Preliminary drawing

This is what I came up with playing around in Sketchup.  It may seem like a lot of extra work to draw the model in 3D, but I like the way it helps me to visualize how things will look, and it's great for finding out how pieces will fit together.  It's also helping me learn how to use Sketchup effectively, which seems like it could be a handy skill.

The plan at the moment is to build the model in 55n3.  The scale is odd, but the gauge is nice and even.  I have some other 3' gauge locos I'd like to build one of these days, and it would be kind of nice to see them all fitting and working together.  As I look at the loco, though, most of the dimensions seem to be driven more by proportion than scale, so the model might just as easily be Sn3.5.  In fact, it might fit that scale even better!

More work on the drawing

Tonight, in my spare time, I worked on the drawing a bit more.  I added a cab and dome, which took a lot longer than it seems it ought to.  I also cleaned up the boiler, figuring out where the openings need to go for the mechanism.

I can't decide whether I like the dome better in blue, like the boiler, or in polished brass.  I drew both:

By the way, that door is drawn 5' tall and 2' wide.  That seems small, but it's a small loco.  Should I make it bigger, or would that have been fairly prototypical for a small 3' gauge loco like this?

Not sure why but. . .

http://commons.wikimedia.org/wiki/File:LNWR_4ft_6in_2-4-2_Tank_2288.jpg

Most domestic UK small tank engines seem to have inside cylinders. Outside cylinders were more usual on tender locomotives. Another typical domestic UK characteristic is having spoked non-driving wheels,as well as spoked drivers.

I suspect however that "anything the customer asked for" was likely for export (colonial) locomotives

NWSL has small spoked wheels in regular HO, although "wagon style".

Raising the roof

I added couplers (Kadee #5, at HO height), and raised the roof a scale foot, making the door openings 6' tall and giving it much more of a narrow gauge look.

Bear in mind that this is narrow gauge.  There were certainly some narrow gauge inside frame engines with inside cylinders, but putting them outside made things a little less cramped.  That, and I just like them.  I suspect it would look a bit odd to have a big plate there and a pilot truck in front.  I'll have to play with some ideas, though.  The nice thing about Sketchup is that it's easy to change things!

I found this photo on line, which gives a rough idea the style I'm thinking.  I might even tilt the cylinders up and shorten the front truck.

I'm planning on building outside frames for the trucks.  As much as I like spoked wheels, they're not cheap.

Some "truck info" as I understand it

Trucks were used at the front of steam tender engines to help steer the loco more smoothly into curves at higher speeds.

The extra non-driving wheels on a lot of UK ( and I think Europe too) style slower speed tank engines were just "radial" axle weight carrying wheels. They didn't pivot at all - just had some sideways movement to allow for reasonable curves.

I can't speak with authority on this, so just mentioning it for cosmetic design input for your project.

Trucks

I always appreciate the input, Andy.  It definitely helps to toss ideas around, and it's a lot of the reason I post stuff like this here.

My thoughts on trucks at the moment (as always, highly subject to change) are to make the front truck swivel, and have the rear axle rigid in the frame - probably with extra side play.  Being a tank engine, I can see the advantage of a truck on each end, but I can also see the possibility of having at least one of the axles not being in a truck proper.

What I might do is to make a cosmetic outside truck frame, but just mount the axles so they have a little side play but not in a truck.

More progress

This is what I do in the hotel, when I can't do anything else..

Even if I never build it, I'm learning a few neat techniques in Sketchup.

I'd love to hear people's opinions, good or bad.  I'm sort of flying blind here, drawing something that looks good to me without any idea if I'm getting anywhere close to something that would really have been built.  I'm still on the fence about the cylinders.  Inside would certainly be easier to model, but I'll have to do a little research and see if I can make it look right.

Did engines with plate frames ever have the frames spread wider at either end to make extra room for cylinders, fireboxes, etc.?  Or were the frames pretty much always straight from buffer plate to buffer plate?  Also, should the bottom of the window be lower?  It's about 4' above the footplate at the moment, and I like the proportions, but that does seem a bit high.  Maybe since the firebox (motor) extends into the cab it would be about right?

SAR Wx inclined cylinders...

Dear Ken

The inclined cylinders on that (South Aust Rwy Wx class) loco are that way to avoid interferring with the leading-pony axleboxes when they swing into the curves...
(The inclined cylinders weren't that way for aesthetics, and made engineering the inside-valvegear relationships tat extra bit harder... )

Happy Modelling,
Aim to Improve,
Prof Klyzlr

PS certainly plate-frames had "joggles" in them to suit cylinder, overall-clearance, firebox width, and leading/trailing pony truck swing...

Final version, maybe

I'm not going to bother drawing things like the rods (probably) or handrails, details, etc.  Here it is in the rough:

I would be happy to hear opinions on colors, design, style, etc.  The truck frames are a pretty rough guess, though they look reasonable to me.  I ended up having to incline the cylinders to make room for the front truck, and I like the look.  If you look closely, there's a notch in the frame to make room for a firebox which I did not bother to draw (I forgot).

I'm thinking that some sort of cow catcher pilot might look good, though the end plates are certainly easier to build.

Final Version

Looks very proportional.

Comment on the colors, looks to circus like to me. But, it's my opinion.

Here's the the type of valve gear you should use on this engine.

Bernd

Thanks

I am still on the fence about the red frame.  I'd like to keep the end plates in red and the majority of the model in blue (though with black & white lining, much like at Puffing Billy).  I'm not sure what to do with the deck, whether to leave it blue or paint it black.

Before clicking on the link, I expected some sort of Hackworth gear.  The gear in the video is fascinating and unusual.  Sadly, I think I'm going to use inside gear because I don't like modeling tiny moving parts.  I cheat as much as possible!

The colours are rather bright

The colours are rather bright in the rendering, but you probably only have so much control over that.  Blue and red on locomotives was not rare in Europe.  Green was also common.  If you are going for a European vibe, the colours should work.  A little brass trim would help, too.

55n3, 55n3!!!! What moron

55n3, 55n3!!!! What moron would even consider 55n3!!!!

For more on 55n3:

http://www.55n3.org/

Amazing the blasphemy one finds while meandering thru forms

Harold

A moron like me!

Harold,

Where do you think I got my inspiration?

I've been following your pages for quite a while now.  I'm glad you found this thread - hoped you would!

Toning it down a bit

I agree, the colors (colours?) were too bright, and the red frame was a bit much.  I like this a bit better.

I'd add brightwork, like brass rings around the portholes, handrails, etc., and of course things like compressors, plumbing, headlights, and so on, but I don't really feel like drawing them, and I don't think I'd gain much by doing so.

I'm glad that nobody (so far) has stepped up and said "those trucks are completely wrong" or something equally challenging.  I expected it, too, since I made it up out of my imagination.  Did I get it right, or are you just being nice?

By the way, in case anybody (Harold?) is curious, I chose to raise the couplers 2mm higher than the Kadee standard for HO scale.  That brings them very close to 26" high at the center, which is the height the D&RGW used, and presumably other US 3' gauge lines as well.  Since one of the things I'd like to build one day is a hypothetical Southern Ry. version of an outside frame Mikado, it makes sense to standardize the coupler height with the first piece of equipment.  That, and they look better a little higher up.  They'll still couple to an HO car, but about half of the coupler faces will be exposed, so I wouldn't call it reliable.

colour/color

I let the Canadian spelling for colour slip in, just because we were talking about an apparently British engine.  Most words use the British spelling in Canada, officially, anyway.  Normally I write things using American spelling on a North American forum.  I only use the umlaut in my name when writing in German, too.

By the way, in case anybody

I would just put them HO height. Never could understand the idea that Colorado was some kind of standard for narrow gauge.

Narrow gauge is a "run what you brung" operation. Most narrow gauge operations were link and pin so coupler height was all over the place and there was no interchange.

Harold

coupler height

Couplers were lower on narrow gauge engines because the drivers were small, and the center of gravity was lower to compensate for the narrow gauge, to help with stability.  The draw force through a frame and the couplers should be at the same height.  Couplers on a narrow gauge would look funny if they were at the same height as standard gauge engines.

EDIT:  I reread the previous post and concluded he meant the same actual height as opposed to scale height.  That might look OK, but it depends on the prototype.

Colour and couplers

Actually, I missed your use of the spelling, Jurgen.  I was using the spelling for the same reason.  Having a little fun with the variations in our lovely language.

In my case, I have always had a thing for Colorado narrow gauge, and I may want to model it again in the future.  I might as well plan ahead, and since (as you pointed out) there was no official standard, any height is as good as any other.  There is an argument in favor of using the HO coupler height to go along with the track gauge, but I don't really see myself wanting to run the two scales together except as a goofy demonstration.

I have a theory on the idea of Colorado NG being a defacto standard.  At least in the US, it was arguably the largest system, it lasted longer than most, steam lasted longer than on most other lines, the scenery it ran through was frequently stunning, and portions of it still exist and are active.  When many people think about 3' gauge railroading (if they think about it at all), Colorado narrow gauge is what they think of.

weird gauges

I like to think about metre gauge and 760 mm gauge railways...though not 3 foot gauge, admittedly.  There is a lot of interesting stuff which was and still is running around in Europe.  I have pondered adding one or the other gauge to my future layout plans...but I will now return your to your regularly scheduled thread.

A Short History Of Why Colorado NG Was the Standard

One important thing to remember is that many of the excellent, well built, modern freight car fleet of the Florence and Cripple Creek Railroad were purchased by narrow gauge operations in the states of Montana, California, Nevada and Utah for use after the shut down of the F&CC right after the turn of the century.  Since the F&CC had all of these cars built to meet the standards of the D&RG who was the sponsor of the F&CC, with the shipping of these cars all over the Western US, the D&RG in a de facto manner established the standards for the 3 foot narrow gauge lines.  I should also point out that the D&RG and the DSP&P and the Colorado Central who were the primary components of the other major narrow gauge system in Colorado all shared standards and were able to exchange cars and locomotives when necessary.  Both AC&F and many of the other national car building companies also built their cars to these same standards as did the Baldwin and Cooke locomotive builders. 

Therefore, while individual modelers may not want to use the D&RG as a standard, the prototype car and locomotive builders of the day had no such hesitation.

Since we are talking 55n3

Since we are talking 55n3 here, I doubt if there will be any "Colorado" equipment to worry about.

HO height works best with the equipment available:

Harold

Colours

Ok Ken. I like those colours better. Again my opinion.  (BTW, this forums spell checker doesn't like the spelling)

55n3 huh? Isn't this what they did with the large scale LGB and such?

Bernd

5.5mm/ft goes back to 1963 to

5.5mm/ft goes back to 1963 to model British narrow gauge on 12 mm track.

http://www.blackhamtransfers.com/55/5andahalfassn.html

Just happens to work out for 3 foot narrow gauge using HO track.

Harold