ok, now like years ago i was on some tour at some steam tourist trap, excuse me, i mean excursion, and the guide was talking something about the drive wheels jamming up if they were set in the same position. Anyone know anything about this?
Hey, first topic of the year!
…Would it possibly be if the engine main side rods happen to be in the exact parallel position to the rails…Perhaps then the piston could not effect any movement of the wheels with out something getting them off dead center…I imagine if this was possible, the engine would also have to be on absolutely flat grade so gravity woudn’t move the engine.
[:)]I think that you are right Modelcar, the pistons would get “centered” and the loco could not move, without a push on the train to get the pistons off center. But in the old days, with friction bearings on cars, even if the train was on a slight grade, it wouldn’t move very easy.
Modlecar: You are correct. What was being talked about at the steam trap (excuse, rr excursion) was the practice of quartering. If you look closely at a steam locomotive with rods (normal configuation) you will see that the main rods and wheels are 1/4 turn apart and not 1/2 turn (or revolution). The comment about not being able to start the locomotive with “halved” rods is correct. It won’t start by itself. The rods need to be off-set and the most efficient placement is 1/4revolution, or 90 degrees off. When you hear the locomotive in operation, there is a power stroke for each 1/4 revolution, so you hear four “chuffs” per revolution.
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 e
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,
[#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. [:(!]
…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.
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]
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
…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.
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.
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![:)]
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)
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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.
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