blue streak 1Not knowing the power efficiency of GG-1s with its unique traction motor setup can only speculate that is one reason GG-1s were limited to the listed timetable speeds.
I suspect that power directors knew how to dispatch 'around' a fast train when high speed would have been necessary. If doubleheaded GG1s on freight were commonplace, and tripleheaded GG1s documented (not just balancing power) what would make you think that a single GG1 running faster would draw excessive power? Mr. Klepper might comment on whether the 387A was more or less tolerant of undervoltage at higher rpm.
On the other hand, I could easily agree that if the high speeds were not 'economically necessary' it would make sense to restrict GG1 speed, especially in congested regions or times where high speed would overload the plant.
I remember there being substantial improvements in substation capacity as well as trolley-wire size as part of the Metroliner program (this was covered in Pennypacker's article on them in Trains in the '60s, was it not?)
I had not thought that one of the reasons for the non-adoption of the 428A motor (as in the DD2) even though it was going to be the 'standard' for the Harrisburg-Pittsburgh electrification might have involved power overload. But yes, I agree that would make some sense.
daveklepperThe speedometers on Metroliner MUs were digitial. I am sure they could register 199 mph if that were obtained. I often rode behind the engineer and frequently saw 120mph. But only once 136 mph top.
And I have a photo showing 115 on a Metroliner speedometer. Its a ride I will never forget.
JL ChicagoClaims that the T1s were the fastest steam locomotives were not made by the people who rode the trains and wrote books and articles about their experiences. All of those writers claimed the Milwaukee Hiawathas as the fastest steam trains. Specifically Gerard Vulliet, EL Thompson and Cecil Allen all timed (or compiled timings) in their books and articles and all 3 claimed the Hiawathas as fastest. If the T1s were faster then no one recorded it and published it at the time.
It is not wise to make the mistake of confusing what a locomotive design is capable of with what a train it pulls to make money is scheduled to achieve.
Alfred Bruce of Alco rather famously noted that the Milwaukee As were capable of 128mph, and I have no particular reason to call him a liar. However, this speed if achieved on a train with paying passengers -- even with Nystrom suspension -- is not exactly wise. The "high speed" T1 reports were test runs, and I will grant you it's strange that at least one of these didn't have a recorded speed methodology (at least, one that has survived). But that does not affect whether the design was physically capable of achieving high speed.
I'd be interested in seeing what a T1 pulling a consist of Nystrom-trucked cars west of Fort Wayne might have been able to reach. That would be far closer to a fair test of engine speed than using a typical PRR consist, which by some reports did not even ride anywhere near as well as the T1 itself did at speeds around 115mph or so, let alone faster than that. And the T1, certainly as built and probably as modified up to about 1947, was likely to have resonant instabilities in suspension and guiding somewhere in the high 120s somewhere, and almost certainly with respect to the reported maxima in the low 130s where 'poor spring rigging' and 'hard riding' would probably be notable understatements for the actual dynamic behavior that was occurring.
The PRR Technical and Historical Society has details of the T1 test runs in one of their Keystone magazine issues. If I find it I will post some quotes. But I do recall the top speeds recorded were in the low 100s and by that I mean 10x. Not even 110. Could they go faster? Maybe, but no records exist of higher speeds.
The PRR was an 80 mph railroad. I've not seen a higher max authorized speed than 80 in any PRR employee timetable. Nor have I seen a pass to pass timing exceeding 80. The Milwaukee had a 100 mph MAS in their ETTs for the Hiawathas and Chippewas. And there are pass to pass timings requiring mid to high 90s just to maintain schedule.
If you went 100 in a PRR T1 consider yourself lucky! If you didn't reach 100 in a Hiawatha you were behind schedule. And as noted above, the T1 speedo went to 100. The Hiawatha speedos went to 120. That pretty much sums up what the loco designers were relatively thinking of in terms of speed.
I'm not knocking the T1 but it's a stretch to call it the fastest.
JL ChicagoThe PRR Technical and Historical Society has details of the T1 test runs in one of their Keystone magazine issues. If I find it I will post some quotes. But I do recall the top speeds recorded were in the low 100s and by that I mean 10x. Not even 110. Could they go faster? Maybe, but no records exist of higher speeds.
I think all the test results from the Keystone articles ... all the Keystone articles, in fact ... are in the T1 Trust repository and have been read by the engineering committee members.
The T1's actual railroad purpose was not to travel at very high speed; it was to pull the longest possible train at 100mph where needed (reading between the lines, precisely as JLChicago indicated: to make up any lost time on an 80mph service). Design spec was 880 trailing tons at 100mph, and I think that was the envelope that controlled the testing PRR did.
There is one piece of circumstantial evidence that I consider important, and that is the recorded testing done on the N&W J class. There is little if any interpretation of those test results that does not support operation of the locomotive at 110mph with a brief maximum at around 113mph. This in a test the motive power department already understood as 'limited by wheel diameter'. It seems strange to me that a locomotive with higher drivers, shorter stroke, radically lower augment, and better center of mass and lead-truck design would not ... at some point ... be tested at least to the point the J was pushed. But the way PRR used available high speed was somewhat similar to N&W's: the engine was given a high-speed dash capability (which happened to be sustainable indefinitely given a long enough stretch of suitable track for that speed, something in relatively short supply on N&W) and was balanced for some higher theoretical speed or rpm above that. Whether anyone conducted actual testing on the locomotive to verify balance at the higher speed is unknown to me; Kiefer (on NYC) conducted greased-rail tests which indicated suitable (meaning not bouncing!) balance up to 161mph indicated for a Hudson (probably a J3a, and I'd think one of the engines with roller rods, but the report didn't say) and perhaps that or a test-plant run would be 'good enough' high-speed testing to establish the condition. This is similar to a Smokey Yunick review of a RV back in the Sixties (I think in the old Mechanix Illustrated) which was tested at over 100mph -- he said "would you drive it that fast? Of course not, but it is presumably extremely stable at ordinary speed..."
The PRR was an 80 mph railroad. I've not seen a higher max authorized speed than 80 in any PRR employee timetable. Nor have I seen a pass to pass timing exceeding 80.
I think thereupon hangs something of a tale. PRR was very late to the party with what most of us would consider modern steam (one of the drawbacks of having really successful transition designs like the E6s/K4s), and between 1928 and the Depression started making a big push to build a much faster railroad. I think it is in that framework that PRR got carried away with both its piston and turbine designs from the middle Thirties on (perhaps being a bit overinspired by what Milwaukee in particular was doing -- compare the oil-fired E8 Atlantic project, or think of the T1 (as I do) being two well-balanced Atlantics under a big common boiler). Staufer has made the point that PRR would have been much better served by building M1s, or the 4-8-4 with "5/4ths the capacity of a M1" that the original Q1 thing was supposed to be, using lower drivers and the better balancing of the Thirties to reach the same running speeds the K4s did ... which were those of an 80mph railroad with maybe a low-90s dash capability.
There was stuff like this on the freight side, too, with the Q2s being perhaps the most dramatic example: they didn't even get near peak horsepower until nearly 15mph over the PRR freight-train speed limit. (They were intended as wartime power, so I think a certain amount of slack can be cut for their designers, but it is not surprising that those big overripe tomatoes were quickly retired in favor of the Fs; it is not surprising that the V1, which was actually approved for production in the early '40s, was not proceeded with; in retrospect it was a bit silly for Baldwin to develop and sell a 120mph 6000hp diesel-electric locomotive with a full articulated cast underframe for the 80mph trains.
Dave Klepper knows something about the 'Fleet of Modernism' truck designs and their riding. My understanding of the situation (which backs up what JLChicago is saying to an extent) is that much of the "modern" PRR equipment was exhibiting some form of bad ride in just the range that the T1 would be beginning to show the distinctive-competence advantages of divided drive over a comparable 4-8-4. If they had adopted contemporary Nystrom truck designs, with so much of their running down in the range Nystrom's trucks would show hard riding and/or overdamping, they might have had to implement some kind of variable suspension or even active suspension (air-bag bolster suspension being practical for many years, but not particularly cost-effective or failure-tolerant). If the Depression hadn't shut down the upgrading, if the electrification hadn't taken money away from modern steam for a while, even if the PRR had more services that corresponded in both length and demand to what the Hiawathas (or other high-speed services requiring more capacity than motor trains could provide) then something more than an 80mph railroad might have come about. I suppose we will never know what would have happened if the postwar streamliner renaissance had come off as expected; PRR wouldn't have gang-built enough T1s to solve the doubleheaded-K4 capacity issue without at least thinking there was speed reserve for some considerable speeding-up when the business case required it. But there's still a considerable distinction between what a contemporary Hiawatha consist weighed and what a first-rank (or even 'typical') PRR mainline train did.
The Milwaukee had a 100 mph MAS in their ETTs for the Hiawathas and Chippewas. And there are pass to pass timings requiring mid to high 90s just to maintain schedule.
No one is going to argue that the Milwaukee made both a study and practice out of useful high speed. The first reliable locomotive runs over 100mph were, in fact, with that somewhat unlikely-looking F6, the predecessor of the streamlined F7. The interesting thing to me was how fast the actual high-speed steam (A and F7) disappeared after Milwaukee started buying diesels, and what happened to the pass-to-pass timings when somewhat higher average speeds became possible with the diesel-electric power.
And as noted above, the T1 speedo went to 100. The Hiawatha speedos went to 120. That pretty much sums up what the loco designers were relatively thinking of in terms of speed.
No, that sums up what the railroads owning the power intended them to be operated at. It says very little about what the actual speed capability of the designs is. The argument about ultimate high speed from the T1 is not, and should not be, whether PRR trains with these locomotives ever reached speeds much above, well, what Milwaukee trains did every day of necessity. Nor is it, really, whether PRR actually conducted test runs to prove the design envelope. (If you wonder why the T1 Trust modeling and simulation development is so extensive, it's to determine how much of the promise of the design can be demonstrated, and which design details may need to be adjusted to realize full high-speed performance and stability.)
Look at the tone of the anecdotal references if you need to see the difference between MILW and PRR. The president of Alco proudly confirms his designs for the former would (easily!) reach 128mph. Over on PRR people get hauled on the carpet for 'flying without a pilot's license' for far less ... and that little controversy about reading 118mph off a 100mph speedometer isn't going away yet, although I'm not going to be any more judgmental than that. Moreover PRR did not train their crews in the appropriate care and treatment of modern divided-drive power with front-end throttles; they took early to feeding poorer grades of coal than the firebox had been specified for; they cut the whole high-speed experiment very short by 1948 without even finishing the list of modifications that were needed to realize the full range of speeds inherent in the design (and yes, that would include proper damping as well as snubbing.)
JL ChicagoEvery PC employee timetable I have (and I have all but a couple) clearly showed a 90 mph limit for GG1s hauling Metroliners.
Edit: I was wrong-- GG1s 4887 and up were still allowed 100 in the 5/70 timetable; back to 80 mph in the 7/71.
JL ChicagoI think it was in Reed's book on the Hiawatha where I read that while the As we're easy on the track the F7s were hard. Not a surprise since I roughly calced the reciprocating weight on the F7s to be double the As.
Reading between the lines in Scribbins reveals something that might be more ominous. The late Hiawatha consists (according to Chapelon) could run as heavy as 780 tons, and of course were regularly accelerated up to 100mph (I had not fully realized before looking at the graph in the 1952 LLAV that the locomotives were running 100mph five miles outside Milwaukee going eastbound!) with, very probably, faster running when required. As with the Niagaras I wonder if there was more chronic main-pin cracking and fracturing than has made it to common knowledge.
(The As were unusual in being front drivers. That is, the main rod from the piston drove the front wheels to limit reciprocating weight.)
It's not just to reduce the reciprocating mass; the resultant of the two rods tends to stabilize the main driver motion in the pedestals better, and of course the main and side rods can be kept nearly in line (and the cylinder-to-cylinder distance absolutely reduced, giving some of the advantage of keeping reciprocating mass closer to the locomotive centerline that Woodard described for 'central machinery support' in 1928, and that is evidenced on the streamlined Belgian 4-4-2s of roughly the same period). I'd have liked to see what Timken rods on an A would have given ... or what might have been possible with 'one-half a T1' running gear with 84" drivers and the late-steam optimization of small bore and relatively long stroke, perhaps with a booster to give three-driver-axle-like performance at starting and during acceleration to medium (or, with better booster design, fairly high) speed.
I also did a calc a ways back and need to see if I can find it but if memory serves me right the As which were oil burners consumed 3 or 4 x the amount of the diesels. Now I'm guessing the As burned bunker which was cheaper but still, that's a huge advantage for the diesels.
That would be about right, but you should probably keep the debt service on the diesels in the equation for their fuel cost, as it would remain a bottom-line cost of dieselization. I'd look at the water costs as being significant, both in treatment and in any schedule modifications needed for water (larger cisterns on tenders, or A-tanks, being prohibitive for light engines on light consists).
The only thing wrong with the As was success: they created a demand that no five-car trainset was likely to be able to fill no matter how quickly you could turn it. I wondered many years ago whether the 'next step up' for Milwaukee wouldn't in fact be a double-Atlantic divided-drive locomotive, particularly as it shouldn't have been difficult to achieve better track dynamics at high horsepower (even the short-stroke T1 with unoptimized exhaust produced 6760ihp on test at 100mph, and had specific water consumption as low as 13.6 (the lowest, I think, ever recorded for American power, and a very good figure for simple expansion) at somewhat lower (but still representative of express service) speed. Here, however, we come on a different limit: how long a train of lighter Nystrom equipment would be accommodated at physical station platforms. A double Atlantic might be as much overkill as a good modern 4-8-4 of equal size in that respect...
But wouldn't an 84"-drivered conjugated duplex in, say, the orange Olympian Hi scheme be an interesting thing to watch? I too regret I wasn't alive back then, and continue to be increasingly impressed with the final years of what they did with steam!
[quote user="JL Chicago"]
daveklepperAlso, on rereading my first posting, the fact that the speedometer needle was wiggling at speeds over 100 does not really mean that the speedometer was reading those higher speeds. It may have just been wiggling around 100! From varying forces within the speedometer mechanism.
I don't think it was uncommon for even the slight grade changes on the PRR main between New York and Washington to exert enough 'push' from the train to run the locomotive 3-4mph high -- I have observed this effect with modern consists in Baltimore-Washington commuter service. However, if I recall correctly, the speed encoder was a DC generator directly connected to a leading-truck axle, which wouldn't surge even with adhesion problems or show oscillations in feedback, and the only issue with 'overshoot' would be physical vibration in the d'Arsonval movement or whatever of the actual speed-recorder gauge -- the retrofitted speed recorders in the NJT rebuilt E8s had an enormous amount of viscous damping for precisely that reason. I would be surprised if any train with the mass of a GG1 added to the front could exhibit short-term speed fluctuations upward ... at least not with correct train handling ... that would kick the recorded speed up very far or very fast.
While technically there wouldn't be any allowance over "100mph" for downgrades, wind, etc., just as there isn't any leeway between "79mph" and "80mph" in enforcement of the Esch Act and ICC order provisions, I was given to understand that up to around 4mph "gain" is now allowed on brief downgrades, perhaps for energy-conservation or brake-maintenance reasons, and I have observed this level of excess (clearly objected to by the various nanny systems on the engine or push-pull cab) a number of times in the past decade or so.
See the 120 mph T1 post. I was not suggesting oscillations in speed. However, having ridden behind T-1s, I can report a phenomenon reported before. Somewhere, between 55 and 60 mph, several timese I did notice a subtle back-and-forth oscillaton, enough to be annoying when trying to read or sleep, but not anything suggesting danger. At the time, I put it down to lack of damping in the draftgear between loco and tender or tender and the first coach.
Mr. Klepper, I think you got 'stepped on' in transmission.
I'm trying to keep the GG1 top speed issues separate from the T1 top speed business. (I do not think they have the same mechanism in their speedometers, for one thing; the only real similarity is the limit of dial calibration.) So if I appear to be posting in one thread in reply to something in the other, it's only in the interest of keeping the topics distinguished going forward.
If it is 90 miles from Zoo or Arsinal to Penn-NYC, the average speed for 42 minutes is 128.6 mph. Now figure in the slowdowns for N. Phila, the famous Frankfort curve, Trenton, Newark, Portal Draw, possibly tunnel speeds, and the throat at Penn, and it is quite likely that the max was higher than the 136 that I observed just once.
Does anyone remember hr can provide data on how slower were the Metroliners behind GG1s as opposed to mu operation?
daveklepperIf it is 90 miles from Zoo or Arsinal to Penn-NYC, the average speed for 42 minutes is 128.6 mph.
Circa 1978, many? most? Metroliner schedules were around 3 hr 20 min NY to Washington to allow for the GG1 haulage.
http://www.timetables.org/full.php?group=19780730&item=0011
However, I can report riding an all-coach train run as an extra or as an advanced section of the parlor Congressional (no morning congo during WWII) that ran from Washington Union to Penn Station, NYC, in three hours and five minutes, with stops only in Philadelpha (30th St.) and Newark. I did check mileposts on occasion at 100 mph, mile in 36 aeconds. Overall averege speed 72.9 mph, including the two stops and speed restrictions. I was told running this train was a frequent occurance. Every seat was taken, and there were standees.
Ahh the good old days.
Back in 1967 or '68, I rode the PRR and PC behind GG-1s between Trenton and Washington, DC. One time I asked the conductor how fast we were going between Baltimore and DC, and he hold me 110.
when I was still a lineman, we were working the wiretrain south of Havre de Grace in 1980 or 81. just before Conrail killed thier electrics. the Road foreman and a boss from Washington were doing radar checks right at the south end of the Perryville draw. when we got a call from the P'Ville tower around 100 pm to stop work and get off the train and away from the tracks. before we could do that a frieght blew past use like we were not there. then we heard the Baltimore Power Director saying on the road channel the power was off #3 track. (we were on #1 track).from sub 16 to sub 17. We were told to pick up the bosses and take them south to the head end of the frieght. while we were moving our gang foreman ask what had happen and what was going on. seems they clocked MD-117 w/2 GG-1's and 60+ cars at 105 mph coming across the drawbridge. (speed limit on the bridge at the time was 65 mph for Pass, 45 for frieght. ) when we got to the headend, South of Oak interlocking, they pulled the Enginner P.A.(Pappy)Smith (62 Yrs old) out of service along with the fireman and conductor. When ask why he was going so fast Pappy replied he was late for date in DC. that stunt got him 30 days off without pay. and we spent the rest of the day inspecting the drawbridge for any wire damage. luckly nothing was found. also look up Reds Hallowell. He would break the century mark during late Metroliner testing with G's in order to set the schedule baseline.
That sounds crazy.
A string of general-purpose freight cars with the 3-piece trucks going 105 MPH? This must be well beyond their "critical speed." How did nothing jump the track?
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
Paul MilenkovicThat sounds crazy. A string of general-purpose freight cars with the 3-piece trucks going 105 MPH? This must be well beyond their "critical speed." How did nothing jump the track?
'Back in the Day' the B&O assigned their F3 passenger engines to the Chicago Division to operate between Chicago and Willard. They retained their 98 MPH passenger gearing. When 4 or 5 were placed on a 'TimeSaver' - they would click off the 120 miles from Pine Jct to Garrett in 80 to 90 minutes - averaging between 75 & 80 for the complete run.
Never too old to have a happy childhood!
rrlineman when I was still a lineman, we were working the wiretrain south of Havre de Grace in 1980 or 81. just before Conrail killed thier electrics. the Road foreman and a boss from Washington were doing radar checks right at the south end of the Perryville draw. when we got a call from the P'Ville tower around 100 pm to stop work and get off the train and away from the tracks. before we could do that a frieght blew past use like we were not there. then we heard the Baltimore Power Director saying on the road channel the power was off #3 track. (we were on #1 track).from sub 16 to sub 17. We were told to pick up the bosses and take them south to the head end of the frieght. while we were moving our gang foreman ask what had happen and what was going on. seems they clocked MD-117 w/2 GG-1's and 60+ cars at 105 mph coming across the drawbridge. (speed limit on the bridge at the time was 65 mph for Pass, 45 for frieght. ) when we got to the headend, South of Oak interlocking, they pulled the Enginner P.A.(Pappy)Smith (62 Yrs old) out of service along with the fireman and conductor. When ask why he was going so fast Pappy replied he was late for date in DC. that stunt got him 30 days off without pay. and we spent the rest of the day inspecting the drawbridge for any wire damage. luckly nothing was found. also look up Reds Hallowell. He would break the century mark during late Metroliner testing with G's in order to set the schedule baseline.
Possibly if he had only done 80 they would have let him get away with it!
daveklepperSomewhere, between 55 and 60 mph, several times I did notice a subtle back-and-forth oscillation, enough to be annoying when trying to read or sleep, but not anything suggesting danger. At the time, I put it down to lack of damping in the draftgear between loco and tender or tender and the first coach.
I believe E.T.Harley has commented on this effect in both T1s and Q2s, and of course it was dramatically manifested in at least one of the test-plant runs of the Q2. The cause was attributed to transient 'phasing' of the two engines in sync, and potentially to a lesser extent momentum effects in the steam pipes. It would probably be exacerbated by any slack, or improper tuning/damping, of the Franklin radial buffer.
Paul MilenkovicA string of general-purpose freight cars with the 3-piece trucks going 105 MPH? This must be well beyond their "critical speed." How did nothing jump the track?
I had the same argument when I first heard about the Super C. And those fellows were using the train brakes a lot to get over the road (see the article, I believe in Classic Trains a few years ago, that was a firsthand discussion of handling that train).
The three-piece truck is remarkably compliant and steers well. The great problem comes if there is any play in the fit between the bolster and sideframe, leading to resonant 'lozenging' (also sometimes called 'skew'). Some idea about counteracting this led to the various designs of truck with the little X-member keeping the sideframes aligned longitudinally while preserving the 'three-piece action' -- I still see these sideframes (with brackets) occasionally on container trains, but usually (so far in my experience, always) without the actual brace installed. I do know they are still used in other countries, and would be a very prudent thing to have installed -- probably along with good, stiff constant-contact side bearings -- if operating a train at "105mph" with three-piece trucks were going to be considered. But that story was from an earlier day and a more innocent time, when (returning to the T1 a moment) we have stories about crews running the engine so fast as to shake up people riding in passenger cars with nowhere near the truck sophistication (or state of maintenance) necessary. I have little doubt the engineer in question could get the train to that speed ... but I also have little doubt he wasn't thinking too hard about the 'least maintained' car in his train, or the effect that the contemporary trackwork might have in exciting at least one truck into resonant lozenging (something that has to be seen to be believed... but from far, far away!)
Paul Milenkovic That sounds crazy. A string of general-purpose freight cars with the 3-piece trucks going 105 MPH? This must be well beyond their "critical speed." How did nothing jump the track?
To get truck hunting going, you need tangent welded rail. Curves and jointed rail will kill it. Except for the welded rail laid in the late 60s for the Metroliner project, there was still lots of jointed rail on the NEC in the late 70s. Still, G's pulling a freight at 105 is a bit suspicious...
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
Don't know, that is why the towerman at Perryville had us clear up. he was knocking down the signals like a banshee from Davis to the drawbridge. that is why the crew got pulled and Pappy Smith ended up with a 30 day unpaid vacation. Never heard of a freight going close to that except for the SUPER "C" the ATSF ran. Guess it was a big piece of luck.
You had to been there to see it. a lot of sneaky hi-wheeling went on before the Chase wreck with enginners and train crews.
I remember in the early 50's looking out the lower half of a dutch door with the conductor. He asked me if I knew how fast we were going, needless to say I didn't and he told me that we were cruzing at 90mph! This of course impressed me greatly since I was still a young fellow. From this experence I have no doubt that the GG-1 could go much faster if allowed.
K4s_PRR I remember in the early 50's looking out the lower half of a dutch door with the conductor. He asked me if I knew how fast we were going, needless to say I didn't and he told me that we were cruzing at 90mph! This of course impressed me greatly since I was still a young fellow. From this experence I have no doubt that the GG-1 could go much faster if allowed.
K4s_PRRK4s_PRR wrote the following post 3 hours ago: I remember in the early 50's looking out the lower half of a dutch door with the conductor.
I suspect that you meant the upper half as the lower half only opens when the upper half opens. The top half can open with the lower half closed. Lower half open would allow you to slide out and would be dangerous.
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