Super Simplex 0-6-0
Moderator: Harold_V
Re: Super Simplex 0-6-0
David,
A combustion chamber is an enlargement of the firebox into the tubesheet. It is not an enlargement of the grate area, but an extension or protrusion of the top of the firebox into the tubesheeet. The tubes are shorter, but the space in the top of the firebox is greater, allowing better combustion, and there is an enlargement of the crownsheet, allowing greater efficiency in heat transfer. If you have not built a boiler before now it certainly will make your first boiler more challenging to fabricate.
So you asked "...will this reduction of the grate width effect the performance of this locomotive significantly?" Yes, if the area of air flow through the grates is lessened, and the area in plan at the grate allows less coal surface to burn. In that case there will be fewer BTU's heating the water. But it's not the "grate" per se, because you can adjust the number, width, and depth of the bars, to get the same air flow through the now lessened cross section of coal. Perhaps the depth of the coal bed can be slightly increased (depends upon the coal quality, size, etc.).
You also asked "Can I compensate in other ways?" The implication in making smaller cylinders is that your boiler will generate less steam with a smaller grate. So the suggestions were related to making more steam within the space that you have. Can you make the firebox longer and have the same size fire? Perhaps. Can you effectively increase the area of air flow through the grates? Perhaps.
Regards,
Andy
A combustion chamber is an enlargement of the firebox into the tubesheet. It is not an enlargement of the grate area, but an extension or protrusion of the top of the firebox into the tubesheeet. The tubes are shorter, but the space in the top of the firebox is greater, allowing better combustion, and there is an enlargement of the crownsheet, allowing greater efficiency in heat transfer. If you have not built a boiler before now it certainly will make your first boiler more challenging to fabricate.
So you asked "...will this reduction of the grate width effect the performance of this locomotive significantly?" Yes, if the area of air flow through the grates is lessened, and the area in plan at the grate allows less coal surface to burn. In that case there will be fewer BTU's heating the water. But it's not the "grate" per se, because you can adjust the number, width, and depth of the bars, to get the same air flow through the now lessened cross section of coal. Perhaps the depth of the coal bed can be slightly increased (depends upon the coal quality, size, etc.).
You also asked "Can I compensate in other ways?" The implication in making smaller cylinders is that your boiler will generate less steam with a smaller grate. So the suggestions were related to making more steam within the space that you have. Can you make the firebox longer and have the same size fire? Perhaps. Can you effectively increase the area of air flow through the grates? Perhaps.
Regards,
Andy
Re: Super Simplex 0-6-0
Hi Andy,
Okay, I understand what you mean by combustion chamber. Your definition makes complete sense. I have done some sliver soldering before, but, I have not built a boiler. Yes, it does sounds like it might be a bit more challenging. In looking at the print of the boiler, I think this would be tough for me to do.
I like your suggestion of modifying the grate to allow the same air flow as originally designed. You are right, it is the area of the air flow, not specifically the grate size. I can probably lengthen the fire box a little with not too much trouble. Modifying the grate for more airflow is probably the easiest thing to do.
Thanks so much for these suggestions,
David
Okay, I understand what you mean by combustion chamber. Your definition makes complete sense. I have done some sliver soldering before, but, I have not built a boiler. Yes, it does sounds like it might be a bit more challenging. In looking at the print of the boiler, I think this would be tough for me to do.
I like your suggestion of modifying the grate to allow the same air flow as originally designed. You are right, it is the area of the air flow, not specifically the grate size. I can probably lengthen the fire box a little with not too much trouble. Modifying the grate for more airflow is probably the easiest thing to do.
Thanks so much for these suggestions,
David
-
- Posts: 2930
- Joined: Mon Nov 10, 2014 1:39 pm
- Location: Woodinville, Washington
Re: Super Simplex 0-6-0
Here is a copy of Meyer's 1896 locomotive construction. It looks like a free download.
https://archive.org/details/modernlocomotive00meyerich
You might try working the formula's for fire box size and cylinder size to see how they match with your reduction in grate area.
Also, maybe mentioned earlier, optimizing your smoke box draft might help,compensate for your planned reduction in the firebox. For example, maybe you can get a 10% or 15% increase in air flow by changing the petty coat or nozzle placement. Another mystic art no doubt!
https://archive.org/details/modernlocomotive00meyerich
You might try working the formula's for fire box size and cylinder size to see how they match with your reduction in grate area.
Also, maybe mentioned earlier, optimizing your smoke box draft might help,compensate for your planned reduction in the firebox. For example, maybe you can get a 10% or 15% increase in air flow by changing the petty coat or nozzle placement. Another mystic art no doubt!
Moderator - Grand Scale Forum
Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge
Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge
Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
Re: Super Simplex 0-6-0
Thanks for the link Glenn. This looks like quite a resource!
David
David
-
- Posts: 2930
- Joined: Mon Nov 10, 2014 1:39 pm
- Location: Woodinville, Washington
Re: Super Simplex 0-6-0
Yep, it is an interesting book. I have a printed version - bought it years ago and recently started re-reading it. So far I've used some of the formulas to verify axle diameter and figure out weight bearing loads for various wheels diameters. Meyer's prototype formulas seem to produce the same results everyone is commonly using for 7.5" ga. So am guessing should scale down to verify your boiler design considerations.
Moderator - Grand Scale Forum
Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge
Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge
Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
Re: Super Simplex 0-6-0
Just a small update on this project, as you can see, the date on the first post was June of 2015. It took 9 months to get the chassis running on air. My boiler is finished and passed inspection in May of 2017. I have been running the locomotive ever since, even though it is not quite finished. Currently, it is almost done and mostly just needs to be painted and a few other details. That will probably happen during the winter of 2018/2019. This running season will be more fun and less work. I am not interested in a project that drags on for years, as the fun part for me is running the locomotive, the construction was actually pretty boring and only a necessary evil. I'm glad it is mostly done.
The boiler was constructed pretty much as per the drawing, all copper and silver solder. The locomotive seems to steam well even with the fire box being slightly reduced in width. I don't know for absolute sure, as I have nothing else to compare my experience to. I did add holes along three sides of the ash pan to get more air through the grate. It has been quite a learning curve learning to coal fire a small locomotive.
I wanted to express a word of thanks to the kind folks on this forum that have given me advice on the grate, fire box, and especially for helping me to select an appropriate torch for constructing the boiler. I am a machinist by trade, and the boiler was something completely different for me, but, I made it through.
You all have probably seen my references in past posts about my web site dedicated to documenting my locomotive build. The web site could also be useful for any one building a miniature steam locomotive, especially a first time builder. There are lots of photos under the three main photo sections labeled "Running Gear", "Boiler Construction" and "Plate Work & Piping".
Here's the link: https://supersimplex.yolasite.com/
Thanks again everyone!
David
The boiler was constructed pretty much as per the drawing, all copper and silver solder. The locomotive seems to steam well even with the fire box being slightly reduced in width. I don't know for absolute sure, as I have nothing else to compare my experience to. I did add holes along three sides of the ash pan to get more air through the grate. It has been quite a learning curve learning to coal fire a small locomotive.
I wanted to express a word of thanks to the kind folks on this forum that have given me advice on the grate, fire box, and especially for helping me to select an appropriate torch for constructing the boiler. I am a machinist by trade, and the boiler was something completely different for me, but, I made it through.
You all have probably seen my references in past posts about my web site dedicated to documenting my locomotive build. The web site could also be useful for any one building a miniature steam locomotive, especially a first time builder. There are lots of photos under the three main photo sections labeled "Running Gear", "Boiler Construction" and "Plate Work & Piping".
Here's the link: https://supersimplex.yolasite.com/
Thanks again everyone!
David
Re: Super Simplex 0-6-0
A Beautiful Locomotive. Well built!
~RN
~RN
Re: Super Simplex 0-6-0
Thank you so much!
David
David
- Benjamin Maggi
- Posts: 1409
- Joined: Wed Apr 25, 2007 10:38 pm
- Location: Albany, NY
Re: Super Simplex 0-6-0
Congrats on your most excellent locomotive!
"One cannot learn to swim without getting his feet wet." - Benjamin Maggi
- Building: 7.25" gauge "Sweet Pea" named "Catherine"
- Building: 7.25" gauge "Sweet Pea" named "Catherine"
Re: Super Simplex 0-6-0
Hi Benjamin,
You caught me again! I hope you found my website useful. There is lots of information for first time builders. I just recently added a page for making cone unions.
https://supersimplex.yolasite.com/How-t ... -Union.php
Enjoy!
David
You caught me again! I hope you found my website useful. There is lots of information for first time builders. I just recently added a page for making cone unions.
https://supersimplex.yolasite.com/How-t ... -Union.php
Enjoy!
David
-
- Posts: 2930
- Joined: Mon Nov 10, 2014 1:39 pm
- Location: Woodinville, Washington
Re: Super Simplex 0-6-0
Work of Art! Plus I love that design. Classic English locomotive. Well done!
Moderator - Grand Scale Forum
Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge
Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge
Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
Re: Super Simplex 0-6-0
Glenn, thank you so much!
David
David