Because film isn't dead. It just smells funny:
Drivers - Santa Fe 2912 by Chris May, on Flickr
As always, thoughts, comments, critiques and questions more than welcome!
-ChrisWest Chicago, ILChristopher May Fine Art Photography"In wisdom gathered over time I have found that every experience is a form of exploration." ~Ansel Adams
very cool -- I thought of Sheeler almost immediately
and I had never seen the "Boxpok by Baldwin" before. Makes it look almost as if Baldwin were taking credit for inventing Boxpok ... :^)
How do you this?
Take a huge, heavy duty industrial machine, and turn it into a piece of art work full of fantastic details?
23 17 46 11
I recall seeing a similar image in Trains some years ago - it apparently hung in a railroad executive's office. When I took a photography course, I sought to duplicate said image, using my N Scale Berkshire. I took it to orthographic and it came out pretty cool.
Not sure I can dig it out right now.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
Someone want to tackle explaining to me what all the equipment is?
The sander, I know. Other than that, is that a brake shoe?
Chris - great photo - love your quip....
She who has no signature! cinscocom-tmw
Yes, that is a nice picture, Chris. It's sad that not all of the valve gear is there, and there is no connecting rod to the wheel--but, as Mookie noted, there is a brake shoe hanging down, and the sander might be ready to drop some sand.
Johnny
Mookie Someone want to tackle explaining to me what all the equipment is? The sander, I know. Other than that, is that a brake shoe? Chris - great photo - love your quip....
Thanks to Chris / CopCarSS for my avatar.
A driver without the rods being attached. The virtical element in the middle of the top left is the hanger for the piston valve timing mechanism, which is not installed at this time. The big circular object that is off center of the pictured driver is the bearing for the side rods that couple all the drivers on the locomotive together. The raised elements at the top, bottom and right side of the driver are counterweights to balance the weight of the rods when they are attached and the locomotive is operating. You are right about the brake head and the sander, however, the break head does not appear to have a brake shoe attached to it.
Never too old to have a happy childhood!
Steam?
Mookie Steam?
Is the name Edward Weston familiar to you, Chris?One of the first railroad books I ever owned was The Railroads of America, by Merle Armitage. I was about seven years old at the time, and could barely read it, but I loved the pictures and the maps of the various railroads. I think the only one of the hundreds of pictures in the book where the photographer was given credit was captioned "Closeup of Santa Fe driving wheels, by Edward Weston."
I opened up this thread, and thought of that shot right away. Of course, you can't hold a torch to him...he somehow caught some drive rods in his picture!Seriously, I was bowled over. Very nice!(The book was quickly worn out by a zealous kid...I did replace it, and could look for it in the dungeon, but I think I have my facts straight.)
Carl
Railroader Emeritus (practiced railroading for 46 years--and in 2010 I finally got it right!)
CAACSCOCOM--I don't want to behave improperly, so I just won't behave at all. (SM)
BaltACD Mookie Someone want to tackle explaining to me what all the equipment is? The sander, I know. Other than that, is that a brake shoe? Chris - great photo - love your quip.... A driver without the rods being attached. The virtical element in the middle of the top left is the hanger for the piston valve timing mechanism, which is not installed at this time. The big circular object that is off center of the pictured driver is the bearing for the side rods that couple all the drivers on the locomotive together. The raised elements at the top, bottom and right side of the driver are counterweights to balance the weight of the rods when they are attached and the locomotive is operating. You are right about the brake head and the sander, however, the break head does not appear to have a brake shoe attached to it.
As well as the items described so far, there is a mechanical lubricator mounted on the end of the motion bracket with its drive linkage from the expansion link of the Walschearts valve gear still in place. It is interesting to compare this with the lubricator in the photo of the New York Central Hudson in Wizlish's post above. Since the Hudson has Baker valve gear which lacks the expansion link, the lubricator is placed further forward and driven from the piston valve itself. Also, behind the right hand driving wheel, the laminated spring that linked the axlebox to the loco frame is just visible.
Regarding the "Boxpok by Baldwin" annotation, the earlier 3765 type had Baldwin Disc wheels and the 2900 type introduced Boxpok wheels to the Santa Fe. ATSF used LFM disc wheels on their own rebuilds. Perhaps Baldwin actually cast those wheels. Baldwin was a part owner of GSI who owned the Boxpok design. It might be worth pointing out that the Boxpok was more successful than the elegant Scullin disc wheels as shown on the NYC Hudson and the Baldwin Disc and was used to replace both those types.
M636C
BaltACDThe raised elements at the top, bottom and right side of the driver are counterweights to balance the weight of the rods when they are attached and the locomotive is operating
Does this deserve more discussion, or would that be TL:DR for Mookie?
Each of the three weights does a different and important thing, and in addition the counterweights are angled slightly on this locomotive (ISTR something like 4 degrees 31 minutes) to refine the balancing still further. These are part of the reason the 4-8-4s could reach higher speeds, and run reliably at them, than the nominally 'faster' 3460 class.
I confess I don't know what the 'third' small weight does, and am not able this morning to work through what it might counterbalance (like part of the valve gear mass or inertial load). I for one would be highly interested in any discussions on this general subject.
I usually like the time and not how the clock works but on this one - I have watched video of the Big Boys at top speed and it always thrills me to see how fast those side rods move and how efficient the whole engine looks. That's a lot of clock going down a track.
Mookie,
Very true. With all the moving parts, steam, smoke, water, fire, all the animation they seem to be alive. A diesel, not so much. I just like diesels more than stink engines, sort-a, kind-a, I think, then again?
Bob
I must clarify that I did not know about the counter weights. So once again, I learned something.
Bob - I agree.
Can someone explain what a counterweight does?
Murphy Siding Can someone explain what a counterweight does?
To sound simplistic - a counterweight offsets weight elsewere on a lever (and a wheel is sort of a round lever).
If your kids are on a see-saw, but one weighs more than the other, you might add weight (a rock?) on the side of the lighter child so that the two are evenly balanced. You've added a counterweight.
If you look at the tires on your vehicle, you'll likely spot several counterweights, albeit small. These wheel weights offset imperfections in the wheel and tire.
On a locomotive, it gets a lot more complicated, witness the three weights on the wheel in question. The wheel with the drive rod connected to it will have the largest counterweight, because it's got the most mass connected to it (both the drive rod and the connecting rods). The other drivers don't need as much mass to balance out the weight of the connecting rod, so their counterweights are smaller.
I'm going to go out on a limb here (yes, that means I'm guessing) - the third, smallest, counterweight was placed in part to answer to the other added counterweight, which was probably added because not enough weight could be added to the primary counterweight.
Just like the tires on your car, I would opine that despite efforts to accurately compute the appropriate counterweight design, in the end it came down to a certain amount of trial and error.
CShaveRR Is the name Edward Weston familiar to you, Chris?One of the first railroad books I ever owned was The Railroads of America, by Merle Armitage. I was about seven years old at the time, and could barely read it, but I loved the pictures and the maps of the various railroads. I think the only one of the hundreds of pictures in the book where the photographer was given credit was captioned "Closeup of Santa Fe driving wheels, by Edward Weston." I opened up this thread, and thought of that shot right away. Of course, you can't hold a torch to him...he somehow caught some drive rods in his picture!Seriously, I was bowled over. Very nice!(The book was quickly worn out by a zealous kid...I did replace it, and could look for it in the dungeon, but I think I have my facts straight.)
Concerning counterweights, is there still some pounding even with the best practice of counterweighting?
Thank you for all the responses and information regarding the elements in the photo!
Ed - In this case, I was attracted to the warm tones and just played with the composition until the geometry worked for me. This was definitely one of those cases where the waist level finder of the old Yashicamat definitely made me see and think differently.
Carl - Edward Weston is certainly a known name! Of course, I always think of Pepper No. 30 first when thinking about him. I didn't realize he had done a detail of Santa Fe driving wheels. I will definitely have to see if I can find that!
Carl, is this the shot you were referencing?
There may be exceptions, but the counterweights were made by casting the driver with an open void in the area of the couterweight, and the void was subsequently poured full of molten lead to gain more weight than would be provided if the weight was just composed of the native iron casting of the wheel.
Deggesty Yes, Mr. Weston was faster and stronger than Chris! What did he do with the rods after he caught them? Concerning counterweights, is there still some pounding even with the best practice of counterweighting?
Yes, there would still be pounding. The counterweights are not in the same plane as the drive rods and so the wheel has a "wobble" in the plane of rotation.
Some wheels had counterweights on the back side of the wheel near the drive pin (which also had to be counterbalanced) to try to even out the wobble. Some even had weights on the wheels on the opposite side of the engine trying to counterbalance the weights on the first side to even out the wobbles. That is one reason for the larger weight near one edge between the drive pin and the main counterbalance weight.
There is also pressure applied from the drive rods/side rods in making the wheels rotate, and that pressure is uneven during the rotation; alternately pushing on the bottom of the wheel and pulling on the top of the wheel (in forward motion, the opposite in reverse) and it is not 'continuous' either, but relatively sinusoidal, that cannot be counterbalanced and produces additional pounding.
Semper Vaporo
Pkgs.
Our automobile wheels are normally balanced to within 1/4 ounce of perfect. What was the tolerance on steam engine drive wheels?
Semper Vaporo Deggesty Yes, Mr. Weston was faster and stronger than Chris! What did he do with the rods after he caught them? Concerning counterweights, is there still some pounding even with the best practice of counterweighting? Yes, there would still be pounding. The counterweights are not in the same plane as the drive rods and so the wheel has a "wobble" in the plane of rotation. Some wheels had counterweights on the back side of the wheel near the drive pin (which also had to be counterbalanced) to try to even out the wobble. Some even had weights on the wheels on the opposite side of the engine trying to counterbalance the weights on the first side to even out the wobbles. That is one reason for the larger weight near one edge between the drive pin and the main counterbalance weight. There is also pressure applied from the drive rods/side rods in making the wheels rotate, and that pressure is uneven during the rotation; alternately pushing on the bottom of the wheel and pulling on the top of the wheel (in forward motion, the opposite in reverse) and it is not 'continuous' either, but relatively sinusoidal, that cannot be counterbalanced and produces additional pounding.
Deggesty Perhaps I should ask my daughter to find my copy of The Locomotive Up To Date, and bring it down to me?
BaltACD Our automobile wheels are normally balanced to within 1/4 ounce of perfect. What was the tolerance on steam engine drive wheels?
I have no idea. After the discussion of weights on the backside of the wheels, I recalled that this is sometimes done on vehicle wheels, too...
I would imagine that a large part of the tolerance for counterweights has to do with design speed as well. I don't recall if that dynamic changes by speed - ie, perfectly balanced at one speed is less than ideal at another.
Even very tight axle boxes (bearings) would not eliminate the pounding... the wheel wobble would still pull the wheel (or the whole locomotive) side to side and that would be transferred to the rail as a sideways movement. At any sort of speed it would be more like a vibrator, but still cause wear on the track.
tree68the third, smallest, counterweight was placed in part to answer to the other added counterweight, which was probably added because not enough weight could be added to the primary counterweight.
It's not that.
The principal counterweight is to balance the mass of the 'rotating' components. That includes a proportion of the main rod (only one end of which is rotating with the wheels - the other end and part of its mass is 'reciprocating' longitudinally with the crosshead, and I will return to this in a bit, but some proportion of its mass can be taken as 'rotating' for balance purposes.
This can be done precisely, and in fact could be (relatively easily) taken down to pounds or even ounces of 'residual imbalance'. In Europe this was enhanced by using dynamic balancing (like the method used for those car wheels) where the driver pair is spun at high speed in a sprung frame, and the relative force observed and corrected. Bobweights on the crankpins (similar to those NYC used when transporting locomotives dead-in-train with rods off) can be used to simulate the rotating mass.
The point to remember here, though, is that the track is capable of absorbing a relatively large amount of 'overpressure' from augment, so very precise watch-balance-wheel like adjustment is not necessary. Ralph Johnson has a good discussion of this in his book on steam-locomotive design (which is still in print to my knowledge!)
Now, the reciprocating component can't be balanced with rotating weights in the wheels. In any case, it produces a longitudinal imbalance which tries to yaw the locomotive around the main driver pair axis, and which produces surge or longitudinal pulsations especially when high power is being developed. To counteract this, too much mass is intentionally placed in the counterweighting (this is called 'overbalance') so you get a compromise between surge and vertical augment that is chosen for a given range of service speed. Johnson tells how to calculate this following p.266
Some late steam practice called for the complete or near-complete elimination of overbalance completely - this began to become more and more practical as lightweight rod construction made the reciprocating mass lower and lower. Several classes of Australian locomotive, including a very unlikely-looking design of 4-6-0, were in fact built or converted to zero overbalance and ran quite nicely on light rail (where vertical absence of augment was more important than perceived surge). Langer in 1947 designed a geared arrangement (for Westinghouse) that counteracted the momentum or speed-related aspect of reciprocating balance; this device deserves reflective study. Two interesting ways to use the valve-gear drive to produce opposite inertial force were the 'salmon rods' used in France (e.g. on the Algerian Garratts) and Kupka's patent from 1934. It does not appear from the records that the French actually understood how much reciprocating balance they could get, or needed to get, out of some of the salmon-rod experimentation, as we see the lightening holes getting larger and larger and then a discontinuation without further comment...
Meanwhile, the 'car wheel' analogy breaks down at this point, because a driver pair involves two wheels fixed rigidly at opposite ends of an axle, with crankpins at 90 degrees to each other in a regular 2-cylinder DA locomotive. In addition, the counterweight's resultant acts in a plane closer to locomotive center line than that of the rods out on their pins. This is what the fixed 'larger' weight on the main at about 90 degrees to the counterweight is for. In some cases the same result is accomplished by 'angling' the counterbalance as mentioned by Eksergian in the late '20s (and described by Johnson in pp.261-266).
Voyce Glaze's balance method for the J class 4-8-4s has a further refinement: the mains are the wheels with the most critical amount of 'balancing' requirement, and hence he only placed enough overbalance in them to counteract the vertical component of peak piston thrust (which is about 80lb) - all the rest of the overbalance is divided in the other wheels. (Remember this is just for longitudinal balance, and is minimized by the Timken rods ... but the 'rightness' of the approach is easily seen by the speeds that could be reached by what is otherwise like a bigger, heavier idea of a Reading T1.
There is a CSR paper that generally covers balancing
http://static1.squarespace.com/static/55e5ef3fe4b0d3b9ddaa5954/t/55e636b2e4b03a241b77f162/1441150642832/wp_slrwd_2.pdf
and this short page has some additional information not covered directly in the CSR material
http://trumpetb.net/loco/cbal.html
I have seen at least one example on the Web of how the Santa Fe did balance calculations for the 2900 class, but I can't find it now. For some reason I remember they did both angling and provision of fixed 90-degree weight, and there was a dynamic reason for this, which might be related to the 2900 class having to be built without the lightweight rod alloys used for the 3776 class.
WizlishIt's not that.
Corrections always welcome. It's all a learning process...
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