Steam Locomotive Vacuum Brake Ejectors
#1
Posted 11 June 2015 - 08:36 AM
I believe there were generally 2 Ejectors on a vacuum braked steam locomotive. There was a "Large" Ejector which was used to rapidly exhaust the brake system when the brake controller was set to Release. Alternatively, the Large Ejector control could be operated directly if there was no Release sector on the brake controller. There was also a "Small" Ejector which could be left running to compensate for leakage while the train was in motion and thus avoid dragging brakes.
If these Ejectors were purely mechanical, I would have had a go at writing a patch myself. However, they do/did use boiler steam and I don't have the knowledge to build that into the steam model. Would a steam expert be prepared to tackle this? It is after all an as-yet unimplemented feature of MSTS. In the bug report is a suggested workaround patch which could be used to get the affected models moving but it does not emulate reality. This patch is being independently tested at the moment to see if the workaround is acceptable to those running the affected models.
Dennis
#2
Posted 11 June 2015 - 10:34 AM
Since this is new functionality for Open Rails (though not for MSTS), would you please add a blueprint to our tracker (https://blueprints.launchpad.net/or). You can link your blueprint back to your own post to provide the details.
Blueprints help us developers to stay focused, keep track of what is needed and what is ready for inclusion in the project.
Thanks,
#3
Posted 11 June 2015 - 01:36 PM
#4
Posted 12 June 2015 - 11:01 AM
cjakeman, on 11 June 2015 - 10:34 AM, said:
James Ross, on 11 June 2015 - 01:36 PM, said:
Blueprint now added.
Dennis
#5
Posted 12 June 2015 - 12:32 PM
That would free up a key assignnment for other usage.
#6
Posted 12 June 2015 - 12:48 PM
copperpen, on 12 June 2015 - 12:32 PM, said:
This was the normal way except for some locomotive classes which had no Release sector on the brake controller and used the Ejector valve directly to release the brakes. Hence the problem with some, seems to be particularly GWR, models.
Dennis
#7
Posted 12 June 2015 - 03:14 PM
dennisat, on 12 June 2015 - 12:48 PM, said:
Dennis
I believe some LMS locomotives (the 3F, I think, comes to mind?) had separately controlled ejectors as well. To release the brakes, the brake handle was moved into the 'off' position, isolating the brake pipe from the atmosphere, and the small ejector was opened to build a vacuum.
#8
Posted 23 June 2015 - 12:21 AM
Dennis
#9
Posted 23 June 2015 - 01:45 AM
I am intrigued by the fact that you find some vac braked engines undrivable. I have not found one so far. Could you perhaps say which ones are affected?.
#10
Posted 23 June 2015 - 02:42 AM
copperpen, on 23 June 2015 - 01:45 AM, said:
Two examples I have personal experience of are 7820 and 7828 on the West Somerset Railway. The locos in File ID 30443 on UKTRAINSIM apparently have the same problem. Not being a dedicated steam person, I don't really know how widespread the problem is. The odd gripe about this pops up every now and then on UKTRAINSIM. Apparently some users are resorting to amending the eng files but not many people are confident about doing this.
Dennis