[Csantucci]

Hi Peter,
I've seen that you have commented out the use of the two MSTS variables that inhibited water refilling outside a certain speed range (SteamWaterScoopMinPickupSpeed and SteamWaterScoopMaxPickupSpeed). This way water refilling is possible also above 100 mph. Does this make sense?

[steamer_ctn]

Hi Carlo,

Csantucci, on 03 April 2019 - 05:34 AM, said:

I've seen that you have commented out the use of the two MSTS variables that inhibited water refilling outside a certain speed range (SteamWaterScoopMinPickupSpeed and SteamWaterScoopMaxPickupSpeed). This way water refilling is possible also above 100 mph. Does this make sense?

Yes these parameters are no longer required, as OR now calculates the minimum speed required for water to start entering the tender based upon the physical dimensions of the water scoop. Thus the worry of a content creator finding accurate information on the water scoop is removed.

In regard to the maximum speed, as far as I am aware, in reality, the water scoop will not stop working at a particular speed. Based upon some of my research I have seen suggestions that trying to fill at "excessive" speeds may cause damage to the tender, or flooding the footplate, etc. As a consequence, the filling speed was regulated from an operational perspective (ie the driver was expected to regulate their speed), rather then the water scoop not operating.

As this feature is still a work in progress, I am still researching an appropriate way of modelling a suitable operational scenario.

If anybody has any prototypical technical information relevant to this situation I would be interested in looking at it.

Thanks

[Csantucci]

Thanks for the clarification.
So, if the train runs too fast, at least a message about an incurred damage could be displayed.

[darwins]

Hi Peter

Quote

In regard to the maximum speed, as far as I am aware, in reality, the water scoop will not stop working at a particular speed. Based upon some of my research I have seen suggestions that trying to fill at "excessive" speeds may cause damage to the tender, or flooding the footplate, etc. As a consequence, the filling speed was regulated from an operational perspective (ie the driver was expected to regulate their speed), rather then the water scoop not operating.

Whilst I doubt that the scoop would stop working, I suspect that the efficiency would drop at higher speeds, due to a greater proportion of the water going everywhere else than in the tender tank!

A significant operational problem was water going through open carriage windows, not just of the carriage behind the tender but also those of trains travelling on adjoining lines.
http://www.railwayco...sc/troughs.shtm
We will also need to look out for the forthcoming edition of the Railway Magazine

Also not sure if you saw this one Taking water at speed as it gives some figures for the amount of water collected.

Another article here.

Not had a chance to test this feature yet, or to look at double heading. But no doubt I will get there.

Reading between the lines of all of these I have the impression that the most efficient speed of pickup would be about 40-45 mph with a normal scoop with the modified LMS scoop being able to pick up more efficiently up to about 60 mph.

[copperpen]

Far as I can work out, in the UK diesels were limited to 70mph for water scoop to the lighter construction of the mechanism. Steam was likewise limited, but to what speed I cannot confirm, but it was probably similar to the NYC pickup speeds, initially 60mph due to the design of the scoop. NYC eventually raised speed to 80 mph after successive redesigns of the scoop. It was a concern that to push speed higher would result in burst water tanks due to overpressure, so further increases were not pursued.

[darwins]

For UK with the original scoops I believe it was 60 mph.

This was later raised to 70 mph possibly after the LMS improved their scoops c.1933 with 75 mph later allowed only on the WCML.

These speeds were continued by BR and applied to all trains passing over water troughs (not just those picking up water) to prevent damage caused by water from trains on other running lines.

[steamer_ctn]

Hi Copperpen and Darwins,

Thanks for the information and articles (some of them I hadn't seen).

Based upon the info, I believe that the following comments apply:
i) Passengers in the first car could be drenched by water spray from normal operation (especially at higher speed). However a real risk is evident of overfilling the tender (some of the references have photos of a "wall of water" coming out of the tender). Also whilst OR uses a button control, it appears in reality that a screw may have been used to raise and lower the scoop, hence a lot slower operation. See this video as a demonstration.
ii) It appears that the efficiency of the scoop was "capped" at a certain speed. Thus no matter how fast the train traveled, the amount of water taken on board would not increase. The Ramsbottom article suggests that this occurred at around 22mph for the locomotive being tested.
iii) Certainly it appears that if sufficient vents were not available in the tender then the increased air pressure created by the ingress of the water at a fast rate could "explode" the tender.

I have some thoughts about how to incorporate i) and ii) into the model, but I am not sure about iii) at the moment. How might this be handled in the game?

Were there posted speed limits applied to sections of track with troughs?

One other question I have is, could the water scoop be broken if lowered outside the water trough (both US an UK)? Currently OR flags an error message to this effect, but it appears that no permanent damage is done, as the water scoop will still work next time it is tried in the trough. I feel that this is a bit inconsistent, and if damaged it shouldn't work until activity is restarted, alternatively it is not damaged. Thoughts?

darwins, on 04 April 2019 - 04:07 AM, said:

We will also need to look out for the forthcoming edition of the Railway Magazine

This appears to be a May 2018 edition, can you obtain a copy?

@Darwins- Are you in a position in the near future to see if there are any technical test reports and maybe plans for different water scoops fitted to tenders @ the NRM? In particular it would be good to get some water scoop dimension information if possible.
Thanks

[longiron]

Some interesting information about New York Central and their track pans

https://nycshs.files...trackplans2.pdf

[darwins]

Quote

whilst OR uses a button control, it appears in reality that a screw may have been used to raise and lower the scoop, hence a lot slower operation. See this video as a demonstration.

In UK this was always a screw control. For tender locomotives it was of course on the tender, for tank locos at the rear of the cab (not sure how that applies to making 3-D cabs but it means it is not part of flat cabs). Longiron's NYC article suggests that later scoops in USA may have been steam operated.

Quote

It appears that the efficiency of the scoop was "capped" at a certain speed. Thus no matter how fast the train traveled, the amount of water taken on board would not increase. The Ramsbottom article suggests that this occurred at around 22mph for the locomotive being tested.

There is some suggestion in the articles that for a normal scoop that water up take should decline if speed is too high. The NYC article suggests that more modern scoops would pick up more water at higher speeds. In either case the difference is not very large.

I do not think that (iii) "the exploding tank" is needed in OR. This may possibly have happened with a very early tender somewhere during the introduction and testing but was probably quickly remedied by design of internal bracing and tank vents. I am not aware of any documented example.

Quote

Were there posted speed limits applied to sections of track with troughs?

So far I have only seen speed limits posted in magazine articles, there are none listed in the LMS Sectional Appendices or General Appendices for 1933. (Nor are water troughs mentioned in them at all!)

Quote

One other question I have is, could the water scoop be broken if lowered outside the water trough (both US an UK)? Currently OR flags an error message to this effect, but it appears that no permanent damage is done, as the water scoop will still work next time it is tried in the trough. I feel that this is a bit inconsistent, and if damaged it shouldn't work until activity is restarted, alternatively it is not damaged. Thoughts?

As stated in the articles above, troughs had open ends with the track having a gradient leading down to them at either end. This means the MSTS idea of breaking the scoop if it is lowered a little bit too early or raised a little bit too late is wrong. I would suggest giving an allowance of a few hundred yards either side of troughs rather than at the trough ends. If the scoop was lowered where there are points, crossings, AWS ramps, spare rails or anything else in the four foot AFAIK it would be broken and could not be used again.

Directionality is another point.

Most scoops only worked in the forward direction, although a few tank locos had scoops for both directions.

Peter, I can check for technical data (but think that Ramsbottom may be all you will get). Also will try to get Railway Magazine. Give me a couple of weeks please!

[steamer_ctn]

Hi Darwins,

Thanks for the feedback and ideas.

darwins, on 04 April 2019 - 09:48 PM, said:

So far I have only seen speed limits posted in magazine articles, there are none listed in the LMS Sectional Appendices or General Appendices for 1933. (Nor are water troughs mentioned in them at all!)

This tends to suggest that there might be not have been any adverse consequences for excessive speed through a water trough.

What were the posted speed limits on the sections with the water troughs in them?

darwins, on 04 April 2019 - 09:48 PM, said:

As stated in the articles above, troughs had open ends with the track having a gradient leading down to them at either end. This means the MSTS idea of breaking the scoop if it is lowered a little bit too early or raised a little bit too late is wrong. I would suggest giving an allowance of a few hundred yards either side of troughs rather than at the trough ends. If the scoop was lowered where there are points, crossings, AWS ramps, spare rails or anything else in the four foot AFAIK it would be broken and could not be used again.

This makes sense. I am not sure what can easily be coded. Certainly to look ahead and work out when the train is about a 100m from the trough is something that I wouldn't have a clue how to do.

The other suggestion about points, crossovers, etc might be possible, but again I an not sure if this can be done easily.

One thing I would love to see is an indication that a water trough is coming up in the HUD.

darwins, on 04 April 2019 - 09:48 PM, said:

Peter, I can check for technical data (but think that Ramsbottom may be all you will get). Also will try to get Railway Magazine. Give me a couple of weeks please!

Thanks, any other technical information would be helpful if possible.