My N&W class A 1239 (gauge 5", 1 in 10 scale)

Where users can chronicle their builds. Start one thread and continue to add on to it.

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Asteamhead
Posts: 339
Joined: Tue Jul 31, 2012 1:59 pm
Location: Germany, Duesseldorf

Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)

Post by Asteamhead » Fri Dec 01, 2017 2:19 pm

Harold, NP317 and Fender thank you all!
Fender: Good point with the correct explanation. The front wheel set is running with a little less friction on the rollers thus the wild running, stealing all the steam from the back engine. Once down on the rails both wheel sets will dig in. To reduce spinning of just one wheel set there is a hidden combination of levers which can be set to override cut off of the front wheel set. This new device had been desribed earlier in this thread. It seems to work as intended yet wasn't used at any prototype as far as I know.

Some photos are showing the front end of the tender now ready to work.

Best regards
Asteamhead
Attachments
A tender T22 I, front view with tacho (left) and brake handle (right),red.jpg
There wasn't a handbrake at the prototype as far as I know?
A tender T22 I, front with speedometer and handbrake lever,red.jpg
A tender T22 I, footstep extended,red.jpg
The footsteps can be extended and fixed
A tender T22 I, ladder being fixed by springs, water connection,red.jpg
Those parts are prone to be bended or destroyed
A water filter with connection to tender,red.jpg
Showing the quick(air-)connection used for the water tube from tender

Smokey N Steamer
Posts: 49
Joined: Sun Jul 29, 2012 4:09 pm
Location: Seattle, WA

Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)

Post by Smokey N Steamer » Wed Dec 06, 2017 12:13 am

A question in regards to your grates when working with the stoker--since the stoker crushes lumps of coal to a small, uniform size when conveying it to the firebox (smaller than hand-firing), the air holes of the grates must be made narrower than in hand-firing to prevent stoker-fed lumps from falling thru the grates into the ashpan. Is this true with your "A"? But wouldn't that reduce the net gas area thru the grates? What effect does that have on the draft thru the firebed? More airflow? Less airflow?

ALSO--BTW, the YouTuber's comment on the screw reverse gear was refering to the one controlling the Baker valve gear on the driving wheels, not the stoker.

Asteamhead
Posts: 339
Joined: Tue Jul 31, 2012 1:59 pm
Location: Germany, Duesseldorf

Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)

Post by Asteamhead » Wed Dec 06, 2017 6:10 pm

Hello Smokey,
A grate of standard size wouldn't be useful, you're right. Thus I tried a two piece grate made of high temperature stainless steel by means of water cutting. The air holes are just 2.3 by 35 mm (1/12 " by 1 1/4 "). Free gas area is about 1/3 of the total grate area, which is fairly low. Quite different from usual prcatice :idea: !
Size of (anthrazite) coal fed by the stoker may vary from less then 1/4 " to 1/2 ". Bigger lumps will be crushed or may be fired by hand.
The generous total grate area of about 1 sqare foot however turned out to burn coal of any size by just medium draft! But I wondered, if that tiny grate would withstand the bright red to yellow coal fire. With some cooling of both ashpan and grate by the exaust steam of the stoker engine, all went well :) .
Some photos are showing the grate after some running.

All the best by
Asteamhead
Attachments
A grates after running  4 hours on first test. Showing about 2 pounds of ash and remains,red.jpg
Grates were used in an oven for test for 4 hours
A grates after the test,red.jpg
Annealed to blue, still o.k. yet
A-grates-Thermax,red.jpg
Water cutted grates
A Firebox support for grates and ashpan red.jpg
Exaust steam of the stoker will be blast over the ashpan for cooling purpose
A Grates to be removed to sides red.jpg
Left side grate removed to the side

Asteamhead
Posts: 339
Joined: Tue Jul 31, 2012 1:59 pm
Location: Germany, Duesseldorf

Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)

Post by Asteamhead » Sat Dec 23, 2017 3:52 pm

Hello Steamers,
Installation of the stoker is finished and proven now. Thus one last post this year.
The A's tender T 22 is now equipped with stoker, coal bunker and two additional front water tanks. These are intended to support the engineer's seat safely. All parts may be removed easily from above. Firing by hand out of the bunker will be still possible, in case it's needed.
Coupling of tender to the loco is done by one main bar while the stoker auger is pushed into the loco's part of the stoker. Same with the driving shaft. Then the joint cap and the main bar will be fixed. Water hoses are to be clicked into the tender connections, that it is. To be seen in one of the earlier posts.
Later on air and lighting connections will be added, too.

Wish you a Happy Christmas and a fine start into the new year!

Asteamhead
Attachments
A tender T22, view from above with coal bunker, additional water tanks and bracket for the seat,red.jpg
Total capacities are: water 64 Liters, coal about 10 pounds
A tender T 22 I, front end with brackets for the coal bunker red.jpg
The coal bunker may be removed to the top. Doors may be opened to allow firing by hand
A tender T22, front view with stoker, coal bunker and front water tanks,red.jpg
Air openings may be used for a water checking device
A Tender 22T, front plates of water tanks with water connections and filters,red.jpg
Water outlets are combined with filters (coarse)

User avatar
Fender
Posts: 2470
Joined: Wed May 02, 2007 8:33 pm
Location: Chattanooga TN

Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)

Post by Fender » Sat Dec 23, 2017 6:08 pm

Very impressive accomplishment! Have you calculated what the steam consumption of the stoker engine will be when running, in comparison to the consumption of the locomotive engines? My understanding is that on some other attempts at stoker firing live steam locomotives, the boiler could not produce enough steam for both.
Dan Watson

Asteamhead
Posts: 339
Joined: Tue Jul 31, 2012 1:59 pm
Location: Germany, Duesseldorf

Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)

Post by Asteamhead » Sun Dec 24, 2017 6:19 am

Hello Fender,
Good point!
Regarding steam production of the boiler versus combined steam consumption of stoker, blower and jets I had some thoughts and measuring, believe me!
Estimated steam production (minimum) are 6 pounds of superheated steam per pound of coal being fired.
Stoker engine and jets need about a pound of (superheated!) steam per pound of coal blasted into the firebox.
Steam needed continously for the feedwater pump and somtimes for the blower are to be considered, too.
Thus about 75 % of the total steam production of about 120 pounds per hour may be delivered to the main engines. That will do!
Some measures which were choosen to reduce steam consumption of all the auxiaries were:
Providing (moderately) superheated steam to blower, stoker engine and - jets. And to the main engines, of course.
Very effective blowers. Small size jet nozzles of just 0.7 mm.
The use of ball bearings throughout for both the main engines and the encapsulated stoker engine as well within the stoker gearbox.
The coal crushing device had to be improved by try an error yet! :idea:
Some data:
The stoker engine develops > 1 Nm at the shaft @ 600 rpm when working hard @ 60 to 100 psi steam. This is about 1/10 hp. Gear Ratio is 1 : 33.
Some further improvements of the auger, the auger joints and the coal crusher may allow to reduce the gear ratio.

Best regards
Asteamhead

Asteamhead
Posts: 339
Joined: Tue Jul 31, 2012 1:59 pm
Location: Germany, Duesseldorf

Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)

Post by Asteamhead » Mon Jan 08, 2018 5:28 pm

Hello friends,
Just an additional video on youtube of the working stoker, throwing the fine coal into the firebox of my A 1239.
You can watch the black coal being distributed over the red hot firebed. To me, it's more fun compared to watching the open fireside in my living room. Have fun!

https://www.youtube.com/watch?v=8MwdjgAOtPw

Asteamhead

A stoker with red hot fire and the black coal flying.
Attachments
A stoker with red hot fire and the black coal flying,red.jpg

Harold_V
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Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)

Post by Harold_V » Tue Jan 09, 2018 2:51 am

That sucker really works! Really enjoyed the short presentation. Keep sharing your astounding work with us.

H
Wise people talk because they have something to say. Fools talk because they have to say something.

alco2350
Posts: 32
Joined: Tue Jan 02, 2018 7:20 pm
Location: Houston, Texas

Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)

Post by alco2350 » Wed Jan 10, 2018 10:14 am

That is awesome! I would have never believed that a mechanical stoker in that scale would have worked!

Britt

Asteamhead
Posts: 339
Joined: Tue Jul 31, 2012 1:59 pm
Location: Germany, Duesseldorf

Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)

Post by Asteamhead » Thu Jan 11, 2018 8:33 am

Hello Harold and alco2350,
Thank you for your kind recognition!
It took some time of investigation and a lot of construction work, indeed. Studying ' Locomotive Cyclopedia ' ,1947 issue veary carefully helped a lo to understand the ingenious :idea: HT prototype. Some more Information about HT stokers was found from European Railroad Companies SNCF, PKP and DB, which all used stokers made by Stein & Roubaix licenced by Standard Stoker Cy. in US .
During the 1980s and 1990s I got several chances to both ride and work the HT stokers by myself on steam locomotives :D . Their clock like working impressed me much more than any coal shovel did!
Thus I decided trying to built my next life steam locomotive with a thing like this. This is life steam as desribed in a blog just recently: You may do whatever you intend to bring to life if you only can :) . Don't let you stop by 'That will be impossible, we tried already :( ' or 'Do you really need that :?:'
What you need to steam around is just a simple 4-wheeler with a short but wide boiler! But our hobby is so much richer if we can model a fine prototype engine as close as possible, isn't it?
Will report experiences of first runs on rails with heavy trainloads.

Asteamhead

Steve Goodbody
Posts: 122
Joined: Thu May 25, 2006 7:16 am

Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)

Post by Steve Goodbody » Thu Jan 11, 2018 12:20 pm

Your loco is incredibly impressive work, I take my hat off to you.

Regarding the stoker, and purely out of academic interest, do you see any noteworthy effects from the steam jets in the firebox? Perhaps less-than-usual soot buildup in the flues or smokebox due to the greater volume of flue gas? Or alternatively perhaps greater-than-usual soot build-up in the smokebox due to the higher moisture content of the flue gases?

It also looks like the fire is very lively when the stoker is in action with lots of sparks being thrown off. Do you think that's due to the steam jets hitting the surface of the firebed? Alternatively perhaps more air is being drawn through the fire as a result of the jets creating a lower pressure immediately above the firebed?

As (I suspect) the only person who has actually built and tested a working mechanical stoker your observations, experience and views would be of great interest.

Best regards
Steve

Asteamhead
Posts: 339
Joined: Tue Jul 31, 2012 1:59 pm
Location: Germany, Duesseldorf

Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)

Post by Asteamhead » Fri Jan 12, 2018 7:12 pm

Steve, thank you!
After firing the a boiler some 20 hours by stoker, the tubes still looked quite clean yet. This may be due to using anthrazite coal for most of the time.
But the haze of steam over the fire seems to improve combustion as it does with oil firing. The jets were used with pretty low preasure not to throw the coal onto the fire brick :lol: . For the last video, jets had been adjusted to a bit more steam to better show the flying coal.
Don't forget the fire door was open all the time with the blower on. The engine's draft is not much stronger than that of the blower fully on to reduce sparking. The exaust will guarantee a 'self cleaning front end' yet :) .

To all: The story of that stoker was shown already on the Live Steam board ''The stoker is done' by Trainman 4602, page 2, 2012. there is some more detailed Information. Just two more photo of the engine and the gearbox.

Asteamhead
Attachments
Stoker engine, valve gear adjusted for left turn red.jpg
Simple valve gear driven by the crossheads
HT stoker gearbox disassembled, red.jpg
Planet gear with total reduction of 1 to 33 made of a bicycle drive

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