Update on the Steamers V2

Discussion of rolling-stock creation & re-painting.

Update on the Steamers V2

Unread postby dtrainBNSF1 » Tue Sep 12, 2017 12:48 pm

Dear friends,

It's been a LONG time since I posted anything related to steam locomotive mods. I've been without a computer for a while but now I've got a new one and I am pleased to announce that I am back to my regular shenanigans of tinkering around with steam engines for TS2017.

During the nearly year away from Train Simulator and modding I used my pad to do some research on steam locomotive design and power computation, including how to properly calculate drawbar horsepower, indicated (cylinder) horsepower, tractive effort, speed, and a better method of estimating a boiler's evaporation rate. To illustrate the difference in my old method and the new method I've found let's look at one of my first mods on the site - the Big Boy mod. According to sources the highest rate of evaporation for a steam locomotive boiler ever recorded was at the Altoona Test Plant with a Q2 4-4-6-4 with about 137000lbs/hr, and what was recorded at the Test Plant had to be taken with a grain of salt because these figures were impossible to reproduce on the road in day-to-day operation due to the fact that the engines there were pushed to their absolute limit and were expertly handled far beyond the abilities of regular drivers. What is the evaporation rate of my Big Boy mods? 168,000+ lbs/hr! WAY to high to be believable. In real life the Big Boys were likely to have an evaporation rate of 120-125000lbs/hr.

I'm also planning on reworking the weights of my locomotives and tenders to reflect them when empty. I regularly use figures from steamlocomotive.com for the weights, but the loco weight is in working order and the tender weights are when full of coal and water. Given that in the associated bin files there are places for capacity and in the sim file there's a space for water mass my previous mods were probably a bit heavier than in real life which makes a difference performance-wise as the locomotive has to move not only the tonnage it's pulling but also its own weight.

I'm also changing the way the mod interacts with the tevsspeed and the tevscutoff files to something similar I saw when I looked at the Jubilee locomotive. In the Jubilee locomotive the tevsspeed file values are all "1". The reduction to tractive effort due to speed was all taken account for in the tevscutoff file which is way longer than any other tevscutoff file I've seen in other locomotive for Train Simulator. This is similar to the FEF-3 where most of the tractive effort reductions are done in the tevscutoff file, and when you think about it it makes sense. The cylinders on a steam locomotive take in steam based on the reverser setting. When the reverser is at full forward or full reverse the cylinder gets filled with a large amount of steam and the expansion and pressure of this steam is what pushes the pistons and turns the driving wheel. The cylinders are more than happy to take large amounts of steam, but due to the amount of pressure in the cylinder it's not going to move very fast. With lower reverser settings there's less steam in the cylinder which means more room to expand and less pressure which means the piston can move faster, however because there is less steam in the cylinder there is also less force pushing against the piston and therefore less force being transmitted to the drive wheels and thus less tractive effort. At least that's how I think of it anyway. I'm no expert, so I might be a bit off.

Anyhow my method takes into account wheel diameter, evaporation rate, cylinder volume, number of cylinders, speed in rpm, and whether or not the locomotive has such modern innovations as feedwater heater to produce tractive effort up to 250rpm. From 250rpm onwards a second method is used which takes into account a steam locomotive's mean effective pressure at various speeds. To illustrate, here is a theoretical set of tractive effort and drawbar horsepower values of the 700 from 50rpm to 250rpm (given that the SP&S 700 has a maximum drawbar pull of 5000hp):

SP&S 700
Theoretical Evaporation: 90189.98525776769

50rpm(11.44791666666667mph)=69756; 2129.495666666667hp
15mph=69756;2790.24hp
16.78509146427353mph=69756;3122.295573818305hp
17mph=69541.61252356774;3152.553101068404hp
20mph=66548.88621270886;3549.273931344472hp
25mph=61561.00902794404;4104.067268529603hp
30mph=56573.13184317923;4525.850547454338hp
35mph=51585.25465841441;4814.623768118678hp
40mph=46597.3774736496;4970.386930522624hp
43mph=43604.6511627907;5000hp
45mph=41609.50028888478;4993.140034666174hp
50mph=36621.62310411997;4882.883080549329hp
55mph=31633.74591935515;4639.616068172089hp
250rpm(≈57.24mph)=29399.59259701259;4487.521147794005hp

So plenty to do with mods and to start things off I'm going to release a mod for the K4s which I talked about for a while and then my computer died so I couldn't release it.

In short I'm back and I'm ready to go back to work on mods. I'm working on my Masters Degree right now so serious work with Train Simulator is probably going to have to wait until the weekend regularly.
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Re: Update on the Steamers V2

Unread postby dtrainBNSF1 » Tue Sep 19, 2017 2:13 pm

I'm getting my feet wet with RW_Tools a bit more than before (I used it previously to convert files to read-write and unpack .ap files). I've looked through the available tutorials on the site, but I can't find anything in relation to editing the physics of rolling stock. I got the editor to clone the engine I'm editing so that I don't alter the original, but I can't adjust anything in regards to power and speed. Does anyone know of how to use RW_Tools to adjust the physics?
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Re: Update on the Steamers V2

Unread postby buzz456 » Tue Sep 19, 2017 3:20 pm

Do a open 2016 files in files pick your file open it and change whatever you want. When you do a save it saves the the previous one as a .bak in case you need to go back. It will do that continuously so you get .bak, bak1 etc. Nice feature for changes .
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Re: Update on the Steamers V2

Unread postby dtrainBNSF1 » Thu Sep 21, 2017 2:29 pm

I did a "Test Mod" to see if I have the gist of how RW_Tools works, and my test subject was not a steam locomotive but a Diesel locomotive: the Dash 9 (I had a modified version already but it got lost when my last computer died). Using RW_Tools I altered the weight, fuel, amps, name, max power, max force, max power at rail, max continuous force, max dynamic brake force, as well as changed the locations of the referencing blueprints. I even changed the combined power handle notches so that there are 8 notches instead of 9. It was a nice little exercise that I whipped up this morning and after tests I am happy to say that with this proof of concept mod done I can move forward with modding the K4s.

I like the graphing feature in RW_Tools. Here's a snapshot of the TE curve, the dynamic brake curves (including extended range), and the TE vs throttle curve (all based on figures from Al Krug).

Tractive_effort.jpg
Tractive_effort.jpg (254.91 KiB) Viewed 254 times


Dynamic_brake.jpg
Dynamic_brake.jpg (265.46 KiB) Viewed 254 times


Combined_power_handle.jpg
Combined_power_handle.jpg (254.17 KiB) Viewed 254 times
If what you've done is stupid but it works, then it really isn't that stupid at all.
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Re: Update on the Steamers V2

Unread postby dtrainBNSF1 » Tue Sep 26, 2017 5:53 pm

I believe I have my parameters for the K4s mod now. I just need to check a few numbers, and then the fun part starts: Testing. Ho-oh boy. BTW: Did you know that historically a K4s never made it to 100 mph in service? The highest recorded run with a K4s was on a descending .51% grade with a 1000-ton test train at 91 mph - close, but no cigar. And here DTG/RSC is telling us in the Loco Information page that these things have a top speed of 100+ mph.

I got tired of using the test track, so I built my own custom test route which is just a really REALLY REALLY long straight piece of track that is as flat as a pancake. I'll most likely add various stretches of grades to test lugging capabilities, but for the speed tests its just that long flat piece of track. I don't even know how long it is really. I just stretched the track to 500m and clicked a bunch of times.
If what you've done is stupid but it works, then it really isn't that stupid at all.
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Re: Update on the Steamers V2

Unread postby dtrainBNSF1 » Mon Oct 02, 2017 7:26 pm

K4s is coming along smoothly; still a work in progress, though. This last weekend was a bit busy with some travelling to see the folks at home, but work still continues.

If anyone recalls from my first Update on the Steamers thread, I complained a lot about the braking system in the G-Trax locomotives because for some reason they don't always fully release and when the brakes do not fully release it throws off the results of all my tests because of the increased resistance which can either make it harder going uphill or worse - it can make the train stall on the hill, ruining the test and wasting all that time that I used to get to that point in the test *!sad!* . This afternoon I had some time and I pulled up the Berk's simulation file with RW_Tools and compared it to the sim file of an American steam locomotive I knew had working brakes which actually fully release 100% of the time. Anything I saw different in the Berk's sim file I changed. Afterwards I fired up TS2017, grabbed the slightly modified Berk and put it in a QD scenario and for about 5 minutes or so I just sat there applying and releasing the brakes - and they fully released every time !*brav*! ! Later I'll try it with a train behind it, but for now it looks like the problem with the brakes might be solved !!det!! . That's a little something to look forward to later. Now I just gotta remember how I fixed that floating driver issue...
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Re: Update on the Steamers V2

Unread postby CArailroader » Tue Oct 03, 2017 12:12 am

Fantastic news about getting the brakes to fully release! It is the biggest pain-in-the-rear to eventually have to save a scenario, exit and then resume to have the brakeline charged to 90psi.
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Re: Update on the Steamers V2

Unread postby dtrainBNSF1 » Tue Oct 03, 2017 11:58 am

Took the Berk out for a brake test with 8 of Dick Cowan's heavyweights on Horseshoe Curve. The brakes worked just fine after several brake applications, and the base Berk actually performed better than I remember it performing previously - the only thing I've done to it is adjust the braking system. I've been modding steam locomotives off and on for a while so my style of driving steam locomotives has changed quite a bit since I started doing this modding thing a few years ago, coupled with getting to know Mrennie's Connie and FEF-3 (I haven't got the Jupiter yet, but maybe next paycheck), and more recently Just Train's BR Clan Class locomotive, which if you haven't gotten that particular locomotive then I highly suggest that you do. It is far and away superior to DTG/IHH's previous Clan Class and it's not all that hard to get used to in "Hot Mode" (ready to run). Just keep the boiler water between 50-75%, keep the firemass around 760 lbs on the mainline, get used to hitting that "E" key in order to unlock the reverser and you should be fine. It's not as complicated as driving the FEF-3. I haven't driven it in "Warm Mode" yet where you have to finish prepping the locomotive before work, and I'm glad they didn't include a Career Scenario with that procedure because players would probably lose so much time in prepping the locomotive that they'd lose most of their points by the first scheduled waypoint.

Wow. That turned into a ramble. THE POINT: I've gotten better at driving steam locomotives since undertaking this whole steam mod project. Back to the Berk. The Berk with base physics did well with an 8 coach load on a 1% grade. Can it be improved? Oh baby yes it can. After the K4s is done.

Gotta get that done. Gotta get that done.

On the topic of the K4s, according to steamlocomotive.com there were no less than 5 different tenders employed on the K4s during its career, and for the life of me I can't tell which tender they used in the game because the coal and water amounts in the game don't match the capacity of any of the tenders. For now I've taken a guess, but I'm not 100% sure. I know that it's not nearly big enough for a "Coast to Coast" tender and I know by looking at photographs of the first production K4s that it's not the very first type of tender used by the class. The included K4s looks like it uses the tender that PRR 1361 carried around during its time in exursion service. Can anyone out there confirm this for me? Which tender is it? And what is its coal and water capacity? And yes I checked the wikipedia entry but again it doesn't match the capacity of any of the 5 tenders used in service 100%.
If what you've done is stupid but it works, then it really isn't that stupid at all.
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