# Coal-fired vertical boiler logging locomotive



## Jim Schulz (Aug 10, 2009)

My next project is a coal-fired vertical boiler logging locomotive. Justin Koch (Triple R Services) is building the boiler for me so the boiler design will determine much of the final design of the entire locomotive. At first I thought I might like it to be 1:13.7 scale, but now I'm leaning towards 1:20.3. Because it's a figment of my imagination, it may end up being something that can be used in both scales. At first I thought a "Tom Thumb" design from the pioneering days of locomotive design would be something to pattern it after, but it will likely end up being something like a late 1800s logging locomotive blacksmith special.

What I've got so far:

a) coal-fired vertical boiler built by Justin Koch (Triple R Services). 8.25 inches tall overall and 2 5/8 inches in diameter. The mock-up boiler in the pictures below will sit about 1 inch lower on the deck.
b) Sierra Valley 7/8ths inch scale 1.75" diameter straight spoke wheels with axles long enough for outside frame cranks and Bachmann 1:20.3 coupling rods (I may have to fabricate different coupling rods. The boiler is a tight fit between the wheels).
c) MSS twin double acting marine engine for paddle steamers.

The final design is still a work in progress, but the "Mary Ann," Queensland Australia's first steam engine built in 1873 at John Walker and Co's Union Foundry, has inspired me. Hints of the The Dunkirk Iron Works' "Grasshopper" (New York) might also make its way into the design. Mike Martin's 7/8ths inch scale "backwoods logging locomotive" also gave me inspiration. Although the locomotive could work in both 1:13.7 and 1:20.3 scale, I think I'm going to use 'ol Ben (Railroad Ave. Models) as my scale rule. If he looks at home, then it's the right scale for me.

I plan to use the MSS engine to power both the driving wheels and a flywheel for track side accessories. Since this is a coal-fired boiler and therefore takes more effort to keep in steam (steam up to clean up), I want it to be doing something for longer periods of time than just running around the track. _I could use some help on gear ratios and sprockets._ It's been suggested I use anywhere from 10:1 to a 3:1 gear ratio. What size sprockets do you suggest to drive the wheels and the flywheel? Both the sprocket that drives the wheels and the sprocket that drives the flywheel will be on the same axle. I plan to loosen the set screw on the sprocket that drives the wheels when the flywheel is powering track side accessories.The mustard tin will be a water tank after it's cut in half, painted black, and with a Trackside Details water hatch covering a Goodall valve plumbed to the boiler.

Here's some pics of what I'm talking about:

The "Mary Ann":




















A Dunkirk: 











Various logging locomotives: 






























Mike Martin's backwoods logging locomotive: 












What I've got so far:


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## David Leech (Dec 9, 2008)

Jim, 
I'm sorry, but I really don't think that the corrugated cardboard floor will stand up to the heat very well. 
Especially with all the coal cinders, there is a very slight chance of a fire! 
I kind of think that you need Justin to make you a second boiler so that you can make the one with two boilers! 
Are you going to have the firebox door facing the side for ease of firing, unless of course you are on the 'other' side? 
I'm sure that you will keep us up to date on this project along the way. 
Al;l the best, 
David Leech, Delta, Canada


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## Jim Schulz (Aug 10, 2009)

David, thanks for the tip! That's why I post here. You guys see something I've overlooked







. Seriously though, I was planning on an all wood frame and deck. Do you think I'll need a brass plate floor around the boiler?


I'm thinking that the fire door can face the back. With a low-profile water tank to the side and a short-wall coal bin I'm thinking I should be able to get at the fire. I'll likely add a roof too, so there'll be a post to consider. I think it should be OK.


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## Jim Schulz (Aug 10, 2009)

OK, let's say I do 3:1 gear ratio. Using the BAGRS project engine suggested sprockets and chains, am I correct if I put a 7-tooth sprocket (.41" pitch diameter) on the shaft between the pistons; that sprocket then engages a ladder chain, which drives a 24-tooth (1.38" pitch diameter) sprocket on the flywheel axle. Another 7-tooth sprocket on the flywheel axle engages a ladder chain connected to a 15-tooth (.87" pitch diameter) sprocket on the driving wheels axle.

Then, when I disengage the 7-tooth sprocket on the flywheel axle (i.e. loosen the set screw on the sprocket which is connected by chain to the driving wheels) how will the gear ratio (7-tooth to 24-tooth) affect the flywheel accessories drive?

Make sense? Not sure I get it. With all this talk of teeth, maybe I should call a dentist







. Here's a better look at the MSS engine:


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## Charles (Jan 2, 2008)

To tie into Jim's post about the vertical boiler by Justin, it is being offered by TRS for projects if anyone is interested:
Vertical boiler


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## HMeinhold (Jan 2, 2008)

Jim, 
your overall reduction is 1:7.3 (7/24 * 7/15). This should give you a slow running powerful loco. Your accessory reduction is 1:3.4 (7/24), which is probably good for fast running equipment. You can always gear down within your accessory. It is better to run the belt at higher speed with less torque. So you should be OK. 
Regards


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## xo18thfa (Jan 2, 2008)

Do a two speed transmision. Two gears, two pinions. Gears are fixed on the axle. Pinions are on a sliding shaft moved by a yoke.


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## Jim Schulz (Aug 10, 2009)

I'm also considering connecting the chain directly from the drive shaft to the wheel axle. If so, would the 7-tooth sprocket (on the drive shaft) to the 15-tooth sprocket (on the wheel axle) be around a 2:1 ratio?


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## HMeinhold (Jan 2, 2008)

2:1 (or better 1:2) will be way too fast. I would go with at least 1:4 
Regards


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## Eric M. (Jan 3, 2008)

Gotta side with Henner on this one. 1:2 will be a speed demon. Go for at least 1:4. The Accucraft Shay is in the neighborhood of 1:4 and the Regner Konrad/Wili is something like 1:5 and they work great. Go for the lower gearing and then you can do some real work with your engine. 

Regards,


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## Jim Schulz (Aug 10, 2009)

OK, here we go:


Two 7-tooth sprockets between the pistons (https://sdp-si.com/eStore/PartDetai...roupID=170)

One 18-tooth sprocket on the driving wheels axle (https://sdp-si.com/eStore/PartDetai...roupID=170)

One 16-tooth sprocket on the flywheel axle (https://sdp-si.com/eStore/PartDetail.asp?Opener=Group&PartID=51212&GroupID=170)

And chain to link them together (https://sdp-si.com/eStore/PartDetai...roupID=169) 


There will be a throttle on the steam line, so I can control the speed. If it doesn't work out, I'll try different ratios.

The frame consists of 1/2" x 1/4" sills and end beams. Length: 10 inches; Width 3.5 inches. The axles are on a 1/2" x 1/4" wood mount glued and screwed with #4 x 3/4" button head sheet metal screws and held in place with Du-Bro 3/16" nylon model airplane landing gear straps blackened with permanent magic marker. There are two brass tubes over the end of the axles. The inner tube is 5/32" diameter sticking out far enough so that a crank can be attached to it later on for outside crank coupling rods. The outer tube is a 3/16" diameter sleeve held in place by the landing gear strips.


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## Jim Schulz (Aug 10, 2009)

I've added buffers to each end of the frame bringing the overall length to 10 3/4". (By the way, the width is 3 1/4" - not 3 1/2" as I said in a previous post. The space between the frame is 2 3/4" to accommodate the 2 5/8" diameter boiler. I used black permanent magic marker to blacken the wheels. Now for the temporary deck and engine assembly....


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## Brooks (Jan 2, 2008)

Jim, the wood floor of my coal BAGRS burned through, even though I had shielded it with an aluminum pan made from flashing (flashing rested on the wood). You will definitely need a metal plate of some sort under your boiler. In addition, you might consider making your floor boards easily replaceable in case they burn out as mine did. Elevating the metal above the wood, perhaps with washers, might help, too.


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## Jim Schulz (Aug 10, 2009)

Hi Brooks, 

The boiler will extend through the deck inside the frame with an ash pan underneath. It will be held in place with "L" brackets on either side of the boiler and then bolted to the top of the deck. I was thinking ceramic insulation wrapped around the boiler between the boiler and deck/frame would protect it from scorching. 

Jim


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## Kurt Sykes (Feb 28, 2008)

Hi Jim. 
First of all. 
I am very,very sorry that I did not get back to you sooner. 
I have a link that might help you, 
http://www.panyo.com/project/index.htm 

I bought mine from John Thomson ready to run. 
It does run great. 

Kurt


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## Jim Schulz (Aug 10, 2009)

Running on air:


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## Jim Schulz (Aug 10, 2009)

I've got a binding issue. Looks like the sprocket on the driving wheels axle is a little off, causing the axle to bind against the frame. You can see in the video how the axle travels up and down in the journal when there are no brass sleeves in place, which will be used for the outside cranks assembly. I tried adding an extra link in the chain to allow for the movement, but it was too much slack. So I took that link out, returning it to its former rather taught length, and elongated one of the links slightly, which seems to have solved the problem. Any other suggestions other than putting on a new sprocket and reaming it out straighter next time?


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## hawkeye2 (Jan 6, 2008)

I suspect that when you put the sleves in place you will see a bind and release situation. Streching a chain link is a band-aid, not a solution. I would suggest a longer chain with some method of adjusting it such as an adjustable engine mount if you aren't using an idler shaft or a chain tensioner. If the sprocket that is mounted on the axel isn't centered you will get an acceleration/deceleration with every revolution which will manifest itself as a vibration and jerky travel.


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## Jim Schulz (Aug 10, 2009)

Here's a clip after the chain adjustment and a spot of oil on the axles:


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## Jim Schulz (Aug 10, 2009)

I added this little bit I picked up on e-Bay the other day. I figure a governor (in this case cosmetic only) would have been needed for when the engine was set up for cutting wood.


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## Jim Schulz (Aug 10, 2009)

Here's a YouTube clip of Justin test firing the boiler. It's the first minute of the clip:

http://www.youtube.com/watch?v=s5NOzqP1l4A&feature=player_detailpage


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## Jim Schulz (Aug 10, 2009)

Since I've moved on to a bigger project, I thought I'd post some final pictures of how far I got. Thanks for following this topic! Hope you can see what I had in mind.


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