A and AE

Thu Feb 12 10:45:20 EST 2015

First, I'm somewhat confused here.Are we talking about the Virginian 2-6-6-6 compared to the C&O 2-6-6-6? If so, could we please call it by the proper class of AG and not AE? The AE was the plodding 2-10-10-2 the Virginian use fr a totally different type service in a very different area of the system.
Second, every book or article I've read on the H-8/AG tells how they were mis-used engines being used in the opposite type service for which they were designed. Many railroads did the same thing. A race horse shouldn't be used for plowing and vice versa. 

Third, I don't think the AG wasn't liked by the Virginian which caused it to lose favor and be retired early. I have always read the engines were very late in the development of the railroad and the pure economics of dieselization was more the cause of the early retirement of them, the BAs and all the rest of the steam engines.
I don't have enough knowledge to get into any debate about HP vs TE vs FA and all. I do think that a higher drivered engine with a high capacity boiler designed to run fast and move the freight isn't going to be able to compete with something like the Y classes dragging coal. The Western Maryland found out their M-2 Challengers just weren't made for the service they required just like many other roads and engine classes.
Agree or disagree but at least..........call it an AG!
Roger HuberDeer Creek Locomotive Works
P.S.-The A was much cooler looking than the H-8 or AG! LOL

      From: NW Modeling List <nw-modeling-list at nwhs.org>
 To: NW Modeling List <nw-modeling-list at nwhs.org> 
 Sent: Wednesday, February 11, 2015 9:29 PM
 Subject: Re: A and AE

Eric,

I have not personally heard or read anything to indicate the A was a slippery beast. Both the A and Y6's factor of adhesion is less than 4, but neither was considered uncontrollable. Part of that could also be the crews being very well trained on their monsters, part of it the design and execution of the locomotive as well. Some have suggested due to the A and Y's low adhesion and not being slippery vs. the Pennsy T-1 having a high FoA and being slippery that the rule of 4 might be more of a guideline, and not set in stone. 

I have heard of A's running fast (time) freights or merchandise trains stopping at the bottom of the Blue Ridge and having a very hard time getting the train moving again without pusher help, but not having a problem moving these heavy trains at a good clip unassisted. Fast freights on the N&W were run on a passenger train like schedule, and were usually around 5,200 tons, needing very high speeds and power on the head end to blast up most grades unassisted. The A was rated at 13,000 tons of slow or 'drag' freight Not sure if that helps answer the question or not. I also have not heard of the H-8/AE being slippery either. I have heard they were fairly easy locomotives to run. The H-8/AE was rated at 5,000 tons for freight at 50mph, and they struggled to pull the 10,000 tons at slow speeds that the C&O wanted them to pull in drag opperations (where they spent most of their time). From the tonnage alone, it shows how the A bested the H-8 until 60mph, at which point the H-8 becomes the better locomotive.

The A and the H-8/AE were really two different animals. The A came first, and the C&O asked Lima for a locomotive to best the A. They got the H-8 from Lima, but Lima did not fully understand what the A was meant for. The A was a locomotive who could scream along at 70 mph+, but did her best work at 30-40 mph. Right at coal drag top speeds, since this is what the N&W needed/wanted. The C&O wanted a locomotive just like the A, and frankly the H-8/AE did not deliver. Lima misunderstood the A, and assumed it was a high speed freight locomotive like the Challengers. The H-8 makes its power at high speed, just like the Bigboy and Challenger. However, in coal drag service, this power is a waste, because it can not be reached (the H-8 and AE both were used as drag locomotives). The H-8 was most successful hauling heavy troop trains at high speeds during WWII (a role she was really designed for) The C&O loved the H-8, the Virginian did not seem to like the AE as much, shown by the very short lives they lived.

 As far as coal goes, all 3 locomotives ran on West Virginian Bituminous coal, and would have been very similar in quality. 

Some more people here will know more than myself, I am sure. Both were good locomotives, just one was not used for what it was designed for.

Jon

On Wed, Feb 11, 2015 at 5:55 PM, NW Modeling List <nw-modeling-list at nwhs.org> wrote:

I have been ruminating on a comment made in this forum several weeks ago to the effect that the N&W A was a superior engine to the VGN AE or C&O H-8, because the A produced more tractive effort with far less weight (and implied stress) on the track, despite the fact that it was an 8 year older design.  The claim of higher tractive effort for the A surprised me, but is theoretically accurate based on boiler pressure (300 psi for the A vs 260 for the AE and H-8), cylinder bore (24” for the A vs 22.5 for the AE and H-8), stroke (30” for the A vs 33” for the AE and H-8), and driver diameters (70” for the A vs 67” for the AE and H-8).  The net result is a theoretical tractive effort of 114,000 pounds for the A vs 110,000 for the AE and H-8.  Despite the larger drivers and shorter stroke, the A achieves its higher theoretical tractive effort through its larger cylinder bore and higher boiler pressure. But an (equally theoretical) analysis indicates that the A’s factor of adhesion was 3.44 (indicating a propensity to slip pretty easily), whereas the AE was 4.49 (indicating a VERY “planted” locomotive), and if the weight rumors of the H-8 were true, its (theoretical) factor of adhesion would have been a bit higher than even the AE. Both classes were designed to run at 70mph, but the design philosophies to do so were different.  The longer AE stroke and smaller diameters would have resulted in ~15% higher piston speed at any given speed, but the same dimensional differences would have resulted in ~15% lower static load on the main and side rods for a given tractive effort.  This and the ~18% smaller piston mass would have allowed ligher main and side rod mass and potentially easier dynamic balancing—thereby allowing the AE and H-8 to achieve the 70 mph design speed, even with 4.5% higher driver rpm than the A. I think it’s undisputed that the AE / H-8 design produced nearly 40% more horsepower than the A. So here are the questions I’m driving to:  Did the A slip on starting?  Were the AE and H-8 notoriously sure-footed on starting?  Could either type start markedly heavier trains than the other under similar consitions? Could the A run any train at 50mph that it could start? Could the AG start any train it could run at 50mph? Did N&W and VGN operate the A and the AE over similar profiles at any given time (e.g., Narrows to Roanoke, or Roanoke to Norfolk)?  Did they use coal of approximately the same grade on these runs?  Did one deliver more ton-miles per hour, over similar profiles, with approximately equivalent quality coal? -Eric Bott
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