Nostalgia & History > Farewell To Interlocking Towers

I was a towerman and used to pull the levers at Redondo Junction and Mission Towers in Los Angeles. For all intents and purposes, those two towers were practically identical to what you see depicted in this video.  Mission Tower had 247 levers in its heyday, with two lever pullers guided by a supervisor.  Redondo had 40 levers.  The two towers have since been shut down and their movements are controlled from a remote site in Pomona.  Hobart Tower is also shut down and is controlled by the BNSF dispatcher in San Bernardino.

Railroading has changed tremendously since I received my first paycheck from the Atchison Topeka & Santa Fe Railway Company way back in 1979.  

One has to wonder how much more will change in the next thirty-eight years.   

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Very cool!  Imagine explaining how a manual system with all the rods extending to the switches worked.
Are there any towers left with the big handles controlling the steel rods left I wonder?

mp51w Wrote:
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> Very cool!  Imagine explaining how a manual
> system with all the rods extending to the switches
> worked.
> Are there any towers left with the big handles
> controlling the steel rods left I wonder?

The pistol grip machine in the video has a mechanical locking bed similar to that in a mechanical machine. The logic is the same in both. That leaves only the mechanical transmission of the switch and signal movement instead of electrical. That part is accomplished with one inch steel pipe carried on rollers (picture in this post http://www.trainorders.com/discussion/read.php?18,4207900,4207900#4207900). Direction changed by use of cranks http://1.bp.blogspot.com/-gacXDj8OMBk/UU86iSAKvdI/AAAAAAAAIkg/h_srn36bnKw/s1600/BRIGHTON_PARK-semaphore-mast-pipeline-cranks.jpg or deflecting bars http://arrts-arrchives.com/images2/dflbar.jpg. Expansion and contraction of the pipelines was compensated by two cranks connected end to end https://farm5.static.flickr.com/4019/4579522008_04e3e25aa2_b.jpg. The pipelines connect to the interlocking by a section called leadout http://www.rrsignalpix.com/works/smrockerleadout.jpg, where the direction of the pipe movement is changed from parallel to the track to perpendicular, through the front of the tower. The leadout may be cranks, or rocker shafts as shown in the picture. The rocker shaft rotates by way of a crank that is pulled up/down by the pipe connecting it to the lever. The concept was ingenious, and a mechanical plant looks complex, but it's actually many simple elements that look complex when combined into a system.

Mechanical and electric interlocking use virtually the same logic to control signals and switches. The means of transmitting the commands to the appliances (switches, signals) is different. There were also air interlockings, using a machine like that in the video, but transmitting the energy for moving switches by way of compressed air controlled by electric contacts in the interlocking machine.

TAW

 

This cartoon says it all. 

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I believe in the 80's there was a vhs video made about toronto terminals and towers.  I have never seen that video but would love to.  Unfortunately I am not aware of it being on DVD or streaming. (I don't have VHS anymore) Does anyone know if it is available anywhere?

The supervisor in the video says:
"There is a difference between the digital age and what we have here."

What he has there works and has worked for many years and would
continue working for many years.
The product of the digital age will probably be a piece of ****.

Just look at the postings from a few weeks ago concerning the Joe Szabo Control Center
at CUS that brought everything to a standstill for the umpteenth time.  CUS is already on
at least its third "computerized" control system.

The pre-computer machines also had the advantage of washing out those who had no business
working in a tower.  By the time you qualified on one of those machines you not only understood
the flow of traffic but also how the signal system worked.  Nowdays any idiot can sit in front of a PC
and as long as they say "over" at the end of each sentence management thinks they are 100%.

Just the opinion of someone who has worked everything from a pipeline machine to the new digital
wonders.
 

I agree wholeheartedly with everything you said, Englewood!  
 

That is the same version of control panel that they had at the Joliet UD Tower at the junction of the RI, MC, AT&SF and the GM&O.
That is except that they didn't have a lighted board but rather a paper schematic framed and mounted on top of the machine.

Bob Krieger
Cheyenne, WY



Edited 1 time(s). Last edit at 03/23/17 09:42 by Bob3985.

Englewood Wrote:
-------------------------------------------------------
>
> Just look at the postings from a few weeks ago
> concerning the Joe Szabo Control Center
> at CUS that brought everything to a standstill for
> the umpteenth time.  CUS is already on
> at least its third "computerized" control system.
>

Unfortunately, the operating system (ARINC) Amtrak uses in Chicago is inferior plagued with quirks which resulted in massive service disruptions.  A blood bath between dispatchers at a commuter agency and management led to the plug yanked out of the wall replacing ARINC with Wabtec’s TMDS.  They identified massive deficiencies in safety appliances which were not solid resulting placing MofW forces at risk.     


DIGCON was a superior system. Their greed led to their demise.   
 

Englewood Wrote:
-------------------------------------------------------
> The supervisor in the video says:
> "There is a difference between the digital age and
> what we have here."
>
> What he has there works and has worked for many
> years and would
> continue working for many years.
> The product of the digital age will probably be a
> piece of ****.
>
> Just look at the postings from a few weeks ago
> concerning the Joe Szabo Control Center
> at CUS that brought everything to a standstill for
> the umpteenth time.  CUS is already on
> at least its third "computerized" control system.
>
> The pre-computer machines also had the advantage
> of washing out those who had no business
> working in a tower.  By the time you qualified on
> one of those machines you not only understood
> the flow of traffic but also how the signal system
> worked.  Nowdays any idiot can sit in front of a
> PC
> and as long as they say "over" at the end of each
> sentence management thinks they are 100%.
>
> Just the opinion of someone who has worked
> everything from a pipeline machine to the new
> digital
> wonders.
>  
With mechanical, relay NX interlocking, and relay CTC, I called maintainers less in a decade than I did in a year or so of the solid state stuff.

And then...can you imagine a panel that doesn't show train symbols? Our first computer machines in Seattle had trouble keeping the symbols straight. I kept them turned off (probably can't do that now). Management would throw a fit. The signal department would throw a fit. It's not possible to know where the trains are. Turn them on!

Mmmmm, not possible for YOU, maybe. I don't have a problem.

A colleague turned them off when training students and made them work without. THAT generated a firestorm.

TAW
 



Edited 1 time(s). Last edit at 03/23/17 11:06 by TAW.

Anybody know what make and model hardware are shown in the video?  Mission and Redondo (and San Bernadino West Yard, Riverside Jct. and Hobart) all used General Railway Signal Model 2 "pistol grip" hardware, which is similar, but not identical to the machine shown.  The Model 2 was developed around World War I, but this looks like a more modern design.

D F W

I seem to recall that Terminal Tower at LAUPT used air operated switches and the plant did not have pistol grip levers.  They had levers that you moved from maybe a ten o'clock position to a two o'clock position on a vertical plane.

Obviously it was a different model and perhaps different manufacturer than what Mission and Redondo were equipped with.

Though it's differrent than the computer age the logic is simular. Just look at an interlocking a dog chart and think normal, reverse, etc. and think of the binary code which is on and off.  Yes, I may be oversimplying it, but those early interlocking engineers had something there.

Victor A. Baird
​http://www.erstwhilepublications.com



Edited 1 time(s). Last edit at 03/24/17 20:53 by wabash2800.

wabash2800 Wrote:
-------------------------------------------------------
> Though it's differrent than the computer age the
> logic is simular. Just look at an interlocking a
> dog chart and think normal, reverse, etc. and
> think of the binary code which is on and
> off.  Yes, I may be oversimplying it, but those
> early interlocking engineers had something there.
>

Not only that, but a locking bed could contain IF logic through the use of movable parts called swing dogs. A mechanical locking bed is indeed a mechanical processor on which the logic of relay and solid state interlocking were based.

TAW

Wildebeest Wrote:
-------------------------------------------------------
> Anybody know what make and model hardware are
> shown in the video? 
>
> D F W

GRS Model 5 Form F
The Toronto Terminal interlockings were installed in 1931.
There were three interlockings:
John St., which I believe is the one in the video, with 169 working levers,
Cherry St. with 71 working levers, and
Scott St. with 169 working levers.