SMS and Eng File Info For Oil Burners/ Stoker Fed Locos

It turns out to be relatively simple to make the code changes required to get rid of the shoveling sounds and substitute code that will play sounds for an oil blower or stoker. The biggest drawback at present is the fact that there are no public domain files that contain those sounds that I can upload to the sound library.
I have found a really loud external sander sound that does a good imitation of an oil blower. It came from the sound file for the ShayD, but sounds the same as the one included in the SPS 700
sound files. The SPS 700 also has two sound files for stoker sounds that were not used in their .sms files. I am going to use these for my own locos until I can record my own sound files.
In addition to the code substitutions, it is necessary to think through some changes to the .eng file that would be needed. In stoker fed locos, my references tell me that the grate coal mass
was usually kept to a depth of 3-4 inches, assuming an almost continual feed of coal into the firebox. Since TrainSim requires the firebox door to be open to feed coal, this can create a
problem if the loco must travel through long tunnels. Assuming 50lbs per cubic ft for the weight of coal, the proper ideal fire mass would be about 12.5lbs per sq ft of grate area. This should be sufficient to allow firing to shut down for most tunnels.
Oil burners are a different animal again. There is no grate fire mass, the fire being sustained only by the continual operation of the oil blower. We cannot live with that in TrainSim because
of the tunnel problem. Finding a compromise fire mass will again depend on what is required to get through the existing tunnels. I am considering using between 6-8lbs of coal per sq ft of
grate area while running on Marias Pass.
Changes to the .eng file defaults on the shovel should also be considered so that one can find a firing rate that will not build the fire mass up too much. I am going to try notching the
shovel tonight to see if that will work. Even if it does not, the default .eng file code:
Shovel ( 0 1 0.1 0 NumNotches( 0 ))
should be changed to:
Shovel ( 0 1 0.05 0 NumNotches( 0 ))
Now for the changes to the cab .sms file. First, locate the streams associated with the coal shoveling routines. There will be two of them. Delete the first and substitute the following for that stream:
Stream ( Skip ( **** Stoker/Oil Blower sounds. ****)
Priority ( 5 )
Triggers ( 2
Variable_Trigger ( Variable3_Inc_Past 1 StartLoopRelease ( 1
File ( "Your_sound_file.wav" -1 ) SelectionMethod ( SequentialSelection ) ) )
Variable_Trigger ( Variable3_Dec_Past 1 ReleaseLoopRelease () ) ))

Then locate the second occurrence and substitute the same code for it. I recommend doing it one stream at a time to avoid missing closing brackets. The substituted code turns the variable trigger into a
discrete trigger since there is only one sound file to use at present and shoveling rate has no effect on seletion of the sound file.

Bill Hobbs

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

RE: SMS and Eng File Info For Oil Burners/ Stoker Fed L, baldwin, Apr-24-03, 04:05 PM, (1) RE: SMS and Eng File Info For Oil Burners/ Stoker Fed L, Bill Hobbs, Apr-24-03, 11:55 PM, (2) RE: SMS and Eng File Info For Oil Burners/ Stoker Fed L, crick14b, Apr-25-03, 05:30 AM, (3) RE: SMS and Eng File Info For Oil Burners/ Stoker Fed L, Bill Hobbs, Apr-25-03, 11:20 AM, (4) RE: SMS and Eng File Info For Oil Burners/ Stoker Fed L, black5, Apr-25-03, 12:48 PM, (5) RE: SMS and Eng File Info For Oil Burners/ Stoker Fed L, baldwin, Apr-25-03, 04:06 PM, (6) RE: SMS and Eng File Info For Oil Burners/ Stoker Fed L, Bill Hobbs, Apr-25-03, 04:13 PM, (7) RE: SMS and Eng File Info For Oil Burners/ Stoker Fed L, heffed, Apr-25-03, 07:34 PM, (8) RE: SMS and Eng File Info For Oil Burners/ Stoker Fed L, Bill Hobbs, Apr-26-03, 02:17 PM, (9)

Conferences | Topics | Previous Topic | Next Topic

Hi BillInteresting reading here. I have been doing some experimenting with firemass and shovelmass figures working towards the same sort of goal. What I have found is that to large a firemass figure starts to send the steam generation figure down when the actual mass gets up near the figure. The way I have been working is to find out the grate area and calculate an ideal and max figure, which are the same for this to work, based on 6 inches depth. This seems to give good results on every engine I have tried so far. To then get a realistic fuel consumption figure I have been adjusting the burnage rate, and the amount per shovelful. Its a bit of trial and error to get these right and at the moment I am using the auto fireman in order to observe the results under different styles of driving.mervyn@madasafish.com

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

Mervyn,
The "coal burnage" actually refers to the way in which boiler performance is estimated/evaluated. In determining the indicated horsepower of a boiler, tables were developed showing the lbs of coal and steam per indicated horse power. For instance, a saturated steam boiler working at 190psi would require 3.47lbs of coal and 25.75lbs of steam per ihp. This would yield an evaporation ratio of 7.43. A boiler working on steam superheated 233 degrees (as in a Schmidt type A superheater) would require only 2.49lbs of coal and 18.8lbs of steam per ihp. The brake horse power (power actually developed at the wheel rim) would be somewhat less because of inefficiencies in the cylinders. I have developed a chart of these basic numbers for boiler pressures from 120lbs to 240lbs and for two types of early superheaters, based on data I found in an old locomotive manual. It is in Excel form and I could make it available in the library if anyone is interested.
The firing difficulties you mentioned are also related to the rate at which new fuel is added to an existing fire. "Green" fires waste a lot of the combustible material and old manuals for engineers and firemen warn against letting the fire get too heavy or too light.
By the way, are you aware of the discussions that took place earlier on this forum concerning the fact that Kuju missed the fact that steam locos are reciprocating engines and that it is necessary to double the actual cylinder volume to get the correct steam consumption. When I read the discussion, I set up a series of tests to evaluate this, using 100gals of water in the boiler and 100gals in the tender in order to make close estimates of water consumption. At the same time, I tested fuel consumption using 100lbs of fire mass and 100lbs in the tender. Things work out very close to the old tables if one does double the cylinder volume.

Bill Hobbs

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

BillYou wrote this belowBy the way, are you aware of the discussions that took place earlier on this forum concerning the fact that Kuju missed the fact that steam locos are reciprocating engines and that it is necessary to double the actual cylinder volume to get the correct steam consumption. When I read the discussion, I set up a series of tests to evaluate this, using 100gals of water in the boiler and 100gals in the tender in order to make close estimates of water consumption. At the same time, I tested fuel consumption using 100lbs of fire mass and 100lbs in the tender. Things work out very close to the old tables if one does double the cylinder volume.It is good to see this is now being taken seriously it works well since I stumbled across it months back now.....anyway It would be great if you were to upload your Excel Form for us to look at.Regards Rick........Ex BR 1950 60s

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

Rick,
Yes I take it very seriously. I have probably enjoyed fooling around with the .eng and .sms files more than running trains. In order to understand the behavior of steam locos better, I done a lot of modeling in Excel. This table is one part of that. A spreadsheet to take basic info about the prototype locos and come up with a proforma analysis of its performance (and values for TrainSim variables) is another. I'll try to get it posted in the library sometime this weekend. Currently the spreadsheet contains some other calculations including my estimates of the cutoff power curve (relating to the cylinder card diagrams). Are those of any interest?
I am actually putting together my own version of a boiler sim to interface with my model RR sound system (it has a computer interface) to see if running models with more realistic "steaming" effects is possible. I have no clue whether TrainSim does things in a similiar way to my analysis, but certain ways of doing things seem natural choices. Even if it doesn't work out, I have learned a lot in building the simulator in Excel.
I guess we all get our enjoyment where we find it.

Bill Hobbs

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

I'd like anything that helps get the .eng better.
I have a technical background so enjoy tinkering with the file...but you do it much better than my 'pick up info here and there approach'.
Thanks.
Georges from London.

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

This 'coal burnage' excel sheet looks to be interesting. I would like to see it and try to apply the figures to what I am trying to do. What I have been looking for and not yet found is the relationship between the cylinder volume in cubic feet, and the weight of that volume of steam at various pressures, bearing in mind that in the sim, both throttle and reverser affect the pressure of steam in the steam chest which is where the cylinder steam comes from. This means that in order to achieve a realistic usage of steam you have to operate at fairly high settings, which in turn causes difficulties in adhering to posted speed limits.mervyn@madasafish.com

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

That info is included on the spreadsheet.

Bill Hobbs

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

>Since
>TrainSim requires the firebox door to be open to feed coal, You know, I've been wondering if it actually does. At least in the case of the automatic fireman.I've noticed sometimes while in a tunnel when the firebox is shut, I still hear shoveling.When you are being the fireman, shutting the door definitely stops the shoveling, and it's easy to see because of the HUD. But with the auto fireman, (most of the relevant info is no longer on the HUD) I can't think of any way to tell if it is indeed stopping, or if the sim "cheats" and allows the fireman to stoke while the door is shut. You can open the door manually at the end of the tunnel, but it's hard to tell by the image how much is actually in there.Does anyone know if this is actually the case or not?If so, you could deal with the constant stoking problem by using the auto fireman. I personally hate using him, but it may be a workaround.-Jeff

Union Pacific is my drug.

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

Jeff,
I think the reason that you hear the shoveling in the tunnel is that the multiple repititions of the shoveling .wav files in the .sms file don't properly get shut down. I have looked closely at the changes in the fire mass when this is going on and see no evidence that fuel is being added.
In the responses to my topic on running the oil burner, Rick mentions that one can open the firebox door again after entering the tunnel and resume firing. A very useful discovery.

Bill Hobbs

Alert | IP

[ Home | MSTS Forum | MSTS FAQ | File Library ] Copyright © 2002 by Nels Anderson. All Rights Reserved.