I’ve been having trouble finding some more info about these two locomotives on the internet.
Does anyone know anything about them?
What were they used for, and on which line, for how long, what problems did they have etc.
And also some more technical information about them, like to speed, tractive effort etc.
thanks
I recommend tracking down the A. Staufer books “Pennsy Power” I and II. There are photos of both huge duplexes and some stats.
They were not articulated but rigid frame. What I have read suggests that they were in many respects successful as far as steam power goes and addressed some of the shortcomings of the T class 4-4-4-4s, but came too late for the PRR to see any basis for making them production run engines. The railroad had committed to diesels by then and the handwriting was on the wall for steam.
Dave Nelson
There was only one Q1. It was the test engine. You will see pictures of it both streamlined as built and semistremlined after the maintenance guys got to it. The idea behind the PRR T1, S1, Q1 and Q2 was that by splitting the drivers into two groups smaller pistons and side rods could be used reducing the pounding and wear problems as well as reducing steam consumption for the same amount of work. All of the were rigid frame so there was no articulation. They used steam once and were not compund engines. The Q1 had the second set of drivers reversed so the piston was at the firebox end. This proved to be a bad location as it was very dirty and limited the firebox size. the production Q2’s had this reversed. The thought on the Q1 was that it would reduce the whellebase size to not have the cylinders between the dirvers. The crews loved the Q2’s. They said they could fire them with mud and they were great engines. Maintenance costs caught up to them and the they were all retired very early in favor of traditional steam during the diesel conversion years. There is a very good paperback book “Pennsy Q Class” by NJ International if you can find one. There were a total of 27 Q-2’s built. They ran primarily from Crestline west. With tender they weighed over 1,000,000 pounds. 300psi boiler pressure, 9680 sq. ft of heating surface, 100,800 pounds of starting tractive force + 15,000 pounds for the booster. Designed for high speed service the PRR 50mph limit for freight did not alow them to operate at peak efficiency hence their early demise. The Q1 was a 4-6-4-4. the production Q2 was a 4-4-6-4. Both had 69" drivers to the best of my knowledge. All were retired by 1955. They were used in all forms of freight service.
Actually the Q1 had 77" drivers. Apparently PRR wanted to run their freight FAST. The total engine weight was 593,500 lbs and tractive effort was 81,793 lbs, upped to 90,943 with a booster. Note that even with a booster the Q1 couldn’t match the I1Decapod for sheer pulling power.
The Q2 did, indeed, have 69" drivers, which made a lot more sense for a freighter. Engine weight was 619,100 lbs and TE was exactly as noted above by ndbprr. It is interesting that these locomotives did not last until the end of steam, while the older 2-10-0s, 2-8-2s and 4-8-2s did.
Thanks…
ndbprr, you said Q2 were made for higher speeds, do you know what was its maximum speed?
Also, Where exactly and for what kind of trains were they mostly used (Q2)?
It’s my understanding that there will be an article on at least the Q1 in a future issue of PRRT&HS magazine, The Keystone. I believe the author has either submitted such an article or will soon. Not much has ever been written about the Q1, so it should be interesting.
The above cited NJI book was written by Tom Harley and is about the only comprehensive history so far on the Q2. It’s worth the effort to track down. Exceptional drawings included. My copy’s been referenced so often it’s falling apart!
One reason the Q2’s were retired so quickly is that they did not present any performance improvement over the J1 2-10-4’s in PRR’s freight service, but they cost more to operate and used more coal and water. So they were set aside by about 1950-51 and the J1’s soldiered on to 1956-57 on the Sandusky Branch.
In 1948, a Q2 was tested on N&W against a Class A and didn’t fair very well. It used more coal and water per unit of work than the A and was slower between terminals with approximately equal tonnage. There were constant complaints about the front engine slipping, even on sand All this in spite of a larger boiler and a reputation for enormous horsepower. It developed something like 7,980 indicated HP at 57 mph on the Altoona test plant, but these figures were achieved using very high evaporation and firing rates. Two weeks ago, I tracked down some daily PRR correspondence concerning the N&W test and the Q2’s performance, but have not been able to find a copy of the actual test report. Maybe some year…
I have no idea of how fast they could have run I would expect something on the order of 75mph but that is a guess. They were primarily used in priority freight service. There a couple of pictures of them pulling hoppers and none that I know of in mail and express service. Mostly box cars, livestock , fruit and vegetable reefers and stuff that had to get to its destination with a premium attached to it.