Model Railroading > "Drop" Switching Move

I was reading Northwestern Pacific in Color by Scott Inman and Ed Mackinson and was intrigued by a switching move described as a "drop" move. On the Petaluma & Santa Rosa Branch north of Sebastopol no runaround track existed at the end of the branch. The crew would perform a "drop" move where the locomotive in front of a short consist would accelerate and pull the cars towards a facing point, pull the pin and uncouple before crossing the turnout, while a crewmember on the ground throws the switch after the locomotive passes, which puts the cars in the spur. The locomotive can now couple to the other end of the cars and pull the train in the opposite direction. A quick search of this move comes up with a "drop" or "flying switch" move. Sounds like something that would be frowned upon in modern railroading.

Has anyone tried to simulate this operation on a small scale switching layout? It seems that it would take quite the coordination between accerating the train, throwing the turnout (ideally one that is NOT a slow speed mechanism), and some kind of uncoupling magnet (i.e. Kadee) activated at just the right time to get the locomotive in the right spot and a couple of cars to coast into a spur. Seems like with DCC and some momentum controls (and arguably some practice), it could make an interesting and unique move.

Best,
Jonathan



Edited 1 time(s). Last edit at 07/15/19 20:18 by californiarails.

There is just not enough room on a layout to make the move practical. A momentum would have the loco pausing when you need to be accelerating in the opposite direction like right NOW if not earlier.

Watched an SP crew do that in Suisun, CA once, quite the feat of physics. Would probably be easier to do in a larger scale. Good old Newton’s law about momentum means there are a number of factors: how many cars; space to get up to speed; level vs grade; loaded vs empty cars; and probably some others I’m not thinking off. It was something else to watch in person.

Nathan

Posted from iPhone

It wasn't just something to watch Nathan, it was something to perform.  We would do them when I worked for the FW&D in Texas back in the early 80's. Some times it was easier to drop than to run around the cars.  Sometimes you didn't have any choice.  First couple of times I participated I was on the switch.  It was nerve racking.  Timing was critical.  One issue you didn't mention was the locomotive. You had to have one that had a fast start. A real trick was dropping when you had a consist of 5 or 6 locos.  

RLR

There was an article years ago in MR where somebody created a way to simulate a freerolling move. By making a section of track move slow in one direction and snap back.   
The option you could do is slope the track before the turnout in question.  Uncouple on the grade, move the loco past the switch, , reverse the turnout, release the "brake" on the cars and roll them in.  
Because of the way large scale couplers can be tripped, the prototype move is possible.  

Wolfie

I used to watch the Susquehanna perform this feat daily on their Passaic Branch where I grew up - it was pretty cool to watch...

I’ve done it on one of our outdoor 1.5” scale railroads.

It’s a BIG problem if one doesn’t make sure there is enough speed for
the car to clear the switch, otherwise the car fouls the switch and the engine 
is blocked from the rest of the train and in effect, stranded.  Of course we can
just push the car to clear the switch but in the real world, that’s a tough one.

The H O G comes in handy many times in the smaller scales! 

WrongWayMurphy Wrote:
-------------------------------------------------------
> I’ve done it on one of our outdoor 1.5” scale
> railroads.
>
> It’s a BIG problem if one doesn’t make sure
> there is enough speed for
> the car to clear the switch, otherwise the car
> fouls the switch and the engine 
> is blocked from the rest of the train and in
> effect, stranded.  Of course we can
> just push the car to clear the switch but in the
> real world, that’s a tough one.

While a switchman on the UP here in Cheyenne we would make drops on a regular basis. In fact at some locations we would make a "Dutch drop". That involved shoving the car onto an inclined track, getting the unit out of the way, line the switch and kick the handbrake off and let the car roll by the locomotive. In fact, interestingly, this past weekend I showed that exact move to our model railroad club in the mall. We have a switching area that has an incline down to the industrial tracks. So to get the cars on the other end of my loco, instead of using the switches to run around them, I stuck a map pin in the right of way to hold them on the grade, moved the loco out of the way, lined the switch for the movement and "pulled the pin" to let them roll by my loco and then continued on to spot the cars. It worked as good as it did around the Cheyenne yard in real life.

Bob Krieger
Cheyenne, WY

Uncoupling a moving train in HO would be troublesome. The other thing would be stopping the moving cars as there’s no brakeman riding a hand brake. Got to do this a couple of times on the real thing. It was fun. Discovered what poling pockets were for...

Back in the late '40's or early '50's Model Railroader did an article of building an O scale boxcar with a sorta flywheel inside, chain drived to one truck.  Don't remember how he handled the uncoulpling, but it gave the car enough momentum to overcome even the poor bearings of the time, to get a car to roll into a siding.

-John



Edited 1 time(s). Last edit at 07/17/19 13:50 by LarryDoyle.

ChrisCampi Wrote:
-------------------------------------------------------
> Uncoupling a moving train in HO would be
> troublesome. The other thing would be stopping the
> moving cars as there’s no brakeman riding a hand
> brake. Got to do this a couple of times on the
> real thing. It was fun. Discovered what poling
> pockets were for...

I've seen drop switches made on more than one occasion, but only once did I ever see a poling pocket used. It was more than 20 years ago on Conrail in Illinois, and was precisely a case where a car being drop-switched didn't roll far enough to clear the switch.
 

The poleing pocket usually only got used on a failed drop and the car died too soon. In Los Angeles, I was on a graveyard yard job which pulled the Los Angeles Junction interchange each night. Since it was our "go home" move we dropped the entire interchange cut, sometime forty cars into the assigned track to avoid going the whole length of the yard twice since the tie up tracks were on the west end of the yard and the pull in move would have been east bound. If you "bottle the air", which today is a definate no no, all you have to do is follow the rear car into the track, open the angle cock and put the train into emergency. When I first hired out we did not have radios so this was a normal practice when delivering interchange to SP's Taylor yard. As the train pulled into the assigned track you ran after the rear car when in the clear and put it into emergency. Good old railroading in the good old simpler days. I have said this before, but when I hired out the rule book fit in your back pocket. When I retired it was in a large notebook with a handle.
JB

toledopatch Wrote:
-------------------------------------------------------
> ChrisCampi Wrote:
> --------------------------------------------------
> -----
> > Uncoupling a moving train in HO would be
> > troublesome. The other thing would be stopping
> the
> > moving cars as there’s no brakeman riding a
> hand
> > brake. Got to do this a couple of times on the
> > real thing. It was fun. Discovered what poling
> > pockets were for...
>
> I've seen drop switches made on more than one
> occasion, but only once did I ever see a poling
> pocket used. It was more than 20 years ago on
> Conrail in Illinois, and was precisely a case
> where a car being drop-switched didn't roll far
> enough to clear the switch.
>  

Yep! And the poling pockets were easier to find then the pole. We weren't aloud to bottle the air either. Must have been amazing doing what 3rdswitch did with a forty car cut.

That was part of the daily operation on the Ventura County Railway at several industries. There were a few times that the brakeman manning the switch would line it under the engine, and after going sideways a boxcar would slam into into it. Splaining and excuses would be made and that was that, just another day on the VC. Working there from 1984 to 1996 had it funny moments and good memories. 

In 1970 when SP was training a group of us students as future trainmen, we practiced that move under very close supervision. It scared the you know what out of me, as I knew how easy it was to derail a car.

Model Railroader had an article years ago on how to install a brake in a caboose.  It was a large ball bearing on a metal track inside the caboose.  On a downgrade, the ball bearing would roll to the end of the metal track and depress a rub-strip against the wheels of one truck.
Might be useful for descending very steep grades.
Or in a yard where you gravity-drop a caboose onto the end of a departing train like PRR had at Enola.



Edited 2 time(s). Last edit at 07/17/19 10:35 by RRTom.

Curious, wouldn't this depend upon which way the caboose was turned?  Also it sounds like the caboose would brake anytime the cab was moving downhill, or if the cab was turned the other way, and was accelerating uphill, depending upon slack?
G

Yes the caboose had to be facing one way.

Back in the day when there were 2-3 employees on the ground the MILW Rd performed 2 types of drops. First was the single drop people are talking about here with a facing point switch and the second was a double or "Dutch" drop with a trailing point switch.

The single drop involved getting the car up to speed, giving the brakeman a short bump for the slack to pull the pin. Then the engineer took off spritely for the facing point switch lined on the diverging route. When the engine cleared the switch was lined for the straight track and the car rolled by the parked engine. The engine came out grabbed the car on the other end and went back to finish the work. On a good this was all done at walking speed.

The Dutch drop required starting farther back so the car had longer room to roll. It was also cut off at a higher speed so it didn't stall out fouling the switch. So the first half of the drop starts exactly as the first single drop and the car and the engine are cut away and moving the same direction. When the engine clears the trailing point switch it stops dead on the straight track. The switch is lined diverging and the engineer throws the reverser and throttle to start moving TOWARDS the free rolling car. Gut check, will the engine clear and switch get lined back before the car arrives or will something get sideswiped or foul the switch.

I never got involved in any sideswipes, cornering or fouled switches though there were sometimes we had to stop the move in the middle and try again. This was a single unit switch engine move, there was no way it could be done with multiple road power.

If one DCC powered a boxcar and used a second throttle to control the car or caboose the action might be plausibly simulated though it would take a lot of track.