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I was watching some old videos of the B&O railroad in the transition era the other day and they had steamers in a lash-up.

How did they accomplish speed matching? Was it just going close enough to the speed limit on the rails and let the small difference in speed equal out at the coupler? Or did they use a lantern to blink morse code to each other?

I was thinking maybe the lead locomotive set the pace and the trailing steamer just felt around for the speed by feeling how much push or pull was in the coupler. Obviously you know you're going to be around the speed limit. Then you fine tune from there. But I'm not even sure if you can feel whether the locomotive is pushing or pulling in a machine that size.



EDIT: The original title had "lash-up" in it. I removed it and corrected it to "double heading" to prevent others from picking up the wrong lingo.

Last edited by BillYo414
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I will be first…

There is no such thing as a steam locomotive “lashup.” It is a doubleheader. Yikes.

You don’t “speed match” when running a locomotive (any locomotive) in a doubleheader. Each locomotive pulls on the train with whatever power setting is applied by the engineer. The two engines may not be pulling with equal power, but both are adding their power to the effort of pulling the train.

The throttle in a locomotive (steam or diesel) is not a “speed” control. It is a power control. When running NKP 765, I’ve had the throttle wide open at 3 mph, and also at 79 mph. Same for running a diesel. Starting out, you might have the throttle in Run 8 (wide open) to accelerate, or climbing a grade at 10 mph, and you could also have that throttle in Run 8 at 79 mph.

Last edited by Rich Melvin
@Ron045 posted:

Uht Oh!!!  You said "Real Life" and "Lash-up".  The "real" and "scale" folks are going to hammer you now.  I wonder who will be first?

Ohh boy haha

@Rich Melvin posted:

I will be first…



Noted! I didn't actually know there was a difference in a lash-up vs double heading. I don't actually know where I picked up these phrases. I'll remember double heading. I definitely feel like I should have realized the speed vs power control given the way locomotives work. Off topic but serious question, but do you turn up the power or the amperage in an electric locomotive?

Anyway, back on topic! That's interesting! I would not have expected that to be the case. I would have expected there to be some sort of communication between engineers to get the efforts close.

The throttle in a diesel locomotive has nine positions, idle, plus Run 1 through Run 8. Changing the throttle position changes the power output of the locomotive. Internally, the governor sets the rotational speed of the Diesel engine based on the throttle position, and the electrical control circuits control the voltage sent to the traction motors. The current drawn by the traction motors can be 1,000 amps or more at low speeds.

An electric locomotive functions in a similar fashion. The throttle controls the power, while internal circuits determine how much voltage to send to the traction motors to develop the commanded power setting,  thus controlling the power output of the locomotive.

Last edited by Rich Melvin
@BillYo414 posted:

Ohh boy haha

Noted! I didn't actually know there was a difference in a lash-up vs double heading. I don't actually know where I picked up these phrases.

The term "lash-up" is a toy train/hobbyist term apparently started by Lionel. In the real railroad word, the term "lash-up" is not used. Steam locomotives are double headed, while diesels or electrics are MU'ed together into an "MU consist".  

I'll remember double heading. I definitely feel like I should have realized the speed vs power control given the way locomotives work. Off topic but serious question, but do you turn up the power or the amperage in an electric locomotive?

Advance the throttle.

Anyway, back on topic! That's interesting! I would not have expected that to be the case. I would have expected there to be some sort of communication between engineers to get the efforts close.

Remember, back in the days of regular steam, the engine crews, i.e. Engineers and Firemen plus Conductors and Brakemen, were all very, VERY familiar with their operating territory (they ran over the same tracks, day in and day out), thus they KNEW what to do and when to do it.

Since the original post was curious about "matching" double headers, share with him the way two steam locomotives start off together.  I'll bet most  folks would like to know how your do it.

The engineers open their throttles and the train starts to move. It is really that simple.

There is no “magic” to this. Recall what I said about the throttle being a POWER control, not a SPEED control. If one engineer opens his throttle and the other doesn’t, it’s no big deal. Both engines are going to move regardless. In some situations, the train might be started with only one engine working, in order to save a little fuel. The second engineer would open his throttle to add the power of his locomotive to the train to help only when needed.

Care must be taken stretching the slack in the train, just as an engineer would do in every start, but it is not all that different than starting a train with a single locomotive.

@SteveH posted:

Increasing the Voltage increases the power.  Ohms law comes into play here: Voltage = Current (in Amps) times Resistance or Reactance.  Watts Law: Power in Watts = Volts times Amps (current)

I'm electrically challenged, to be honest. The electrical engineers I have worked with said it's a common symptom of being a mechanical engineer But I just wasn't sure if amps or volts are advanced to increase the speed. I know watts are power. I see below that voltage is increased. I'm sure this seems as simple as the sky being blue to some but it's interesting to me because it's not my strong point. I appreciate the explanation!

@hokie71 that was an awesome video!

@Hot Water Does MU mean multiple units?

My original question was just about how steam engines matched speed when double heading at any point; start, going, stopping. I assumed diesels/electric locomotives were controlled in groups by electricity (stop me there if I'm wrong!) but steamers are ran by people. So I was wondering how they managed not to fight each other. Pooling the power is a simple enough explanation for me. Especially if you have engineers that are familiar with their machine and their route. 

I would have just thought it would be hard on parts to be pushing and pulling one another if speeds are not kept consistent. I thought maybe there was a trick they used to signal to one another what they're doing.

I am very happy with the outcome of my original question though! I was looking to learn one thing but I learned a heck of a lot more. Now I can harass people that come over and run trains

You cannot advance amps. A piece of electrical equipment only draws the number of amps it needs to work. You could connect a 12-volt battery capable of delivering 1,000 amps to a 12-volt light bulb, and all that will happen is that the bulb will light up.

You increase amps by increasing the voltage. The increased voltage will cause the equipment being powered to draw more amps and develop more power…more watts.

MU = Multiple Unit

It might help the OP to know that, unlike our model electric trains with worm gearing,  real locomotives can roll freely.  So that is why in real life one locomotive can pull the other as explained earlier.

Steam locomotives have "neutral"? For the sake of a lengthy write up, no need to get into the depths of the plumbing (the pipefitting?). A yes or no is fine. I'll look it up on my own.

That does help though! I was unaware. I thought the pistons in the cylinders would have caused some issues with compressing the air in them unless opening the valve to drain them (the blowdown valve?) allows enough air in and out to stop the compression. Having the ability to roll freely explains a lot haha

There had better not be any air in a steam locomotive’s cylinders! When working superheated steam, the temperature in the cylinders is high enough to ignite the valve oil if oxygen is present. Nothing ever goes into the cylinders except steam. The valve oil that lubes the valves and cylinders is atomized in the steam.

When a steam locomotive moves, either the throttle is open a little to admit steam and lube to the cylinders, or the locomotive may be equipped with Drifting Valves that allow the locomotive to move with the throttle closed and still keep the cylinders lubed.

Steam locomotives do have a “neutral” of sorts. The valve gear can be set to move the locomotive forward or backward. When the gear is “on center” between forward and reverse, it could be said to be in “neutral.” But you would not allow a steam engine to be moved with the valve gear in this position. The valve gear must be set in the direction of travel.

The “Blow Down Valve” is back on the firebox. It is used to “blow” mud, scale, and other impurities out of the boiler. The valves on the cylinders that allow water to escape are the Cylinder Cocks.

John Sethian’s point about steam locomotives being free-wheeling is a good one. There is no worm gear on a real steamer.  😉

I very much appreciate all the answers to these questions. I can't help but feel like there is a great deal more going on with a steam engine than I realized. I thought it was much simpler than I'm now finding out. I saw a cut away diagram at the county fair and the museum in Scranton, PA so I thought I had a good grasp on the inner workings of a steam locomotive. I wasn't aware that the cylinder were lubricated with oil atomized in the steam. I also thought the blowdown was what you see coming out the bottom of the cylinders when they're just getting going. Now I know they're cylinder cocks. I saw a video in my recommendations on Youtube a while back titled something like "How to operate a steam locomotive" but I didn't think I would get much out of it so I skipped it. I feel like maybe it would have been worth watching.

I do understand what you mean by the valve gear being on center now that I think about it. I rode on a steam traction engine as a kid and your description of being on center reminds me of watching the engineer (is that what they are on a traction engine?) put a lever in the middle of its travel when we were stopping. I thought it was odd as a 10 year old but hadn't given it much thought until you mention where the valve gear might be set for direction. I can only think that is what he was doing.

There is a museum in Youngstown restoring some narrow gauge steamers from steel mills. I could have probably learned a lot of this information there. Maybe I'll find some time to give them a hand in exchange for some hands on experience and learning.

Believe in a steam locomotive doubleheader, each locomotive shoulders more or less of the pulling load in a variable manner.  The slack in the connecting couplers of the two locomotives  will run in, then out. This is in reaction to changes in topography and train behavior (such as the train hanging back on a hill), plus each engineer's actions. Musings of an arm-chair railroader.

Mark, you are close, but not quite right. If the lead locomotive is pulling on the train the slack in the coupler between the two locomotives will stay stretched.

If the lead locomotive is pulling on the train, the joint between the two locomotives is stretched. If the second locomotive was just rolling along, then the engineer opens the throttle and increases its power output, the tension on that joint may diminish a little, but it cannot run in to a slacked condition because the second locomotive cannot overcome the power of the lead locomotive AND the weight of the train behind it.

It is easier to visualize this if you remember that the throttle of a railroad locomotive (steam or diesel) is a POWER control, not a SPEED control.

@BillYo414 posted:
…There is a museum in Youngstown restoring some narrow gauge steamers from steel mills. I could have probably learned a lot of this information there. Maybe I'll find some time to give them a hand in exchange for some hands on experience and learning.

I know that museum well. I used to live in Struthers. We moved to Columbus in 2017.

Jim Marter (the namesake of Marter Yard) was a dear friend. George Seil is also a long-time friend. Next time you see him, say hello for me!

Last edited by Rich Melvin
@Rich Melvin posted:

It is easier to visualize this if you remember that the throttle of a railroad locomotive (steam or diesel) is a POWER control, not a SPEED control.

This is my biggest take away from the thread. Thinking about it like this makes the most sense to me.

@Rich Melvin posted:

I know that museum well. I used to live in Struthers. We moved to Columbus in 2017.

Jim Marter (the namesake of Marter Yard) was a dear friend. George Seil is also a long-time friend. Next time you see him, say hello for me!

I live in Struthers currently! Born and raised and I hope never leaving I believe that museum also has classes on running steam equipment but that may have been years ago. I will remember to say hi if I run into this George Seil.

Billy, you are a young fellow, to judge by your photo.  I'll give you a pass because of your age.

Steam engines are old school.  Today's railroading relies a lot on processes.  Old school railroading relies on learned skills and good judgment.

Skill and good judgement, supported by knowledge of air brakes and knowledge of locomotive mechanical operation, as well as knowing the railroad physical characteristics and the Operating Rules -- that's the entire answer to your question.

Last edited by Number 90

Having worked/ volunteered at a couple railroad museums for the last 7 years, I can tell you that the more you learn about steam locomotives, the more you realize you don't know about them. Every single aspect of a steam engine's construction and operation is vastly more complex than most people, even railroaders outside of the steam environment, realize. The principles are simple, but there is much more than meets the eye. Don't feel bad about not understanding it all.

As Rich pointed out, power application is the key component to double heading. I was fireman on a steam double header last week. I was in the second locomotive and we were not working hardly at all. The lead engine did 90% of the pulling, we were just along for the ride. I still had to keep the fire hot, keep my steam pressure up, and have plenty of water in the boiler, but I wasn't working nearly as hard as my counterpart 70' ahead of me was.

I remain mystified as to why there are not more broken couplers, or yanked out drawbars between the two double headers, if power does not have to be synchronized between them. Playing "crack the whip" in sudden start-ups, which l have read was not popular in the caboose, also broke couplers and drawbars, did it not?   Hard to visualize a huge steamer just along for the ride, and, some western roads ran helpers in the middle of the train, where l can imagine "straightlining" derailments on curves, if power was not carefully matched.  If didn't happen, it sounds like some lucky law of physics.

Colorado, you have to grasp the concept that the throttle is nothing more than a POWER control, and has nothing to do with speed. Nothing has to be “synchronized” when two steam locomotives doublehead. Each engine will pull with whatever POWER level is set by the throttle. One locomotive might be pulling a bit harder on the train than the other, but they are not “synchronized” in any way.

Back in 1984, we doubleheaded the 765 with the 611. The 611 was in the lead. The reason for the doubleheader was just to move both locomotives from Bellevue, Ohio to Cincinnati on the same train, thus saving a crew and a few dollars. The train was light and the route was level, so there was no need for the doubleheader from an operations point of view. 611 did all the work and we just drifted the 765, working only enough steam to keep the cylinders lubed.

There was no slack running in and out, no “crack the whip” action anywhere, and no couplers banging. It was a nice, smooth ride.

@colorado hirailer I think what you're missing is the concept that both engines are pulling. One might pull more than the other but my understanding is that they're both pulling. I imagine it's the same way that every guy on the rope in the tug-o-war doesn't bench press the same weight but they're all pulling.

I also (this is kind of unrelated) think that much of the issue IS the concept of power instead of speed. I'm going to mark it down as part of older machinery compared to my car, truck, and dirtbike. I ran a Keystone Skimmer Shovel at the county fair. Controlling boom up/down and left/right and bucket in/out was all clutch. It was an odd experience when you're used to a forklift at work where the levers automatically go to "neutral" and each lever movement causes something to happen. Operating this shovel was like having all the power, all the time; then gauging how much power I applied via the clutch. Jamming the lever to engage the clutch gave me instant response. Gently engaging the clutch gave me more controllable and smoother response. I was using a clutch to decide how fast to apply power.

I don't think that's how a steam engine is operated. I'm just trying to illustrate that a steam engine, like that shovel, uses different principles to operate than I'm accustomed to. Once I realized that, the responses in this thread were easier to contemplate. When I first read them, I thought "what? no. That just doesn't make sense."

@ed davis posted:

In Alvin Staufer’s B&O Power book there is an incredible photo of triple headed EM-1’s at West Farmington OH hauling coal on the Lake Branch. I can only imagine how the ground shook when they went past.

And here I thought those guys doing crazy double and triple headers with O Scale locomotives on Youtube were just flexing I saw a stationary Big Boy in Scranton, PA.....it's hard to comprehend three of ANY engine of comparable size pounding along. That's a lot of power in one spot. I can't believe the rails stay together.

I'm grateful for the internet and air conditioning but it would have been unbelievable to see three EM-1's move freight like that.

Last edited by BillYo414
@BillYo414 posted:

And here I thought those guys doing crazy double and triple headers with O Scale locomotives on Youtube were just flexing I saw a stationary Big Boy in Scranton, PA.....it's hard to comprehend three of ANY engine of comparable size pounding along.

Such a triple header could simply have been a power transfer move, and thus one or two of the EM-1s may not have been working all that hard.

That's a lot of power in one spot. I can't believe the rails stay together.

Such main line trackage generally had/have 4 spikes per tie-plate, thus lots and lots of strength. Also remember that the weight was distributed over many, MANY axles. When compared to todays modern diesel electric locomotives that are far more capable of transmitting much higher tractive forces to the track, the steam locomotives were way out classed. Then again, that is why todays track structure is far more robust, with current rail at 132 to 141 pounds per yard, while main line rail back in the steam days was only 90 to 100 pound per yard rail.

I'm grateful for the internet and air conditioning but it would have been unbelievable to see three EM-1's move freight like that.

All those cylinders though? And a whole lotta chuffing? Sounds pretty awesome regardless of whether they were doing any work.

That's interesting about the track! I didn't even think about that way; lotta axle putting down power to spread the load. That's a good point. I also didn't know we have used heavier rail in recent years. I would have thought, regardless of axle count, older rails were heavier strictly because of heavier engines.

@BillYo414 posted:

All those cylinders though? And a whole lotta chuffing? Sounds pretty awesome regardless of whether they were doing any work.

That's interesting about the track! I didn't even think about that way; lotta axle putting down power to spread the load. That's a good point. I also didn't know we have used heavier rail in recent years. I would have thought, regardless of axle count, older rails were heavier strictly because of heavier engines.

You must understand that, back in the steam days, the axle loadings were NOT all that high (except for the C&O). Large steam locomotives generally had axle loadings of around 65,000 pounds to 70,000 pounds per axle (for the VERY heavy  locomotives, while the C&O thought nothing of axle loadings of 80,000 pounds). While current high HP diesel electric locomotives (6 axle versions) are still about 70,000 pounds max. On the other hand, current freight cars at 286,000 pounds are over 71,000 pounds per axle. Thus, many current freight cars are "harder" on the track structure and bridges than the vast majority of steam locomotives.

It all comes down to axle loadings and Cooper Ratings for bridges (you try a Google search for Cooper Rating).

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