4-6-4 vs. 2-8-4 question.

NKP Berk: 69 inch drive wheels, max Horse Power of about 45 to 50 MPH. Designed for fast freight service, i.e. 60 to 90 cars at 60+ MPH.

NYC J3a: 79 inch drive wheels, can't remember their HP, but designed for FAST passenger service, 12 to 16 passenger cars at 80+ MPH.

Thus, the NYC Hudson would NOT do very well in the New River service, since the track speed limit is generally to low for a 79" drivered locomotive to achieve max performance.

Sort of comparing apples and grapes. 

I figured as much about the NYC Hudsons, but the NKP Hudson had 73 inch drivers...

 I know Rich had said the MLW 4-8-4 struggled with the train because the speeds were too low to get into the ideal power range of the Northern with the bigger drivers...

How would 611 perform?  Can't remember the size of drive wheels, offhand.

611, with it's 69 inch drivers, would run right beside 765 if not pull away from her with the same train. 611 is one of the heaviest Northerns ever built... and for sure one of the most powerful. They were rated at 80,000 pounds TE vs 765 at 64,100 pounds...

611 really deserves to run again!  I wish we had some organization here in the US that would work for the benefit of "Historic Steam" in general regardless of original railroad.  Too many neglected treasures.

The J's had 70" drivers, and yes she deserves to run again.  Won't happen but....

If wishes were iron horses...

Rusty

Then you'd all have a shot to run out my J-Class Hudson; when I took it out on the Water Level Route, where she belonged!

in all reality, if wishes were iron horses, then Lionel and MTH and Williams and Atlas and 3rd Rail and Weaver would be out of business, because we wouldn't have to recreate said iron horses in our basements!

thanks,

Mario

The New River Train scenario is all about DRAWBAR HORSEPOWER, pure and simple. Throw out all the calculations about tractive effort, boiler horsepower, cylinder horsepower, etc. All that counts is how many horses are available at the coupler to pull the train.

The 611, capable of somewhere near 6,000 drawbar HP would do a better job on the train than the 765, which is capable of around 4,500 drawbar HP. An NKP Hudson likely did not have that kind of HP and would not be able to maintain the same speed as the 8-coupled engines. The NYC Hudson on the other hand, probably can develop somewhere over 4,000 drawbar HP, and so would do a pretty nice job on those trains.

It's all about horsepower.

It's just money.  Why does Steamtown look more like a junkyard than a museum?

More for the file labeled "If we're SO rich, SO smart, and SO great.... Why not?"

Rich, how does one figure out the DRAWBAR HORSEPOWER?

CofG

"The Right Way"

It's just money. 

Yeah...

As my mom was so fond of saying: "Wait till you got to go out and earn it, kid!"

Rusty

CoG

I think Rich might be a little busy today.

The formula for computing DBHP is:

drawbar pull (in pounds) x speed (in MPH) / 375 = Drawbar HP

611, with it's 69 inch drivers, would run right beside 765 if not pull away from her with the same train. 611 is one of the heaviest Northerns ever built... and for sure one of the most powerful. They were rated at 80,000 pounds TE vs 765 at 64,100 pounds...

Steam Fan

The N&W Js have a low factor of adhesion at 80,000 lbs TE.  The 765s factor of adhesion is closer to 4, so the rated figure represents power that is usable under a wider variety of track conditions.  

I found a document with horsepower and drawbar pull curves for the J.  The horsepower is a little lower than the figure Rich mentioned but still over 5,000 HP across a very broad speed range.  It is worth noting that when a J is just getting into its peak HP range at 40 MPH it is still producing about 45,000 pounds of drawbar pull.  That is equal to the starting DB pull of many Pacifics.  That comparison is a good illustration of the magnitude of the change from Standard Railroading to Super Power. 

See page 6 for the graph and test data.

http://files.asme.org/ASMEORG/...y/Landmarks/5609.pdf

611 does deserve to run again being one of the most powerful Northerns built. I would also like to see 1218 run again. It would then be the most powerful steam locomotive running in the world having substantially more power than UPS Challenger.

Where is Bill Gates?

PS. I`m also told there is one DM&IR Yellowstone that could be resurrected. Not that would be something.

Where is Bill Gates?

Priority Areas of Focus

Our work in infectious diseases focuses on developing ways to fight and prevent enteric and diarrheal diseases, HIV/AIDS, malaria, pneumonia, tuberculosis, and neglected and other infectious diseases.

Bill and Melinda have other priorities. 

Ted, where do you find drawbar pull( in pounds )? Would that be the actual weight of the train your pulling?

CofG

"The Right Way"

Or, where is Warren Buffett?  And he actually owns a railroad.

There's actually 2 surviving Yellowstones... one in Two Harbors, and one at the Museum in Duluth. The one in the museum is inside and looks to be in fair shape.... from a casual observation.

The original question I posed still remains unanswered.

How many coaches could a NKP Hudson theoretically pull up the Gorge???

Thanks for the good discussions!

Dave

I believe that any engine with three driver sets would not be a good application on a mountain division with a heavy passenger train. Speed limits, as Rich indicated, would reduce the effectiveness of any high drivered steam engine, and any such engine would be limited as to drawbar pull by limits to its adhesive weight.

The use of a NKP Berk on this train is a great match to the adhesive weight of the engine and the speed range at which it produces high drawbar HP.

While the N&W J is rated at a starting tractive effort of 80,000 lb. vs the NKP Berk at 64,100, there is not as much of a difference in performance of these two engines as you would expect. Both tractive effort numbers are a CALCULATION based on steam pressure, driving wheel size, cylinder diameter, and cutoff at starting. The J would do a little better on a grade with this train than the Berk, but my guess is that speed-on-grade would not differ by more than a few mph at most. The stiff and rigid frame and suspension of the J would be a disadvantage if there are sharp curves on this route. So i continue to believe that the Berk would more than "hold its own" against other engines.

5432, you still can't grant the N&W J any credit at all. 

You haven't any conception of the conditions that the J faced every day.  The Pocahontas Division from Williamson to Bluefield is at least as crooked as C&O's 765 territory, and probably more so - and it's all uphill eastbound.  Your talk of the stiffness of the J's wheelbase has no connection to reality.  It faced curvature every day that would make you cringe.

The J performed under all types of weather conditions with heavy trains on N&W's mountains and curvature.  Its 80,000 pounds of starting drawbar pull was USABLE; it could have run up the New River grade at track speed all the way.

You may have every facet of the Niagara's achievements at your fingertips, but you have no idea at all what you're talking about when you discuss N&W's J.

The J was specifically designed for the demands of N&W's passenger traffic.  It had sufficient reserves of power and speed to make up time with their heaviest trains.  It was capable of, and achieved, 100 MPH running daily on two specific territories - east of Petersburg on the Norfolk Division, and west of Ironton on the Scioto Division.  It was also capable of starting an eastbound 16-car Cavalier at Northfork on a 1.4% grade and accelerating it to track speed - in the rain or snow, if that's what it happened to be doing.

EdKing

Unfortunately, if Buffett built a railroad, it would probably be in China.

Mr. King,

I don't know the New River train route, nor its grades, so can't comment re curvature. If someone can post ruling grade and curvature in that location, I can make a comparison of a N&W J on the limiting grade vs. a NKP berk under the same conditions with the same train.

Oh, and I forgot that the J has the specs, including cylinder size and driving wheel diameter, of a freight engine......

Perhaps, but he already owns BNSF and has spoken often about the importance of rail for the USA's future.

In any case, I was talking about the preservation/restoration of 611.  

Amazing! What an incredible beast.

So?

Rusty

611 would devour any other eight coupled steamer out there, I can think of.

The only ones that would stand a chance in comparison would be the Erie

and C&O 2-8-4s.  For continuous high speed running, the AT&SF 2900 and

3776 units would likely be close.  Oil does have it's advantages....but

nobody ever boiled water like N&W....NOBODY !

You have GOT to be kidding with that comment. Even so, what part off 100+ MPH is unclear??

There are supporting recordings made by O. Winston Link of J's accelerating an EB Cavalier out of North Fork.  The engineers spared nothing in getting these trains up to speed between stations.   Some are published, some are not.

There were many 12 degree curves on the line between Williamson and Bluefield, some of them reverse curves.  Just to round things out, Jug Neck curve east of Bluefield was about 12 degrees 30 min reverse (IIRC) on the way down to the New River at Glen Lyn. Ed King can back me up on this or add to.  He actually worked for the N&W, I was just a bystander. 

I've said this before, but the J's starting tractive effort of 80,000 lbs was confirmed many times on test when they developed over 80,000 lbs drawbar pull, provided rail conditions were favorable.  However, the principal function of their large cylinders was to accelerate trains from 25 mph to 65 mph as quickly as possible, something they did many times every day.

When they were tested in mainline freight service Feb 1958, they were capable of 36-38 mph with a 12,297 ton trains on a 0.03% descending grade.  BTW this was with a relatively economical evaporation and firing rate.  There was a lot going on underneath that party dress they wore.

Felton -

I appreciate your chiming in with more facts, but it remains that we're wasting our time with 5432.

He knows what he knows, and no amount of inconvenient facts will change his mind.

EdKing

What's your point? 

Look, 5432; when you want to argue against the N&W or its steam power, sooner or later you have to deal with the fact that trips up everyone who tries it - the results.  N&W didn't care about making headlines, or impressing the worldwide Motive Power intelligentsia.  They cared about the bottom line.  In the half-decade of 1950-1954 when the railroad was all steam (the electrics went by the board in 1950 and the first diesels hit the property in 1955) the N&W was tops or near the top of all railroads in the US in both Gross Ton Miles per Train Hour per Dollar (the dollar figure takes a lot of impressive locomotives out of the running), Operating Ratio and Gross Income carried over to Net.  This was on a railroad with relatively short hauls, heavy tonnage, steep grades and heavy curvature.

In these years it was done using locomotives that the intelligentsia routinely sniffed at - the too-shortlegged J, the unpopular wheel-arrangement A and the omigod how outdated compound Y-5/Y-6.

In an era when the potential prosperity of a railroad was measured in how much coal it had to haul, the C&O should have mopped up Wall Street with the N&W.  It hauled more coal than N&W (and on the west end it took its Lake coal all the way to Toledo; N&W had to give its Lake coal over to connections at Columbus  until its 1964 merger and share the revenue with them), it didn't have N&W's grades or curvature, and it had roundhouses full of the most fashionable steam power that could be conceived by the mind or built by the hand of man.  Yet C&O never approached N&W's profitablilty.  And I've heard C&O fans dredge up yards and yards of rationale about why this was so; and none of it holds water.

But carry on, 5432.  It's always a pleasure . . .

EdKing

Yeah the specs of a "freight engine"...wink.... that ran like a race horse....and pulled like a mule.  The J's were top shelf power.

Given the specs, would the J theoretically be a good fit for the PRR west of Harrisburg?  Might it have worked better than, say the T-1?

Oh, and I forgot that the J has the specs, including cylinder size and driving wheel diameter, of a freight engine......

What freight engine?

Other than an Erie Berkshire or a GN O-8 I cant think of a freight engine with J like cylinders or driving wheels.  Neither of those had either the boiler pressure or the precise balancing of the J.  And neither of the EVER exceeded 100 MPH.

Ted, where do you find drawbar pull( in pounds )? Would that be the actual weight of the train your pulling?

CoG

Drawbar pull is the force available to pull a train.  If the force available from your locomotive is greater than the drag created by the train you can accelerate.  If the train creates more drag than you have pulling force you will decelerate or will not be able to start the train at all.

Starting tractive effort (T.E.) is calculated based on cylinder size, boiler pressure and driving wheel diameter.  It is also affected by valve cutoff and bearing type.

Drawbar Pull can be measured by a dynamometer car coupled to a tender.  This measurement represents the actual pulling force available to move a train.  The dynamometer car also records speed.  Drawbar Horsepower is calculated from the recorded speed and the pulling force measured at the same instant.

As soon as a locomotive starts moving natural forces start to reduce the drawbar pull available to move a train.  Steam flowing to the cylinders loses energy to turbulence.  Steam flowing out of the cylinders creates cylinder backpressure.  Friction in all the rotating and sliding surfaces detracts from the force available at the drawbar.  All these losses increase with velocity so drawbar pull decreases as speed increases.

Diesel locomotives have the advantage of being able to run their reciprocating engines at peak speed regardless of train speed and electric motors produce peak torque (which provides drawbar pull) at stall speed.  This allows most diesels to outperform steam locomotives at slow speed.  However, electric motors lose torque quickly as their rotational speed increases.  Steam engines lose torque too due to friction loses and changes in cutoff but they lose torque (drawbar pull) more slowly than a diesel electric.  An A-B-A set of F units could out pull a J at slow speed.  They would be evenly matched at about 20 or 25 MPH.  Once the J hit 30 MPH it would just be getting into its peak horsepower range and would start pulling away, and away and further away as speed increased. 

Gilbert- the N&WHS magazine THE ARROW recently published two stories covering the testing of J 610 on the PRR in 1945.  The author, Dave Stephenson, did considerable research and obtained a tremendous amount of correspondence (mainly PRR) concerning this test, and wrote them up beautifully.  These issues are available through the N&WHS website; you may have to buy the whole year's issues but if you're interested in the subject it would be worth it.  These articles also ran in the PRRHS magazine KEYSTONE.

The J would have been tremendous west of Harrisburg, but was too big; it wouldn't fit.  It was taller and wider than PRR's passenger power.

The actual tests occurred between Crestline and Chicago on PRR's race track; it wasn't the best arena for the J, but it did beautifully, spending considerable time at speeds better than 100 MPH.

They also took a T1 down on the N&W, where it showed better economy than the J at speeds over about 85 MPH, between Roanoke and Norfolk, but when they tried it on Alleghany Mountain it slipped still.

EdKing

At the risk of hijacking this thread...

Ed King wrote (in reference to the PRR T1 on N&W):

...but when they tried it on Alleghany Mountain it slipped still.

Perspective - What Ed wrote is true.  However, the T1 stalled with 1,440 tons, equivalent of a 20-21 car passenger train, on a 1.32% grade.  With 1,220 tons, equivalent of a 17-18 car passenger train, the T1 managed 24 mph, not bad for a divided drive high-wheeler engaging in a tractor pull!  FWIW, as part of the same tests, J 604 took 1,758 tons (25-26 car equivalent) up the grade at 25 mph. 

Many thanks!  I appreciate the responses.  It's been a fascinating discussion.

According to Steamlocomotivedot.co. The J produced Tractive Effort numbers at 79,899 and Santa Fee 2900, 3765 and 3766 produced 79,968 numbers of traffic effort. 2900, 3765 and 3766 by their calculation were the most power Northerns Built. 

The ATSF figures found at steamlocomotive.com were calculated as follows:

.85x300x32x28^2/80 = 79,980lbs.

ATSF did not calculate the TE of the 2900's in this manner.  Instead, they used an adjustment factor 0.70 instead of 0.85 to compensate for the limited cutoff incorporated onto the design of the valve gear. 

0.70x300x32x28^2/80=66,000 lbs

There is evidence that ATSF's calculation was too conservative to reflect the actual TE generated by the 2900's.  Who has information on what the actual figure was under test conditions?

Calculating TE on the same basis that steamlocomotive.com used (adjustment factor of .85), an N&W J would exert:

0.85x300x32x27^2/70=84,981 lbs

There is evidence that J's could exert a drawbar pull of 78,000 to 81,000 lbs (implying a TE of 81,000 to 84,000 under the right conditions)

How you calculate TE is all-important, and it may or may not reflect reality. Caveat calculator (with considerable apologies to the Latin scholars here).

The fact that the J did have the specs of a freight engine is, in indeed, a testament as to how great an engine she was/is..what freight engine with those specs could run 100 miles per hour?

Ed Mullan, he who wishes he was at Hourseshoe curve today..

to watch a beautiful engine that IS running now.