I've only seen this done once, in 1981. The yard crew would uncouple the last cut of cars on a train that was backing at about 10 - 15 mph. As the cars uncoupled the train would slow down, and the uncoupled cars would pick-up speed and go sailing onto the desired yard track, with the brakeman swinging off the side of the last car, cranking the hand brake. The cut of cars would then gentle couple with cars already on that track. This procedure was repeated several times flawlessly, quite something to watch. Was this how it was done in the past? I've never seen this again.
Ulrich,
This sounds like kicking cars which is the usual way of switching a flat yard.
Mac
Around here I only see them uncouple cars when the train has come to a complete stop..i.e... the train would backup until the last cut of cars is on the desired track...stop... and then the switchman/brakeman would uncouple the cars. The switchman would then radio the train's engineer to pull ahead. It's probably the safer (albeit slower) way to go...
Ulrich Around here I only see them uncouple cars when the train has come to a complete stop..i.e... the train would backup until the last cut of cars is on the desired track...stop... and then the switchman/brakeman would uncouple the cars. The switchman would then radio the train's engineer to pull ahead. It's probably the safer (albeit slower) way to go...
That's a brutal way to switch cars. Probably all that is allowed per their rules, though. Nothing like giving cars a kick and sending them on their way*
*following all rules, procedures, and special instructions, of course.
And yes, that was the common way to do it when you didn't have a full-blown mechanical hump yard. Guys would ride down the cars, applying brakes to act as blockers, then the rest could be kicked against them. We still have places that kick cars, but hopping on and off cars, applying brakes on the fly is pretty verbotten most places. Again, there's always exceptions.
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
Ulrich As the cars uncoupled the train would slow down, and the uncoupled cars would pick-up speed
As the cars uncoupled the train would slow down, and the uncoupled cars would pick-up speed
Captain Nitpick, defender of the downtrodden, here. No the uncoupled cars would not pick up speed, unless the flat yard wasn't actually flat. They would not slow down as much as the rest of the train.
They could pick up speed if there was a downgrade, but that sounds more like a hump yard.
Patrick Boylan
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It doesn't take much of a downgrade for a car to pickup speed.
If the yard track has no cars in it, the first few have to be placed in position and the brakes tied (I have seen them set the brakes before shoving the poor cars, wheels sliding and squealing). Once there are enough cars with brakes set in the track, the rest can be uncoupled on the fly and safely couple to them (or get close!).
There is an art to deciding how hard to push the cars to get where you want them and not so hard as to knock the end cars out the other end. I have seen a crew have to couple onto the already placed cars and pull them back into place if too many hit too hard.
I have seen them not shove a car fast enough and it stop before clearing the switch and they have to give it a nudge again... I have even seen the switchman lean into the car and push (and I do mean PUSH!) the car a few steps to keep it from stopping too soon (the slight downgrade was then enough to keep it moving to the end of the cars already there.
I have seen cars shoved too fast and the resulting coupling was quite LOUD (of course the severity of the SOUND depends on the type of car... an empty tank or hopper car can resonate quite loudly even with a gentle coupling) Once I saw car shoved too fast and it derailed when it hit the cars in front of it, much to the consternation of the switch crew.
Semper Vaporo
Pkgs.
Watched NS do this in Lynchburg, VA not too many years ago. It was after dark, and from where you can watch the yard, you can't see the whole thing, so all you got was the kick, followed by the disembodied "bang" when the car reached the others on that track.
As has been noted, it doesn't take much of a grade to move a car, or to have it accelerate.
I've rolled out of our station with a four car train, only to discover at the foot of the "yard" that I hadn't turn on the field switch - we rolled out very nicely courtesy of gravity.
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...
Back when we could switch efficiently (kick), we had a conductor with good timing.
He would call the yardmaster, make his kick. The yardmaster would respond. About the time the conductor would ask his question, the cars would make the joint. "What do you want (BANG) next?"
Sometimes we just key up the joints for fun... Empty tanks and covered hoppers make a lot of noise. Grain cars aren't always completely empty or have the gates completely closed either, so the jostling shakes out a fair amount of corn up and down the lead, to the benefit of the local deer and raccoons.
Mike WSOR engineer | HO scale since 1988 | Visit our club www.WCGandyDancers.com
The real art was doing it T'Other way.
Put the engine ahead of the car to go in a track. As with a train going south and a siding having one facing point switch to the north.
One crewman at the switch and another is on the car to be switched or the car ahead of it. Get some speed on the car then throttle back to bunch the coupling. The crewman riding the car pulls the pin, then the locomotive(s) accelerate to put distance between themselves and the car.
After the locomotive(s) clear switch, and not one second before, the crewman at the switch throws same and the freight car is directed in to desired track. Yet another man on the ground swings up from the ground onto the B end of the moving car and uses handbrake to bring it to a stop. Hopefully in the proper spot. If the spot is missed the locomotive(s) can now get in back of the car and spot it properly.
From my bicycle I watched the C&IM do this when I was about 10 years old. It just reinforced my from birth desire to be one of those guys.
gardendance Ulrich As the cars uncoupled the train would slow down, and the uncoupled cars would pick-up speed Captain Nitpick, defender of the downtrodden, here. No the uncoupled cars would not pick up speed, unless the flat yard wasn't actually flat. They would not slow down as much as the rest of the train. They could pick up speed if there was a downgrade, but that sounds more like a hump yard.
If the train is accelerating when the cars are uncoupled then that acceleration would be transferred to the uncoupled cars as well.. i.e. a push prior to uncoupling.
It sure sounds to me like you guys with "accelerate" and "pick up speed" AFTER removing the accelerating force forget basic physics. I work at the Academy of Natural Sciences, computer support to the algae in a microscope eggheads, and my mission is to get to the next "ask the scientist" session at our unnatural science neighbor the Franklin Institute and get expert opinions to confirm what think I remember, that friction will always slow things down ABSENT AN ACCELERATING FORCE.
Google's not my friend this time. It got me to http://www.physics.org/, whose first page has a link to Find out the pint-sized physics of beer, from brewing to drinking. so you can imagine that research line could seriously occupy my time, and perhaps impair my ability to give an explanation you could understand. It'll probably impair my ability to give an explanation I understand too.
The speed can be transferred, but not the acceleration.
We still use gravity drops in places that work but the old flying switch is a thing of the past.
Most of this type of car kicking is done in dead flat yards. You still have to set handbrakes on the first cars deepest in the track to act as stops for subsequent car kicked into the track. But those subsequent kicked cars are not ridden since there is no reason to control handbrakes. The cars are simply kicked hard enough to assure they get to the end of the track. Some cars do not make it that far, and are shoved further later to get the whole string coupled up.
Some cars can stall before they get in the clear of adjacent tracks. It is possible to line the switch over to an adjacent track with a car stalled and fouling the adjacent track. So it is critical to make sure that cars roll into the clear before sending another car into an adjacent track. If a car not clearing the fouling point is hit by another car heading into an adjacent track, it is called “cornering” the car.
There are also yards that are all on a grade, and require a person to ride them and control the speed by handbrakes as they roll. Otherwise they will get away or wreck if they hit another car. This practice may be a thing of the past today. But the system required several riders and a pin puller. The engine would just give a bit of slack for the pin puller to get the pin. No power acceleration was needed because the yard was downhill. These were called rider yards.
Why does the tip of a bullwhip “crack” when used?
The rest of the whip makes little noise but the tip cracks.
Same basic principle is at use when flat switching, after the engineer hits the brakes quite a lot of the kinetic energy is transferred to the last cars (the ones being kicked) and they will pick up speed, or move away from the rest of the cut faster than the shove was applied.
23 17 46 11
"Most of this type of car kicking is done in dead flat yards.—Euclid"
Speaking from experience, both from an engineering standpoint (surveying and designing railroad trackage), and an operating standpoint (switchman and locomotive engineer), most railroad yards are anything but flat—even in flat areas that have been filled along river bottoms and waterfronts. If topography permits, a yard is graded with the leads (most yards are double-ended) higher and body tracks going downhill to a low point in the middle of the yard—this is known as a bowl shaped yard.
These yards are great for switching—just give the cars a kick and they roll right in, and then stop when they get to the bottom of the bowl; no handbrakes required. I worked in several yards with this configuration: CNW's (now UP) Valley Park Yard near Shakopee, Minn., BN's (ex-CBQ) Dayton's Bluff Yard in St. Paul, Minn. (along the Mississippi River), and BN's (ex-NP) Rice's Point Yard in Duluth, Minn.
At Dayton's Bluff Yard we even did a drop on a 55-car loaded coal train when I was student engineering (I gave this job to the regular engineer; I didn't want a part of it given my experience at the time). Anyway, we arrived from the west (we had disposed of the head 55 cars in Minneapolis already), came through the plant at Hoffman Avenue, and stopped at the west end of the yard. After we lined up the lead and bottled the air on the train, the engineer wound up the power (three SD40-2s) and got the train up to almost 10 MPH, then bunched the slack so the brakeman could get the pin. Once uncoupled, we raced the power into the clear, with the other brakeman lining the switch for the lead after we cleared. Our train then rolled by us into the next yard track, just as pretty as you please. I was concerned that the air on the train would leak off and set up the brakes (I had used quite a bit of air coming down the hill at Third Street, about a mile west of Hoffman, and didn't think the reservoirs had been fully recharged yet). But, car after car continued by us gently rolling along on the welded rail. Finally, when the caboose was in the clear, the conductor dumped the air on the train using the air valve on the rear platform; we had changed ends on the power in the meantime. Last move was to grab the caboose and head to Northtown Yard for tie-up.
Most yards aren't so easy to work in; given the local topography they are a on one-direction grade, sometimes on the stiff side, sometimes almost level, but there is a grade there nevertheless.Believe me, the first thing to ask when working in an unfamiliar yard is which is the low end so one knows where hand brakes need to be set.
I spent many years working at BN's 28th Street Yard in Superior, Wisc.; south (railroad west) of the 28th Street grade crossing the yard looked level—but it wasn't! All that was needed to convince one was to release the independent brakes on a locomotive and have the loco start moving (good reason to always apply handbrakes on unattended locos there). We always applied three hand brakes on the east end of all cars to keep the cars from rolling out.
The switchmen would look at their list and determine how many cars were going in each track; we would then "shove room" by stretching the track, making any joints, and then shoving the cars for the room needed. Once done with that we would grab a cut of cars and start "firing missiles." Empties were good for a few "Booms!"
Kurt Hayek
edblysard Why does the tip of a bullwhip “crack” when used? The rest of the whip makes little noise but the tip cracks. Same basic principle is at use when flat switching, after the engineer hits the brakes quite a lot of the kinetic energy is transferred to the last cars (the ones being kicked) and they will pick up speed, or move away from the rest of the cut faster than the shove was applied.
So you're breaking the sound barrier with the last car of the cut? (that being what makes the bullwhip 'crack') ... ;-}
"Same basic principle is at use when flat switching, after the engineer hits the brakes quite a lot of the kinetic energy is transferred to the last cars (the ones being kicked) and they will pick up speed, or move away from the rest of the cut faster than the shove was applied"
Sounds dramatic, but unfortunately not true, at least with cars uncoupled from the rest of the cut. Those cars will have same speed they had before the engineer applied the brakes on the switch engine. Don't believe it?—Let's look at it step-by-step:
Step 1 Switch foreman calls for a kick.
Step 2 Engineer releases engine brakes and places throttle in 8th notch (full throttle).
Step 3 Before cars start moving foreman pulls pin at cut (might have to wait for cars to start moving if slack is out).
Step 4 Movement continues to accelerate; slack is now bunched on all cars.
Step 5 When movement is at desired speed (let's use 10 MPH for this example) foreman swings down engineer (signals engineer to stop).
Step 6 Engineer fully applies engine brakes (speed 10 MPH at beginning of brake application).
Step 7 Slack starts running out from engine, going back along cars; engine is slowing down but each car continues at 10 MPH initially until slack runs out at that car, then the car starts slowing at the same rate as engine.
Step 8 The slack continues to run out along the cars toward the far end until all the slack is out; speed at the far end of the cars is still about 10 MPH (slack runs out much faster than engine brakes can slow cars).
Step 9 At the cut, speed is also about 10 MPH when slack run-out reaches the cut; once the slack is out at the cut the cars attached to the engine begin slowing at the same rate as the engine. Since the pin is pulled on the cars being kicked those cars continue to roll at the same speed as before.
Step 10 The cars attached to the engine begin slowing, while the cars being kicked (with nothing hold them to the rest of the drag) continue on at the same speed and separate from the rest of the drag.
Step 11 Cars cut off continue on and roll into clear on desired track .
I speak from experience—I worked as the regular engineer for many years on the 3:00 p.m. "heavy pounders" yard job at BN's 28th Street Yard in Superior, Wisc.; the job got its nickname from what it did: flat switching all shift.
Kurt I too speak from experience, for the last 17 years I have flat switched every day at the PTRA in Houston, and still do so today.
No, it's a completely different principle. Cracking the wip is from moving the wip handle down, and the wip's inertia tending to try to keep it from accelerating towards the center of the earth any faster than it does at rest, both forces cause the wip to move away from the wipper, until it gets to the end and can't move away any more, so it then accelerates towards the center of the earth, for a brief moment faster than the speed of sound, thank you Overmod.
In order not to compare apples and oranges try pushing the wip like a locomotive pushes a string of cars and see how much noise the wip end makes. Or try snapping a locomotive downward like a wip handle snaps downward and see what happens to the last car in the string.
gardendanceOr try snapping a locomotive downward like a wip handle snaps downward and see what happens to the last car in the string.
Maybe then we could finally see that Calvin & Hobbes penny-on-a-rail effect in real life!
TrainManTy gardendanceOr try snapping a locomotive downward like a wip handle snaps downward and see what happens to the last car in the string. Maybe then we could finally see that Calvin & Hobbes penny-on-a-rail effect in real life!
After a fashion, that's one reason why we don't have cabeese any more.
Acceleration. What if I drive my car at 90 mph and rear-end yours at a red light? Your car will definitely accelerate, I assure you of that. My car will lose some of its momentum in the process (not that it would matter much to anyone inside). Would not the same effect apply for a locomotive bumping some rail cars?
But the car that was bumped into, does not continue accelerating, but after the initial impetus it begins to slow (decelerate) due to friction in the axle bearings, the wheels on the ground/rail, and air, unless another force (gravity) acts upon it.
Yes, the operative word being "after". Likewise, the freight car too slows down for coupling.
Reading the Kurts post ,I recalled my younger years in Dayton , Ohio. Remembering the sound of the car hitting the string as it bunched up the slack, then stretching out for the next car to hit. We lived on Huffman Av. at the bottom of "Eastern Hills" on the PRR. The switch yard was east of Smithville Rd. The other yard was on Findley street and ran from there to Irwin street. That main track was the Big 4 RR.There is where I learned about track torpedoes from switchmen.They sure were loud when hit . That was in a time much nicer. I met two friendly "Bulls" , William and Arnold at different times and they told me where I could go and could not go on rail property. This was in the 1940s. My how times have changed.
Cannonball
Y6bs evergreen in my mind
Ulrich Acceleration. What if I drive my car at 90 mph and rear-end yours at a red light? Your car will definitely accelerate, I assure you of that. My car will lose some of its momentum in the process (not that it would matter much to anyone inside). Would not the same effect apply for a locomotive bumping some rail cars?
The car you hit will definitely accelerate at the time of impact. After that it will decelerate, unless other forces act upon it (gravity:downhill, wind). Other factors will also determine how quickly it decelerates: friction, mass of the car, air resistance, brakes.
So it will be with the railroad cars being kicked. Barring gravity or wind (ask Carl about that), it will begin to decelerate as soon as it is uncoupled from the locomotive (or other cars).
To do otherwise would be counter to the laws of physics.
I don’t see the comparison. The car that gets let go was accelerated only by the locomotive. It is not “bumped” into action.
Actually, I would say that the appearance of acceleration of the kicked car is an optical illusion. As the engine brakes, the slack in the cut runs out. The deceleration in that runout increases as it moves from car to car. By the time it gets to the last car that is still coupled, the slack runout has become most abrupt; so it decelerates that last car at the fastest rate compared to all of the other cars in the cut.
Railcars are amazingly free-rolling. So when the kicked car rolls free, there is no perception of its speed slackening. And yet the last car in the cut abruptly decelerates in a way that is visually obvious. This creates the illusion that the kicked car actually sped up. I don’t believe it can.
Maybe. I'm pretty sure I saw them accelerate.. but who knows, maybe my mind was playing tricks on me.
When I refer to it as an optical illusion, I am not discounting the appearance. It does indeed look like the kicked car speeds up as it leaves the cut.
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