THE magazine of railroading

SEARCH TRAINSMAG.COM

Enter keywords or a search phrase below:

N&W Y7

8164 views
63 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    May, 2012
  • 47 posts
N&W Y7
Posted by Mntrain on Saturday, December 07, 2013 7:12 PM

I have heard that N&W had plans for a Y7 simple articulated, Is there and specs for this engine? 

  • Member since
    May, 2013
  • 2,772 posts
Posted by NorthWest on Saturday, December 07, 2013 7:29 PM

I believe that we discussed this recently, and the answer is yes. I think it was more of a higher speed design like the A, as opposed to the Y6. The original specifications still exist, and may not have yet been scanned. I'll look for the applicable posts.

  • Member since
    August, 2010
  • From: Henrico, VA
  • 6,331 posts
Posted by Firelock76 on Saturday, December 07, 2013 7:30 PM

I checked my copy of "Norfolk and Western, Giant of Steam" to see if I could find anything for you, but there's no mention of a Y7.  I remember reading (somewhere)  there was a Y7 proposed, but as diesels were coming into the picture nothing was ever done about it. 

Sorry, but that's all I've got.

  • Member since
    May, 2013
  • 2,772 posts
Posted by NorthWest on Saturday, December 07, 2013 7:37 PM

Okay, I found a link in a post on an older thread. Look at the drawings, and have fun!

http://www.nwhs.org/archivesdb/detail.php?ID=90311

  • Member since
    August, 2003
  • From: Northern VA
  • 477 posts
Posted by feltonhill on Saturday, December 07, 2013 8:15 PM

Bud Jeffries' book  contains information and a diagram of what the Y7 would have looked like based on available drawings.  I developed a detailed elevation drawing based on that sketch about 10 years ago.   I'll see if I can find the page numbers in the book (s).  I have the original drawing, but don't know how to post the scan.  Nothing seems to work to get the link posted here.

  • Member since
    August, 2010
  • From: Henrico, VA
  • 6,331 posts
Posted by Firelock76 on Saturday, December 07, 2013 8:34 PM

Feltonhill, I suspect you've got the updated edition of the Jeffries book.  Mine's the first edition from 1980.  De-acessioned from the Library of Congress as a matter of fact.  I got lucky.

  • Member since
    August, 2003
  • From: Northern VA
  • 477 posts
Posted by feltonhill on Saturday, December 07, 2013 8:38 PM

I have both versions, and I thought it was in both.  I'll check the "library" tomorrow AM.  It's two floors down and I'm  ready to call it quits for the day.  Apparently there's no way to post photos directly on the forum, so I guess we're out of luck to see the drawing. I don't have any accounts in photobucket , flickr or other photo sharing site.  Sometimes technology works for you, sometimes it doesn't.

  • Member since
    September, 2003
  • 3,787 posts
Posted by Overmod on Saturday, December 07, 2013 11:13 PM

For heaven's sake, Ed King's book on the A has a discussion of this engine, including a number of relevant specs.  Juniatha in a previous post noted that she had looked at some of the surviving drawings and had doubts about some of the detail design.

Voyce Glaze's book is one of the great treasures in the NWHS archives.

It might be noted, as I believe Ed noted, that there was nothing to keep the N&W from building a class of simple 2-8-8-2s after the ICC resolved the issue with permissible number of cars in trains.  It's significant, I think, that this did not happen (but a considerable amount of work was put into making the Y-class compounds capable of more efficient operation).

  • Member since
    August, 2003
  • From: Northern VA
  • 477 posts
Posted by feltonhill on Sunday, December 08, 2013 7:10 AM

In Jeffries' original N&W Giant of Steam, the Y7 text and diagram are on pgs 275-277.  In the revised Edition, they're on pgs 262-263.  Diagram is the same.  One caveat.  The diagram in the book (and the detailed elevation I developed from it) features a Delta trailing truck.  As the design progressed, this was changed to a trailing truck that was similar to the lead truck. 

  • Member since
    August, 2010
  • From: Henrico, VA
  • 6,331 posts
Posted by Firelock76 on Sunday, December 08, 2013 9:30 AM

"For heaven's sake"?  Give us a friggin' break Overmod, not everyone's got Ed King's book. 

And Feltonhill, I checked pages 275-277, sure enough, there it is. Looks like I didn't look as closely as I should have.  "Mea culpa, mea maxima culpa...."

  • Member since
    April, 2001
  • From: Roanoke, VA
  • 1,441 posts
Posted by BigJim on Sunday, December 08, 2013 10:53 AM

feltonhill

In Jeffries' original N&W Giant of Steam, the Y7 text and diagram are on pgs 275-277.  In the revised Edition, they're on pgs 262-263.  Diagram is the same.  One caveat.  The diagram in the book (and the detailed elevation I developed from it) features a Delta trailing truck.  As the design progressed, this was changed to a trailing truck that was similar to the lead truck.

There you go Dave.

.

  • Member since
    May, 2013
  • 2,772 posts
Posted by NorthWest on Sunday, December 08, 2013 11:09 AM

The trailing wheel is further back than on the Y6b, where it was just behind the drivers, and the firebox appears larger. Designed for higher speeds?

  • Member since
    August, 2003
  • From: Northern VA
  • 477 posts
Posted by feltonhill on Sunday, December 08, 2013 2:06 PM

The Y7 has a much larger boiler and firebox  than the Y5/Y6 classes.  A Delta trailer truck has a relatively long side  frame which gives it a characteristic appearance.  When this idea was discarded, the rear of the locomotive frame was revised to accommodate a trailer truck that was similar to the lead truck.  The boiler and the rest of the running gear remained the same. 

The Y7 had 63" drivers, so it would have been a moderate speed locomotive.  It was similar in size to the DRGW L-131 Class 2-8-8-2s although with higher pressure (275 or 300 psi).

  • Member since
    February, 2005
  • From: Vancouver Island, BC
  • 20,620 posts
Posted by selector on Sunday, December 08, 2013 6:45 PM

With the extra diameter, maybe balancing would have been 'improved' sufficiently that, coupled with roller bearings throughout, speeds closer to 65-75 mph might have been intended/hoped for?

-Crandell

  • Member since
    July, 2016
  • 1 posts
Posted by RailroadPreserver2000 on Tuesday, January 10, 2017 4:04 PM
Love the white pass and Yukon route 101 class engine btw I saw heard of the railroad when I was only 3 and got into trains a year earlier and I went to ride the WP&YR last year and I loved it
  • Member since
    December, 2004
  • 539 posts
Posted by tdmidget on Wednesday, January 11, 2017 10:44 PM

Almost scared to ask but what was that about?

RME
  • Member since
    March, 2016
  • 1,407 posts
Posted by RME on Thursday, January 12, 2017 9:26 AM

I'm going right over it to take up Crandell's question from 'before'

selector
With the extra diameter, maybe balancing would have been 'improved' sufficiently that, coupled with roller bearings throughout, speeds closer to 65-75 mph might have been intended/hoped for?

The 'first' part of this is that, from a purely technical point of view, the "proven" combination of lightweight rods and careful distribution of reciprocating mass N&W used would have resulted in a higher dependable road speed.  It seems clear from the historical material that the Y7 represented what the "admission-balanced" version of the Y6 would have been: a locomotive with a high proportion of weight on drivers capable of N&W's economical fast-freight speed, and reasonable acceleration to that speed from any kind of 'check'.

Personally, I think it would have been desirable to use a cast driver of some kind for the main, but it might be noted that if Glaze's balancing is extrapolated to smaller drivers there is room in even a strengthened spoke main for the comparatively small proportion of balance mass the formula calls for (the vertical component of piston thrust and perhaps some of the reciprocating momentum) in that driver.  (I'll say more about cast drivers in a bit.)  Rods would be strengthened to accommodate the effect of more mass in the adjacent drivers.  On the forward engine in particular, more overbalance than 'usual' for N&W might be required, as the relatively short lever arm of the single-axle lead truck would be poor at providing lateral compliance on the order of that seen on the Js, and it could be argued which of the driver axles should receive more or less of the 'overbalance' to help with augment handling.

I'd expect a Y7 to share the design of the equalization on the A class, limiting the vertical excursion between engines to a minimum (as Alco would do later on the Challengers and call "its" improvement) and it is possible that enhanced methods to prevent nosing of the forward engine could be incorporated there.  I'd expect much more damping than 'spring return' force there, if that were to be done.

Now, it might be interesting to contemplate what a locomotive of this type would do if equipped with Timken lightweight rods and bearings sized for the expected loads.  I don't think this is as likely as the installation on the As was (because the parts would most probably not be 'common' between the Js, which had all the tooling and know-how amortized, and the Y7) but it's by far the best approach to implementing rollers in the rods, which was the next 'logical' step for easy semi-automated maintenance in fast freight (which I think was the likely justification for the experiment with roller rods on the last A locomotives).

The use of cast drivers might be necessary on a locomotive this heavy and powerful -- the peak load on critical parts of spokes and rim being much more extreme on the design as a whole, let alone its operation at high road speeds on N&W's typical profiles.  (It is entirely possible that some variant of Web-Spoke would address this perfectly with minimal additional metal)  It would be fun to have seen what N&W decided upon, and then to have watched them 'learn' the secrets of proper disc-driver production... perhaps under license but perhaps not.

Advice of the day:  Do not feed trolls, even under other people's bridges.

  • Member since
    April, 2001
  • From: US
  • 47 posts
Posted by sgriggs on Thursday, January 12, 2017 4:02 PM

With N&W's recognition of the economies of double expansion and their willingness to continue compound development, I'm surprised that the Y7 wasn't designed as a large-drivered compound.  The Y6b design rolled on 57" drivers--very short by late steam standards.  The reports that these beasts were capable of running 40-50mph with those huge (39" dia) and heavy low pressure pistons are nothing short of amazing.  Had the Y7 been designed as a compound with 63-65" drivers, it would have been capable of hauling very heavy trains at fast freight speeds with the economies of a compound, but far less pounding on the machinery (and track) than the Y6b.  And with the large boiler that was envisioned, horsepower wouldn't have tailed off as rapidly as it did above 30mph with the Y6b.

 

Scott

  • Member since
    July, 2006
  • From: Huntsville, AR
  • 698 posts
Posted by oldline1 on Sunday, January 15, 2017 9:30 AM

I thought ALL drivers were cast?

Roger Huber

  • Member since
    January, 2015
  • 825 posts
Posted by kgbw49 on Sunday, January 15, 2017 1:19 PM

It sounds like the N&W Y7 would have been similar to, or even exceeded, the Great Northern R-2 2-8-8-2 class with 63 inch drivers and 151,283 lbs of tractive effort...

Image result for great northern r-2

Image result for great northern r-2

Image result for great northern r-2

Image result for great northern r-2 steam locomotive

Image result for great northern r-2 steam locomotive

Image result for great northern r-2 freight train

Great Northern had 16 of these R-2 units and 14 R-1 units similar in size but with about 10,000 lbs less tractive effort due to 210 PSI boiler pressure versus 240 PSI for the R-2 units.

They labored in the relative obscurity of the lightly populated (at the time) states of Washington, Idaho, Montana, North Dakota and Minnesota.

 

 

 

 

 

 

 

 

 

  • Member since
    April, 2001
  • From: Roanoke, VA
  • 1,441 posts
Posted by BigJim on Monday, January 16, 2017 7:41 AM

RME
The use of cast drivers might be necessary on a locomotive this heavy and powerful -- the peak load on critical parts of spokes and rim being much more extreme on the design as a whole, let alone its operation at high road speeds on N&W's typical profiles.  (It is entirely possible that some variant of Web-Spoke would address this perfectly with minimal additional metal)  It would be fun to have seen what N&W decided upon, and then to have watched them 'learn' the secrets of proper disc-driver production... perhaps under license but perhaps not.

Since the N&W "cast" their drivers, maybe you could explain yourself.

.

  • Member since
    January, 2015
  • 825 posts
Posted by kgbw49 on Monday, January 16, 2017 9:38 PM

A couple of Great Northern R-1 2-8-8-2 photos for Y7 and R-2 comparison purposes...

Image result for great northern steam freight train horseshoe

Image result for great northern r-1 class

 

  • Member since
    April, 2001
  • From: US
  • 47 posts
Posted by sgriggs on Tuesday, January 17, 2017 10:02 AM

RME
The use of cast drivers might be necessary on a locomotive this heavy and powerful -- the peak load on critical parts of spokes and rim being much more extreme on the design as a whole, let alone its operation at high road speeds on N&W's typical profiles.  (It is entirely possible that some variant of Web-Spoke would address this perfectly with minimal additional metal)  It would be fun to have seen what N&W decided upon, and then to have watched them 'learn' the secrets of proper disc-driver production... perhaps under license but perhaps not.

 

Design of the Y7 class was apparently underway when the project was terminated.  The drive wheel drawings can be viewed at the N&W Historical Society website.

Main Driving Wheel:

http://www.nwhs.org/archivesdb/detail.php?ID=47406

 

Front & Back Driving Wheel:

http://www.nwhs.org/archivesdb/detail.php?ID=47419

 

Intermediate Driving Wheel:

http://www.nwhs.org/archivesdb/detail.php?ID=47423

 

These drawings are dated March and April, 1937.

 

RME
  • Member since
    March, 2016
  • 1,407 posts
Posted by RME on Tuesday, January 17, 2017 12:03 PM

BigJim
RME
The use of cast drivers might be necessary on a locomotive this heavy and powerful

Since the N&W "cast" their drivers, maybe you could explain yourself.

Cast disc driver centers (as in Boxpok or LFM) as opposed to 'traditional' N&W spoke. 

N&W went further, and did better, with 70" spoke even on very fast and high-powered locomotives (classes J and A) up to the end of steam.  In part on the J class, this is because Glaze's balancing plan distributed the balance masses in a way that spoke driver centers could accommodate. 

Other roads (the T&P 2-10-4s being a very good example) needed to go to a cast disc for the main driver to allow the desired high-speed balancing; it's hard to see it on 610 but it is there, and necessary.  What I am wondering is whether the loads on the Y7 running gear would have made the use of some form of disc cast driver for the main either desirable or necessary -- or made the use of webbing (as in Web-Spoke) or different rim construction (as in SCOA-P) to reduce strains between spokes and rim.

The detail work on the Y7 running gear stopped just about the time advanced balancing for freight locomotives became an important design priority (and a means of converting 'dogs' into relatively good performers). It is not surprising that the existing wheel drawings (which of course N&W could easily cast without having to pay any royalties) do not reflect what might become optimal with the engines built and used in fast heavy service to their design potential.

I have to wonder whether lightweight rods and better main construction (with room for necessary balance mass) might have helped the K3s before N&W wrote them off...

  • Member since
    January, 2015
  • 825 posts
Posted by kgbw49 on Tuesday, January 17, 2017 12:40 PM

It is too bad the Y7 never got built. It would have been something!

  • Member since
    April, 2001
  • From: US
  • 47 posts
Posted by sgriggs on Tuesday, January 17, 2017 3:41 PM

kgbw49

It is too bad the Y7 never got built. It would have been something!

 

 
 
To their credit, the story of the Y7 shows that the N&W didn't build locomotives for which no business/operating need existed.  Other roads built steam locomotives that were answers to questions nobody asked.
RME
  • Member since
    March, 2016
  • 1,407 posts
Posted by RME on Tuesday, January 17, 2017 5:12 PM

sgriggs
To their credit, the story of the Y7 shows that the N&W didn't build locomotives for which no business/operating need existed.

In my opinion, there was a perfectly good operating need before the Government got onto the wacky train-length-reduction kick, and a perfectly good operating and business need afterward.  It was simply misfortune that the Y7 development happened to fall into that particular timeframe, and that afterward the combination of good A class power and the improvements to the compound articulateds handled the service as required 'well enough' that development of a whole new class wasn't justified then.

 

  • Member since
    January, 2015
  • 825 posts
Posted by kgbw49 on Tuesday, January 17, 2017 9:29 PM

Yes, of course, it must be based on economic need, but it still would have been something to see what the Wizards of Roanoke would have been able to conjure up in a live Y7.

Great Northern had line drawings done of enormous 2-6-6-4 and 4-6-6-4 units with 73 inch drivers and 133 sf of grate area.

The GN also strongly considered following up their R-2 locomotives with a massive 2-8-8-4 with 69 inch drivers and 180 sf of grate area. This engine would have rivaled and may have surpassed Big Boy in size, but still with a rigid wheelbase of just 18 feet, no longer than the rigid wheelbase of their O-8 Mikados with 69 inch drivers.

Of course, history shows that none of these were built either, but that doesn't mean they wouldn't have been amazing machines.

 

 

 

 

 

  • Member since
    April, 2001
  • From: US
  • 47 posts
Posted by sgriggs on Wednesday, January 18, 2017 8:30 AM

RME

 

 
sgriggs
To their credit, the story of the Y7 shows that the N&W didn't build locomotives for which no business/operating need existed.

 

In my opinion, there was a perfectly good operating need before the Government got onto the wacky train-length-reduction kick, and a perfectly good operating and business need afterward.  It was simply misfortune that the Y7 development happened to fall into that particular timeframe, and that afterward the combination of good A class power and the improvements to the compound articulateds handled the service as required 'well enough' that development of a whole new class wasn't justified then.

 

 

 

In my mind, the Y7 would have been able to haul dead freight on flatter divisions more economically than the A (via longer train lengths).  It would have been able to match or exceed the Y5/Y6 types in hauling heavy tonnage up mountain grades, although it could not match the efficiency of the compounds.  I also question whether the Y7 would fit everywhere the Y5/Y6 could go.

  • Member since
    March, 2016
  • From: Burbank IL (near Clearing)
  • 9,791 posts
Posted by CSSHEGEWISCH on Wednesday, January 18, 2017 8:42 AM

The train-length reduction issue was based on state statutes (usually 70 cars) which were stricken by the Supreme Court as an unconstitutional state regulation of interstate commerce.

The daily commute is part of everyday life but I get two rides a day out of it. Paul

Join our Community!

Our community is FREE to join. To participate you must either login or register for an account.

Trains free email newsletter
NEWS » PHOTOS » VIDEOS » HOT TOPICS & MORE
GET OUR WEEKLY NEWSLETTER DELIVERED TO YOUR INBOX
Connect with us
ON FACEBOOK AND TWITTER

Search the Community