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TheDark January 24th, 2017 10:46 PM

Locomotive design sequence
 
It is possible I am misremembering, but I seem to recall someone had posted an FF&S design sequence for locomotives. However, I cannot find it now. Does anyone know where in the vast internet this might be located?

LeperColony January 25th, 2017 10:52 PM

Off hand, the only reference I've ever heard was where Ask Dave pointed out that they never really managed to get an adequate locomotive design system.

TheDark January 25th, 2017 11:02 PM

Quote:

Originally Posted by LeperColony (Post 557602)
Off hand, the only reference I've ever heard was where Ask Dave pointed out that they never really managed to get an adequate locomotive design system.

I ran across that during my Google search. I feel like I saw one that included the power generation tables and part of the design sequence included calculating stats for the locomotive on its own and with different masses based on expected consists. I was thinking it might have been the one Dave mentioned, posted by whoever wrote the system, but now I can't find it.

timerover51 January 26th, 2017 01:04 AM

Are you looking forward to a locomotive design of a specific type of locomotive, or just a good description of a locomotive design?

whartung January 26th, 2017 02:49 PM

And what are you looking for in locomotive design?

Specifically, about the only thing that a locomotive really has going for it in distinction to any other wheeled vehicle is it's necessity for weight to provide tractive force in order to pull the cars.

Obviously, when you get in to the weeds and consider the differences between, say, a narrow gauge gear driven locomotive and a 4-8-8-4 mountain locomotive are more than just raw horsepower and length.

But, for most purposes, especially game purposes? There's really NOT that much difference.

Then it comes down to basically steam power plant design or, in the modern age, electric motor design.

So, what exactly are you looking for in a design sequence for locomotives?

TheDark January 26th, 2017 07:33 PM

I'm really just looking for something in the vein of the other vehicle construction segments, where the various inputs of size, material, power plant, etc, end up giving protective value, speed, range, etc. I'd like to be able to do up armored trains at various tech levels.

TheDark November 8th, 2017 09:33 PM

I've kept doing research on this, and have the start of a design sequence, although I need to spend a lot of time at some point converting from imperial to metric. Here's the start of what I have for steam locomotives:

MW * 1341.02 = horsepower

For TL3, horsepower/4.24 = area of cylinder face (in in^2) = Ca
For TL4, horsepower/7.42 = area of cylinder face (in in^2) = Ca

2*((Ca/3.14)^0.5) = cylinder diameter = Cd

0.85 * P * Cd * (10*Cd/7) / D = Tmax
P = boiler pressure in psi (200 for TL3, 350 for TL4)
Cd = cylinder diameter in inches
(10*Cd/7) = typical piston stroke in inches (10/7 the bore diameter)
D = diameter of driving wheels in inches
Tmax = maximum tractive effort in pounds

1.2*D = maximum speed for driving wheels in miles per hour

Tmax/0.0625 = weight on driving wheels (pounds)

Each ton pulled requires 4 pounds of tractive effort = Ta (pounds)

375 * horsepower / Ta = maximum speed at load (miles per hour)

Top safe speed is the lower of 1.2*D or 375*hp/Ta. Larger wheels will maximize 1.2*D, smaller wheels will maximize 375*hp/Ta.

Acceleration in mph per 5-second round is 90*hp/Ta.


Rail is measured by weight in pounds per yard or kilograms per metre; the conversion between the two is effectively 2 lbs/yd = 1 kg/m. The maximum axle load for either is 560 * rail weight (i.e. a 50-pound rail can have a maximum weight per axle of 28,000 pounds). Rail weight = rw

Tmax/(560*rw) = number of driving axles required.

Grate area of firebox in square feet = Tmax/600


Things I don't have yet: Carrying wheels (leading bogies, trailing bogies, etc). Weight for non-engine items. Bogie requirements for high speed. Percentage of locomotive weight carried by carrying wheels. Compound engines. Non-steam engines. Stoking (either by fireman or mechanical stoker). Water consumption. Sanding. I'm sure there are other things as well, but those are what pop to mind as I'm writing this.

timerover51 November 9th, 2017 06:49 PM

I was going through one of my Army transportation manuals, and it had a section on military railroads. Two locomotives were mentioned, one steam-powered and one narrow-gauge gasoline-engine powered. The steam locomotive was a big one, and used 4.400 pounds of coal and 3,400 gallons of water per hour. The tender was good for 10 tons of coal, but only 7,000 gallons of water, so it would need water every two hours. I would have to go back and take a look at the narrow-gauge engine gasoline consumption.

Also, have you looked at Project Gutenberg for information on the development of the locomotive? There is quite a lot there covering the development of the steam locomotive.

TheDark November 9th, 2017 07:26 PM

Quote:

Originally Posted by timerover51 (Post 577041)
I was going through one of my Army transportation manuals, and it had a section on military railroads. Two locomotives were mentioned, one steam-powered and one narrow-gauge gasoline-engine powered. The steam locomotive was a big one, and used 4.400 pounds of coal and 3,400 gallons of water per hour. The tender was good for 10 tons of coal, but only 7,000 gallons of water, so it would need water every two hours. I would have to go back and take a look at the narrow-gauge engine gasoline consumption.

Yeah, consumptions could get huge. During their original tests, the Big Boys went through 8-10 tons of coal and 38-42 tons (10k-11.5k gallons) of water per hour. They carried 28 tons of coal and 25k gallons of water to get 2-2.5 hours of endurance.

Quote:

Also, have you looked at Project Gutenberg for information on the development of the locomotive? There is quite a lot there covering the development of the steam locomotive.
I haven't, but I managed to pick up a copy of J. G. A. Meyer's Modern Locomotive Construction of 1892 for information on how things were done.

timerover51 November 9th, 2017 10:53 PM

Just checking on what you had.


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