I have questions about how and where full size rail yards park and couple their trains. I am asking so I can make sure my yard sidings are long enough to accommodate parking my rolling stock and locos. and to make sure I correctly couple and uncouple the cars.
Do full size yards park their locos. and/or rolling stock on a radius, such as the radius of a turnout as long as the end of the loco or car clears the switch? Or do they park them on straight sections only?
When I say park I mean where they are sitting idle for hours on end.
Do full size yards couple and uncouple while on a radius? Or do they do so only on straight sections of the sidings?
Cars, locos or trains generally must observe clearance when spotted (that’s the RR term, not parking) near a turnout. Doesn’t matter which side of the diverging route they’re on.
Coupling does take place on curves. The coupler may need to be adjusted slightly from side to side if the curve is sharp enough to require alignment. Most prototype curves aren’t near as sharp as on the model, so this is less of an issue for them.
You can use Sergent Engineering couplers if you like to do this. Like the prototype and unlike most model couplers, there is no centering spring on the Sergents, requiring you to align them by hand in some cases.
General rule (also FRA regulation) is to park about 225’ from the points of a switch. (that equates to about 4 or 5 car lengths). Try not to leave stuff on curves if you can help it, as mlehman pointed out, as it can be a real pain to couple to again.
OK, I take this to mean they cannot be or are not spotted on a curve or radius of a turnout. So now the obvious questions of how much clearance when near a turnout? Can the train be spotted just where the curve ends and the straight section connecting to it begins? I believe this is called a joint. Or does there have to be more clearance than that? I am also guessing there has to be enough length or clearance for a car to roll when uncoupled and likewise enough space for a car to be coupled to a consist or unit.
I am also guessing that because of the length of some trains part of it has to be spotted on one siding and the other part on another and it may not be on 2 sidings right next to each other, to avoid sitting idle on any curved sections. Am I correct in this educated guess?
While FRA may have a standard requiring 200+ feet of clearance, it’s a rare model railroad that can afford to leave the more than 2 actual feet of clearance this would amount to in HO scale at each turnout. Heck, I’ve got a number of spur tracks that aren’t that long. Should I not spot any cars in them???
Selective compression is your friend in such cases.
There is no restriction I’m aware of that applies to spotting on curves, per se. So long as other factors don’t apply, not a problem to leave cars on curves.
Do full size yards park their locos. and/or rolling stock on a radius, such as the radius of a turnout as long as the end of the loco or car clears the switch?
No,a engine or car can not be left standing on a switch the engine and cars needs to be spotted at the clearance point which is far less then 225’ from the switch…The clearance point is usually marked in yellow.
Do full size yards couple and uncouple while on a radius?
Yes…While we always tried to avoid coupling or uncoupling on a curve but,at times there was no other choice since some yards was built with curves due to curves in rivers,hills etc.
Or do they do so only on straight sections of the sidings?
That would be perfect in a perfect world but,in real life railroading there is no absolute or perfection like we see on manicured layouts.
Use selective compression, of course - but the cars should not just be barely clear of the switch. Even a car length or two would be more realistic.
I’m a little confused on the second part of the OP’s question about parking on two tracks. Rule of thumb is to never park anything on a track that would foul another track. Of course there are exceptions (space is a luxury many railyards don’t have an excess of)
Sorry but,no…A lot of trains are broken in two and spotted on the adjacent track regardless of curvature of the yard tracks…
So now the obvious questions of how much clearance when near a turnout? Can the train be spotted just where the curve ends and the straight section connecting to it begins?
The switch fouling point marker is usually painted yellow and 1-2 car lengths from the end of the switch.
I am also guessing there has to be enough length or clearance for a car to roll when uncoupled and likewise enough space for a car to be coupled to a consist or unit.
Not always…If a yard track is at full capacity then you can no longer use that track.You start building on the adjacent tracks.
Now…As far as adding motive power that will be done even if the switch is fouled by the locomotive consist.
However…On the prototype the train would be pulled out of the classification tracks and placed on the outbound tracks and even then if the train is doubled out it may foul several switches.
Again nothing is cut and dry on the railroad since there is hundreds of situations that can crop up.
Agreed. I wasn’t wanting to diss on your citing of prototype practice. After all, that’s what this part of the forum is about.[Y] I just wanted to note this was like many other things we model, subject to compromise due to space considerations.