Who Built The Highest Quality 4-8-4's?

[GP40-2]

"He seeming has accurate sources on his side"

Actually, he has NO sources on his side concerning the 1948 J3a in terms of total boiler and systemic efficiency. He also dosen't address the issues raised in terms of fluid mechanics for the J3a, but instead tries to rely on data from a generation older J3 from the 1930's. He even admits as such, but still plows ahead with his "estimates" none the less.

Personally, I don't think he even truely understands thermodynamics and fluid mechanics, but has just memerorized a bunch of data, and like a parrot, repeats it when prompted.

[VAPEURCHAPELON]

Hello feltonhill,

„La locomotive a vapeur“ from Chapelon is a good source – there you will find that the 242 A 1 could evaporate 26 tons (here these are long tons of course) of water per hour if fed with COLD water – that means without feedwater heater. But this book has been released 1952 and this was before some important test results were available – especially from his 6cylinder 1-12-0. And I knew Wilhelm Reuter – he was a steamlocomotive designer at Henschel in Germany and for example worked on the South African class 25 4-8-4 (unfortunately he died last year at the age of 83 years). I have visited him and saw his 1000+ book locomotive library (probably one of the largest anywhere) and we talked about Chapelon. He said in one book he found a note that the 242 A 1 on test in Vitry evaporated 31 long tons of water – these are more than 68000 ibs. One more time please let me emphasize that I love all those late US steamers – especially N&W J and NYC Niagara in the case of the 4-8-4s – also Chapelon was largely impressed by their efficiency on mechanical side – cast frames, disk drivers, roller bearings, automatic wedges, self cleaning front ends etc. – and – CSSHEGEWISCH – of course no US designer would have accepted the hours for maintenance required for the Chapelon’s – but – please read again – his locomotives were rebuilds – not new ones! The original engine which Chapelon chose for his first project was so bad that its nickname was “Cholera”. There is not one single sign that on Chapelon’s projects of new engines to be built after the war with all these american devices I have mentioned earlier would have arose a technical problem which couldn’t be solved. And that the majority of French’s last steam in service were two cylinder engines is due to the fact that after the war French’s industry not nearly was able to put out the demanded large number of locomotives and Chapelon itself unfortunately didn’t have had any influence on the 141R design. Remember his own 141P: -this was a bit lighter, a bit faster and much more fuel efficient than the 141R while putting out about 1000 more horsepower – but had about the same running time like 141R. All points together the P was cheaper than the R. The match was that the R outnumbered the P by several hundred %. One can read this in the book “Andre Chapelon – the genius of French steam” written by H. C. B. Rogers published in 1976 or so.

Ant to close this comment and to return to the originally intended to be discussed magnificent US 4-8-4s I largely support the words of feltonhill concerning C&O J-3a. He seemingly has accurate sources on one side – and on the other – tributes to the work of Ross Rowland – maybe he is a great loco engineer – but not a designer. If an engine is doing a bit more than expected one quickly (and logically) becomes euphoric – but the results of euphoria are not necessarily the truth. I didn’t found any note that Rowland accuratly calculated the power ratings of this engine after the runs – and if I remember the Niagara 6023 which in october 1946 accelerated 22 HW-coaches of more than 1600 tons to its allowed 120mph on test – far beyond the excusion runs with C&O 614! But of course it still is one of the greatest steamers!

(3700hp for Chapelon 4-6-2 is indicated hp – but all other than bad for engine of only about 110 tons – not?)

[GP40-2]

QUOTE: Originally posted by VAPEURCHAPELON

Here somthing to marvel about - especially for GP40-2 (although he announced to disappear form the place) and feltonhill:

No, I'm still here. I just said that I was no longer going to post on this subject. I'm a busy person, and I don't have time to enter into protracted discussions with individuals who try to use erroneous and incomplete data to try to make an invalid point.

BTW, this is not directed at you.

[Anonymous]

any shop mechanic will be able to tell you that the baldwins spent more time running, and less time fixing than any of the others.

[CSSHEGEWISCH]

With all due respect to the genius of Andre Chapelon, any comparison between French and North American steam must also consider the fuel/maintenance trade-off. French steam locomotives were rarely used systemwide and spent more time for maintenance between runs than a North American chief mechanical officer would tolerate. North American steam was less fuel-efficient but required less maintenance and spent more time on the road earning money. The late Vernon L Smith of BRC addressed this issue much better in his rebuttal to the superiority of French steam in one of the all-steam issues of TRAINS in the 1960's.

Also note that the last steam locomotives in operation in France were a North American design, the Liberation 2-8-2's of Class 141-R.

[nanaimo73]

QUOTE: Originally posted by jlampke

(How the heck do you get these little smiley faces, etc., inserted into your post?)

When you are typing your response, over on the left it says "show smile list". Click on that and then click on the smile you would like to add.

[jlampke]

Actually, my original question was in regards to the 38 or so 4-8-4's that still exist in the U.S., and Alco, Baldwin and Lima products in general. Only after reading some of the posts and checking out some of the other members' profiles did I realize that we have a lot of Canadians, Brits and some Aussies participating in these discussions. That's why I asked about the Mexican 4-8-4's. Nobody ever mentions them.

To put it straight, I don't think much of the French myself, but the post regarding the French engine is interesting. One of the many things I've learned about steam locomotives here lately is that they are dismally fuel-inefficient. I like to think that they could've been developed to a much higher level of efficiency if diesels hadn't come along so soon.

To quote someone from another post:

"Ah, but the entertainment efficiency is right up around 99%, at least for me."

(How the heck do you get these little smiley faces, etc., inserted into your post?)

Dale: Thanks! [8D]

[feltonhill]

Re: Chapelon's 242A1

I assumed the thread was limited to US 4-8-4's and left it at that. French subjects seem a bit controversial these days. But since you mentioned it, I'm familiar with this 242/4-8-4 although the only decent source I have is Chapelon's book and maybe one other. Judging by your comments about his 2-10-4 and others, you may be referring to that source, too. I don't recall he lists any evaporation figures, but it's been a while since I read it (and my memory isn't improving with age). I also have some info on his 231E conversions. Something like 3,700 HP (have to check what kind, could be IHP or DBHP) out of a loco slightly smaller than a USRA light 4-6-2. Anyway, I need to sort out just what the 242A evaporation figures were, e.g., water input from tender, total input including feedwater heater (ACFI??), or equivalent evap. Makes quite a difference when trying to compare with anything else. I do know that the 4,100 figure is DBHP for the 242A1.

Caught me at a bad time to comment. Taking a couple of days off right now to pursue another interest - live chamber music at a venue back in the mountains of VA - and a lot of the route there runs right alongside C&O's Mountain Sub. Back Sunday.

[VAPEURCHAPELON]

Here somthing to marvel about - especially for GP40-2 (although he announced to disappear form the place) and feltonhill:

I wonder that none has mentioned Andre Chapelon's 242 A 1. I agree that NYC Niagara and N&W class J are the really best - but only second to the late french Chapelon-rebuilds - especially his 242 A 1 French's only 4-8-4! Consider that this engine weighed only about 70% of the heaviest US 4-8-4s but put out 6000HP - more than the majority of US 4-8-4s! And it was only a REbuild! With only little money grown during WW2 from a very unsuccessful 4-8-2! It had a boiler with only about half the heating and superheater surfaces and less than half of grate area than large US 4-8-4s - but it was able to evaporate nearly 70000pounds of water per hour due to Chapelon's own developed powerful draft arrangement! No other of the steam engine designers ever achieved a power/weight ratio like Chapelon. Nearly needless to say that his engines were also the most efficient steamers anywhere by any standard. This man said if the Niagara (and this is valid also for others) had been built with his standards in basic boiler design it would have been able to produce not less than 7500DBHP! And this is a hard "if" because remember that Chapelon rebuilt his first engine as soon as 1929 with efficiency and power results never equalled by any other designer anywhere - ALSO AFTER 1929 (except his rare "pupils" - but after the general end of the steam age and with very few engines)! Ok - many of you will say that for these light non-US trains it's much easier to construct a reliable crank axle - all of Chapelon's engines were compounds - but consider that his most powerful one - the 242 A 1 - was a THREE-cylinder-compound engine - that means the crank axle had only one single crank exactly at its centre which of course is much more reliable than a crank axle for a 4cylinder engine. There probably were lots of possibilities to construct a similar one for the US 4-8-4s which then would have been equal in power output to the Chapelon's. And as David Wardale says - not weight but intelligent detail-design is determining for a reliable part. Chapelon planned to combine the Northamerican robustness and reliability - that means the mechanical standards used there - with his own unequalled thermodynamics. One of his first new engines would have been a 2-10-4 of about 140 short tons with no less than 7000IHP. This one would have been able to do the same work like a near double size US 2-10-4. Some engines were started being built but this has ended because the french government unfortunately decided to electrify. So the 242 A 1 remains beeing the best steamer and the best 4-8-4 ever produced anywhere. This engine proved most impressive that the old steam locomotive with Stephenson's design is far away from any highlight. Sadly it has been scrapped in 1961.

[daveklepper]

I still vote for the N&W J. It was a better mountain climber than the Niagra, but its excellent counterblancing and lighweight rods and general care in design meant it could also run as fast as Niagra, as proved on tests on the Pennsy. But track and grade and curve conditions on the N&W didn't give it much opportunity. The A's were pretty fast to for a 2-6-6-4! They would hall coal trains at 70mph and were also used in passenger service.

[Anonymous]

They are far from my favorite 4-8-4 but I have to vote for the NYC Niagara. Any locomotive that can deliver nearly 1000 miles a day, every day, for years on end has to be top notch.

[txhighballer]

The reason why the shell is so heavy is because no alloy steel was available for construction. Otherwise the ATSF would have essentially gotten 3776 class locomotives. The heavier steel is was alo made them the heaviest Northerns ever built, and the best suited for freight service,which they did quite well.

[Gunns]

I'm not really shure, I know that the 3751 runs at 230 lbs-Sq inch, but she is a 1927 design. Our boiler is .75 inch plate in the shell and .5 inch at the backhead, where it is extensively stayed.
Here is a photo of the 2903s MWP plate, (courtesy of barndad from the IRM) showing the test and working pressures of the 2900s.
http://www.railimages.com/gallery/kevinevans/aaw
the link allow you to "Zoom in" to reat the plate.
We ran at 300 psi and the mild steel shell is much easier to maintain than a high alloy steel, just heavy....
Gunns

[jlampke]

Gunns.... I've wondered about this, and I think you just answered the question. Correct me if I'm wrong here. The reason 4460 has a lower rated boiler pressure than 4449 is due to the metal available and used to make the boiler during the war. If that's the case, and 4460's boiler is made from lower quality metals, how would that impact the life expectancy of the boiler? [?]

[Gunns]

QUOTE: Originally posted by Texas Zepher
I also seem to recall that, as produced, the 2900s were much heavier than originally planned because the war effort took all the modern light weight building materials for aircraft.

Yes Our boiler is made of mild steel, giving the 2900s (ours is 2926) a loaded weight just shy of a million pounds. On the other hand the extra weight gives us a lot more traction, and mild steel is simpler to maintain too.

Side refrence the link I put up only refered to opperating or near opperating in the country.
Gunns

[Texas Zepher]

QUOTE: Originally posted by CSSHEGEWISCH
There were less 4-8-4's built for service in North America than SD45's, it was a relatively uncommon wheel arrangement. ... any 4-8-4 was a first-rate steam locomotive, I find it surprising that more roads didn't own them.

I think they came too late. An example: While Santa Fe really liked the 2900 class once they got them in 1943, if I understand / remember correctly, they really wanted FTs. The War Production Board dictated the purchase. I also seem to recall that, as produced, the 2900s were much heavier than originally planned because the war effort took all the modern light weight building materials for aircraft.

[jlampke]

How about the 4-8-4's that are South of the U.S.? Who built them? What is type QR-1?
Has anyone seen any of them? I heard one is operational. Does it see much use?

[Anonymous]

I was told Lima had the "Cadiliac of Steam". My votes however for all around is the A-3/4 of the NP.

[wallyworld]

S1 Niagara...hands down for a flat lands runner..N&W J for mountain climbing. Beauty is in the eye of the beholder.

[andrechapelon]

QUOTE: Originally posted by dtpowell

Definately N&W at Roanoke! Take a look at UP's 800's. I understand they used the J as their point of reference.

HUH? How could that be? The first UP 800's (FEF-1's) predated the first J by about 4 years. UP 800-819 were outshopped by ALCO in 1937. The next batch, FEF-2's #'s 820-834 were outshopped in 1939. N&W #600, the first J, didn't come out of Roanoke until 1941.

Andre

[AltonFan]

QUOTE: Originally posted by CSSHEGEWISCH

At the risk of being drawn and quartered by a mob of steam enthusiasts, I will venture this little tidbit: There were less 4-8-4's built for service in North America than SD45's, it was a relatively uncommon wheel arrangement. That being said, I would agree with feltonhill, any 4-8-4 was a first-rate steam locomotive, I find it surprising that more roads didn't own them.

The answer to this is relatively simple: 4-8-4s were HUGE! Some railroads considered them, but when they found a suitable design would have required rebuilding roundhouses, turntables, shop facilities, and occasionally passenger terminals, something smaller was considered. I seem to remember one of the Louisville-named lines acquired Berkshires for just this reason. C&NW's H and H-1s were restricted to the mainlines between Chicago and Omaha, and couldn't enter the passenger terminal in Chicago until the trainshed was modified. And a 4-8-4 was not likely to be downgraded to local service, either. These really were specialized engines.

The 4-8-4 appeared on the eve of the Depression, so a number of railroads were in no position to buy equipment. When WWII came, the government limited designs available, and the railroads were seriously considering diesels.

[feltonhill]

For those who may be getting tired of this exchange, please take a look at the recommended reading list at the end, if nothing else. There are several general and specific sources that will help all who are interested to understanding what’s going on inside steam locos. As you can tell, they’re a complicated animal to figure out.

Now, in response to a diminishing number of requests, let’s give this another try.

The following figures are from the respective railroad’s locomotive diagrams:

C&O J3a NYC S1b Difference
Grate area , sq.ft. 100.0 101.0 +0.1%
Direct htg surf, sq.ft. 482 499 +3.5%
Indir htg surf, sq.ft. 4,339 4,320 -0.4%
Total hgt surf, sq.ft. 4,821 4,819 -0.1%
Superheater, sq.ft. 2,058 2,073 +0.7%

These figures are almost the same.

The table on page 658 in December 1946 RME shows a 2.7% increase in DBHP (comparing the average of two runs for 275 psi and 300 psi) and is a record of the constant speed tests. The two curves on page 657, on the other hand, indicate the effect of increased boiler pressure on maximum output characteristics of the locomotive at all operating speeds. The Class J curves were calculated by N&W using a method developed by Baldwin, at 275 psi and 300 psi, a 9% increase (Test Report Chart 1). The maximum DBHP at 40 mph was about 4,660 at 275 psi and 5,100 at 300 psi, a 9.4% increase. So the table and graphs reflect two different results of raising the boiler pressure.

For corroboration of this increase, Paul Kiefer’s book A Practical Evaluation of Railroad Motive Power, (mentioned earlier) shows the same thing at page 13. DB Pull and DBHP curves are shown for the Niagara at 275 psi and 290 psi, a 5.5% increase. The maximum DBHP at 60 mph was about 5,050 at 275 psi and 5,300 at 290 psi, a 5% increase. The curves show the same configuration as the N&W-developed curves, i.e., raising the boiler pressure while changing none of the other physical characteristics of the locomotive will raise both DB pull and DBHP.

Total resistance losses are a peculiar thing. Most formulas indicate that total resistance rises significantly with speed. However, with modern 4-8-4's, tests seem to indicate that total resistance responds more to operating conditions than speed. The Niagara test data indicates that the average HP loss at 63.8 mph was 1,524 HP (average of data line 1207 in the report summary). The range of all tests, including the maximum power run was 1,210 HP at 57.5 mph to 1,680 HP at 65.1 mph. The average fits within this range. The running gear of 614 and the Niagara look very similar, so I suspect that they would give the same results under similar load conditions.

Another way of calculating total resistance is to use IHP and DBHP curves, also found in the Niagara test report. These curves show a range of 1,200 to 1,248 HP loss at 60 mph. So although 1,200 HP loss from cylinders to rear of tender may seem like a lot, it’s supported by actual test results.

My 4,000 DBHP estimate for the J3a reflects everyday operation, dispatchable horsepower if you will, not test conditions. These would be: evaporation rate of 85 lbs of water per SF of direct heating surface, or about 80,000 to 82,000 lbs of water from the tender per hour, and 250 degrees superheat. These are all very moderate, easily achievable figures for any 4-8-4 of comparable size. According to the Feb 1936 RME, the original J3's, which had a greater total heating surface that the J3a, were estimated at an evaporation of 79,640 lbs per hour.

My estimate of IHP and DBHP at this evaporation level are as follows:

614 as built - 5,300 IHP at 80 mph, 3,900 DBHP at 40-50 mph
614 presently (without ESI) - 4,900 IHP at 80 mph, 3,600 DBHP at 40-50 mph

Could 614 do better than this at higher evaporation rates? Most likely, but what’s an appropriate figure to use? Because there is no test data for 614 as built, I’m reluctant to predict what its maximum output would be. This is because I have no information regarding boiler steaming at high demand, pressure loss in the steam circuit between boiler and steam chests at high flow rates, the ability of the valves to handle large quantities of steam at speed, and the drafting characteristics that balance back pressure in the exhaust with the amount of vacuum produced in the smokebox. If this information is out there somewhere, now’s the time to bring it forward. That way we can get some real-world information on this last of the commercially built 4-8-4's

Recommended reading

Likely still available for sale:
Central Headlight, August 1975, Road Testing of the Niagaras by Richard Dawson (was available from NYCHS)
NYC Locomotive Diagrams - Niagara specifications (NYCHS)
C&O Locomotive Diagrams - J3 and J3a specifications (C&OHS)
C&O Greenbrier Type 4-8-4 Locomotives - Nuckles and Dixon (C&OHS)
The Red Devil and other Tales for the Age of Steam - David Wardale. Part of Chapter 6 covers the 614T tests during ACE program, pgs 384-402.(still in print)

Out of print, have apparently become “collectibles” and can be expensive:
The Steam Locomotive, Ralph Johnson (full range of locomotive design)
A Practical Evaluation of Railroad Motive Power - Paul Kiefer (includes information on all NYC modern steam power)
Railroad Engineering, First Edition - W. W. Hay (generally accepted standard text on the subject)

Probably available only in libraries and railroad historical society archives:
Railway Mechanical Engineer, February 1936, first series of C&O J3's
Railway Mechanical Engineer, December 1946, N&W J test
Locomotive Data, 12 Edition, pg 25, method used by N&W to compute Class J curves
The full Niagara and J tests survive in HS archives, but are not for sale AFAIK

Support the railroad historical society of your choice. It’s the only way this information will be preserved and kept available for research. Money and volunteers are always needed.

[GP40-2]

Feltonhill, I really don't want to beat this to death either (this is more than likely my last post on this subject), but as you said "here goes".

In one of your early posts, you stated matter-of-fact that the J3a did not have the "specifications" and "proportions" of the NYC engine. Then you back- pedeled somewhat and stated the C&O/NYC locomotive's specs where "almost the same". What you neglected to say was that the 614's grate area was almost the same as the NYC (within 1% of each other), but the 614 has 14% more evaporative surface area and 10% more superheater area.

Yes, I have read and studied the N&W J tests when they raised the pressure. Yes, you are right that the HP was raised on the margin. You make it sound like raising the pressure from 255 to 275 (C&O vs. NYC) or 275 to 300 (N&W J) is going to pay huge dividends in HP. Again, what you neglected to say was that the N&W tests showed only a 3%-4% increase in maximum HP from the pressure increase. Like I said, pressure and volume are inversely proportional. Choose your poison, but the HP difference is going to be marginal.

Fluid Mechanics plays a much larger role in how much HP a steam locomotive makes than raising the thermodynamics by relatively small pressure increases.

I also disagree with you that the N&W tests were not done in response to the diesel-electric's increasing market penetration. Yes, they decided to dieselize later in the game, but they were very well aware of the diesels efficiency early in the game. The J tests were to increase fuel efficiency, not to increase power. Steam locomotive builders were lucky the bean counters at GM wouldn't let EMD put turbos on the 567 earlier, the increase in power and efficiency of a turbocharged diesel vs. a non turbo is huge. So large, that the steamers would of been junked by the early 1940's, and no J, S1, and no J3a would of been built for us to even have this discussion.

Last, I really am having a togh time understanding your estimate of the 614 DBHP. First, you try to use the IHP of a generation older J3 to establish your estimate of the 614, then admit the J3a was the result of more modern thinking. To quote you "No doubt about the changes to the J3a’s boilers being in line with the final and likely best thinking of the late steam era." Not only that, but the J3a's running gear was also in line with " the final and likely best thinking of the late steam era" so I really have a hard time believing a free rolling engine like the 614 is going to loose 1000 HP from the cylinders to the coupler.

My problem with your comments is not with contrasting the 614 with other 4-8-4's. As you said the 614's proformance speaks for herself. My problem is with you making matter-of-fact statements, then admitting you don't have all the engineering specifications , or use older data from a different locomotive, or when you do have some facts, you leave out the magnitude of the difference.

I think your estimate of the 614 DBHP is absurdly low, and while I admit the 614 may not have (barely-like the N&W and NYC engines) broke the "magical" 5000 DBHP barrier, it is certainly (in top running order) closer to 5000 DBHP than your estimate.

[nanaimo73]

Thank you.[:)]

[feltonhill]

Belpaire boilers - Well, PRR and GN thought they were worthwhile here in the US but that's about it. Elsewhere in the world they had quite a few devotees.

Various advantages have been alleged for the Belpaire firebox (boilers are about the same). The most obvious is the configuration of the staybolts and the more direct stress pattern through them. In a Belpaire, the crown sheet and top of the firebox (the visible part that gives it a flat-topped look) are roughly parallel to each other, and the stress through the staybolt heads is more or less a straight line. In a conventional boiler, the crown sheet is slightly domed but the boiler is cylindrical. The staybolts have to compensate for one radius at the top and another at the bottom, and the forces at each end are skewed, particularly at the boiler shell. So the Belpaire is theoretically less expensive to maintain. I've never seen an actual cost comparison. There are also supposed to be big gains in direct heating surface, but I can only see an increase in steam volume above the crown sheet. This is a positive point, but I may be missing something else.

ATSF 4-8-4's were oil burners and as such were configured a little differently than coal burners. ATSF and SP GS 4-8-4's like 4449 tended to have less direct heating surface (firebox and combustion chamber) and more indirect heating surface (tubes and flues) than similar sized coal burners. I've read, but can't recall the source, that this has something to do with the burner characteristics, flame front/shape, and radiant heat transfer.

Would a Belpaire improve ATSF 4-8-4's? Don't know. As a practical matter, I doubt it. Kip Farrington's book, Santa Fe's Big Three, contains a reprint of a detailed performance test of 3766 transcribed in large part from ATSF Test Report 87312. One of major deficiencies that could have been corrected was noted by E. E. Chapman, Engineer of Tests. 3766 had a considerable pressure loss between the boiler and cylinders. It reached 170 psi at high speed and capacity output. Whether this was corrected on the 3776 and 2900 classes I don't know. Their specs are identical. However, ATSF locomotive diagrams indicate 3766 had two syphons and the newer classes only had one syphon. Compared to other large 4-8-4's 3766 never reached high IHP or DBHP outputs at speed because of this pressure drop (5450 IHP at 65 mph and 4550 DBHP at 50 mph). Really though, these figures are high enough to ensure very good performance in daily use, so it probably didn't matter very much unless ATSF was going to enter the "my 4-8-4 is bigger and badder than your 4-8-4" contest. Something tells me the road didn't care about that sort of thing. They moved the trains, that's what counted.

[feltonhill]

UP829,

Thanks for the source. I'll see if I can round up a copy of the book next month. NWHS has a copy in its archives and I show up there there three days a month, supposedly to get some work done, but all that information around.... Sorta leads to a lot of diversions.

[nanaimo73]

feltonhill,
I would be interested in your thoughts on Belpaire boilers. Do you think the extra costs were worth the gains ? Would the ATSF 4-8-4s been even better with them ?

[Anonymous]

QUOTE: Originally posted by feltonhill

The only information I have is probably what you saw in the Nov 1959 issue of Trains mag. It looks like the C1a would have had a stock Niagara boiler with a T1 type running gear. No valve gear was specified, but the cylinder drawing looks like it had conventional piston valves. The details underlying the illustration were dated 3/28/45, according to the caption. I've seen another very similar dagram for this loco, but can't find it. I don't believe it was ever seriously considered by NYC. It existed onlyas a proposal or concept.

A sketch, preliminary diagram, and a short description of the C1a was included in Al Staufer's "NYC Later Power" p.269.

The book also mentions that the 1946 tests included a comparison of 6023 with 79" drivers and with the 75" drivers saved from 6000, but doesn't say much about the results.

[CSSHEGEWISCH]

At the risk of being drawn and quartered by a mob of steam enthusiasts, I will venture this little tidbit: There were less 4-8-4's built for service in North America than SD45's, it was a relatively uncommon wheel arrangement. That being said, I would agree with feltonhill, any 4-8-4 was a first-rate steam locomotive, I find it surprising that more roads didn't own them.

[feltonhill]

The only information I have is probably what you saw in the Nov 1959 issue of Trains mag. It looks like the C1a would have had a stock Niagara boiler with a T1 type running gear. No valve gear was specified, but the cylinder drawing looks like it had conventional piston valves. The details underlying the illustration were dated 3/28/45, according to the caption. I've seen another very similar dagram for this loco, but can't find it. I don't believe it was ever seriously considered by NYC. It existed onlyas a proposal or concept.

Its performance would probably have been little different than the Niagara except at higher speeds. Also, NYC was extremely disciplined about speed and operation, and most if not all of its mainline locomotives were equipped with a device called Locomotive Valve Pilot, which among its other features, I believe had a speed tape included. So the opportunity to get out and run unobserved was very limited compared to other roads with did not keep this kind of record. Actually, the Niagara didn't need much help for normal service, so the C1a would probably not produced any great improvement. In fact, It probably would have been less useful in regular service. Duplexes were always more sensitive to rail conditions (although the PRR T1's tribulations were considerably exaggerated in most past accounts). The extremely short stroke (26" in the C1a's case) may have compromised cylinder efficiency at lower speeds (say under 60-65 mph) because of the large amount of clearance volume compared to a locomotive with a 32" stroke. This is not my opinion, but that of N&W's Robert Pilcher, who had considerable expertise and success with N&W's locomotives over the last years of steam. On the other hand, NYC had no significant grades outside Albany Hill, so the ability of a duplex arrangement to use steam more economically while cruising at 80-85 mph for prolonged periods may have been beneficial. Locomotives like the Niagara and N&W J set a very high standard of performance and operating economy and would be very hard to top in their respective services.

Somewhere along the line (wish I could remember the source), there was a statement like this: it was harder to build a bad 4-8-4 than a good one. Apparently the proportions were just about right all the way around. You could make them bigger (e.g., ATSF, N&W, WM, UP) or smaller (e.g., NC&StL, NdeM, GTW), but they would end up pretty good regardless.