Nostalgia & History > Spring Switch Signaling before CTC?

Say at the beginning or ending of double track at a remote location. I'm thinking a spring switch would likely be utilized. Obviously this would be an interlocking. What kind of scenarios would there be for who controlled:

Tower or block station at spring switch

Next tower or block station?

Dispatcher?

Examples would be great.

Spring switches could be used without any remote control. Meets would occur on authority of timetable and train order; the only difference is that after the meet, the train leaving the siding (or second track) didn't have to wait to realign the switch. If the track had automatic block signals -- and often it did, otherwise there wouldn't have been enough traffic density to justify a spring switch in the first place -- the swing switch would be tied into the track circuits.



Edited 2 time(s). Last edit at 09/01/14 06:19 by ctillnc.

I never ran west of San Luis Obispo but, one of my colleagues who was with SP on the west end told me spring switches on the SP sidings were all on the west ends on the west side of SLO and on the east ends east of SLO. I know the ones I saw between SLO and L.A. were on the east ends. Wonder why.

>I never ran west of San Luis Obispo but, one of my colleagues who was with SP on the west end told me spring switches on the SP sidings were all on the west ends on the west side of SLO and on the east ends east of SLO. I know the ones I saw between SLO and L.A. were on the east ends. Wonder why.

Not counting the S/Ss at the ends of DT, in my days, W/E Santa Margarita and W/E Bradley only. E of SPBI, E/E Conception and both ends of Sudden (not familiar with things E of SBA). If you want to go further West, W/E Salinas and both ends of Castroville (although these were within "poor man's CTC limits), and Perry had spring switches at each end. The unique thing about Perry is that the opposing signals were directly opposite each other across the Main Track, rather than before the switch in each direction of approach. Money has a lot to do with "why".

Spring switches at the ends of DT ABS exist today east and west of Dodge City, Kansas on BNSF (I think the points are called Wright and Sears). They are normally lined for movements with the current of traffic. The double track is yard limits, and track warrants govern movements east and west of the DT.

This same arrangement existed at Hahn (just north of Albuquerque) on NMRX until fairly recently.

BSB

I was told by old heads, these were installed in order for first class trains to meet each other and reduce delay. When these trains were gone they were left in and dispatchers knew where they were and used them accordingly to make meets. For a few years in the 70s, 98 & 99 met at Wellsona and then Grover but no SS. Some had SS at both ends, some east and some west. Examples; (90 met 75 at Elkhorn. 98 met 91 at San Lucas, 76 met 371(Adv.Zipper)at San Ardo, 374 met 371 at McKay, 76 met 373 at Wellsona, and 373 & 374, the Zippers, met at Margarita the end of CTC. On the east end, 372 met 371 at Grover, 372 met 373 at Antonio, 372 met 75 at Concepcion, 90 met 99 at Narlon and 76 met 91 at Naples. This from TT 175 April 27, 1958. On the west end there were still 2nd and 3rd class trains that had meets like 920 met 919 at Soledad, 922 met 923 at Henry. On the east end we only had 1st & 2nd class trains. 916 met 75 at Waldorf, 912 met 99 at Sacate.

We did have one that was in "Poor Mans" CTC at both ends of Castoville and the west switch at Salinas. They didn't want to put out the money for a switch machines so they put up a big signal head below the regular signal, that would show the letter "S". You would get a flashing yellow out in the country, a yellow and then a red at the switch. If the "S" was lit, the brakeman got down and lined you in and the conductor lined up behind. When the dispatcher was ready, he would give you a green signal and you would trail out through a spring switch. They had the same thing going east at Texum (K Falls) and finally put in a motor in the 80s.

If you can get a TT from the late 30s and early 40s it would show a bunch of different trains, Starlight, etc. I think these sidings were changed to SS when they changed out all the semaphore type signals with search light types. You can still see the foundations from what were called "Distant" signals, back then.


Nudge



Edited 1 time(s). Last edit at 09/01/14 11:19 by spnudge.

How is the signaling handled: automatic?


BigSkyBlue Wrote:
-------------------------------------------------------
> Spring switches at the ends of DT ABS exist today
> east and west of Dodge City, Kansas on BNSF (I
> think the points are called Wright and Sears).
> They are normally lined for movements with the
> current of traffic. The double track is yard
> limits, and track warrants govern movements east
> and west of the DT.
>
> This same arrangement existed at Hahn (just north
> of Albuquerque) on NMRX until fairly recently.
>
> BSB

Spring switch at end of double track at Coyote
circa 1942-- the automatic signal has a P plate

http://www.flickr.com/photos/barrigerlibrary/12353009664/sizes/k

Probably the same at Corporal

http://www.flickr.com/photos/barrigerlibrary/12352547775/sizes/k

and Watsonville Jct

http://www.flickr.com/photos/barrigerlibrary/12352493375/sizes/k

and the east end of Garnet

http://www.flickr.com/photos/barrigerlibrary/12352960923/sizes/k

and Bena

http://www.flickr.com/photos/barrigerlibrary/12352599705/sizes/o

Can't tell about the signals west of Elko

http://www.flickr.com/photos/barrigerlibrary/12237799035/sizes/k

Guess this SFe "x-over" might have a spring switch at each end?

http://www.flickr.com/photos/barrigerlibrary/12229127895/sizes/k



Edited 8 time(s). Last edit at 09/01/14 13:58 by timz.

The signals in question were set up to tied in to the ABS TCs. So when say a east man cleared the west switch at Bradley, the west man in the siding would get a green signal. They were all set up (in ABS) with a box mounted on the main line signal. If the signal wouldn't clear, the brakeman would walk up, open the door and push the button on what track you wanted. If the block was green and he wanted to change it to another rail, it would go into time. Some guys would keep pushing the button and the time would re-set and start all over again. You had to tell the young guys to only push it once, close the door and come back to the power.

Nudge

On going from double-track to single track or vice versa I would assume the normal and reverse set-up of the spring switch was based on direction superiority wasn't it? For example, if eastbound trains were superior to westbound trains, the normal position (straight) would allow eastbound to run through the switch at maximum speed rather than slow down on the reverse position. Am I right? But perhaps some switches on single to double or double to single track were large numbered wye switches to allow maximum speed when entering or leaving the switch? But perhaps there was always a speed restriction when dealing with spring switches?



Edited 1 time(s). Last edit at 09/01/14 14:28 by wabash2800.

wabash2800 Wrote:
-------------------------------------------------------
> On going from double-track to single track or vice
> versa I would assume the normal and reverse set-up
> of the spring switch was based on direction
> superiority wasn't it? For example, if eastbound
> trains were superior to westbound trains, the
> normal position (straight) would allow eastbound
> to run through the switch at maximum speed rather
> than slow down on the reverse position. Am I
> right? But perhaps some switches on single to
> double or double to single track were large
> numbered wye switches to allow maximum speed when
> entering or leaving the switch? But perhaps there
> was always a speed restriction when dealing with
> spring switches?


Set up so nobody had to throw a switch for normal movement. At end of double track, facing would be lined with the current of traffic. At the ends of a siding, lined for the main.

TAW

The SP (and maybe some other RRs) used a locking device on Spring Switches.

A movement trailing out of a siding would push against the switch points causing them to first move between the point and heel, and this motion caused a lever to pull out a locking dog at the points. Otherwise the points could not be forced open just by trying to pry them open at the tips of the points.
This device required the weight of a locomotive or loaded car to unlock, an empty or a caboose would not do it. A few crews forgot and shoved work trains caboose-first out and they bit the dust.

These facing point lock SS locations had a 35 MPH speed restriction for the first wheels of the movement only.

IIRC this applied to westbounds at West Santa Barbara and eastbounds at East San Luis Obispo. The movement was on the straight side of the turnout, but the engineer would slow down to 35 and as soon and the wheels went over the points, widen out on the throttle.

Spring switches almost always had a "buffer" or a shock absorber mated to the spring to slow down the speed with which the points would close after wheels passed through. Pettibone-Mullikan (sp?) made one called "The Mechanical Switchman". There was a standard test to see how long it took for the points to close. We would place about a 2" obstruction (e.g. a spike maul) between the point and the stock rail, force the switch handle closed (with the spring taking up the motion). Then we'd knock the obstruction out and time how many seconds for it to close. IIRC acceptable times were between about 3 and 6 seconds.

Here is an image from 2007 but I forget where, you can see the switch stand with the "SS" sign and the unlocking rod leading over to the right side. The buffer is barely visible, it is a black cylinder lying on its side between the points and the switch stand.

---

> On going from double-track to single track or vice
> versa I would assume the normal and reverse set-up
> of the spring switch was based on direction
> superiority wasn't it?

Not superiority of trains but current of traffic on the DT section. Keep in mind that the "Normal" and "Reverse" positions of a turnout are what the RR says they are, not whether Normal is the straight direction and Reverse is diverging, although this is usually the case.

> For example, if eastbound
> trains were superior to westbound trains, the
> normal position (straight) would allow eastbound
> to run through the switch at maximum speed rather
> than slow down on the reverse position. Am I
> right? But perhaps some switches on single to
> double or double to single track were large
> numbered wye switches

The technical term for these is "equilateral turnout".

The 35 mph railstiesballast has referred to is to give sufficient time for the point lock to release so the points will move over. Another consideration the danger of over pressurizing the hydraulic oil in the buffer apparatus of the spring mechanism (the unit is a Pettibone-Mulliken Mechanical Switchman -- it's similar to a door closer in action and is intended to reduce wear on the points).

ISTR that the South Shore made a normal practice of routing trains in one direction through the siding and the other direction up the main (spring switches at each end), which greatly facilitated meets without needing power switches. I'm not aware of a class 1 which made a practice of this with sidings, although spring switches were quite common at ends of DT. They were set up so a train leaving single track would always be gong with the current of traffic when it entered DT.

railstiesballast Wrote:
-------------------------------------------------------
> The SP (and maybe some other RRs) used a locking
> device on Spring Switches.

The Santa Fe had spring switches on almost every siding in single track territory but did not feature facing-point switch locks. The only facing- point switch lock I ever saw was at the west end of Wagon Mound and it was eventually removed in favor of the standard non-locking type.
Not sure why Santa Fe felt comfortable without the facing-point lock. It may have been the initial cost and the maintenance as facing-point locks were always in need of adjustments.

> [at the end of double track] if eastbound
> trains were superior to westbound trains, the
> normal position (straight) would allow eastbound
> to run through the switch at maximum speed?

Never occurred to me to wonder about that--
I'm guessing if we look at examples we'll
find that wasn't true, but dunno of an
example offhand.

>> [at the end of double track] if eastbound trains were superior to westbound trains, the normal position (straight) would allow eastbound to run through the switch at maximum speed?

>Never occurred to me to wonder about that-- I'm guessing if we look at examples we'll find that wasn't true, but dunno of an example offhand.

As I mentioned elsewhere, the position of a spring switch at the end of DT has nothing to do with superiority of trains. It is in "Normal" position when it routes trains coming from single track to the proper current of traffic on the double track. If superiority of trains was a factor, inferior trains would always have to stop and line the switch for their movements (and line back), which defeats the purpose of installing the spring switch -- the purpose being to allow trains to move between single and double track without stopping.

However, with meets at sidings, superiority of trains does come into play, and inferior trains must line themselve in (and line back), which is precisely the same situation if there is no spring switch. All a spring switch does in this case does is to allow the train to leave the siding without having to line any switches.

railstiesballast wrote:

> …These facing point lock SS locations had a 35 MPH speed restriction
> for the first wheels of the movement only. …

Just to clarify, the 35 mph restriction was for trailing point movements, and for the entire train, because this was the direction that would actuate the “spring switch” mechanism; facing point movements were maximum authorized speed. This was for spring switches equipped with switch point locks in signaled territory.

For example, Coyote, south of San Jose, it was 35 mph for eastward movements from the eastbound main to the single track but westward movements (facing point) it was 70/55 – Reference Page 35, SP ETT 15, February 3, 1980.

I do agree with "railstiesballast" in that I vaguely remember a restriction for facing point movements where the switch was not equipped with facing point locks that required the lower speed. If I could find my old SP rule book I could look it up; I think it was Rule 538 or something like that.


EtoinShrdlu wrote:

> ISTR that the South Shore made a normal practice of routing trains
> in one direction through the siding and the other direction up the main
> (spring switches at each end), which greatly facilitated meets without
> needing power switches. I'm not aware of a class 1 which made a practice
> of this with sidings, …

This is a very isolated and unique application, and many would contend the Northwestern Pacific was not a “Class 1” but it was part of the SP and fell under SP’s track standards, but at Burdell they had spring switches at each end of the siding that routed westward trains down the “main” where the weigh in motion scale was and eastward trains down the “siding” that bypassed the scale. It was also the only place (I know of) where the siding speed (35 mph) was higher than the mainline speed (10 mph).



Edited 3 time(s). Last edit at 09/02/14 13:28 by Railbaron.

EtoinShrdlu Wrote:
-------------------------------------------------------

> ISTR that the South Shore made a normal practice
> of routing trains in one direction through the
> siding and the other direction up the main (spring
> switches at each end), which greatly facilitated
> meets without needing power switches. I'm not
> aware of a class 1 which made a practice of this
> with sidings, although spring switches were quite
> common at ends of DT. They were set up so a train
> leaving single track would always be gong with the
> current of traffic when it entered DT.

SP established that arrangement at Vincent (between LA and Mojave) but called it double track instead of main and siding.

TAW

TAW Wrote:
-------------------------------------------------------
> EtoinShrdlu Wrote:
> --------------------------------------------------
> -----
>
> > ISTR that the South Shore made a normal
> practice
> > of routing trains in one direction through the
> > siding and the other direction up the main
> (spring
> > switches at each end), which greatly
> facilitated
> > meets without needing power switches. I'm not
> > aware of a class 1 which made a practice of
> this
> > with sidings, although spring switches were
> quite
> > common at ends of DT. They were set up so a
> train
> > leaving single track would always be going with
> the
> > current of traffic when it entered DT.
>
> SP established that arrangement at Vincent
> (between LA and Mojave) but called it double track
> instead of main and siding.
>
> TAW

YOU'VE GOT TO BE KIDDING!!!!

Unless, the ETT defined each siding as DT while stretches between each station were defined as one main track.

In any case, the train in the direction required to take the curved route at the switch would be required to reduce speed, receiving an approach or diverging approach ahead of the switch. It would seem to me that this would unnecessarily delay low density traffic.

Or, was this dark and it was all handled by TT&TO?

What am I missing?

-John

LarryDoyle Wrote:
-------------------------------------------------------
> TAW Wrote:
> --------------------------------------------------
> -----
> > EtoinShrdlu Wrote:
> >
> --------------------------------------------------
>
> > -----
> >
> > > ISTR that the South Shore made a normal
> > practice
> > > of routing trains in one direction through
> the
> > > siding and the other direction up the main
> > (spring
> > > switches at each end), which greatly
> > facilitated
> > > meets without needing power switches. I'm not
> > > aware of a class 1 which made a practice of
> > this
> > > with sidings, although spring switches were
> > quite
> > > common at ends of DT. They were set up so a
> > train
> > > leaving single track would always be going
> with
> > the
> > > current of traffic when it entered DT.
> >
> > SP established that arrangement at Vincent
> > (between LA and Mojave) but called it double
> track
> > instead of main and siding.
> >
> > TAW
>
> YOU'VE GOT TO BE KIDDING!!!!
>
> Unless, the ETT defined each siding as DT while
> stretches between each station were defined as one
> main track.
>
> In any case, the train in the direction required
> to take the curved route at the switch would be
> required to reduce speed, receiving an approach or
> diverging approach ahead of the switch. It would
> seem to me that this would unnecessarily delay low
> density traffic.
>
> Or, was this dark and it was all handled by
> TT&TO?

I remember the arrangement on the Shore but not the details, which are locked away in a timetable in my archives exactly somewhere.

The Shore was TT TO.

TAW