Mystic transformers was located in Winchester (may still be, ought to check), and the name came from the nearby Mystic River, not because there was any mystery about the products sold!
Dave,
Thanks for the tale of the cab rides. A couple of classic cases for DC current in an audio frequency transformer would be a single ended output transformer (e.g. on an AC/DC set) and a plate modulation transformer.
In the process of looking up the section on ATC in the Handbook, I ran across to references to Railway Electrical Engineer magazine. Turns out that Google Books has a scanned copy of the 1922 issues with several reports of various automatic train stop and train control developments, though nothing on the coded cab signal system.
- Erik
Quoting Dave Klepper: " The few times a steam subsituted, I could not enjoy a cab ride, because I had to be relatively clean at work at Mystic."
Poor Dave!
Johnny
It was and is the onboard equipment that must have the filter charadteristics broad enough to accept 91.67Hz as well as 100Hz, but the track relay filters could be extremely narrow-band, since they don't move to the 100Hz locations.
I designed a whole bunch of transformers for Mystic Transformers that were required to work with a dc primary offset. The trick was to determine the air-gap in the magnetic structure that would prevent oversaturation of the steel while still preserving useful efficiency (between 50% and 80% depending on the strenth of dc current, no. of coils, area of steel pole crosssection). I did not have formulas for this and developed my own rules of thum, based fortunateliy on trial calculations, not on prototype failures! With a dc componant, unless just a trickle, an air-gap is esential. (Of couse it isn't air, it's glass or other insulatng material.) With simple inductors, just adding more steel is usually the anwer, and this means also more coils. These were all successful designs with repeat orders. Mostly military.
What wonderful days those were! Engine pass on the B&M, commuting with my Raleigh bike on the front open platform of the wood combine behind the GP-7, riding the power unless I was outranked and had to ride the folding-bench in the baggage section or in a coach seat behind. Returning to my MIT dorm, usually via a very late dinner at Semeoni's Italian Restaurant in Cambridge on the loop where the Type 4 Watertown cars turned off Central Square, always meant the question: Do I bike to the station and wait for the next train or bike the whole way downhill? The few times a steam subsituted, I could not enjoy a cab ride, because I had to be relatively clean at work at Mystic.
It's quite possible that the passband of the on-board filters are wide enough to pass 91.67Hz as well as 100Hz. I'd suspect that the track relays are more selective - think many, if not all, use a reference signal derived from signal used on the track circuits. The track relays are the more critical as a continuous 100Hz signal would be interpreted as the most restricting aspect by the on-board equipment, while the track relay could give a false clear for the block.
If there was anyone on this forum who would know about the adverse effects of a DC current on a transformer or inductor, it would be you.
Take Care!
Presumambly, for the filters for the on-board equipment, 91.67Hz was and is sufficiently close to 100Hz. The condition does exist today.
oltmannd The RF&P had four aspect cab signal - pretty much like the PRR's. The big difference was the RF&P used commercially available 60Hz carrier for the track circuits. PRR used their own 100Hz supply. When Conrail installed cab w/o wayside on the Boston Line, they stuck with the 100Hz PRR standard -since nearly all the locomotives were already equipped for this. CSX inherited the Boston Line and would up with two standards. It was cheaper and easier to change the RF&P to 100Hz than it was to retrofit the nearly the whole loco fleet for two carrier frequencies. Consequently, CSX and NS both use the PRR standard. Amtrak's primary carrier remains 100Hz but they also use a higher secondary carrier to get their additional "faster" aspects.
The RF&P had four aspect cab signal - pretty much like the PRR's. The big difference was the RF&P used commercially available 60Hz carrier for the track circuits. PRR used their own 100Hz supply.
When Conrail installed cab w/o wayside on the Boston Line, they stuck with the 100Hz PRR standard -since nearly all the locomotives were already equipped for this.
CSX inherited the Boston Line and would up with two standards. It was cheaper and easier to change the RF&P to 100Hz than it was to retrofit the nearly the whole loco fleet for two carrier frequencies.
Consequently, CSX and NS both use the PRR standard. Amtrak's primary carrier remains 100Hz but they also use a higher secondary carrier to get their additional "faster" aspects.
Don,
I ran across a reference in section 19-161 of the 8th edition of Standard Handbook for Electrical Engineers where a railroad went for a carrier frequency of 91 2/3cps (Hz) for trackage where there was both the 11kV 25Hz "trolley" and DC third rail. The DC on the transformers and impedance bonds would cause the 4th harmonic of 25Hz to be generated which then interfered with the relays designed to pick up 100Hz. I recall seeing this in other sources as well.
The combination of 25Hz overhead and DC third rail sounds like Penn Station to me.
oltmannd schlimmOne, that really does not quite match the timeline Overmod gave, as the rails were doing quite well pre-Depression and 1940 onwards through the early to mid 1950's. Railroad were going bankrupt at a pretty good clip during the depression. Coming out of WWII, there was heavy investment in plant and equipment for a few years, but by the late 1940s, the die was cast. Go read annual reports from the NYC and PRR during the first few years of the 1950s. Lots of gloom and doom. One telling fact (I forget where I read it) is that tie replacement rate on the NYC in the first part of the 1950s was about 1/10th of what it needed to be for steady state. Both the NYC and PRR were in trouble and they knew it. They were "eating their foot" to stay alive. By the mid 1950s, they had pretty much given up. The NYC took another stab at shoring up the railroad when Perlman was around, but he was chewing through capital at a huge rate, and still not getting the property "over the hump". To his credit, he was trying to make the Central relevant and useful, but truly profitable was beyond his grasp. schlimmTwo, that says that profits trump safety. If the ICC had cared, it could have found federal dollars. Federal money was found to help subsidize the PRR electrification to DC, 1933, for example.. Safety is a relative term. There is no such thing as "Safe" and "Unsafe". Some things and methods are safer than others but none are perfect. There are counterbalancing costs, too. There is only so much production capacity in the economy. If we spend some on "this" then it's not available for "that".
schlimmOne, that really does not quite match the timeline Overmod gave, as the rails were doing quite well pre-Depression and 1940 onwards through the early to mid 1950's.
Railroad were going bankrupt at a pretty good clip during the depression.
Coming out of WWII, there was heavy investment in plant and equipment for a few years, but by the late 1940s, the die was cast. Go read annual reports from the NYC and PRR during the first few years of the 1950s. Lots of gloom and doom. One telling fact (I forget where I read it) is that tie replacement rate on the NYC in the first part of the 1950s was about 1/10th of what it needed to be for steady state.
Both the NYC and PRR were in trouble and they knew it. They were "eating their foot" to stay alive. By the mid 1950s, they had pretty much given up. The NYC took another stab at shoring up the railroad when Perlman was around, but he was chewing through capital at a huge rate, and still not getting the property "over the hump". To his credit, he was trying to make the Central relevant and useful, but truly profitable was beyond his grasp.
schlimmTwo, that says that profits trump safety. If the ICC had cared, it could have found federal dollars. Federal money was found to help subsidize the PRR electrification to DC, 1933, for example..
Safety is a relative term. There is no such thing as "Safe" and "Unsafe". Some things and methods are safer than others but none are perfect. There are counterbalancing costs, too. There is only so much production capacity in the economy. If we spend some on "this" then it's not available for "that".
Deferred or omitted maintenance was a way of using the cash flow to finance "diversification", aka, getting out of the railroad business: PC, CNW, IC, D&RGW. Sure, you can say it's a corporation and they can do what they want, but it drained needed resources from what these outfits had been, namely railroads. Of course many changed their names as part of the process: Northwest Industies, Illinois Central Industies > Whitman (after divesting the railroad), Rio Grande Industries.
There was an enormous unused production and labor capacity in the US during the Depression. That is a hallmark of an economic downturn. A stimulus/loan from the feds for useful infrastructure has been and continues to be a wise investment.
C&NW, CA&E, MILW, CGW and IC fan
Paul Milenkovic oltmannd There are counterbalancing costs, too. There is only so much production capacity in the economy. If we spend some on "this" then it's not available for "that". Don, you must be new around here .
oltmannd There are counterbalancing costs, too. There is only so much production capacity in the economy. If we spend some on "this" then it's not available for "that".
There are counterbalancing costs, too. There is only so much production capacity in the economy. If we spend some on "this" then it's not available for "that".
Don, you must be new around here .
"You're filthy rich! You can drink any wine you want? Why do you drink THAT wine?"
"How do you think I got this rich!"
-ancient TV commercial for some kind of crappy wine....
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
oltmannd If your loco fleet is already equipped, and you can eliminate the wayside intermediate block signals, then it's a "win" just based on that. When Conrail had to replace the ancient and decrepit signal system on the B&A, they did exactly that. What makes the economic of it go is having to replace the block signal circuits.
If your loco fleet is already equipped, and you can eliminate the wayside intermediate block signals, then it's a "win" just based on that.
When Conrail had to replace the ancient and decrepit signal system on the B&A, they did exactly that. What makes the economic of it go is having to replace the block signal circuits.
I always wanted block signals for my model train layout, but when I was young, the electronics parts cost too much lawnmowing sweat, and now that I am old and transistors and LEDs are cheap, I simply don't have the time.
So my railroad line has cab signals, that's the ticket! And it sure does need them based on the double track with crossovers, reverse traffic passing, and the insane frequency of trains (didn't I just see that same train go by just 20 seconds ago?).
And I operate my Talgo at way over 79 MPH.
(OK, OK, already, I will take my remarks over to the MR forum . . .)
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
cx500But as I said earlier, eventually the old equipment reaches a point where a major upgrade is forced, such as converting to solid state equipment. And with a host of more useful projects competing for capital funds, it is not surprising that a legacy system would be closed down. I will note that on cab signal territory with no wayside signals, the situation is very different and the cab signal system would most likely be modernized out of necessity.
Coded track circuit and wayside cab signal equipment has been microprocessor based since the mid-1980s. It had a bit of a bumpy start (US&S's micro-code and micro-lock weren't quite ready for "prime time" when they went in on Conrail's Boston Line.)
The locomotive equipment followed closely behind. A basic Harmon Ultracab system was about 1/2 the price of a US&S non-solid state cab signal box in the early 1990s - and quite a bit more sophisticated. For example, it could do a 'self test' as well as "talk" to the cab electronics.
blue streak 12. The assumption that all these Cab Signal systems is just for passenger seems very short sighted. If so why is both CSX & NS adding to these systems before and after PTC legislation/.
The incremental cost of adding cab signal to territory that is already using coded track circuits is pretty low. If your loco fleet is already equipped, and you can eliminate the wayside intermediate block signals, then it's a "win" just based on that.
When Conrail had to replace the ancient and decrepit signal system on the B&A, they did exactly that. Despite all sorts of malfeasance between CR's C&S dept and the supplier (that got a few pretty high up guys fired), it worked out well enough that it was the template for doing new signalling in other areas going forward. Plans for doing the ex-RDG Harrisburg Line and ex-PRR Alliance to Cleveland were in the works. CR started work on the Harrisburg Line and NS finished it, plus continued on with the Chicago line Alliance to Cleveland.
What makes the economic of it go is having to replace the block signal circuits.
CSX converted carrier frequency on the RF&P from 60 Hz to 100 Hz, but outside of that, I don't know of any expansion of cab signalling on CSX.
daveklepper Is Harmon Electronics a separate former company that Hamon Automotive? Was Sidney Harmon involvled in Harmon Electronics?
Is Harmon Electronics a separate former company that Hamon Automotive? Was Sidney Harmon involvled in Harmon Electronics?
I have no idea. Harmon Electronics was (is) located in Grain Valley, MO. Just outside KC.
blue streak 1 cx500 Probably a big factor was the age of those mandated safety systems. Electrical components such as relays don't last forever. Move forward several decades and replacement parts for obsolete technology are no longer readily available. Custom orders are expensive, assuming you can locate a supplier that is even interested in manufacturing the needed parts. The only way to avoid the problem of obsolescence is to replace the entire system every 10 years or so, maybe even sooner with today's rapidly changing technology. Those higher train speeds were of no benefit to the freight traffic, and passenger trains weren't contributing enough to justify spending the money. So the speed of the few remaining passenger trains were reduced as a very cost-effective decision. John I must challenge these statements. 1 These systems are not obsolete. How could Metrolink have bought new ATS inductors and cab equipment for all their routes after Chatsworth?. As well BNSF's transcon required new inductors for the additional double & triple tracking tracking. The ATS system is very robust and newer complete operating parts can be manufactured to new electrical standards. I can imagine if a single signal or CP needed new equipment it would be readily available.? 2. The assumption that all these Cab Signal systems is just for passenger seems very short sighted. If so why is both CSX & NS adding to these systems before and after PTC legislation/. 3. How many freight incidents in the past few years would have been avoided by a past system and a lot cheaper than PTC ? 4. The major differences are the pickup sensors of ATS is mounted on the front axel which picks up outside the right hand rail. All others ACS, ATC, ACSES, etc use a sensor between the rails mounted under the front of the ahead of the front axel. With solid state electronics all it takes is different programing to operate on the various RRs or even different divisions. 5. Amtrak has never added the UP system to their loco since it does not operate usually on UP tracks with UP's system. That is why it takes a UP leader when detouring over UP out of Chicago.
cx500 Probably a big factor was the age of those mandated safety systems. Electrical components such as relays don't last forever. Move forward several decades and replacement parts for obsolete technology are no longer readily available. Custom orders are expensive, assuming you can locate a supplier that is even interested in manufacturing the needed parts. The only way to avoid the problem of obsolescence is to replace the entire system every 10 years or so, maybe even sooner with today's rapidly changing technology. Those higher train speeds were of no benefit to the freight traffic, and passenger trains weren't contributing enough to justify spending the money. So the speed of the few remaining passenger trains were reduced as a very cost-effective decision. John
Probably a big factor was the age of those mandated safety systems. Electrical components such as relays don't last forever. Move forward several decades and replacement parts for obsolete technology are no longer readily available. Custom orders are expensive, assuming you can locate a supplier that is even interested in manufacturing the needed parts.
The only way to avoid the problem of obsolescence is to replace the entire system every 10 years or so, maybe even sooner with today's rapidly changing technology. Those higher train speeds were of no benefit to the freight traffic, and passenger trains weren't contributing enough to justify spending the money. So the speed of the few remaining passenger trains were reduced as a very cost-effective decision.
John
You are mostly correct, as far as it goes. I will agree that with solid state electronics all it may take is different programming. But the field side of many installations would have been originally built decades before solid state electronics. Railroad signal engineers are very competent and can (and do) work miracles in getting very different operating systems communicating with each other with 100% reliability.
Where the traffic volume and mix justifies, making the expenditure to modernize all the components, or expand the system, makes a great deal of sense, which is no doubt why your examples are doing just that. But in other places, shifting traffic patterns may have eliminated most of the original reason for the installation. We also see former main lines with simpler wayside signal systems go dark when traffic shrinks to a trickle.
So it is not surprising that ATS (and cab signals if they supplement wayside signals), whose original installation was often instigated by regulatory requirements for high speed prestige passenger trains, may now be deemed a luxury in today's environment on a freight road. As long as the incremental maintenance costs were minor they would be accepted. But as I said earlier, eventually the old equipment reaches a point where a major upgrade is forced, such as converting to solid state equipment. And with a host of more useful projects competing for capital funds, it is not surprising that a legacy system would be closed down. I will note that on cab signal territory with no wayside signals, the situation is very different and the cab signal system would most likely be modernized out of necessity.
Railroad signal equipment has to be fail safe, close to 100% reliable, and do this over a temperature range of at least -40F to 130F, with similar swings in humidity. That is a challenge even for modern solid state electronics. The cost for just one installation is significant; over a 120 mile subdivision it becomes multiplied many fold.
blue streak 1 5. Amtrak has never added the UP system to their loco since it does not operate usually on UP tracks with UP's system. That is why it takes a UP leader when detouring over UP out of Chicago.
IC's ATS system was similar enough to C&NW's so that Amtrak's ex-IC units could lead out of Chicago on detours. The "Cab Signal from Hell" which could work with almost any ATS/ATC/Cab signal system was installed in the 1970s on some Amtrak E-units and SDP40Fs. Not sure what happened after that.
daveklepper And don't forget that the PRR elecdtrification included ATC!
And don't forget that the PRR elecdtrification included ATC!
Yes. PRR installed ATC on their electric fleet and on the passenger diesel locomotives. The diesel freight fleet was not ATC equipped. When Conrail stored the electric fleet and went with diesels under the wire, the level of safety dropped a bit since the diesels didn't have ATC. ATC probably would have prevented the Chase MD crash which is why the FRA mandated it for ANY train on the corridor.
The old suppression style ATC which required a 17# reduction to prevent a penalty brake is was ill-suited for modern freight train operation, so Conrail invented LSL ("locomotive speed limiter") in conjunction with Harmon Electronics (now part of GE) to perform the ATC function. It requires the train reduce speed and stay under a "worst case" braking curve by any mean available. Use of air brake is not required.
The combination of LSL and cab signal was offered as a product called "Ultracab" by Harmon. It exists today and the current version is the NS standard.
daveklepper Washington - Richmond still has it? Very glad if so.
Washington - Richmond still has it? Very glad if so.
Yep.
schlimm All very interesting, but unfortunately diverts from the major points raised by Blue Streak and Overmod. The question remains why mandated safety systems that allowed for passage at higher speeds were allowed to be discarded? Was this a "fox guarding the henhouse" script?
All very interesting, but unfortunately diverts from the major points raised by Blue Streak and Overmod. The question remains why mandated safety systems that allowed for passage at higher speeds were allowed to be discarded? Was this a "fox guarding the henhouse" script?
As a rough equivalent, go down to your local computer supplier and ask for one that can read a 5.25" floppy disk. Be prepared to get laughed at!
Victrola1 There is now pending before the Commission docket No. 29543, which is an investigation instituted May 20, 1946, on its own motion, to determine whether it is necessary, in the public interest, to require any common carrier by railroad to install block signal system, interlocking, automatic train stop, train control and/or cab signal devices, and/or other similar appliances, methods and systems intended to promote the safety of railroad operation, upon the whole or any part of its railroad on which any train is operated at a speed of 50 or more miles per hour. Hearing therein will be held in the near future. INTERSTATE COMMERCE COMMISSION WASHINGTON INVESTIGATION NO. 2988 CHICAGO, BURLINGTON & QUINCY RAILROAD COMPANY REPORT IN RE ACCIDENT AT NAPERVILLE, ILL., ON APRIL 26, 1946 Inv-2988 SUMMARY Railroad: Chicago, Burlington & Quincy Date: April 25, 1946 Location: Naperville, Ill. Kind of accident: Rear-end collision http://ntl1.specialcollection.net/scripts/ws.dll?websearch&site=dot_railroads
There is now pending before the Commission docket No. 29543, which is an investigation instituted May 20, 1946, on its own motion, to determine whether it is necessary, in the public interest, to require any common carrier by railroad to install block signal system, interlocking, automatic train stop, train control and/or cab signal devices, and/or other similar appliances, methods and systems intended to promote the safety of railroad operation, upon the whole or any part of its railroad on which any train is operated at a speed of 50 or more miles per hour. Hearing therein will be held in the near future.
Kind of accident: Rear-end collision
http://ntl1.specialcollection.net/scripts/ws.dll?websearch&site=dot_railroads
The basic reason ATC and ATS were discarded on many lines is because the "higher speed" trains (> 79 mph) for which these systems were required went away as the intercity rail passenger network shrunk. The ICC and later the FRA had authority to allow removal in these cases. The CNW ATC system on its east-west line survived because most of the line didn't have a wayside system.
Much of the PRR electrification was financed by loans from the RFC, hardly a subsidy since repayment of said loans was part of the package.
oltmannd schlimmThe question remains why did the ICC make the shift that not only stopped expansion of ATC and fast track, but eventually led to removal of ATC and downgrading track from 100 or 90 to 79mph or lower? Because the wheels were coming off the industry - you couldn't squeeze blood from a stone.
schlimmThe question remains why did the ICC make the shift that not only stopped expansion of ATC and fast track, but eventually led to removal of ATC and downgrading track from 100 or 90 to 79mph or lower?
Because the wheels were coming off the industry - you couldn't squeeze blood from a stone.
One, that really does not quite match the timeline Overmod gave, as the rails were doing quite well pre-Depression and 1940 onwards through the early to mid 1950's.
Two, that says that profits trump safety. If the ICC had cared, it could have found federal dollars. Federal money was found to help subsidize the PRR electrification to DC, 1933, for example..
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