MiningmanDid not the same thing happen to the S1?
Not to my knowledge. And even with "7200hp" not particularly likely.
Or was it the S2?
Not a chance. Those rods just connected the gear-driven axle sets to the outer pairs.
What you need for this kind of catastrophe is an extended main pin, with dicey web thickness between pin and axle fits in the driver center (as you know, the T1 had the ABSOLUTE thinnest measurement here that Baldwin considered feasible, for the reduced piston thrust of short-stroke "Atlantic" size cylinders, this with driver centers sized for 80").
Part of the 'secret agenda' with duplex drives was that the thrust of many modern engines with Timken lightweight rods got up into the range that main-pin stress raisers got established and propagated. As I've said, I suspect that kind of catastrophic failure would become more and more documented as the urge to decrease rotating and reciprocating mass and lateral offset became greater (assuming big steam remained popular past the late Forties).
Add to this the fun, and perhaps unsurprisingly functionally under-documented, note by Chapelon in LLAV that if you subtract the lateral play observed in rod bearings from the permitted lateral, the 'logical' conclusion is that the rods are flexing laterally with every revolution. While conveying substantial stress, and while the stress in the pins is all one way with rotation, that in the rods most certainly is not...
NO ONE expects the main pin failure! Its chief effects inspire fear ... fear and surprise, surprise and fear, in attempting to provide ruthless efficiency...
and perhaps an almost fanatical devotion to Porta?
"Trouble at the mill"
...."What kind of trouble?"
"Apparently the flayrods gone askew on the treadle"
( Spanish Inquisition skit from Monty Python)
Did not the same thing happen to the S1? Or was it the S2?
Union Pacific had vertical headlights on some of the early Streamliners, the idea being similar to the angled headlights -- the projected fast-moving searchlight beam supposedly acting like spotlights at a Hollywood premiere to arrest the attention of nearby motorists and get them to Recognize High-Speed Death Is Near while still far away from crossings.
I have never seen a reference that said that it worked as expected, on any road that tried them. To my knowledge all were removed or disabled early; whether or not this was due to ICC/FRA regulations requiring them to work all the time if installed I do not know.
Picture of an E-4 Hudson in Chapelon's LLAV (I use Carpenter's 1952 translation) appears to confirm that the 'upper' feature is, as I would have expected, the red light C&NW used to show a stop or emergency-brake application to facing trains on double track. (I believe NYC tried implementing this at the very end of steam, with the little indicator in those Pyle double-sealed-beam headlight arrangements, but don't know that for sure.)
You do know there is a painting of the 'critical moment' when the main pin failed -- and it's linked in some posts on these forums!
wjstix On the CNW E-4, looks like it has two headlights, most likely one main headlight and one Mars light - similar to set-up on passenger diesels. What appears to be a third headlight on the top of the front of the engine might be a red emergency light, but since it appears to have some sort of grillwork where the light would be it might be a protective housing for the engine's horn.
On the CNW E-4, looks like it has two headlights, most likely one main headlight and one Mars light - similar to set-up on passenger diesels. What appears to be a third headlight on the top of the front of the engine might be a red emergency light, but since it appears to have some sort of grillwork where the light would be it might be a protective housing for the engine's horn.
Jones 3D Modeling Club https://www.youtube.com/Jones3DModelingClub
Thank you 'Hydro Man'!
NDG FYI. Two Headlights. CP 2527 with Two 2 Headlights on Test w wood consist. Montreal West c. 1951. http://www.trainweb.org/oldtimetrains/photos/cpr_steam/2527_headlight.jpg Note Nachod Signal to left governing entrance to single track on curve, Montreal Tramways.
Impressive. Thank you very much for sharing!
Thank You.
The headlight of PRR K4s #1361
Photo by Kenneth Cooler King from facebook
A publicity pics off PRR, but looks real and cool. Never have seen a similar pic of T1, Q2 though.
Miningman You have written extensively on the major problems with Baldwin Diesel locomotives. Now they had good data and success with E7's on the Detroit Arrow early on. There is no doubt they held a loyalty for long time friend and ally Baldwin. The orders for the Centipede's and Bp20 Passenger Sharks were not massive but they were substantial. It's easy to see the trust was there beforehand but in reality they rolled the dice and lost.
You have written extensively on the major problems with Baldwin Diesel locomotives. Now they had good data and success with E7's on the Detroit Arrow early on. There is no doubt they held a loyalty for long time friend and ally Baldwin. The orders for the Centipede's and Bp20 Passenger Sharks were not massive but they were substantial. It's easy to see the trust was there beforehand but in reality they rolled the dice and lost.
Imagine PRR adopted the N&W J class with larger Drivers instead of wasted tons of money to buy untested early diesel for passenger trains...... Imagine PRR spent more times and resources to improve the quality or even redesign their rail tracks between Chicago and Pittsburgh to increase the average speed from 67mph to 90mph or more, shorten the total travel time between New York to Chi town from 16 hours to 14 hours or less......Imagine PRR cherished their steam engine like Class S1, Q2, T1 and rebuilt heavyweight passenger cars and sleepers instead of buying tons a brand new passenger cars from Budd when the overall ridership was observably unsaveable in late 40s......these are some hindsight thing from me, but c’mon, imagine is a fun thing!
SD70Dude Many (most?) steam locomotives had a 32V DC electrical system. Not sure how that originated or how it was chosen.
Many (most?) steam locomotives had a 32V DC electrical system. Not sure how that originated or how it was chosen.
32V is what you get from 16 lead-acid cells in series, a very common voltage used in RR passenger cars, farm generating plants (Delco was a big producer of these beasts), and windchargers for farm use. A lower voltage filament was a lot more rugged than the equivalent wattage at 110VDC.
Back in the 1920's & '30s, there was a significant market for 32V appliances, toasters, mixers, refirgeators, etc. This was a time when many apartments in the downtown sections of big cities had DC power, utilities running anywhere from 25 to 133Hz, so making 32V appliances wasn't much of a problem.
Overmod:
Keep in mind that tungsten filaments have a positive tempco for resistance, so the brightness scales with voltage with a power somewhere between 1 and 2. Carbon filament bulbs had a negative tempco, which meant that brightness scaled with a greater than 2 power of the voltage. Part of the production process with carbon filament bulbs was to put a bunch of bulbs in a box and vary the voltage to determine the rated voltage for the individual bulbs - IIRC, the bins were 5V wide.
- Erik
Overmodthe real problem was Baldwin build quality mirroring their steam-locomotive production in too many ways with too many detail-design catastrophes. I don't think that could have been predicted by PRR (which as we know was shockingly lacking in sensible design acumen at many points in their motive-power history!)
Thank you Overmod and Miningman! I never expect that I can learn so many things from this forum, I really appeciate you guy's generous sharing! Speaking about the T1s, if I was the leader of PRR, I would have agreed with Baldwin's suggestion, or you could say a warning, to not risky using the Franklin poppet valves on the first 50 T1 order. It is proved that Baldwin was right and the first order was the one and the only one order for the production version of T1.
Despite the glowing test reports of 6110 and 6111 from the test plant, the operational performance of the production version was far from satisfactory. I do agree with some people's view that Franklin poppet valves played an important roles to "encourage” PRR to ditch reciprocating steam locomotive, but I never think it was Franklin's fault, it was probably just a result of mismatch and misuse (T1 was often used to make up time by excessive speeding) and T1 really came too late. I wonder if PRR set a speed Limit for T1 at 90-95mph would help or not, (the average operational speed between Chicago and Pittsburgh, PA was 66.9mph in 1938.) Beside speed, I don't understand why the front end of T1 were not made "foldable" /removable like a front-end cover of a automobile or German DB Class 10 / BR 10 001, 002(it was built a few years after T1's retairment though), how could the leaders of PRR approved something that was so observiously impractical! ...... Anyway, I am still studing this topic because I actually love PRR's duplexes, all of them!(The streamlined casting of BR10 001 provided accessibility for maintance. A screenshot from my train simulator)
MiningmanHey here's a thought. What if the PRR had hired Paul Keiffer right at the start instead of the New York Central?!!! Now that could be some interesting alternative history.
Paul Keiffer's ideas probably got ignored, banned or heavily modified by the PRR HQ or we might have had a PRR 4-8-4 like this: ( a lazy photoshoped pic of a fantacy PRR 4-8-4, original source is Hagley Digital Archives)
( English is not my first language, thank you for your tolerance! )
Hey here's a thought. What if the PRR had hired Paul Keiffer right at the start instead of the New York Central?!!! Now that could be some interesting alternative history.
Jones1945why they used Franklin Type A poppet valve gear instead of the newer and more reliable Type B on T1s (except 5500 which was considered the best T1 they had)? Why they purchased so many problematic Diesel Engine like "Centipede" and BP20 from Baldwin in post war without any testing in advance?
Keep in mind that 5500 was the only locomotive to my knowledge equipped with Franklin type B-2 gear, the importance being that this was a conversion adapting rotary-cam drive (much simpler than 'nightmare boxes' driven by midget Walschaerts) to the free-breathing eight-valve-per-cylinder layout that T1 type A provided. The stock Franklin type B valves, as refined by Vernon Smith et al., were not specifically designed to optimize high-speed admission or release at high horsepower, although type B worked quite nicely as a system for reducing steam consumption and some of the need for high steam quality at speeds up to 100mph or so, I suspect that with three valves it would not be much superior in practice to the piston-valve-converted T1a at achieving 'super speed'. (One of the great advantages of the T1a was in automatic reduction of pure high-speed high-horsepower slipping if that proves to be an operational difficulty with the T1 chassis, but that's another story.)
It may be important to recall that as late as April 1945, the 'future' of New York Central high-speed passenger power was the C1a, a locomotive that shared many details with the T1 (including very short stroke and ultra-lightweight rods) but which from the beginning used a correctly-sized firebox (albeit fired more economically to take advantage of the nominal lower water rate) and right-sized Baker gear. I believe it is clear that the 64T version of the pedestal tender would give full Harmon-to-Chicago range for the C1a, but not alternative designs which is one reason you never saw the design tried on Niagaras.
At that time in development work, the Niagara was still considered more of a derivative of the Rock Island and D&H 4-8-4s, with some improvements in the boiler, steam separation, and running gear. I don't think it was fully understood how useful a free-running, well-balanced 4-8-4 could be until the 79" drivers had been put on; there were still some teething troubles with lateral deflection of the running gear that may or may not have led directly to reducing steam pressure (you can find some truly terrifying pictures of the aftermath of lateral buckles if you know what you're looking at) but there wasn't much argument within just a few months that the Niagaras did everything NYC expected from the C1a except the unrefueled range ... and without all the panoply of drawbacks associated by then with the duplex configuration.
Baldwin didn't have much chance to get long-term testing of the Centipede passenger locomotives, more because EMD had E7 design in the can by 1945 and to be competitive Baldwin needed something very high speed, very fast. To be fair this was still in the era where Baldwin thought they would have high-speed diesel prime movers (412s, then 408s) in the Essl modular design, and then fairly quickly develop free-piston power for the best combination of flexibility, production cost, and maintenance. When all that didn't work out they were left with tugboat engines, very good tugboat engines but not much of an answer for high horsepower and reasonable CG; the real problem was Baldwin build quality mirroring their steam-locomotive production in too many ways with too many detail-design catastrophes. I don't think that could have been predicted by PRR (which as we know was shockingly lacking in sensible design acumen at many points in their motive-power history!) and the Dilworth team was probably not giving away the crown jewels of what made EMD competitive from the Locomotive 103 days forward.
MiningmanThe glory 'few months' of the T1's. Beautiful scenes of running a T1, #5540. Lot of incredible scenes and information. How about those container cars! This is undeniably a pinnacle, perhaps 1946 being the crown after the war years. The Pennsy, and everyone else sure had their act together. Niagara s, T1's, S2, C&NW rebuilt Zeppelin's, N&W J's all pointed to an exciting, solid and foolproof future that was an illusion for the railroads. Mysteriously, to me anyway, is how Pennsy reported their first 'loss' in that year.
This is undeniably a pinnacle, perhaps 1946 being the crown after the war years. The Pennsy, and everyone else sure had their act together. Niagara s, T1's, S2, C&NW rebuilt Zeppelin's, N&W J's all pointed to an exciting, solid and foolproof future that was an illusion for the railroads.
Mysteriously, to me anyway, is how Pennsy reported their first 'loss' in that year.
Totally agree with you! I consider 35-46 was the golden years of the fallen flags, sadly part of the reason is because of the World War II boosted the traffic, and because of World War, Aerospace science and technology had a great leap forward and the federal government probably thought that spending as much as effort and resources to develop Aerospace was the most beneficial thing for the country and the world in long term (not going to talk about the "1952 Washington, D.C. UFO incident", that would gone too far and off topic ) thus the railroad industry “probably” became a secondary thing in the federal government's point of view and they milked all railroads as hard as they could by heavy taxes. The fallen flags had no chance.
The glory 'few months' of the T1's. Beautiful scenes of running a T1, #5540. Lot of incredible scenes and information. How about those container cars!
By the time Sputnik sent shock waves the railroads were in full freefall, shopworn, deferred track maintenance, massive layoffs, considered outdated and old fashioned, the respect turned into ridicule.
How it all went from 1946 to that point can be debated endlessly.
For a very brief moment they sure had the confidence and ability to face the future little knowing the deck was stacked against them.
Thank you very much for sharing your professional insight here Overmod! I tend to believe that it was 200,000 to 250,000 candlepower, a figure used in an advertisement of Pyle National in 1940s, I didn't save the pic from the internet though. I believe your analyze on this topic that directly converting candlepower to lumens by using the 12.57 factor cannot get us a meaningful result. I am an amateur railway enthusiast, in this case I can only take a wild guess. I bet the lighting effect of old train headlight was like a 4000 to 6000 lumens flashlight we use nowadays on brightest mode, with a much larger diameter and light reflector inside, it might be even brighter Btw, I found a clip of headlight reflector test in the PRR movie "Clear Track Ahead!" (1946), please check it out if your are interested in this topic (time stamp is 24m39s)
Be difficult to work through all the necessarily-empirical measurements to determine what the "700,000 candlepower" represented. I would have to wonder if the mathematical conversions involved have given a result in line with those for modern sealed-beam lighting even though they are within an order of magnitude and use much better optics and focus adjustment.
The bulb of course does not translate its rated 250W entirely into visible light, and there is no discussion of the frequencies of visible radiation that 'count' as the output of the bulb -- whether they are included in the 1/683 factor of conversion. Likewise the radius from the filament/focus where the cross-section of the headlight beam is computed is significant, as some very large percentage of the emitted light energy is represented there (and would have to be extrapolated across a full steradian at that radius for candela, nominally within spitting distance of candlepower). Note that this radius is, or ought to be, where the beam reaches the appropriate range above track level -- as with the generations of earlier large-reflector headlights, the reflector is aimed somewhat down rather than parallel to the direction of travel. (You can see the effect almost overemphasized in many early etchings or artworks showing locomotives, where the beam is aimed much closer to the locomotive almost like a cone intersecting the track; it seems pretty clear in the cut accompanying the PM article.)
I do not think just applying the 12.57 factor from cp to lumens is going to give a meaningful result here.
I don't know what appropriate conversion might need to be made for a PAR56 to give effective beam intensity in candela; erikem can backstop all these thoughts and calculations reasonably effectively.
I found this articles in Popular Mechanics July, 1938. The whole magazine has been uploaded to Google books
700,000 candlepower is equal to 8.7 million lumens!! I can't believe it's true!
Overmod The 'standard' GE headlight bulb for steam applications was as I recall the 250P25 32V. (The size code represents 25 eights of an inch diameter, and P is a round envelope shape.) Initial output is 4650 lumens with nominal 500 hour life. Incidentally, that second picture is not of T1 5500, it is the 'replica' prow that has been constructed for the T1 Trust.
The 'standard' GE headlight bulb for steam applications was as I recall the 250P25 32V. (The size code represents 25 eights of an inch diameter, and P is a round envelope shape.) Initial output is 4650 lumens with nominal 500 hour life.
Incidentally, that second picture is not of T1 5500, it is the 'replica' prow that has been constructed for the T1 Trust.
Thank you for correcting me Overmod, I can't believe I forgot the number of the T1 building by T1 Trust is 5550 not 5500! Speaking of T1s, I remember in the book "Black Gold - Black Diamonds: The Pennsylvania Railroad & Dieselization" by Eric Hirsimake, one of the problem T1 6110,6111 had were the sockets vibreated loose caused headlight bulbs failed. By the way, a 4650 lumens headlight with light reflector inside it must be very dazzling! One of the reason I am interested in this topic because I always think that Steam locomotive running at night with its headlight turned on is a very cool thing. I remember when I was a kid, I always draw steam engine on a sketchbook (even though I hadn't seen a steam engine in person until I grew up), adding headlights, paint the light beam in yellow on my fantacy steam engine was one of the funniest thing for me. Thank you very much for providing the light bulb model, with more keywords and details, I can't dig deeper on this topic.
timz6200 lumens would be the bulb's total light output -- 200000 candela refers to the light intensity within the beam, lumens per steradian or some such thing.
Thanks! I just watched a video demonstrate how powerful is a 6200 lumens flashlight on youtube, thats "crazy bright"!
6200 lumens would be the bulb's total light output -- 200000 candela refers to the light intensity within the beam, lumens per steradian or some such thing.
Jones1945Assumes a headlight which had a light reflector installed, used a 100 watt (about 1000 lumens) incandescent bulb inside, I believe it was still bright enough during extreme weather at brightest mode, I have seen how a 1000 lumens flashing can do on youtube, its actually very bright.
Headlight bulbs were brighter than that. Considerably brighter. Modern 'standard' voltage is 74, but some older systems that 'charged' at 72V nominal only provided 64V nominal battery voltage to devices such as lighting. Steam turbogeneration was (as I recall) generally in about the 32V peak range. Bulbs however are rated in watts (for a given nominal voltage) in indicating the I2R power dissipation and hence the candlepower/'lumen' output of the incandescence.
Current PAR56 sealed-beam lights, per FRA (see 49 CFR 229.125) are 350W and produce 6200 nominal lumens initially (the light output degrades somewhat over the 500-hour nominal life of the lamp). Multiply this by two for the headlight, then add two for the ditch lights. It is common to see a SI equivalent, usually 200,000 candelas, used for the bulb's nominal light output.
Of course when the light is on 'dim' the light output is much lower...
Overmod These lights did have reflectors, and some care was taken to design them so that the brightest part of the filament in the bulb was at the geometric focus of the parabolic mirror
wjstix You can't judge how bright a headlight is during the day, cloudy or not.
Thank you very much for your very detailed response! I really apprecicate it and I mostly agree with you guys. I did try to find pics or evdiences of steam locomotives headlight at night from 30s to 50s, but I can only found some touched up photos which probably used for promotional proposes. Anyway the answer is more clearer for me now after reading you guys first hand experiences or professional knowledges about lightings. To sum up, headlights of steam engines in the past was like a flashlight we use nowadays, it shoot a beam a long distance but does not necessarily light up all of the area close to the flashlight thus when people looks directly to it, it is as bright as the Sun, but it looks dimmer when people looks at it from the side. Assumes a headlight which had a light reflector installed, used a 100 watt (about 1000 lumens) incandescent bulb inside, I believe it was still bright enough during extreme weather at brightest mode, I have seen how a 1000 lumens flashing can do on youtube, its actually very bright.(Pic 1: A PRR K4s headlight shooting lights beam at night. Source: online archive of Railroad Museum of Pennsylvania)
(Pic 1: Headlighs of T1 5550 underconstruction, Source: http://www.wikiwand.com/en/Pennsylvania_Railroad_5550 )
====
Remember - most railroad rule books require headlights to be in the dim position
2014 CSX RulesThe headlight on the leading end of a train must be dimmed when: a. Required to provide for the safety of employees, or b. At yards where switching is being done, or c. Approaching passenger stations where stops are to be made, or d. Standing behind a stopped train, or e. Standing on a main track in non-signaled territory, or f. Approaching and passing a locomotive consist on the head end and rear end of a train on an adjacent track, or g. Using hand signals.
a. Required to provide for the safety of employees, or
b. At yards where switching is being done, or
c. Approaching passenger stations where stops are to be made, or
d. Standing behind a stopped train, or
e. Standing on a main track in non-signaled territory, or
f. Approaching and passing a locomotive consist on the head end and rear end of a train on an adjacent track, or
g. Using hand signals.
Never too old to have a happy childhood!
You can't judge how bright a headlight is during the day, cloudy or not. I drive along a rail line (actually two mainlines running parallel) going to and from work every day. During daylight hours, you can hardly tell the headlights are on. At night, they're incredibly bright.
It's kinda like big league ballparks that shoot off fireworks when the home team hits a homerun. It's not very impressive during day games, much more visable at night.
Note too that headlights have more than one brightness setting, so can be on, off or dimmed by the engineer.
timzThink PRR E7s had brighter headlights than other E7s?
Not at all, really! Just noting that the ones I saw were single-bulb reflector lights, and EXTREMELY bright in the line of the beam.
All the seven-light arrangements I've seen were on older units (I think nothing more recent than an E6) and I don't know if these were 'factory' options or special order components. The history of 'optical warning' of high-speed trains is an interesting subject (some details are covered in Kratville's book on the UP Streamliners) as at least some of the idea was to provide very bright beams either projected in front of trains or vertically into the sky like rotating premiere searchlights to signal motorists that Something Significant Was Approaching. Since this was a prominent component of the later rationale for adoption of ditch lights, it may merit more attention than it has historically received.
One very probable reason for disuse of the seven-bulb headlight would be the FRA requirement that all bulbs be working 'as installed' on inspection. Those familiar with the Southern Pacific's foray into safety lighting in the '60s will remember how that ended, with openings plated off ... and safety not at all enhanced.
Think PRR E7s had brighter headlights than other E7s? Anyone got an E7 manual showing available choices?
The T1 picture I have (at a coaling tower in Indiana) is indeed double sealed-beam, with the bulbs vertical (as in the GG1s that were converted). It is possible (I have not yet found any drawings for the T1 conversion) that the mounting is the same basic or perhaps even detail design. It appears to be the same idea of putting the two bulb mounts in a plate and installing this in the opening for the reflector mount.
I had very little experience with PRR reflector headlights EXCEPT to note that when the ones in E7s on the Bay Head line were on 'bright' and you were directly in line with the beam they were dazzlingly bright, about as bright as the sun to a 4-year-old watching from a car going across a grade crossing. I in fact thought (by comparison with the sealed-beam lights on some of the RS units going through Tenafly on the Northern Railroad) that this had to be one of those fancy 7-bulb high-speed lights, until the locomotive motored past, in Tuscan glory ... with relatively dim headlight appearance to the side.
As with many laser applications, too much 'beam visibility' to the sides just shows that light's being wasted from the main purpose of illuminating the parts of the ROW the engine crew immediately needs to see. These lights did have reflectors, and some care was taken to design them so that the brightest part of the filament in the bulb was at the geometric focus of the parabolic mirror.
On the other hand, of course there was a dimming function (or meets would have been dazzling just as an opposing crew would need reasonable detail vision to check the following train for problems). I do not know whether this was done with resistors or simply by controlling the turbogenerator, but there are people here who will definitively know. As you can readily imagine there is little use for the headlight as a road-illuminating device during the daytime, and particularly if regulated via turbogenerator speed (and hence steam mass flow conserved, which might be substantial) running dim in the daytime would have economy benefits, so I would not be surprised to find it was intended more as a safety device then.
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