VGN 2-10-10-2 - my 2014 challenge
#31
doctorwayne Wrote:
modelsof1900 Wrote:.....steam blowing out through stack....

I've never been too fond of the replication of steam sound, especially in HO, but the smoke/steam effect on those BLI locos is, to me at least, laughable - like a giant cigarette on wheels. Misngth Watching video clips of the real ones only reinforces that view.

Wayne

I agree...Instead of causing an illusion, they manage to make a joke...
Gus (LC&P).
Reply
#32
A first attempt for clarifying of sound of N&W Y6B - in original.

Before that, what I have written about steam sound of mallets is correctly, four chuffs at each older mallet that is working after the original mallet principle. But maybe there is an exception or more as one?

The N&W was this railroad with one of highest development in use of mallet engines. I have found an original N&W drawing with title "Arrg't. of Intercepting Valve and Separate Exhaust Valve, H.P. Cylinder, Loco. Class Y5,Y6,Y6a,Y6b" that maybe gives an explanation for existence of a separate exhaust pipe from HP-cylinder to exhaust nozzle. An item that not exist on normal mallets!
Maybe - and I would prefer to say maybe in moment - the Y6B sounds with eight chuffs while starting and slow running driven by additional HP-steam to LP-cylinders while exhaust steam from HP-cylinder will go to exhaust nozzle. So it will clarify the eight chuffs that we believe to hear in video.
A friend (a steam engine specialist) and I will try to study a few more documents for a more exact explanation.

Maybe I was wrong with my opinion to sound of modells of Y6B but not generally for all mallets. I hope that I can still give some further explanations.

jwb Wrote:ANOTHR EDIT: This site <!-- m --><a class="postlink" href="http://locodriver.co.uk/Vol05/Part09/02/index.html">http://locodriver.co.uk/Vol05/Part09/02/index.html</a><!-- m --> says "The N&W Mallets were provided with a simp[l]ing valve, enabling them to operate as four cylinder simple expansion locomotives. At starting, the exhaust from the high pressure (HP) cylinders was taken directly to the blastpipe, instead of to the low pressure (LP) cylinders as normal. This eliminated back pressure on the HP pistons at starting and meant an increase in tractive effort." Also, the Wikipedia entry on compounding says, "The eternal problem with compounds is starting: for all cylinders to take their weight, it is advisable to have some way of short-circuiting the HP cylinders and getting steam at a reduced pressure directly to the LP cylinder(s); hence many of the patented compound systems are associated with particular starting arrangements."
I have a feeling that simpling valves were common on Mallets.

jbw, your statement agrees with my opinion, I also still use a "maybe" - not for intercepting valve.
But I can not agree with your last sentence. All mallets had this simpling valves. The LP-cylinders need HP-steam for starting, yes.
But not all mallets are equipped with a second valve for a direct connection from the HP-cylinder exhaust steam to blastpipe! This an item that exist only on modern mallets. And that make the difference of original four chuffs for a standard mallet to eight chuffs of the Y6B.
Cheers, Bernd

Please visit also my website www.us-modelsof1900.de.
You can read some more about my model projects and interests in my chronicle of facebook.
Reply
#33
Now I will write a last text to "excepting valves", "separate exhaust pipes" etc.
I think I have to say that I was wrong. Yes, intercepting valves are an item that mallets have had in early times already. And with intercepting valves is strong connected separate exhaust pipes, which go directly to main exhaust pipe ore more yet to a specific exhaust nozzles. We hear while starting additional four chuffs coming from exhaust steam to the normal chuffs of LP-cylinders, if a mallet is working as an simple articulated engine . Maybe that the HP-chuffs a reduced noise because there are smaller pipes used as those from LP-cylinders, but there are eight chuffs together. My correction and my opinion, now.
Printed and to read about that theme in 1922 Locomotive Cyclopedia of American Practice.
Cheers, Bernd

Please visit also my website www.us-modelsof1900.de.
You can read some more about my model projects and interests in my chronicle of facebook.
Reply
#34
I happen to have the full DVD of which the clip I linked was a sample, and I went back and watched the whole thing. The guy who made the film, E.C.Eddy, appears to have been a very knowledgeable railfan with good contacts in the N&W. He says in the narration that the Y6bs worked simple up to 10 mph. Above 10 mph there was a second option, feeding reduced-pressure steam into the low-pressure cylinders directly from the boiler. It seems to me that this would also have caused a back-pressure problem from the high pressure cylinders, and some or all of the high-pressure exhaust might have had to be sent straight to the blastpipe.

The modifications for the Y6b [as originally designed, but see the post below] appear to have been unrelated to the use of steam. I don't know how far back these modifications go on the N&W Y class, or how common they may have been with other Mallets in the US.
Reply
#35
This site <!-- m --><a class="postlink" href="http://www.steamlocomotive.com/chesapeake/?page=nw">http://www.steamlocomotive.com/chesapeake/?page=nw</a><!-- m --> says that the second option of routing high pressure steam directly into the low pressure cylinders via a booster valve was added to the Y6bs in the mid 1950s. It also suggests that the improvements in N&W Mallets after 1930 came from Worthington feedwater heaters and cast steel frames.
Reply
#36
I have to write it almost forgotten, of course, also the AE was equipped with intercepting valves. And thereby also "my steam engine" worked with eight chuffs per wheel rotation. This conclusion is now fairly easy.
Cheers, Bernd

Please visit also my website www.us-modelsof1900.de.
You can read some more about my model projects and interests in my chronicle of facebook.
Reply
#37
Hello Bernhard---for someone like myself who considers changing couplers on cars to Kadees a challenge :oops: ,I am very very impressed with your attention to detail and workmanship---your locomotive is a beautiful work of art Worship
Reply
#38
Nutbar, thanks.
Until now I have no more done than a few sketches to draw on a computer and repair a slight defect exhaust pipe. Not a big problem, and not a lot of work. I would say however that I am not sure if I can realize also all these ideas.
Cheers, Bernd

Please visit also my website www.us-modelsof1900.de.
You can read some more about my model projects and interests in my chronicle of facebook.
Reply
#39
Here's a link to a video of the Black Hills Central mallet...currently the only operational mallet in the US...
<!-- m --><a class="postlink" href="https://www.youtube.com/watch?v=B_wDrEGJpts">https://www.youtube.com/watch?v=B_wDrEGJpts</a><!-- m -->

Of course, we're supposed to have an operational C&O 2-6-6-2 in Maryland before long...too...

I'm a big fan of the AEs as well. I like all VGN power, but the AEs were something else...
Michael
My primary goal is a large Oahu Railway layout in On3
My secondary interests are modeling the Denver, South Park, & Pacific in On3 and NKP in HO
<!-- m --><a class="postlink" href="http://thesouthparkline.blogspot.com/">http://thesouthparkline.blogspot.com/</a><!-- m -->
Reply
#40
Michael,
thank you very much for your post. Time comes nearer for reworking my AE, I think.
Cheers, Bernd

Please visit also my website www.us-modelsof1900.de.
You can read some more about my model projects and interests in my chronicle of facebook.
Reply
#41
    In a Clean out and going through 1/8th of my model railroad magazine collection I came across this .

ERIE RR
Reply
#42
ERIE man, hallo!
Yes, the AE stands permanently on my worktable and you can see it on some pictures from time to time however only in connection with other projects. In present time is the biggest problem that I do not have a really use for this model and unfortunately the model with its extra wide front cylinders do not run on the modules of my friends which are the only chance to run the loco on different sessions.
And there are also to many other preferred projects which I lve to realize. However I should hold it in my mind that there will be a great project in future and maybe that I will start with that.
In this days I have started the digitalizing of a smaller Mallet, a 2-6-6-0 Denver & Salt Lake brass model where I friend realized also a rubber belt drive and the model runs excellently. The whole gear line is equipped with ball bearings and so he received this very smooth run. See the picture.
I have planned also a rubber belt drive with two motors but without ball bearings for my VGN 2-10-10-2 model and I'm sure that this will be a simple way with a good chance for success.

[Image: caandy-06k.jpg]

Thanks for remembering to a long waiting project, unfortunately too long!
Cheers, Bernd

Please visit also my website www.us-modelsof1900.de.
You can read some more about my model projects and interests in my chronicle of facebook.
Reply
#43
Bernhard,

there is another extreme VGN loco:

[Image: dsc00026wwxui.jpg]
This is the running gear of the once VGN Triplex after it's rebuilding into a 2-8-8-0 Mallett. The generous space available inside the boiler made it possible to mount 2 smaller motors, each with an own independent drivetrain.




[Image: dsc01801tokq2.jpg]
Each motor also got it's own decoder. Because of the smaller seize of the motors ist was possible to use smaller decoders too. Here are of Zimo MX600 type.




[Image: dsc0180309klf.jpg]
They are arranged in a sort of shelf above the rear motor as this photo of the unready rear engine shows. Also there were NMRA 8-pin sockets made. The wires still have to be restrained. The upper decoder was later fixed with double tape.
Electrically both drive trains have a common current pick up base.
Mechnically they are independent.
Electronically they are a permanent consist under the same adress.


Cheers Lutz
Reply
#44
Lutz, I do not love this piggyback arrangement of motors.
I think also that the sloping position of both (!) gear boxes looks very maverick without a bit of technical smartness. Sorry, not my solution!
Cheers, Bernd

Please visit also my website www.us-modelsof1900.de.
You can read some more about my model projects and interests in my chronicle of facebook.
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)