[SP 0-6-0]

Has any attempt been made at offering single pipe as it is in MSTS? I would love to get the Milw Boxcab units to work in ORTS.

I do agree that maybe the wag files for the trucks could be reconfigured into eng files but then all of the eng files would have to be re-adjusted. These locos setup is a strange for sure. Not sure why Wag files were used over eng files?

Robert

[Csantucci]

An ORTSCompressorWorksInMUMode parameter could be created to be optionally inserted in .eng files.
This could be handled in two different ways:
1) default is as now; when parameter is present and equal to 1 and the loco is MUed, and same conditions are true for the leading loco, that loco's compressor is engaged even if there are wagons between leading loco and this loco
2) default becomes the opposite, that is any loco's compressor is engaged independently from its position; when parameter is present and equal to 0 that loco's compressor isn't engaged if there are wagons between leading loco and this loco even if the loco is MUed.

Which solution should be selected?

[steamer_ctn]

Csantucci, on 12 May 2018 - 11:02 PM, said:

An ORTSCompressorWorksInMUMode parameter could be created to be optionally inserted in .eng files.
..........
Which solution should be selected?

I don't believe that this functionality should be implemented unilaterally.

On single air pipe systems, I would envisage that it would be extremely unusual that air compressors on locomotives would be MU operated when separated by non-locomotive vehicles. If it was done it would potentially create issues with the brake pipe pressures and propagation. For example, as a worst case scenario, if a train had a locomotive at the start and end of the train, such as in a push-pull operation, and both locomotives compressors operated simultaneously, then the BP pressure potentially would increase at either end of the train, thus causing uneven brake release, etc.

Thus for single pipe brake systems, I think that the current arrangement of only allowing MUing of the air compressors on adjoining leading locomotives most represents the correct operation for these types of brake systems.

The MUing of air compressors on locomotives separated by non-locomotive wagons is more applicable to twin pipe, and elector-pneumatic (such as EP and ECP systems in MSTS speak) systems.

If the functionality is considered core to these types of brake systems, rather then adding an additional parameter, perhaps the functionality should be added to the relevant brake classes in OR as a standard default operation.

[jared2982]

On modern diesel locomotive when used as DP power this is exactly how it works. When you release the brakes on the controlling locomotive consist a radio signal is sent to the DP consist(s) and that locomotive also increases brake pipe pressure from the rear or/and middle of the train depending on the placement of the engines. However on steam engines or manned helpers there is no control of the brake pipe pressure from additional locomotive consists.

[superheatedsteam]

If desired, the DPU trains that use Harris Locotrol systems can transmit power and brake instructions to the remote units independent of what the head end is doing. You can have have the head end of a train descending a hill and braking while the mid train units are still powering to crest that hill.

https://en.wikipedia.org/wiki/Locotrol

As I understand it, in the US single pipe system, any MU units connected together will have their reservoirs connected via the MR (Main Reservoir) hose. In effect this creates one large reservoir between those physically connected locomotives to increase air capacity and to share the load among the air compressors.

Pin 22 on the electrical jumper cable between the locomotives controls the compressors to act as one and share the load of maintaining the air pressure.

OR doesn't simulate distributed power (yet) but remote units can and do supply air to the brake system. Bankers that just push from the rear but do not connect the brake pipe obviously don't assist but connected 'in-train' DPU units certainly do. In fact DPU's improve braking performance as the propagation signal to apply and subsequent release of brakes is more responsive compared to just head end power.

May I suggest an additional parameter of ORTSdpu or similar that would allow DP units to be part of brake pipe equation.

I found the following which may be of interest in relation to MU control.

http://www.railway-t...mu-control.html

Cheers,

Marek.