Steam & Excursion > Steam Files PRR #13

PRR Q2
 
By 1942 the Pennsy was in the throes of its duplex-drive addiction and had turned out the 4-6-4-4 Q1 that we looked at in the last installment. This locomotive proved to be very unsatisfactory, so the design team of Carleton Stine, Harry Decker and H.W. Jones went back to the drawing board and came up with the new and improved 4-4-6-4 Class Q2 high-speed freight hauler completed in August 1944, during the height of WWII. The major differences were the rearrangement of the backwards rear cylinders to face forward, and the rearrangement of the front and rear axle configuration.
 
I got to thinking about this and wondering how it fit into the War Production Board restrictions and regulations related to new designs and allocation of resources. Clearly the Q1 and Q2’s were more experimental and prototypes rather than tried and true designs like the C&O T-1’s that were developed by PRR into the J1 or the N&W Class A’s, one of which the PRR tried out in the Fall of 1941.
 
*note: C&O T-1’s, with the hyphen were Texas type 2-10-4’s. PRR T1’s (no hyphen) were the duplex-drive 4-4-4-4’s.
 
The prototype Q2, #6131 was followed by a production run of 25 more in later 1944 and into 1945 numbered 6175 – 6199.  So enthused with the Q2 was PRR that they cancelled 25 of the 2-10-4’s that were on order from Lima. Hindsight being that probably was not a good idea.
 
The PRR had done a comparison of the Q2 and the J1 and is summarized as follows:
 
The J1 had 200 sq. feet less heating surface
The Q2 and J1 had about equal grate area
The J1 produced 5700 lbs. less tractive effort
The Q2 had 30 psi higher boiler pressure
The J1 developed 7000 indicated horsepower at 57mph with 57% cut-off
The Q2 developed 8000 ihp at 40% cut off (6645 drawbar HP)
The Q2 was 43,220 lbs. heavier for 1000 more horsepower
The Q2 had a Belpaire firebox and the J1 had a standard firebox
 
Now the key is the PRR was a 50 mph railroad, and at that speed there was very minimal performance difference.
 
Specs of the Q2 are:
 
Cylinders: Front; 19-3/4 x 28 and Rear; 23-3/4 x 29
Driver diameter: 69 inch
Boiler Pressure: 300
Tractive Effort: 100,000 lbs   with booster: 115,800
Factor of Adhesion: 3.9, probably a little light
 
Issues with the Q2 were:
 
High water consumption (tender capy was 19,000 gallons)
High maintenance costs and out of service time
Leaks developed in the barrel seam of the boiler just in front of the rear cylinders
 
At one time Jack Francis the Master Mechanic at Conway complained he had 25 of the 26 Q2’s out of service at once.  This was not a good omen, especially with the ever newer and better diesels coming out by EMD, ALCO and Baldwin in particular. Out on lines west of Pittsburgh once again the old dinosaurs of the past generation went back to work on the front lines showing everyone how to move tonnage on the Standard Railroad of the World.  The old M1’s once again reigned supreme.
 
I think a case could be made for the fact that PRR became too enamored by the Altoona Test Plant and designing super locomotives based on the test plant criteria. N&W had said as much after testing a Q2 against a 2-6-6-4 Class A. In reality PRR was not designing the proper locomotive for a 50 mph freight operation, and one that could be efficiently and effectively maintained. All were out of service by 1951.
 
Speaking of that Q2 vs. A test, here is a brief summary of the results.
 
Locomotives tested; PRR 6180 and N&W 1210
 
Date: During August 1948
Location: N&W’s Kenova Division
 
Test trains; three loaded westbound coal – 11,500 tons and three mty hoppers trains east consisting of 175 cars.
 
The Q2’s as we have seen generated 100,000 lbs of tractive effort and adding the booster, 115, 800. The class A generated 114,000 lbs, and did not have a booster.
 
The Q2 used more steam per unit of work equating to more fuel.
 
The Q2 averaged 28.10 mph with the eastbound mtys vs. 31.7 mph with the A which used 31.4 % less coal. That coal savings was a big deal no doubt to the bean counters.
 
The Q2 was found to be very slippery and the slip control device was not working properly. Apparently this was a common problem of the fleet.
 
Overall the 2-6-6-4 outperformed the Q2, and the more work the locomotives were required to perform, the better the A did. N&W quickly returned the Q2 to the PRR at Columbus Ohio and Clarence Pond, the N&W’s Assistant Motive Power Supt. and largely responsible for the design of the Clas A's  probably took a bow with a smile of approval.

Image is PRR 6191 at an unknown location and date. Photographer unknown.
 



Edited 4 time(s). Last edit at 07/09/25 19:14 by train1275.

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I've always wondered how the Pennsy could justify spending so much on long term unproved motive power only to discover that they were wrong. The example of 25 of the 26 Q2s being OOS at one time.
I'll bet the Q2 vs A sort of smeared their face in it. Test plant performance is fine for providing basic information, but test plant and real life are two totally different worlds.
I'll have to mention the T1 class as fitting in that category. They seemed to be mesmerized with the rigid frame duplex design. I wonder if they tried too many new things in one design. My reasoning is to try one new idea at a time and if it fails, then you knew what you did wrong.
I wonder how much of the duplex madness contributed to them eventually going broke?
I, along with many others, think that a really well designed- 4-8-4 would have served their purpose.
I think they touted "Standard Railroad of the World" a bit too much.
As a young lad of maybe 14, I went downtown (St. Louis) with my Dad while he went to a  B of LE meeting at the YMCA which was next to Union Station. I found a good spot on an upper floor to watch the activity at the station. It was a stub end design and everything backed in. I watched a T1 come in from the east and pulled past the west end of the wye. He started backing the train into the  station and it was going fairly well until he got into all the puzzle switches and the curve of the wye. One engine would slip then the other, sometimes both engines would break loose. It took a while. I wonder what a recorder in the cab would have picked up? It would be rated R.
I'll stick with my Frisco and just sit back and watch PRR operations.



Edited 1 time(s). Last edit at 07/04/25 14:34 by Frisco1522.

One factor may have been EMDs were designed in LaGrange not Altoona.

Bob Wilcox
Charlottesville, VA
My Flickr Shots

bobwilcox Wrote:
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> One factor may have been EMDs were designed in
> LaGrange not Altoona.

I suspect there is some truth to your comment !

Why didn't PRR like regular articulated locomotives?

I've looked for some sort of definitive answer, but I'm not coming up with much. It just seems they had an aversion for articulated mainline power.

Maybe someone out there somewhere can provide some insight.

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