Steam engine drive wheels

[kenneo]

Once in a while the main rod would come off a 4-6-0 and come up through the cab. Ten-wheelers with the firebox dropped between the middle and rear drive axels were very prone to this. The rod that did this was the one between the 2nd and 3rd axel and sometimes it would be a bearing failure and at other times the rod would simply break. Eventually this got fixed, but it was bearing related.

[Modelcar]

....And just think of the oiling system on some of the units...Done manually with an oversized oil can. Something as important as journal bearings to keep all that heavy stuff rotating and not freeze up and fail...was at the mercy of being lubed by someone remembering to do it....Not automatically...!

[jchnhtfd]

QUOTE: Originally posted by Modelcar

....Yes and the faster it goes it looks like it would do it quicker...! I just can't imagine how the bearings and journals holding heavy side rods stand the loading when an engine is at speed. What a tremendous amount of energy trying to effect it to fly apart.

And yet hold together they did[8D], mile after mile after thousands of miles. One of the really great triumphs of Man the Builder[:)]. A great testament to the men who designed them, who built them, and who ran them. Other than sailing ships (I don't mean yachts), I can't think of anything else quite on that plane.

[Modelcar]

....Yes and the faster it goes it looks like it would do it quicker...! I just can't imagine how the bearings and journals holding heavy side rods stand the loading when an engine is at speed. What a tremendous amount of energy trying to effect it to fly apart.

[kenneo]

Doyle McCormak says that a steam locomotive is a machine attempting mechanical suicide using the centrifugal disintagration method.

[Modelcar]

....I totally agree...watching the mechanical gear whirl around and back and forth and the rotation of the wheels and cams and levers timing valves.....and to think all this was dreamed up more than a century ago....Wow...!! Also to keep those heavy parts from flying off....Pretty great accomplishment.

[jchnhtfd]

At least on a car you can (theoretically!) achieve dynamic balance as Modelcar described -- trouble is, on a steam engine, you have those whacking great rods whirling around out there. To get full dynamic balance, you'd either have to have the same weight revolving in the same plane, less weight farther out (and compensating weight on the inside) or a lot more weight closer to the plane of the wheel (and compensating weight on the inside). Needless to say, options one and two don't work... at least for more than one revolution! -- and option three has some very real limitations. Still, they did pretty darn well, all things considered.

Watching a big steam engine at speed has always amazed me... you really can't get much better in terms of mechanical magic.

I'd like to see a bubble balancer being used for, say, an 84" driver! That would be fun!

[Modelcar]

Yes....good comparison. When wheel weights are installed on both sides of the [auto], wheel rim the dynamic balance was accomplished a lot closer than in comparison to installing all the required weights on one side of the rim. One may not know just where in the rim width the weight was really required to effect a prefect balance but sharing equal amounts of it to both sides went a long way to dynamic balance. At least in using a bubble balancer to set up the required weights.

[kenneo]

Yes, Modelcar, it sure did. The roundhouse would correct that by adding weights similar to what is done with auto tires. Much easier with the car. And the engine crews could tell who had done the balancing, too. It had to be done each time the locomotive got a new set of shoes (wheel rims).

[Modelcar]

Sooblue....yes, I understand what you are saying...and i'll eventually get it accomplished but it can get so frustrating at times.....The last unit was run by Windows 98se. I did have one in the past that used Windows 95, which I think worked better that the 98se.
XP is supposed to have capabilities to install programs, etc...better than in the past.

In the conversation in posts back a few....about balance on steam engine wheels....It is my understanding that static balance was achieved very well..[with heavier spots cast into the wheels to offset the weight of the journal and rod assys...but dynamic balance was a different situation...Rod weight on the very outside of the wheels centerline and their counterbalance located roughly centerline of the wheel thickness and when that situation was rotated the one weight that was outside of the wheel circle caused dynamic inbalance....It wanted to cause wheel wobble. That's my way of reading it anyway.

[sooblue]

QUOTE: Originally posted by Modelcar

....Yes I remember all the sayings about how the T-1 was not a successful engine...but Raymond Louie sure designed their outer skin to make them oh so handsome...I did get to see a few in action but don't really remember that much about them. Seen them coming through the Pennsylvania Passenger station at Johnstown, Pa.

Sooblue...Part of the trouble is me with difficulty getting my peripherals back up and running. No problem with the printer because it is a H-P same as this new computer and it was able to take it right in but my scanner's CD-ROM to install the driver did not include XP so I had to download a new driver for the scanner [A visioneer, 5800], and I did that but some where I'm still not getting it all together because I can't make it perform yet...Frustrating...Haven't tried the video cam or mic. yet....I simply am not fluid enough with XP yet to make it work well for me...and I haven't read any instructions on XP yet so maybe I can glean some info there when I try that...

XP tip of the day (maybe)[banghead]

I'm not sure how windows 95 and on up worked but with XP when I drop a program cd into the reader/burner XP opens a wizard window that does all the rest to load said softwear. It even locates the hardwear if its plugged in and on.
I have occasionaly gotten a pop up that will tell me that the softwear I'm trying to load is dos based which is uncompatable with XP but in some cases XP can change the softwear to conform with XP (something like "run like" )
[bow] instructions good [bow]
Sooblue

[Modelcar]

....Yes I remember all the sayings about how the T-1 was not a successful engine...but Raymond Louie sure designed their outer skin to make them oh so handsome...I did get to see a few in action but don't really remember that much about them. Seen them coming through the Pennsylvania Passenger station at Johnstown, Pa.

Sooblue...Part of the trouble is me with difficulty getting my peripherals back up and running. No problem with the printer because it is a H-P same as this new computer and it was able to take it right in but my scanner's CD-ROM to install the driver did not include XP so I had to download a new driver for the scanner [A visioneer, 5800], and I did that but some where I'm still not getting it all together because I can't make it perform yet...Frustrating...Haven't tried the video cam or mic. yet....I simply am not fluid enough with XP yet to make it work well for me...and I haven't read any instructions on XP yet so maybe I can glean some info there when I try that...

[jchnhtfd]

There's nothing like 'em, for sure! I think some very interesting things could be done with coal and turbines and electrics now -- the technology has changed so much -- but until the cost of oil goes up a lot, diesels are cheaper -- and the way railroad budgets are today, that's a big factor!

[sooblue]

Hi Jamie,
Thanks for sharing your passion.
There are far too few of us who have a passion for steam locomotives. When I talk about steam being a living breathing entity I usually get a blank stare. There is nothing better then climbing aboard a tea pot and learning the art of running it.
My personal passion is keeping steam. I would be in nervana as a fireman on any locomotive. Not that I would ever turn down the throttle, but firing is just as much an art as train handling.
I've often felt that steam would make a comeback when we run out of oil. We have an abundance of coal in this country. Wishfull thinking I guess but who knows.
Steam and turbines were made for each other.
Thanks again!
Sooblue

[jchnhtfd]

Me and my big mouth[:(]. It's all so complicated...

Sooblue -- that does help[:)]! However... Balance. There are two kinds: static and dynamic. Steam engines (except some really small, slow ones!) are indeed beautifully balanced -- statically. That is, if you were to pick one up (yeah, right[:D]!) and all the bearings and what not were free, the drivers could be stopped in any position and wouldn't tend to turn -- there is no 'heavy side' in the drive mechanism. However... the problem is the dynamic balance: while there is no heavy side, as soon as the things start to turn, they want to twist back and forth as the wheels go around. This makes them roll, and also nose or hunt. This is what your dad was talking about, Sooblue; the original railroad rock 'n' roll! Get it wrong, and engines could rock themselves right off the track[:(]! For a variety of reasons, this twisting tendency is less at any given speed for a bigger wheel. Making the side and main rods lighter helps a lot (they are the main source of the problem) and this was part of the inspiration for the Duplex engines, like the T-1 4-4-4-4 (which is basically a very complicated 4-8-4, after all!).

The other part of the problem is keeping the weight on all the driving axles more or less the same. In a rigid frame engine this shouldn't be a real problem, as the equalizers can run the full length of the frame (although the experience of the T-1 may indicate otherwise!). On an articulated, though, it is much harder to get the weight on the drive axles of the front engine to stay the same as the weight on the drive axles of the rear engine. I have to admit that I don't fully understand the arrangement in the Challengers (and the more or less the same arrangement in the Big Boys), but the hinge was arranged so that while the front engine could deflect from side to side, if it tried to bend up and down it couldn't. This made the frame behave, from the weight standpoint, just like a 4-12-4 (or 4-16-4 -- wouldn't that have been something!), and the equalization could then be arranged so that all the drive axles had approximately the same weight on them all the time.

There are other ways to do this, and some of the other later articulateds were very well balanced fore and aft as well. As Sooblue mentioned, some of the early ones were inherently poorly balanced -- but even so, if you could have kept the frame rigid vertically, that could have been taken out with the equalizers (that's what they're for, after all) and all that would have happened would have been the lead or pony truck would have been very light and the trailing truck very heavy (or the other way around).

Not sure about the steaming qualities of the T-1. They may have had a grate area problem. What they did have, for sure, was they were a maintenance bear -- very complicated mechanism to begin with, and two sets! -- and they did have a tendency for one of the engines (could be either one) to slip. Not a problem at low speed, but if it slipped (as it did) at high speed, the results were (as one commentator put it) violent! As you say, they weren't well liked...

[sooblue]

QUOTE: Originally posted by Modelcar

....Yes, one hears all kinds of advice on op systems...I can say this: My W 98se, did way too much locking up...Had used it since 2000. Friends in my circle told me..."Oh you will like the XP it operates so much better"....so it's really hard to tell until one tries them both I suppose. If I ever get these add ons all working again I'll settle down and go forward.

Say Modelcar,
I am using windows xp which is not dos based and I transfered most of my dos based programs directly to xp using the built in wizards that are in xp.
The wizards change the programing to run in xp I believe.
So I have office 97 and 2000 on xp both of which are dos based.
xp is so much better then the old systems yet it is not without its bugs.
I hope you get things worked out but after you do you'll never go back to the old way.
I went from a 80486 to this super computer with xp. knocked my socks off man.

[sooblue]

Hi guys,
The T-1 was a 4-4-4-4. The engine wasn't loved, had trouble keeping steam probably because the grate area was too small for the steam use.

I'm not sure what was meant by unbalanced but I am assuming that the power strokes are being referred to. The running gear on steam engines were quite nicely balanced, as well as any crank and rod. There were side forces as well as up and down forces on the rail but in most engines they were reasonable.
My dad used to talk about some engines, mostly yard switchers having a side to side force that made you brace yourself in order to stand up.

Passenger engines had greater diameter drivers because they were pulling a lighter train and the bigger the drivers the farther one stroke got you down the rails. You will find that passenger dedicated engines had the greatest diameter drivers, put them on a freight it better be a short train.

The 4-8-4 northern engines were duel purpose, passenger/freight, primarily because they had a good balance between power, weight and driver diameter.

The 2-8-8-4 yellowstones pulled like heck but were slower because they had smaller drivers. The 4-6-6-4 challengers were duel purpose. They had that balance between power, weight and driver diameter. That's what made them so successful. There pivot for the front engine wasn't any different then any other articulated engine but they did have that four wheel front truck that guided them into curves better.

Looking again at your post jchnhtfd, I should have said that by weight I meant not only over all weight of the engine but more, weight on drivers. The weight of the engine is balanced better on the drivers. The challengers and the big boys were balanced well. Some of the articulateds were light on there front engines which under load could slip. A few of the articulateds were built with the boiler over the rear engine and the front engine was under the smoke box and preheater (very unbalanced weight wise)

Now that I mentioned the above type of articulated I seem to remember that their pivot may have been different then the newer articulated types.
That is why their boilers were over the rear engine only, however that type of articulated died quickly as they were early types.
Maybe that is what you meant jchnhtfd when you mentioned that hinge ?
anyway I hope this helps.
Sooblue

[jchnhtfd]

QUOTE: Originally posted by jchnhtfd

QUOTE: Originally posted by kenneo

Jamie -- Why don't you explain that hinge?

[bow]

I'll research it and get back to you tomorrow![:D]

come to think of it -- I'll bet there's someone on here from Steve Lee's gang in Cheyenne? Anybody? They could do a better job of it than I could even dream of![:)]

[jchnhtfd]

QUOTE: Originally posted by kenneo

Jamie -- Why don't you explain that hinge?

[bow]

I'll research it and get back to you tomorrow![:D]

[kenneo]

Jamie -- Why don't you explain that hinge?

[bow]

[jchnhtfd]

The quartering (90 degrees apart from side to side) is one of the reasons why steam engines -- such wonderful contraptions in other ways, don't get me wrong[:D] -- were and are inherently unbalanced. The bigger the drive wheels, though, the closer they could come to being balanced -- which is one of the reasons why really fast steam engines tended to have large drivers.

It is quite possible for one of the two engines in an articulated to lose its feet and the other keep going. There was one unique locomotive, though, wich was NOT articulated, but had two separate engines: the Pennsy T-1. It was a 4-4-4-4-4 configuration. They had a nasty habit of having one engine slip at speed, with truly spectacular results (if the engineer kept his false teeth in the cab, he was doing real well). Many earlier articulateds had trouble with that, due to weight distribution problems. One of the reasons the Challengers (4-6-6-4) were so spectacularly successful is that they had an unusual hinge for the front engine, which largely solved the problem.

[Modelcar]

....Yes, one hears all kinds of advice on op systems...I can say this: My W 98se, did way too much locking up...Had used it since 2000. Friends in my circle told me..."Oh you will like the XP it operates so much better"....so it's really hard to tell until one tries them both I suppose. If I ever get these add ons all working again I'll settle down and go forward.

[daveklepper]

Computer tip: My friend the expert says that many computers do better with Windows 98 Second Edition than with XP or Millenium, and that the latter two have more "bugs." So he advised me to stay with 2nd Edition. Of course this depends on the specific computer. Mine is a "Terminator" and I hope it doesn't .....me! Also a Pentium I or II laptop is better off with 95 that the latter versions according to this expert, who is in it for a living. Dave Klepper

[kenneo]

QUOTE: Originally posted by BR60103

Aside from the piston problem (being on dead center) if you ever have one of those toy locos where the side rods are attached with 180 degree "quartering" and on only 2 axles, if the wheels are turned in opposite directions, the rods do very interesting things.

[:D] And just what was your first clue? My wife, who is mechanically, severly challanged, understood that one!
[^][(-D][oops]

[BR60103]

Aside from the piston problem (being on dead center) if you ever have one of those toy locos where the side rods are attached with 180 degree "quartering" and on only 2 axles, if the wheels are turned in opposite directions, the rods do very interesting things.

[Modelcar]

....Yea, that's what I'm working with...this new one has W - XP op...Guess it will be fine when I come up to speed but right now I'm operating at a little less speed. It sure seems nice and smooth though....Other one was W - 98se.

[kenneo]

[#offtopic]
ModelCar

Been there and done that. After I installed XP on my machine, discovered that it was not compatible with any of my Win2000 and older programs. So now I have a network, one machine with 2000 and the other with XP, so I can run my scanner, printers, camera and such. [:(!]

[Modelcar]

Eric....This is sort of a complicated subject. I in no way tried to imply the [2] power units of an articulated locomotive were duplicating each other's operation...I understand that each [power unit] has the freedom to grip and or adhere or slip on the rail as the locomotive is trying to do the work of moving the train....and I fully understand they each have the 1/4 spacing to work with to try to apply that torque to the rail. And of course slipping at times in so doing.

Boy, I've had enough complications this week end...I uninstalled my other computer including all cables and connections with peripherals, etc....and installed this new one in it's place and I'm still not up and running with all the add ons. CD ROM on my scanner is not compatible with this OP system....and so on...I guess I've given up on any more of that for this evening...Downloaded a driver for it but I got lost somewhere....Tomorrow is another day. And this OP system is new to me so I'm not fully up to speed on that either...still on the learning curve.

Regards,

[kenneo]

QUOTE: Originally posted by Modelcar

Kenneo: All your points are well taken....I wasn't sure if the design had them out of phase as you said from side to side. And for sure at 1/4 position, it would have the most advantage to turn the wheel. One other thing....on a Mallet I doubt if the front engine and rear engine are in any phase...Separate from each piston / wheel position, etc...so that would always provide a way to move as it would have one in position to start the movement. But it is an interesting subject....[:)]

Good use of the proper names - front engine, rear engine, --- a locomotive is one or more engines, coupled, controlled by one engineer. So, each separate power unit (diesel unit, set of drivers w/cylinders, etc) is an engine. However, a 4-8-4 and a B-B (steam and diesel) are a locomotive if being used as a single unit.

However, a 4-8-8-4 or a 4-6-6-4 (articulated steam locomotives) are always each a locomotive and never an engine because they are 2 engines controlled by one engineer. Multiple unit diesel or electric power consists are locomotives and each individual can be either an engine or a locomotive depending on how it is used. (If confused, read defination again.)

One of the advantages of articulated steam locomotives is that they can keep their feet better than single engine locomotives. One of the engines can lose its feet and the other not (usual case) which makes for better train handling and the ability to haul greater tonnage. Each engine still has its drivers quartered.

You mentioned about each engine being "slaved" to each other as each driver is to all of the other drivers in each engine. No. Things with an articulated are already complicated enough. Remember, you have 2 engines under 1 boiler, which means that you have 2 sets of drivers, 2 sets of rods, 2 sets of cylinders --- almost everything comes in 2's. Slave all of that together? No matter what the method used, the engineering and materials to do that do not exist - and never have.