Full Steam Ahead: A Train Designer Quest

Should design phases voting be on a generalized focus or on Specifics

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Normally one would be calculating the needed boiler thickness, I think.

Can you also include the pros and cons of boiler orientation and boiler tube designs?
 
[] Write-in: Calculate the boiler thickness based on the data you have.
 

Boiler Orientation
[] Vertical
- pros: smaller in size, ease of heating
- cons: less space for thermal transfer

[] Horizontal
- pros: allows for more space for tube heating
- cons: increased weight

Boiler Tube Design
[] Single large straight tube
- pros: simple engineering requirements, light weight
- cons: less efficient thermal transfer
[] Single large reversed tube
- pros: more efficient extraction of thermal energy
- cons: heavier tubing, more complex engineering requirements

As promised the pros and cons of orientation and tube design
 
UbeOne said:
[] Write-in: Calculate the boiler thickness based on the data you have.
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Not an option. The thickness choice is intended as part of the learning process. At the moment, there's not much boiler-making experience on the design team, so it's a "see what works" thing. And I will clarify, it's the thickness of the boiler barrel specifically, ie where the hot hot steam is at pressure. I won't go as far as to say it's completely guesswork but educated guesses are viable here. The thickness will also potentially give some cost reductions in future as you all learn how to boiler.

If you want it, I wouldn't go below 3/8th inch, just as a precaution
 
To further help with the visualization of the two types of orientation I went and found two pictures of early locomotive replicas
 
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So I did some cursory research (read: some google searches) it appears that 3/8th an inch is typically what's used on boilers that use up to 200 pounds of 'pressure' (I assume 'pressure' means PSI) and since we're only doing a quarter of that at, 50 PSI 1/4th an inch is probably sufficient though 3/8th an inch will probably be safer.

We did end up focussing on efficiency so we probably want to lean into that.

[X] 1/4th inch
[X] 3/8th inch

Don't really have a reason for horizontal, they seem to fit efficiency better but that's mostly just instincts, all steam trains we see now are horizontal so it's probably doing something right?

[X] Horizontal

Don't really know about this one, reversed tube will be better for efficiency but heavier and horizontal is already the heavier option, then again the smaller boiler thickness will probably balance that out?

[] Single large straight tube
[X] Single large reversed tube
 
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[X] 1/2 inch
[X] Horizontal
[X] Single large straight tube

I call this the lying short stack, simple and effective.
 
[X] 1/2 inch
[X] Horizontal
[X] Single large reversed tube

More thermal efficiency means getting more bang for our buck, getting more power out of our fuel. More space for tube heating also means more power extracted from the fuel.

I'm taking the 1/2-inch thickness for a margin of safety over what I feel is the minimum safe limit of 3/8 inches.
 
[X] 1/2 inch
[X] Vertical
[X] Single large reversed tube
Weight only really matters right nowfor inertia and hill grade
 
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Jupi wished to show you this vertical boiler lad climbing up a hill showing the marginal improvements on hills for the vertical type.
 
h0riz0n45 said:

Jupi wished to show you this vertical boiler lad climbing up a hill showing the marginal improvements on hills for the vertical type.
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To elaborate (and forcible draw my dear Co-GM out of seclusion) the vertical boiler has another two advantages early on and those are Water Level Tolerance and Simpler Maintenance. The simpler maintenance is self-explanatory in how it is an advantage, but water level tolerance is less so. According to my research the advantage is this. The water level in a horizontal boiler must be maintained above the crown (top) of the firebox at all times, or the crownplate could overheat and buckle, causing a boiler explosion. For a vehicle application expected to traverse hills, such as a railway locomotive or steam wagon, maintaining the correct water level when the vehicle itself is not level is a skilled task, and one that occupies much of the fireman's time. In a vertical boiler, the water is all sitting on the top of the firebox, and the boiler would need to be extremely low on water before a gradient could cause a risk by uncovering the firebox top.
That is not to say that the Horizontal is a bad choice especially as it did in fact become the standard orientation over time this is just for consideration.
 
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