CTC Motorized Switch "Blockhouses"

Not sure of the correct name (They're called "Signal Cabins" on some RR's)?? Does anyone have plans or photos of the small concrete buildings that protect the CTC switch motors?

Thanks, Tom

 

Those are the ones (Less grafitti on my RR)!! Thanks.

Tom

 

Never was sure what those building along the tracks where for, but now I know that they are the remote control for the switch. didn't know the Frisco used these.

 

The BNSF (Old Frisco) signal houses around Springfield all look like the ones in these photos. I think these buildings may have been designed, or even furnished by the signal company (Union Switch & Signal??).
I have a SFH&MS magazine, "The Warbonnet," and Santa Fe's "cabins" are very similar. I can imagine that the signal company spefications to protect the switch motors from heat and cold (And vandalism these days) required fairly sturdy enclosures.

Tom

 

The switch machine (motor) wasn't located in the CTC house. The switch machine was located on the switch headblocks. The CTC house contained the relays and later solid state circuitry, which was used to control the switch machine and signal aspects. The CTC House may contain an event recorder (tape), which documented conditions such signal aspect, length of time the OS section was occupied, the time the OS section was occupied, etc.

As a reminder, only the absolute signals (A-Blocks in Frisco speak), were controlled by the dispatcher. The intermediate and approach signals displayed aspects based on block occupancy and on the aspect of the nearby A-Blocks.

The switch machine could be operated by hand, and the Book of Rules contained rules about operating a powered switch by hand. Rules also were in place regarding the operation of motor cars and hi-rails over powered switches.

 

I dug out my SFRH&MS "Warbonnet" magazine and checked the article and those buildings were called "Instrument Houses" on the Santa Fe. They appear to be the same size and look as in the photos posted.

Tom

PS: I've noticed over the years, that modelers have gone to great lengths to replicate CTC control boards, even with the same style switches. But I can't recall ever seeing an "instrument house" on a layout...

 

Tom

Another commonly-used name for these shelters is "signal bungelow". They are now typically constructed of aluminum and will have had all of the equipment installed and been wired up either at the railroad's signal shop or by the signal equipment supplier and delivered ready-to-install to the site.

Gordon

 

Back in the day when communication between the trains and dispatcher was possible, those block houses also had the phone for the crew members to talk to the dispatcher. When stopped at a red A signal the rules required the crew member to communicate with the engineer when "no oppossing trains" permission to proceed was given. Since that required a fairly long walk back to the train by the head brakeman, most engineers would pull the train up when permission was received and a hand signal was given. I remember one incident when the head brakeman had not gotten the proper permission, but gave the engineer (not me thankfully) the signal, and the engineer pulled the train past the signal to pick up the head brakeman. Well, you can imagine what happened!!! Fortunately, no collission resulted, but the engineer was pulled out of service along with the head brakeman. It was a lesson in not only trusting your crew, but also knowing ahead of time that they understood the rules. Thanks, Terry

 

Chris

Not all power-operated switches are "dual-control", and those that are not can only be manually cranked over by a signal maintainer. For a dual-control switch machine, there is a lever that is used to mechanically move the points once the switch machine is taken out of power.

 

Attached are pp 32-35 from the 1957 Rules for MOW and Structures which cover the manual operation of CTC switch machines, electric locks, and the operation of track cars over mainline turnouts.

The Frisco CTC-controlled switch machines were powered by electric motors, and when activated the points would move rather slowly. One evening, my father took my brother and me down to Tower 4, where we watched a train pass. Knowing that the towerman would restore the switch in front of us to normal, my father told us to wait and to listen. Soon, came the sound of escaping compressed air and the thud of the points hitting the stock rail. The KCT used pneumantic machines, and the sound was quite unique.

 

Karl--Are there any diagrams of the layout and arrangement of the tracks, switch motors, and equipment around the "instrument houses" in your rule book?

Thanks, Tom

 

If you examine some of my dad's KC Sub field notes you'll be able to see the placement of the CTC Houses in relation to the track. Here is the url for the Prescott sheet. The drawing also indicates that the switch machines at Prescott are Hand Cranks, when used in the manual mode.

http://www.frisco.org/vb/attachment.php?attachmentid=5864&d=1224384955

I have attached the standard plans for a #20 turnout. You will see a 15' tie followed
by two-16' headblock ties, which are at the point of switch. The 15' tie held the
"Switch Circuit Controller" or as my father called it, the shunt box. This is shown in the second drawing.
(The second drwaing contains data for a different turnout, so don't let the different dimesions cause confusion.)
When the switch is reversed, the controller drops the nearest signals to red. Therefore any turnout in signaled
territory has this third "headblock" tie. The two headblock ties held the switch stand or the switch machine. Also note in the standard plan that mid-way along the switch points an additional "throw" rod and a bell crank have been placed to
provide an additional connection point to move the switch points.

I have included a picture from the Racor Trackworks Products catalog that shows
an equilateral turnout with the switch machine mounted on the left. In this non-Frisco application,
the shunt box has been placed on an extended tie near the heel of the switch. You can also see the
additional "throw" rod and bell crank.

The last image, also taken from the Racor catalog, shows the application of an electric lock on a hand
throw turnout. Electrically locked turnouts are found in CTC territory. Note the shunt box.

 

Thanks Karl for the great info!

Tom

 

Tom

The photo below is a typical layout at a power switch-equipped siding end (control point), though complicated a bit by the gated crossing just ahead of it. The small equipment cabinet just to the left of the signal facing us is the cabinet associated with the crossing gates while the cylindrical tank peeking out from behind it is the propane tank that fuels the switch heater used to melt snow in winter. The much larger bungelow farther away and to the right is the house containing the equipment related to the control point. (the photo is on the N&W at Front Royal, VA) -- Gordon

 

Those metal buildings that hold the control circuits for switches and signals are made right here in Topeka, KS. Their manufaturing facilites are now located in the old Pay Less Shoe Store distribution center on Highway 24 just east of my house.
Richard