If you don’t like long posts I recomend you hit the “Back” key about now. [:P]
Or, if you can’t sleep…
In another thread (Long Drill Tracks) I said…
“Rather than have a Main blocked or an A/D track I tend to plan my layouts with a passing siding or a third main that can double as anA/D track and /or a switching lead/drill track.”
Hudson asked…
“Can you go into a little more detail on how you do this”?
I don’t think that there is a specific answer. There are a number of scenarios… I’ll try and paint a picture of some I can think of.
[If it matters the reason for using words rather than a sketch is that the concepts apply to a whole range of situations that I would like people to figure out for themselves rather than risk trapping them within a very narrow framework].
[ED:- OOPS! I forgot… in the following text I keep using the word “loop”… by this I mean a Double Ended Passing Siding [:I] Sorry - forgot [8)]].
Okay, here goes…
Back somewhere between 1890 and 1920 (ish) a RR has a single line through a territory and traffic is building.
Operation is by TimeTable and Train Order.
Traffic is growing .
A need develops to pass opposing trains and for Higher Priority trains to overtake ones of lower priority.
.
The first (and cheapest) solution is to put in a switch with a train length dead-end spur.
For meets and passes one train runs straight into the spur or reverses into it.
This is slow and always involves a back-up move at some p
I am assuming that you are talking about N American practice since you mention operation bt TT&TO and that was somewhat unique to N America.You are way too late. They figured this out somewhere in the 1830’s. If its 1890 they have been meeting and passing multiple trains now for the last 40-50 years. They actually have more sophisticated means of operation by 1900 and many of the heavy main lines are double track. The Reading co. double tracked its main lines and was operating using a block signal system by the 1860’s.
Extremely rare and the design of last resort. I would say that 99.999% of all N American sidings are double ended. They might have used this in the 1830’s, but by the 1890’s-1900 it would have been double ended or traffic would be decreasing, not increasing.
If they are operating by train order as you said, there is already a telegraph line at this location. What you are asking about is whether they open a train order office. In the 1890’s, if it was common to meet or pass trains at this location or was a junction, it probably had an open telegraph office.
If they open a train order office at a siding it WILL have a train order signal.
just so you don’t lose all the N American modelers, what he is talking about is a
Okay. Wasn’t useful except as a prompt for correction.
Where I got this “impression” from was MRR, MRC, CTC Board, Trains, Railroads Mags 1950s to present, Many books, Proffessional Journals (about 100ish) scattered from 1850s to 1960s available to me at I Mech E library Services from 1995-2001.
I hoped that I might suggest a line of development of facilities that would show modellers something of how trackplans developed. Bad idea. Clearly Non US citizens are ignorant (at least in Dave H’s several responses to my posts). I will shut my mouth and go elsewhere.
I’d like to say a Big Thankyou to everyone who has kindly taken the trouble to answer my questions.
What you are saying is interesting, but there is a HUGE language barrier here…even though we all speak english. Kinda like talking about British cars…the language is off.
You don’t have to go away mad, just present your hypotheses in smaller bites and as just that hypotheses.
If you are not sure, then ask a question.
But if you say that up until the 1890’s sidings were single ended (which is what you basically said) and nobody questions it then somebody might think its true. And its not. Sorry.
There have been changes in track design, but not for the reasons you’ve mentioned. Most of the changes were due to the increases in the size, weight and capabilites of the equipment and to the changes in operating concepts (run through trains, mergers, pool power).
Example of one-train-length stretches of double track with spring switches were operating in Japan at least until 1974. (Put the DMU train alongside the proper floor-height platform, which was located outside the tracks.)
There was at least one example of a spur passing situation as well, on the Chuo Hon-sen. In fact, every train that stopped had to make a switchback move through a double slip switch (head in, back across main, head out.) The DSS was on a continuous grade, sandwiched between a deck girder bridge and a tunnel portal.
Staff-and-ticket operation (with cable-connected lower quadrant semaphores) was not uncommon on older, less heavily trafficked JNR routes at that time. The levers for the signals were out in the weather on the platform next to the station agent’s door.
As for seasonal-use trackage, check out what went on during the grain rush in the upper midwest. Passing sidings that had been nothing but parking space for empty box cars suddenly became VERY busy - as did the box cars which had been parked on them. A few weeks later, they reverted to their customary somnolence.
Sometimes a passing siding is like a fire brigade - most of the time it isn’t needed, but, when it IS needed, it is needed RIGHT NOW!
The forced perspective, raised N scale dogbone across the top, has hidden reverse loops at each end. The HO mainlines circling the room have adequate train length passing sidings to take care of trains travelling in opposite directions, or to allow higher priority trains to pass. The pass through 7-track, and the 7 track stub-end staging yards, allow one to build a train length consist without interfering with the mainline traffic. The six reverse loops and three wyes, allow many trains to traverse the layout by many routes. To allow for rerailing and scenery improvements, there are six lift outs and “duck under” locations. What appears to be a four track yard across the top, is tracks within a large car ferry. The three track siding on the right side is actually a “coal hopper” barge. Note that there are double-slip switches and cross overs in both of the staging yards, and long drill tracks, which allow the switcher to get to any of the seven tracks, and long drill tracks to build a consist without having to enter the mainlines. This probably would not be practical on a prototype, but makes for some interesting switching and consisting for the four operators handling their 25+electrified, junction box, dual probe switches (which are far faster than DCC code dialing), on each of the four tethered DCC power districts. As usual, one has to use imagination to visualize the compression of distances.(an aside) Note the distortion of vertical vs horizontal enlargement, when you click on the square garage loft layout picture to enlarge it.