The S1 doing 142 in '47? Not questioning the speed too much, but that would've been a full year after 6100's last logged assignment. Quite the sendoff if true.
As little as I immediately understand (boy I have a lot to read), I should clarify my stance on Franklin A. When saying the locos in question were too big, I was referring to how they seemed to wear the motion out, outrunning or out-steaming the valves specified design limits. Comparing that with how every other engine with poppet valves here seemed to be smaller, or not ran at sustained triple digit speeds on the regular, it seemed to me that the PRR didn't account for how much bigger the T1 was, only having the boosted performance of a "dainty" K4 to compare. I had thought the NYC overestimated how powerful their engine was too, but it seems their choice was more deliberate, rather than an oversight.
Not sure I ever considered the T1's nightmare box to be a cause of any failures, though the foreign nature of its design likely deterred many shop crews. I recall one andectdote of one of the Space Sisters being found in a yard, and it taking some disciplinary threats for crews to start prepping it for service.
Now you mention a "double piston" design, I can sort of understand how that would be an alternative to the poppet valve arrangement. With the animations I've seen of Franklin's OC and RC gear, as well as British-Caprotti, a pair of pistons would seem to fit well
Now that I have restarted the computer again, let's try a reply as far as we can get. This may take a while, so wait until all the stuff is composed (again) and added inline.
RailfanGXYConsidering the original topic, I've no doubt in my mind that an S-1b could make 120 mph as well.
The only actual 'evidence' for Niagaras reaching or exceeding 120mph is from Arnold Haas. He is the fellow responsible for the idea that the PRR's S1 ran over 142mph with the Trail Blazer in 1947, and he also noted that he'd seen J3a Hudsons run at that speed many times, so I am nowhere near as assured as Bill Withuhn was that the design would actually go that fast.
I'll mention later how a Niagara might be optimized to actually run at high speed with piston valves.
The closest way to make this comparison is with the N&W J's making 110, multiple times, on the Ft. Wayne Division, all at original boiler pressure.
The 610 also benefited greatly from Voyce Glaze's balancing, which put only about 85lb of overbalance in the mains (nominally for the vertical component of piston thrust at designed 'dash' speed) with the 'rest' distributed in the mains. The requisite stiffening of lateral compliance (which led to at least one derailment of 611 on 'diesel suitable trackwork' during her excursion career) allowed less overbalance than strict formulae like the ones that crippled the ACL R-1s initially, and at least some of the surge component could have been addressed by installing a Langer balancer. On the other hand, there was certainly an issue with the J rod arrangement as designed, or more particularly with fractures in the long rod pin on #4 pair, which was fixed with a whole new design... that unfortunately slung the mains far, far outboard.
The S-1b's had much more power in reserve at 100 mph, and would've been the only locos besides the T1's to develop >4,000 DBHP at such speeds. Certainly the only locos with piston valves!
One could only wonder, therefore, how the two designs would fare with the FSSD Type B-2 or even Type D valve gear.
B-2 as described would have in my opinion been highly suitable to NYC 5550 -- it was the rotary-cam drive of type B or C adapted to drive the eight valves per cylinder of type A as built. Had 5550 actually been proportioned and built as a 'super Niagara', that would have been promising indeed -- but the locomotive was designed and intended to show better operating economy at 'the same' horsepower range as the piston-valve engines, and as a result had grossly 'choked' steam mass flow at what would be required to make use of the precise timing and intake/exhaust separation of the Franklin System gear. Note the promise inherent in the design as it is described in the 1947 survey of motive power... and how the locomotive was scrapped in 1950, without even considering its improvement by use of the 1948 PRR 'list'.
What could have been tried instead was a T1a-style conversion to a new chest arrangement, but using two piston valves per cylinder dedicated to separate admission and exhaust (there was at least one contemporary patent with such an arrangement, and a number of modern designers including Wardale have taken it up). That might have given you the effective performance of the C1a, and in turn at least the possibility that a 64T tender could work as well (the boiler was essentially the same between the two locomotive designs).
Both the NYC's and PRR's "5500's" exhibit benefits and drawbacks of the original Type-A gear. I suspected both types were too large for the motion they were built with and latter research basically confirmed that.
Type B-2 gave PRR's 5500 better performance and maintainability without sacrificing its high speed advantage (as with the T1a), so equipping the same gear to NYC's 5500 would've put its power to better use.
The latter could already develop more power than an S-1b...
The other thing that 'ought' to have been tried, which also concerns porting and dead space, was reversible compression control. This would take the form of a fancier set of Okadee-style blowoff valves with modulated trip, venting not to atmosphere but into well-insulated reservoirs, from which developed mass-flow overpressure could be reintroduced early in the return strok so that the cylinder-tract pressure just equaled available chest pressure at the moment the valves started unshrouding. This would conserve and use a greater proportion of nominally-available superheat and also result in much faster effective 'cylinder filling' with a suitable charge for long expansion in the very short time available.
BaltACDA prima facie case ot Kalmbach IT's loose association with reality. Can't even count straight and display same.
To be fair to the Bangalore contingent, the "problem" here is likely in a mismatch deep in the back-end engine code, between the 'optimized' post-2018 page structure and the system in global settings that is supposed to let you see threads 'last post first' (it blows up when you have it set and try to click on the 'ascending order' control in a particular thread, so there are other improprieties in the codebase). When we actually get the promised 'stage three' renovation, probably about the year 2048... this and the other little foibles will be fixed. At least we can hope they will be.
RailfanGXY Overmod I have tried to answer this five times -- with the 403 Forbidden 'nanny' system each time. Remains to be seen what I may have to do to give it the attention it deserves. Something seems iffy on this end too. When on Page 5, the buttons seem to read -1, 0, 1, 2, 3. Haven't the foggiest why, it's been a while since I've been active here, though hoping it's easier to answer for you
Overmod I have tried to answer this five times -- with the 403 Forbidden 'nanny' system each time. Remains to be seen what I may have to do to give it the attention it deserves.
I have tried to answer this five times -- with the 403 Forbidden 'nanny' system each time. Remains to be seen what I may have to do to give it the attention it deserves.
Something seems iffy on this end too. When on Page 5, the buttons seem to read -1, 0, 1, 2, 3. Haven't the foggiest why, it's been a while since I've been active here, though hoping it's easier to answer for you
A prima facia case ot Kalmbach IT's loose association with reality. Can't even count straight and display same.
Never too old to have a happy childhood!
kgbw49 Have not been able to locate a T1 vs Niagara race photo yet...
Have not been able to locate a T1 vs Niagara race photo yet...
Very overdue, but such a photo has surfaced!
Can't seem to make out the numbers of the racing participants, but no doubt in my mind who 5535's crew was rooting for.
Considering the original topic, I've no doubt in my mind that an S-1b could make 120 mph as well. The closest way to make this comparison is with the N&W J's making 110, multiple times, on the Ft. Wayne Division, all at original boiler pressure. The S-1b's had much more power in reserve at 100 mph, and would've been the only locos besides the T1's to develop >4,000 DBHP at such speeds. Certainly the only locos with piston valves!
One could only wonder, therefore, how the two designs would fair with the FSSD Type B-2 or even Type D valve gear. Both the NYC's and PRR's "5500's" exhibit benefits and drawbacks of the original Type-A gear. I suspected both types were too large for the motion they were built with and latter research basically confirmed that. Type B gave PRR's 5500 better performance and maintainability without sacrificing its high speed advantage (as with the T1a), so equipping the same gear to NYC's 5500 would've put its power to better use. The latter could already developed more power than an S-1b; it just kept choking on that power trying to get it on the rails
timzYes, the dispatcher doesn't care if a passenger train leaves early-- but if it picks up passengers at that station, Amtrak usually doesn't want it to leave early. If a following train can pick up the passengers in a few minutes, the dispatcher can apparently authorize a train to leave ahead of its public-timetable schedule. (Presumably he'd have to radio the conductor and engineer and give them the OK.)
All that is in the hands of the passenger operator.
Yes, the dispatcher doesn't care if a passenger train leaves early-- but if it picks up passengers at that station, Amtrak usually doesn't want it to leave early. If a following train can pick up the passengers in a few minutes, the dispatcher can apparently authorize a train to leave ahead of its public-timetable schedule. (Presumably he'd have to radio the conductor and engineer and give them the OK.)
timz"L" meaning they weren't supposed to board passengers at that stop? If the station was between NY and Washington, that was enough to make an early departure legal. Most other RRs in, say, the 1970s and earlier had rule 92, which flatly forbid leaving any station ahead of time. Nowadays I think many? all? dispatchers are allowed to authorize passenger trains to leave early-- tho there would rarely be any reason to do that.
Most other RRs in, say, the 1970s and earlier had rule 92, which flatly forbid leaving any station ahead of time. Nowadays I think many? all? dispatchers are allowed to authorize passenger trains to leave early-- tho there would rarely be any reason to do that.
There is no longer a Timetable and Train Order form of operation which relies on time and other factors for movement authority.
From the Dispatchers view point today, he or she really doesn't care if a passenger train leaves in advance of the scheduled departure time. Authority for movement is given via either Signal Indication or Track Warrant Control - neither of these means of authority are time related.
"L" meaning they weren't supposed to board passengers at that stop? If the station was between NY and Washington, that was enough to make an early departure legal.
timzSo presumably the employee timetable showed them as discharge-only at Philadelphia and Newark, and they didn't appear in the Form 12 and Form 79 public timetables at all.
I am informed from a different source that some Amtrak trains were given official permission to leave stations early; they were said to be denoted in timetable with code "L". I do not have material to substantiate this, but I suspect timz does.
Most of the years I rode them, they did not appear in the Wash - NY and Phila - NY PRR public timetables. I did ride them though, on occasion, Wash - NY, with a conductor that did not mind. Very useful idea when the regular hourly trains were crowded. I suspect he gave my ticket stub to a regular NY - Wash conductor to hand in, rather than have to answer questions.
davekleppernorthbound Silver Metior, Souterner, East Coast Champion, and Flordia Special frequently arrived at and left Philadelphia, Newark, and New York as much six or seven minutes ahead of schedule.
So presumably the employee timetable showed them as discharge-only at Philadelphia and Newark, and they didn't appear in the Form 12 and Form 79 public timetables at all.
daveklepperBut I also rode trains meeting your description, the northbound Silver Meteor, Southerner, East Coast Champion, and Florida Special frequently arrived at and left Philadelphia, Newark, and New York as much as six or seven minutes ahead of schedule.
I was given to understand that at least part of the reason for 'detraining passengers only' at some of these later stops was to avoid issues with early onward departure -- not just keeping the hoi off the Pullman trains.
I meant advance sections of regularly scheduled trains, most frequently the advanced Congressional, later renamed the advanced Afternoon Congressional.
In other words, both the Central and the Pennsy, instead of running a second section ten minutes behind the schedule train, ran an advanced section ten minutes earlier.
But I also rode trains meeting your description, the northbound Silver Metior, Souterner, East Coast Champion, and Flordia Special frequently arrived at and left Philadelphia, Newark, and New York as much six or seven minutes ahead of schedule. Probably also true of the Broadway Limited, Trailblazer, Jeffersonian, etc, substituting N. Phill. for Phill.
And the northbound Crescent was a special case. At one point the Southern public timetable showed times in the corredor that were probably correct for times when the train ran as an entire train north of Washington. But all times that I rode it, a string of rebuilt P-70's with a PRR diner was attached, it ran as a regular Washington - NY hourly train, with times earlier than those shown in the Southern timetable.
daveklepperI rode such trains in the NY -Washington corridor.
Guess you mean, trains that passed stations ahead of schedule when they were not scheduled to receive traffic at those stations. That was legal in PRR Rule-251 territory-- no train order needed.
daveklepperI rode such trains in the NY -Washington corridor. Believe me, both the PRR and New York Central did. And Amtrak can if it wsnts to in the corridor, but they usually simply assign a temporary train number and issue a temporary schedule.
Multiple track territory was normally not operated under Timetable & Train Orders method of operation - with that being the case Schedule times were of limited to no importance.
I rode such trains in the NY -Washington corridor. Believe me, both the PRR and New York Central did. And Amtrak can if it wsnts to in the corridor, but they usually simply assign a temporary train number and issue a temporary schedule.
Way back when you would be amazed at what carriers did way before Lawyers made this society so afraid of being sued into oblivion for the smallest thing that they force compliance over service. My boss has always run a very safe operation yet way back in the 80's and up to the mid 90's his drivers knew if they had to push the book so to speak to get that load there then the boss and his father had their backs. My late father in law told me countless times of how he threw his logbook in the bunk in the 70's to get loads thru for his boss.
BaltACDCarriers can have trains do what they need or want them to do - to wit a possible train order. FIRST NO. 1 ENG 5501 RUN 1 HOUR ADVANCE FORT WAYNE TO CHICAGO. This would require trains that had to protect against NO. 1 to protect against this train one hour in advance of NO 1's schedule as printed in the Timetable.
BigJimThe point is, if the train was timetabled, it cannot leave a station before the time stated.
Carriers can have trains do what they need or want them to do - to wit a possible train order.
FIRST NO. 1 ENG 5501 RUN 1 HOUR ADVANCE FORT WAYNE TO CHICAGO.
This would require trains that had to protect against NO. 1 to protect against this train one hour in advance of NO 1's schedule as printed in the Timetable.
The reality is, on a multiple track railroad, such a order would not be necessary and the PRR from Fort Wayne to Chicago was a double track primarily current of traffic signaled railroad.
In today's world of railroading Amtrak's Auto Train routinely operates from orign in advance of the scheduled 4 PM departing time from the terminals at Lorton and Sanford.
[quote user="BigJim"]
The point is, if the train was timetabled, it cannot leave a station before the time stated.
[/quote above]
Yes it can, if it is an "Advanced Section" of the train. Which the PRR did regularly with many NY - Washington expresses during WWII. Once rode from Washington to NY in 3hr 5min.
The data may have been from an Advanced Trailblazer or Advanced Broadway.
This was common practice on both the Pennsy and the Central.
Out of curiosity, who is the author of "90 MPH and beyond"? I have a few back issues of the Keystone with T1 related articles but not Autumn 2014.
Edit: Looks like it was Neil Burnell, and I do have it.
--Reed
I've read this entire thread - no one mentions the article in the Keystone in Fall 2014 called "90 MPH and beyond". The author has done significant research to help dispell cliams made by the brits of the world steam locomotive speed record. Much of his findings involve the T-1 on the Ft Wayne Division. Much is documented - some is not. The Franklin Valve story is told in detail especially what the Franklin engineering teams found when they timed T-1 speeds in the loco cabs in daily operation - 140 mph was not uncommon but exceeded the warranty speed of 120. They had to use stopwatches as the speedometers weren't metered high enpough. This and other stories are told in rich detail and is a must read for anyone with interest in the T-1. (My favorite is the alleged elapsed time of the military special during WW2 from Crestline to Chicago.) No wonder the T-1 Trust people want to establish the absolute steam locomotive world speed record once and for all.
carnej1did PRR ever consider modifying the T1 fleet with the electro-mechanical wheelslip control system used on the Q2's?
I have never seen any indication of this, including when reviewing the extant documentation at the Hagley. That's not to say it wasn't discussed, only that no evidence of adapting the equipment or re-engineering the system to passenger standards was made.
In a couple of respects it was apparently well-understood that the system needed major redesigning -- first, the system was virtually useless using its original 'bang-bang' implementation logic, and second, the bearings and pivot arrangement for the butterfly valves were neither reliable nor maintainable in service. (These two issues may be related; the original electromechanical design would have been easy to implement proportionally, but sticking valves would have thrown that operation off badly, leading to full excursion 'by default' as the only operational choice...)
I consider it highly unlikely that any attempt at mechanically valving the steam would be desirable -- the Wagner throttles are not only much less visually obtrusive, they work properly at any degree of superheat and need little if any calibration as they age in service. And in any case a mechanical traction-control system acting on the wheelrims directly is a better form of quick implementation and release for borderline slip conditions, and this as an adjunct of independent brake is much easier to control.
My understanding concerning Juniatha was that she was working too hard to be posting to this forum extensively. Perhaps that will change in future, or she will take a periodic interest in things that happen here.
daveklepperMiningman, please be just a bit more tolerant of spelling and punctuation errors. Sometimes they represent lack of time for checking, typos, and a triumph of impatiance over accuracy.
As well as not having a working spell check on this particular version of forum software. Prior versions did and many other organization's forums currently have spell check.
I apologize if this question has been asked previously on this forum (possibly in an older thread) but did PRR ever consider modifying the T1 fleet with the electro-mechanical wheelslip control system used on the Q2's? I read on the T1 trust site that they have considered such a system for their design..
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
Dave- Of course, in your case it is very understandable...as it is for others. It is easy to see the difference.
Our community is FREE to join. To participate you must either login or register for an account.