousServiceStart ) ) )

ORTSSmallEjector ( 0 1 0.1 0.55 NumNotches ( 0 ) )

Comment ( Locomotive brake - add for steam braked class V2 locos
Comment ( Engine brake should be omitted for vacuum braked V2 locos )
Brake_Engine ( 0 1 0.2 0.0
NumNotches( 1 )
Notch( 0 1 EngineBrakesControllerVacuumContinuousServiceStart ) ) )
and pasted into the default Scotsman and everything seems to work as it should.
You may need to send OpenRails Log files and copies of the eng files if you need me to investigate further.

[Traindude]

darwins, on 23 March 2020 - 12:11 PM, said:

Taking the case of the CTN B1 first of all - I can not reproduce the problem.
Firstly I downloaded the and installed the loco from the CTN website.
Secondly replaced the train brake part of the engine controller section with the one above.
This worked perfectly using OpenRails U2020.03.21-0706

Which version of OpenRails are you using?
You must be using a recent unstable version of OpenRails (released on or after the date of my post) for this controller to work.


Similarly I downloaded the latest version of the V2 from CTN website
Copied
Comment ( Based upon Davies & Metcalfe type VB ejector )
Brake_Train ( 0 1 0.2 0.2
NumNotches( 3
Notch( 0.0 0 TrainBrakesControllerReleaseStart )
Notch( 0.2 0 TrainBrakesControllerRunningStart )
Notch( 0.4 1 TrainBrakesControllerVacuumApplyContinuousServiceStart ) ) )

ORTSSmallEjector ( 0 1 0.1 0.55 NumNotches ( 0 ) )

Comment ( Locomotive brake - add for steam braked class V2 locos
Comment ( Engine brake should be omitted for vacuum braked V2 locos )
Brake_Engine ( 0 1 0.2 0.0
NumNotches( 1 )
Notch( 0 1 EngineBrakesControllerVacuumContinuousServiceStart ) ) )
and pasted into the default Scotsman and everything seems to work as it should.
You may need to send OpenRails Log files and copies of the eng files if you need me to investigate further.

I was using the stable version. I may try the unstable version to see how it works.

Update--it doesn't. I have attached the engine and log files to prove it.

[vince]

I don't know if this has anything to do with the bug but I see the coupler damping line is incorrect:
Damping ( 1e6N/m 1e6N/m )

It should be Damping ( 1e6N/m/s 1e6N/m/s ) as specified in the MSTS Tech Docs: Eng_and_wag_file_reference_guidev2.doc in the coupling section.
The above error is shown in the OpenRailsLog, fist two entries after the specs section.

The 'Match Braces' test in Context shows an anomaly also but I'm not sure how to interpret this.

regards,vince
edit:add info

[darwins]

You have used a very old unstable version of OpenRails
Version = X1.3.1-123-g332ddb9c
You must use a more recent version. January 2020 or later.
The most recent version is available here
Or on the updates tab choose 'Unstable'
.. although the warning says that unstable versions may contain serious bugs, in reality they very rarely do.

[slipperman]

Hi Darwin,
The version of Open Rails you quoted is the one I am using - it was released 31 January 2020. There have been no further "week-end" versions released, as far as I can tell!

Cheers,
Ged

[darwins]

Quote

Hi Darwin,
The version of Open Rails you quoted is the one I am using - it was released 31 January 2020. There have been no further "week-end" versions released, as far as I can tell!

Cheers,
Ged

Hi Ged,
Thanks for that information. It now leaves me confused. Perhaps a member of development team can explain when new features from the U versions get incorporated into the X versions.
The new token for vacuum brakes TrainBrakesControllerVacuumApplyContinuousServiceStart replacing the former token TrainBrakesControllerApplyStart (which should now only be used for air brakes) has been working in the U versions since the date of my original post on 15 January.

So I am a bit confused that a version of OpenRails released later than that date did include the same functionality.
Regards
Darwin

[Traindude]

darwins, on 23 March 2020 - 11:16 PM, said:

You have used a very old unstable version of OpenRails
Version = X1.3.1-123-g332ddb9c
You must use a more recent version. January 2020 or later.
The most recent version is available here
Or on the updates tab choose 'Unstable'
.. although the warning says that unstable versions may contain serious bugs, in reality they very rarely do.

I've downloaded the latest version you mentioned and it now works perfectly.

[steamer_ctn]

darwins, on 24 March 2020 - 11:27 AM, said:

Perhaps a member of development team can explain when new features from the U versions get incorporated into the X versions.
The new token for vacuum brakes TrainBrakesControllerVacuumApplyContinuousServiceStart replacing the former token TrainBrakesControllerApplyStart (which should now only be used for air brakes) has been working in the U versions since the date of my original post on 15 January.

So I am a bit confused that a version of OpenRails released later than that date did include the same functionality.

The current OR release process is a bit fragmented.

There are currently three versions as follows:

i) Unstable - this is a "sandpit" to try new functions and features and will have releases applied as developers added new code patches.

ii) Testing (I assume this is the X version that you referred to) - This will be released on a regular basis. However a feature included in the Unstable version does not automatically transition to the Testing version. It must be reviewed by a developer other then the author, and approved before it will move into the testing version.

iii) Stable - released on a very approximate 12 month cycle - current version was last released in Dec 2018. I am not sure how features are moved from Testing to Stable. I suspect that they need to be approved.

Currently there are a number of feature patches waiting approval to go from Unstable to Testing version. This is purely a "workload" issue where the small number of developers do not have time to do their own releases as well as review other developers work.

So it is possible to have a Testing release version that won't have some or all of the Unstable release features.

Added to this we also have some unofficial versions, such as the MG version.

So lots of choice.

If you want the latest features, I would suggest that you use the Unstable version, however you may need to be prepared to suffer the impact of a bug or two. You can choose when you upgrade, so perhaps you stay with an Unstable version for a while until you see a new feature that interests you.

If you don't want to be bothered by bugs, stick with the Stable version.

You could try the MG version as well, however it use the Unstable version as a base, and therefore form time to time bugs will creep in.
Contributors to both the Unstable version and MG versions tend to try and be responsive to fixing bugs reasonably quickly.

Sadly this situation is not ideal, but this is based upon the current process.