The talk about signaling going down makes me wonder; Has anyone modeled
the sirens that go off when the ctc goes down near and in yards?  Could
be an added twist; and what a suprise the first time it goes off!   JonC

...
..

That was why I made my test Criag. I changed the address to match
correctly rather than counting on the forwarding. and wanted to make
sure it posted. I'm sure some people are not doing this and that fine
but it saves on excess traffic...JonC

Careful with the "A" plate designation. I've got a Penn Central/Conrail rule
book that uses an "A" plate to mean an _Approach_ signal prior to an
interlocking in dark territory. Not sure if these are absolute in all cases.

Dan Mitzel
Oxford, Mich.

> From: "David E. Husman" <dhusman@...>
> ----------
> > From: Dennis Storzek <dstorzek@...>
> > To: ldsig@onelist.com
> > Subject: [ldsig] Signal Question
> > Date: Wednesday, May 05, 1999 10:44 PM
> >
> > From: Dennis Storzek <dstorzek@...>
> >
> > It would seem that this signal, at the very end of
> > visible track, should display an ABSOLUTE STOP aspect, even though the
> > layout won't be CTC, to keep creative types from passing it per rule
> 240-B,
> > "stop then proceed at restricted speed".
> >
> >  What is the reason for this, and
> > which would be more appropriate for my lonely signal standing beside
> single
> > track?
> ===============================
> How about an "A" plate to indicate and "absolute" signal?
> ===============================
>
> Dave H.

>  "Code Fail" in CTC is when there is severe interference, or complete
> severance of the control line, causing loss of code signal and immediate
> loss of control of signals, switches and occupancy detection.
...............
>  At worst there may be signals cleared in the
> field that may conflict with instructions given by the grossly overworked
> (because of the code fail) dispatcher which could lead to a collision.
================================
It would take a failure in the signal cabinet, not a line failure to line
two trains into each other.  Even if the CTC is out, the ABS might
function, which would give protection.  If the ABS is out, it all drops to
Stop or dark.
================================
>  The singular most important variable in any voice based operating
system,
> such as TWC, DTC, and OCS, is communication. Communication is still based
> on a radio system, although cell phones are becoming more common,
> particularly on branches where it isn't cost effective to erect radio
> towers every 30 miles or so.
================================
Assuming of course that somebody has erected a cell phone tower every 30
miles or so.
================================
> When communication breaks down the effect
> although not immediate, occurs within 30 minutes, when most trains reach
> the limits of their authorities. When this limit is reached service is
> suspended until communication is restored.
=================================
Not as much suspended, as everything grinds to a halt (the word "suspended"
can have rule book implications).
=================================
>  Safety too is another aspect of reliability. There are several reasons
why
> T&TO systems were safer than voiced based systems of our day. The easiest
> example is that of a Train Dispatcher issuing orders on a closed circuit,
> that several operators will repeat and check for accuracy.
=================================
No matter how many times anybody repeats and checks the wording, if the
people who are to execute the orders are confused about them, then it may
be letter perfect, but still very unsafe.  That's what is better about the
modern systems, simplicity.

Both systems have the same weakest link, a human being to execute them.  A
train crew that blows by a radio copied track warrant meet is still just as
dead as a train crew that blows by a oft repeated train order meet.
A dispatcher that laps up a train on track warrants has done as badly as a
dispatcher who laps up a train order meet.
The difference is that with the automated systems of DTC and track warrants
there are checks that are built into the machine that make it harder to lap
up trains, much as ABS makes it harder to run two trains into each other.
There are no automated safeguards in train order.  It is entirely dependent
on human compliance with rules.
===================================
>  Would flexibility and performance be indications of a reliable system?
> T&TO was a well devised system that evolved over a period greater than
100
> years. There isn't one way of designating a train's authority now that
> couldn't be accomplished with more flexibility then.
===================================
Debatable.
===================================
>  To really stretch a point, T&TO created a closed environment. A secret
> code only understood by those that executed it.
===================================
Did you have a clubhouse and a secret handshake too? (stretch again 8-))

I think one of the basic reasons that T&TO went away was that is was a
secret, that it took too long to train everybody on the nuances.  As long
as you had been using it for 100 years it was great.  In an environment of
shrinking workforce that was OK since you didn't have to train anybody new.
  When deregulation hit and railroads rebounded, they had to actually hire
people again.  If I have to hire 1000 new people a year and train them on a
system with a 10 year proficiency lead time or a 3 year proficiency lead
time, which one will I use?  There were so many ways to do things that for
the people on the ground it became confusing.  The Masons might be able to
wait 10 years for a member to memorize all the secrets, but a railroad
can't risk playing bumper cars for that long.
===================================
> Dang......what's more scary, reorganizing Air Traffic Control ?
===================================
Actually several former air traffic controllers, now railroad dispatchers,
tell me that dispatching is harder.  You can separate planes in three
dimensions in ATC, while trains are more or less one dimensional.

Dave H.

>  "Code Fail" in CTC is when there is severe interference, or complete
> severance of the control line, causing loss of code signal and immediate
> loss of control of signals, switches and occupancy detection.
...............
>  At worst there may be signals cleared in the
> field that may conflict with instructions given by the grossly overworked
> (because of the code fail) dispatcher which could lead to a collision.
================================
It would take a failure in the signal cabinet, not a line failure to line
two trains into each other.  Even if the CTC is out, the ABS might
function, which would give protection.  If the ABS is out, it all drops to
Stop or dark.
================================
>  The singular most important variable in any voice based operating
system,
> such as TWC, DTC, and OCS, is communication. Communication is still based
> on a radio system, although cell phones are becoming more common,
> particularly on branches where it isn't cost effective to erect radio
> towers every 30 miles or so.
================================
Assuming of course that somebody has erected a cell phone tower every 30
miles or so.
================================
> When communication breaks down the effect
> although not immediate, occurs within 30 minutes, when most trains reach
> the limits of their authorities. When this limit is reached service is
> suspended until communication is restored.
=================================
Not as much suspended, as everything grinds to a halt (the word "suspended"
can have rule book implications).
=================================
>  Safety too is another aspect of reliability. There are several reasons
why
> T&TO systems were safer than voiced based systems of our day. The easiest
> example is that of a Train Dispatcher issuing orders on a closed circuit,
> that several operators will repeat and check for accuracy.
=================================
No matter how many times anybody repeats and checks the wording, if the
people who are to execute the orders are confused about them, then it may
be letter perfect, but still very unsafe.  That's what is better about the
modern systems, simplicity.

Both systems have the same weakest link, a human being to execute them.  A
train crew that blows by a radio copied track warrant meet is still just as
dead as a train crew that blows by a oft repeated train order meet.
A dispatcher that laps up a train on track warrants has done as badly as a
dispatcher who laps up a train order meet.
The difference is that with the automated systems of DTC and track warrants
there are checks that are built into the machine that make it harder to lap
up trains, much as ABS makes it harder to run two trains into each other.
There are no automated safeguards in train order.  It is entirely dependent
on human compliance with rules.
===================================
>  Would flexibility and performance be indications of a reliable system?
> T&TO was a well devised system that evolved over a period greater than
100
> years. There isn't one way of designating a train's authority now that
> couldn't be accomplished with more flexibility then.
===================================
Debatable.
===================================
>  To really stretch a point, T&TO created a closed environment. A secret
> code only understood by those that executed it.
===================================
Did you have a clubhouse and a secret handshake too? (stretch again 8-))

I think one of the basic reasons that T&TO went away was that is was a
secret, that it took too long to train everybody on the nuances.  As long
as you had been using it for 100 years it was great.  In an environment of
shrinking workforce that was OK since you didn't have to train anybody new.
  When deregulation hit and railroads rebounded, they had to actually hire
people again.  If I have to hire 1000 new people a year and train them on a
system with a 10 year proficiency lead time or a 3 year proficiency lead
time, which one will I use?  There were so many ways to do things that for
the people on the ground it became confusing.  The Masons might be able to
wait 10 years for a member to memorize all the secrets, but a railroad
can't risk playing bumper cars for that long.
===================================
> Dang......what's more scary, reorganizing Air Traffic Control ?
===================================
Actually several former air traffic controllers, now railroad dispatchers,
tell me that dispatching is harder.  You can separate planes in three
dimensions in ATC, while trains are more or less one dimensional.

Dave H.

> From: Jim/Natalie Moir <moir5sdr@...>
>
> >I'm familiar with the concept of route
> >signaling, where the upper head shows indications for the main route,
the
> >lower for the diverging route,...
>
> No. No. No.  Route indication is European signaling practice.  American
> signaling practice is based on braking distance and speed.  The signal
> indication is for a speed, at the signal and at the next signal(s) in
> advance.  The indication will call for one of "Normal", "Limited",
> "Medium", "Slow", "Restricted" speeds or "Stop"; or some combination of
> those speeds that have the affect of indicating conditions such as
"medium
> to slow".
========================
Then how do you explain "Diverging" clear, approach, clear slow, approach
limited, etc, etc?  Diverging implies and indicates route.
For example "Diverging Clear" 's indication is "Proceed on diverging route
at prescribed speed through turnout."

I have seen more Eastern RR's with what appear to be speed indications and
more Western RR's with route indications.  I personally attribute this to
Eastern roads having generally more complicated trackage, where route
indications make less sense than speed indications.  No specific  evidence.
==========================
>  Obviously you can _not_ assume the route you will be
> taking.
========================
On a diverging signal I think I can pretty well assume I'm not making a
straightaway move down the main.  I bet I'll be taking the diverging route.
8-)

Dave H.

----------
> From: Dennis Storzek <dstorzek@...>
> To: ldsig@onelist.com
> Subject: [ldsig] Signal Question
> Date: Wednesday, May 05, 1999 10:44 PM
>
> From: Dennis Storzek <dstorzek@...>
>
> OK, here's another couple of questions on signals.
>
> I've been doing some headwork on how I plan to integrate Mike Dodd's SYC2
> staging yard controllers into my layout. One of the things planned is to
use
> the LED driver outputs to drive a model signal on the layout as well as a
> repeater on the panel. It would seem that this signal, at the very end of
> visible track, should display an ABSOLUTE STOP aspect, even though the
> layout won't be CTC, to keep creative types from passing it per rule
240-B,
> "stop then proceed at restricted speed".
>

>  What is the reason for this, and
> which would be more appropriate for my lonely signal standing beside
single
> track?
===============================
How about an "A" plate to indicate and "absolute" signal?
===============================
>  Rule 240-H defines an aspect called "RESTRICTING", Red over yellow,
> that indicates "proceed at restricted speed". Sounds like just what I
need,
> but what is its proper use on the prototype?
============================
A restricting can also be a "lunar" signal (a blue-ish white).  The lunar
version is typically used to give permission to enter non signalled track
such as a non'controlled siding or a branch/yard track/lead.  I would
assume the Restricting you mentioned did the same thing (I know assuming is
a bad thing).  In the rule books I am familiar with, red over yellow is
diverging approach, which might be appropriate, but would indicate you
needed to comply with another signal.
=============================
> Oh yeah, one last one. On the signal representations on a CTC panel, are
> both heads of a signal with two heads shown?
==============================
On a CTC panel absolute signals only are indicated, and then only a yes/no,
red/green, on/off, indication.  In a CTC system the dispatcher doesn't
specifically choose the signal (except for STOP), he chooses a route and
asks the system to provide the most favorable signal aspect possible for
that route.  The dispatcher doesn't know what that signal actually is (well
actually they do since they are familiar with the rules and can talk to the
trains who are more than happy to describe any restricting signals), but
the only indication he gets is that the signal indications have been
"cleared", meaning activated, for that route.  The signals can be "cleared"
by the dispatcher and the best indication the train might get is STOP
(happens all the time when signals are put in fleeting mode).

Some CTC system panels have a red light for signals at stop or not cleared,
green for cleared and yellow or yellow flashing for "clearing" (the CTC
machine is still thinking about it).

Dave H.

Hi Folks

Please ignore this message, the last one I posted to CS.UTK.EDU was
routed through OneList and came back to me with funky formatting.
Everyone elses messages appear normally, so I'm trying out a direct
submission to OneList to see how it comes back..

The paragraphs all ran together, so I want to see if this series of
paragraphs works together properly.

Sorry for the trouble, please return to you previously scheduled
programme...

Craig Bisgeier - Clifton, NJ

Visit the Housatonic Railroad Homepage at:
http://members.microdsi.net/cbisgeier

> Some other procedures with possible bearing on throughput.  Our train
> order boards are kept in red/stop position whenever the telegraph office
> is open.  The operator has to notify the DS of approaching trains and
> receive permission to clear the board if no orders are to be delivered.
> Our orders, therefore, are not concered with "19" or "31" forms and
> procedures.
========================================
This is interesting.  First time I've heard of a RR doing this.  The more
typical procedure I've seen is to keep the TO boards at "clear" and when
the dispatcher tells the operator "Copy 5 west" the operator then puts the
w/b TO signal at stop.

The dispatcher only has to "clear" a train at the points the DS needs to,
as opposed to communicating twice for every train at every manned location
(once to make sure there are no orders and 2nd to OS the train by).  Having
the default as clear really cuts down on a lot of radio/phone traffic with
the DS.
==========================================
> And then there is the Tehachapi syndrome, where the combination of
> longer trains and adherence to prototype track arrangements impact not
> only throughput, but capacity.  We're moving 1200-1500 cars per op
> session, which seems significantly higher than on other layouts.  Whether

> that characterization is accurate or not, those sort of numbers mean
> repeat runs for many cars during a sessions because of present
> limitations on staging.  And operating in 2 eras essentially doubles the
> number of cars needed if we didn't fudge and use some of the older
> cars for both types of sessions.
==========================================
Don't take this as a criticism, its a question on philosophy.

Are the SP sessions more heavily trafficed because you are running more
trains because you can, or is it because you are able to execute the plan
you want?

Does your plan call for running 35 trains and you run all of them or is it
a "Gotta crew, gotta train, gotta go" type of thing where you're running
more trains because there's a vacant slot on the mainline and a train is
back in staging?

Dave H.

>       #          |   Chicago  |       |  |       \      oo#
>   ----#-------------------------------+--+--------+-------#---- track 2
>       #oo        |   bridge   |       |  |         \    oo#
>   ----#-------------------------------+--+----------+-----#---- track 1
>       #oo  /     |   River    |       |  |           \    #
>  branch   /                           PRR           B & O
>  ---------
>       |--oo
>
>
> The operator will have a direction-of-traffic lever for each main
> track, a control for the turnout to the branch, and levers for the
> three cross tracks.
========================
Actually you would need a direstion lever for each of the crossing roads to
clear the crossings road's train in the proper direction.  If you wanted
the full interlocking.  For the purposes of the home road, their direction
is immaterial.
=========================
> The position of the bridge will be detected by
> microswitches.  In addition, there probably will be a timer that will
> "give" a cross track to the PRR or B&O at random times for short
> intervals -
===========================
Sometimes the other RR has the diamond for not so short lengths of time,
regardless of what the rules say.
===========================
> I haven't specified the aspects and indications for the signal
> for exiting the branch line moving east.  Not yet sure of what
> hardware will be used for this position.
============================
In the west it would be stop, diverging approach (red over yellow) or
diverging clear (red over green) if the branch was signaled or restricting
(lunar) if it was a dark branch.

A photo-copy of a 1968 Penn Central rule book has a Slow-clear and
Slow-approach which would be applicable to interlockings (red over yellow,
proceed at slow speed, 15mph, through the interlocking or lunar, proceed
prepared to stop at the next signal, slow speed through the interlocking).

Also the prototype operator would have derails he would have to line
protecting the bridge.
The sequence might be, lower the bridge and lock it in place.  Close the
derails.  Line the switches. Clear the route.

Which has right of way through the bridge, RR or boats?  i.e. Is the bridge
normally up or normally down?  Its done both ways depending on how busy the
channel is.

Dave H.

Dennis Storzek wrote

>I'm familiar with the concept of route
>signaling, where the upper head shows indications for the main route, the
>lower for the diverging route,...

No. No. No.  Route indication is European signaling practice.  American
signaling practice is based on braking distance and speed.  The signal
indication is for a speed, at the signal and at the next signal(s) in
advance.  The indication will call for one of "Normal", "Limited",
"Medium", "Slow", "Restricted" speeds or "Stop"; or some combination of
those speeds that have the affect of indicating conditions such as "medium
to slow".

Obviously the very immediate conditions of a route can determine maximum
speed, and that is probably where the confusion comes in.  It is still
speed signaling.

The overiding condition limiting your speed - and thus your braking
distance - is who is ahead of you and how far they are ahead.  The signals
may be indicating occupancy 2, 3 or 4 blocks ahead.

On an interlocking signal (all the heads in vertical line) it is a
convention, and a convention only, (for example see Phillips Q:#66, p.17,
lower left column) that the "normal" speed be shown on the top signal, the
medium speed be indicated on the middle head, and the slow speed be
indicated on the lower head.  In addition, some indications read, for
example: This aspect means "Medium speed. Medium through turnouts" and this
is misinterpreted to suggest "route indication" but it isn't.  There a)
might be a train in the block ahead, and you have to slow to medium
prepared to stop; b) or you might be going through the "normal" side of the
turnouts; or c) you might be going through several turnouts.... but in any
case at medium speed.  Obviously you can _not_ assume the route you will be
taking.

A relation between "head" and "speed" worked fine (I suppose <g>) before
"limited" speed was invented.  Limited speed is shown as a flashing aspect
(now) on either the upper or middle heads. There is mention of "express"
speed (at 60 mph, used as an intermediate between a normal speed of 90+mph
and a limited speed at 45 mph) but I can not find any use of this speed in
modern practice (post 1950).

Another complication to the simple "this head means X" interpretation is
four block signaling, where the "approach _second_ signal at X" indication
is used.  This is usually for slowing from normal to limited speed at the
second signal, or "approach _second_ signal at medium prepared to stop at
following signal" indication.

Regardless, with four speeds to indicate at this signal and potentially 5
other speeds at the next signal and possibly at the second signal, there is
no simple and single correlation between "head" and "speed"... though the
tendency is put aspects that indicate greater speeds on the heads higher up
on the mast.  As an aside, although aspects are not standardized between
railroads, speeds and indications are standard; and there is great
similarity between aspects.

There are other complications ("speed up" signals) but this gives the
flavor.  If one is getting into signal system design in any seriousness,
you might want to go beyond even Edmund Phillips' book and look at the FRA
Technical Manual as well as the FRA Signals Rules.  Although there a great
differences in signaling between railroads - each system is almost a "one
off custom job" - there are underlying principles (and standards). And the
key one is:

It ain't route signaling: it's speed and braking distance signaling.

	 Jim

Jim Moir/ProTrak (http://www.protrak.cc>

Hi all,

Thanks to those of you who have responded to my request for additional
authors we now have several more chapters claimed!  Way to go!

Due to the hosting difficulties, I think that, at least for the time being,
we will maintain a copy of the PRIMER at its original location:
http://www.vetmed.auburn.edu/~smithbf/BFSpages/LDSIGprimer/TOC.html

Please look to this site for all updates until further notice

Happy Rails
Bruce

Bruce F. Smith V.M.D., Ph.D.
Scott-Ritchey Research Center
334-844-5587, 334-844-5850 (fax)
http://www.vetmed.auburn.edu/~smithbf/

There is a very fine line between "hobby" and "mental illness." - Dave Barry

PRRMO: The PRR Modular Modeling Society! http://prrmo.pennsyrr.com
        _               _
       / \             / \
   ____\_/_____________\_/____   ____________________________________
  |- _______/ O     \_______ -| |_  __  __  __  __  __  __  __  __  _|
  | /      PENNSYLVANIA     \ | | ||__||__||__||__||__||__||__||__|| |
  |/_________________________\|_|_|________________________________|_|
  | O--O   \0   0   0/   O--O | |=| 0==0                      0==0 |=|

Linda, Bill:

I've been talking with some other LDSIG / OpSIG members (Ted Dilorio &
others) here in NJ about getting together a weekend session sometime, but
we are experiencing similar problems to what Linda has described.  Right
now, a lot of the operating layouts in the NJ area I'm familiar with are
down for one reason or another, or operating less often, and the
remaining ones are running at SRO (OK, its a poor simile, most of us
stand anyway).

Another factor is some of the larger railroads around here don't seem to
be well-equipped to handle a whole cadre of boomers.  Or the owners have
so much work to do to restage it's very hard to squeeze in an extra
session between those belonging to their regulars.

A third factor is they are spread out over a lot of the state.  It's a
small state, but many folks could easily be driving 45 minutes to an hour
between sites.  Few railroads are located close together.

I am getting around to asking though, and I imagine offering some setup
help before the date to help restage or clean up will make the trouble of
opening up for an extra session a little less onerous for those who
participate.  This type of experience before the fact can be eye-opening
too for nascient modelers, and offer an opportunity to see the railroad
before the session.

Hopefully, look for something this fall or early winter.  If anyone on
the list in the Northern / Central NJ area has an operating layout and
would like to participate, please let me know.

Craig Bisgeier - Clifton, NJ

Visit the Housatonic Railroad Homepage at:
http://members.microdsi.net/cbisgeier

In a message dated 5/5/99 2:45:07 PM, nicholas@... wrote:

<<Tom  and Jon
Sounds like you guys had a great time wish I could have been there.
Lee>>

Call board shows you and Kelly (and ???) for the first Saturday of any month
you can respond.  Tom

At 10:44 PM 5/5/99 -0500, Dennis Storzek wrote:
>
>Secondly, It seems to me that this signal should clear to something more
>restrictive than green, as the train will be wending its way through hidden
>trackage into a yard. A yellow aspect, or yellow over red, APPROACH,
>requires slow speed running, but also implies that another signal will be
>reached. Rule 240-H defines an aspect called "RESTRICTING", Red over yellow,
>that indicates "proceed at restricted speed". Sounds like just what I need,
>but what is its proper use on the prototype?
>

A restricting signal indicates different things. Some of them are:

You are diverging from the main track and entering other than main track.
Rule 105 applies.

You should expect a train or equipment foul of the main track in the block
ahead.

You should be on the lookout for a broken rail in the block ahead.

A clear signal only indicates one thing consistently. The track is clear in
the block ahead. It doesn't convey information as to what speed the track
is good for. Usually that is defined in the Timecard, Special Instructions,
or by Train Order.

Jack Ozanich erected a telephone box attached to a pole at his yard limit
sign, and entered a notation to his timecard,  contact the yardmaster for
instructions before passing said location.

Should a creative individual pass into the yard without fulfilling said
instruction, they would be a bobo. Jack would let them know it, and it
would be far worse than passing a red signal. <8(

Real railroads are often loathe to erect signals at locations where they
are completely unnecessary. But... there are always exceptions.

Chris Galka
galka@...

At 10:44 PM 5/5/99 -0500, Dennis Storzek wrote:
>
>Oh yeah, one last one. On the signal representations on a CTC panel, are
>both heads of a signal with two heads shown?
>

Nope. I've never seen it, anyway.

No point in the dispatcher knowing what indication the train receives as
the signal system will display in the field the best indication for the
route and conditions. It's pretty failsafe.

In short, they are all clear signals, to the dispatcher at least!

Chris Galka
galka@...

At 03:34 PM 5/5/99 EDT, DaveBPMLRR@... wrote:

   But train-orders takes
>knowledge of the railroad, distances to the next station, grade, running
>times and interpretation of the rulebook and train-order rule, (superiority
>of trains).  This can be a little scary.  Even when working professionally
on
>the coast route, SP using train orders, there were times when you were not
>sure what to do, go or wait?  That's when the radio would save your rear,
and
>sometimes your life.  It's no wonder the SP went to DTC a few years later,
it
>was a lot less confusing, cheaper, less expensive and more reliable.
>

  Truly there was many a senior man who stayed a trainman his whole career,
just to avoid  stress of the conductor's responsibility in such an
environment.

  I would like to take a contrary position on the point reliability though.

  Timetable and Train Orders could effectually operate without radio
communication,  and even for a good deal of time during "wire failure".

  "Code Fail" in CTC is when there is severe interference, or complete
severance of the control line, causing loss of code signal and immediate
loss of control of signals, switches and occupancy detection. At best the
road is blind and incapable of operation at anything greater than
restricted speed for miles. At worst there may be signals cleared in the
field that may conflict with instructions given by the grossly overworked
(because of the code fail) dispatcher which could lead to a collision.

  The singular most important variable in any voice based operating system,
such as TWC, DTC, and OCS, is communication. Communication is still based
on a radio system, although cell phones are becoming more common,
particularly on branches where it isn't cost effective to erect radio
towers every 30 miles or so. When communication breaks down the effect
although not immediate, occurs within 30 minutes, when most trains reach
the limits of their authorities. When this limit is reached service is
suspended until communication is restored.

  Another aspect of reliability of a radio system is the principle of
communication using this wonder of Marconi's age. That is, transmissions
are distorted, corrupted, and frequently walked on by other parties
carrying on a conversation miles away.

  Safety too is another aspect of reliability. There are several reasons why
T&TO systems were safer than voiced based systems of our day. The easiest
example is that of a Train Dispatcher issuing orders on a closed circuit,
that several operators will repeat and check for accuracy.

  Would flexibility and performance be indications of a reliable system?
T&TO was a well devised system that evolved over a period greater than 100
years. There isn't one way of designating a train's authority now that
couldn't be accomplished with more flexibility then.

  For example, A work extra could be given no rights whatsoever. It must
clear the times of scheduled trains, and even extra trains if so
restricted. Or a work train can be given right over all trains, which would
have to protect against it within specified limits. Even some less
restrictive measure could be spelled out in an order for trains the
dispatcher specifically didn't want delayed. The possibilities were endless.

  On my railroad today, A work extra can only be handled one way. All trains
are required to contact the Work Extra and wait until permission is granted
to proceed into it's limits. Several Work Extra's could tie up a railroad
significantly, if they are not prepared to clear, and there is little the
dispatcher can do to facilitate the situation.

  To really stretch a point, T&TO created a closed environment. A secret
code only understood by those that executed it. In that time, operating
departments were run by railroaders, and were not experimental laboratories
for cross trained crew managers,  brainstorming cliques, technocrats, and
endless levels of authority to resolve a simple issue.

  9566 West, stand by. I understand CP 313513 is bad order, but the Corridor
Manager  and Operations Manager are on their conference call; Only they can
contact the Customer Action team to ensure that you ought not to wait for a
priority car while the Car Dept Supervisor checks the road repair truck's
location; contacts and dispatches it to the scene to begin repairs. Your
tail end is hanging out and I've two eastbounds waiting at the next siding
for you, can you clear the main track instead?

Dang......what's more scary, reorganizing Air Traffic Control ?


Chris Galka
galka@...

ping

OK, here's another couple of questions on signals.

I've been doing some headwork on how I plan to integrate Mike Dodd's SYC2
staging yard controllers into my layout. One of the things planned is to use
the LED driver outputs to drive a model signal on the layout as well as a
repeater on the panel. It would seem that this signal, at the very end of
visible track, should display an ABSOLUTE STOP aspect, even though the
layout won't be CTC, to keep creative types from passing it per rule 240-B,
"stop then proceed at restricted speed".

Rule 240-A in the Soo Line signal section of the Consolidated Code gives me
two different ways to accomplish this. I can simply leave the number plate
off the signal mast carrying a single head, and the single red will be an
absolute stop, or I can add a second head with a fixed red, so the red
aspect becomes red over red. I'm familiar with the concept of route
signaling, where the upper head shows indications for the main route, the
lower for the diverging route, which yields red over red if neither route is
cleared, but I've also seen instances where a fixed red was added to modify
the indication shown on the other head. What is the reason for this, and
which would be more appropriate for my lonely signal standing beside single
track?

Secondly, It seems to me that this signal should clear to something more
restrictive than green, as the train will be wending its way through hidden
trackage into a yard. A yellow aspect, or yellow over red, APPROACH,
requires slow speed running, but also implies that another signal will be
reached. Rule 240-H defines an aspect called "RESTRICTING", Red over yellow,
that indicates "proceed at restricted speed". Sounds like just what I need,
but what is its proper use on the prototype?

Comments, anyone?

Oh yeah, one last one. On the signal representations on a CTC panel, are
both heads of a signal with two heads shown?

Dennis Storzek
Big Rock, IL

Is there a discusion list for people who want to do this?  I've just
purchased the PIC development system & chips and would love to swap notes
with someone who's been here.

Lewis Chapman

-----Original Message-----
From: Mike Dodd <mdodd@...>
To: <ldsig@...>
Date: Wednesday, May 05, 1999 3:53 PM
Subject: Re: [ldsig] Interlocking Signals


>From: Mike Dodd <mdodd@...>
>
>At 11:55 PM 5/4/99 -0700, Michael Stimac wrote:
>>Note- there are hybrid approaches, too, in which relay-like logic
>>is used, but solid-state components stand in for relays.  No computers,
>>I/O cards, busses, etc, needed with this approach either.  In the
>>case of the project I alluded to recently, well, I have a neighbor
>>who is interested in doing some solid-state circuit design, so
>>this hybrid approach is the one to be taken.
>
>Anyone attempting such a project would be well-advised to look first at
>dedicated microprocessors, such as the PIC series by Microchip (carried by
>Digi-Key).  For about $200 you can buy a complete development system -
>software for a PC, plus a programmer for the microprocessors.  Not pocket
>change, but you can use it for many different projects - or the same one
>multiple times.
>
>One microprocessor chip and a handful of "glue" chips can replace a lot of
>individual logic chips.  Plus, its extremely easy to change something when
>necessary.
>
>Having designed logic circuits in the past, I can say that using a
>microprocessor instead is better all around.
>
>Mike
>
>------
>Mike Dodd - Montpelier, VA
>Modeling Virginian Railway, 1957
>http://www.mindspring.com/~mdodd/vgn_frame.htm
>
>------------------------------------------------------------------------
>With more than 14 million emails exchanged monthly.
>http://www.ONElist.com
>ONElist is truly helping connect the world!
>

Hi All,
This is a good move using Onelist.  I have been using them as my list server
for almost a year now and can't say enough about the service they provide.
They keep moderators abreast of all changes and updates to the system and fix
problems fast.  Mike and Dave's job will be a lot easier now.  BTW, as to the
concern about spam, it happened only once on my list with a fellow who signed
up for the list.  I filed a complaint to the Onelist administrators and they
took care of it immediately.  I also received prompt apologies from them and
assurance that they take great measures to make sure this never becomes a
problem.  Did I mention that I'm happy with their service? :)

Best Regards,
Ted DiIorio
Anthracite RR List Moderator
LD-Sig Member

In a message dated 5/5/99 8:50:13 PM Eastern Daylight Time, Railliar@...
writes:

<< I wonder if your doing the above will make any difference to those of
already
  "subscribed" to onelist, at least as far as onelist is concerned? >>

Eric,

I was already subscribed on Onelist for the Cadrail User-s group.  Now when I
go to Onelist it shows me corrrectly as members of both the CR-Users and
LDSIG list.  Looked clean to me.

Joe Brann
Orlando, FL

In a message dated 5/5/99 4:10:47 PM Mountain Daylight Time,
davison@... writes:

<< o subscribe everyone to ldsig@onelist.com. >>

I wonder if your doing the above will make any difference to those of already
"subscribed" to onelist, at least as far as onelist is concerned?

eric

In a message dated 5/5/99 10:27:42 AM Mountain Daylight Time,
BillJewett@... writes:

<< Can't wait until
   the tour next year >>

You don't have to.  The Rocky Mountain Region's 50th anniversary convention
June 10-13 will include 3-4 layout operation opportunities plus two days of
operations-oriented clinics.

eric

Dave B. wrote:

> Still planning on coming down for one of your runs.  Don, could you email
> off list again of your dates.  Thanks again and always interested in
> operations and signaling.

Next scheduled op session is Saturday, July 12.  We'll be running
TTTO with big steam and early diesel using analog block control and
some DCC.  We try to accomodate guest operators but can get
inundated, so please contact us in advance if you desire to attend.  If by
email, I'll run it by the ops crew setting up for the particular operation.

Don


---------------------------------------------------------------------
Helping build the HO scale Tehachapi Pass layout of the La Mesa Model
Railroad Club in the San Diego Model Railroad Museum.

Bill J. wrote:

> Can you say a bit more about the differences in procedures?  TT&TO
> dispatching (aside from its requirements for learning the rulebook) can
> tend to be a constraint on layout throughput due, I suppose, to the time
> required to write, dictate, and repeat orders and clearances.  Is there
> any difference in the content of the orders themselves, or does "SP
> practice" just shortcut the transmission process?  How?  Might be some
> good leads for other operations.

Our version of ATSF procedure was to treat the clearance as a train
order, i.e., logged in numerical progression, repeated back, clearance
time assigned by the DS.  Our version of SP procedure lists
unnumbered clearances on a separate page, DS only acknowledges
correctness of operator's listing.

Other procedures essentially the same, although one difference is that
the ATSF said word, then spelled it, while SP spells word, then says it.
Makes for some tongue twisting times when you only get to dispatch
TTTO once every 12-18 months, as seems my lot.

Some other procedures with possible bearing on throughput.  Our train
order boards are kept in red/stop position whenever the telegraph office
is open.  The operator has to notify the DS of approaching trains and
receive permission to clear the board if no orders are to be delivered.
Our orders, therefore, are not concered with "19" or "31" forms and
procedures.

Under ATSF practices, all but one freight in each direction were run as
extras.  Under SP practice, there are several 3rd class freight schedules,
including one about ever 2 hours eastward (uphill).  The majority of
eastward freights thus run on timetable or as sections of a timetabled
train.  That generally makes for fewer train orders and, on reflection,
might have a greater bearing on throughput.

The effect of procedures on throughput not something we've studied,
but more anecdotal recitation of average trains per op session under
different dispatching systems.  For layout design purposes, the
difference between TTTO and CTC seems to have a much greater
effect on throughput.  That, in turn, necessarily drives design of yards,
mainlines, sidings, staging, operating positions (and assignments),
signalling, etc.,  necessary to support the particular type of operation
envisioned for a layout.

And then there is the Tehachapi syndrome, where the combination of
longer trains and adherence to prototype track arrangements impact not
only throughput, but capacity.  We're moving 1200-1500 cars per op
session, which seems significantly higher than on other layouts.  Whether
that characterization is accurate or not, those sort of numbers mean
repeat runs for many cars during a sessions because of present
limitations on staging.  And operating in 2 eras essentially doubles the
number of cars needed if we didn't fudge and use some of the older
cars for both types of sessions.

All this and running trains for the public 6 days a week, too.  Let's put it
this way --  we hope to get the upper floor (with The Loop) built and in
operation before it becomes necessary to replace rail on the lower level.
  Gives new meaning to the old phrase, "onward and upward". <g>

Don

---------------------------------------------------------------------
Helping build the HO scale Tehachapi Pass layout of the La Mesa Model
Railroad Club in the San Diego Model Railroad Museum.

At 11:55 PM 5/4/99 -0700, Michael Stimac wrote:
>Note- there are hybrid approaches, too, in which relay-like logic
>is used, but solid-state components stand in for relays.  No computers,
>I/O cards, busses, etc, needed with this approach either.  In the
>case of the project I alluded to recently, well, I have a neighbor
>who is interested in doing some solid-state circuit design, so
>this hybrid approach is the one to be taken.

Anyone attempting such a project would be well-advised to look first at
dedicated microprocessors, such as the PIC series by Microchip (carried by
Digi-Key).  For about $200 you can buy a complete development system -
software for a PC, plus a programmer for the microprocessors.  Not pocket
change, but you can use it for many different projects - or the same one
multiple times.

One microprocessor chip and a handful of "glue" chips can replace a lot of
individual logic chips.  Plus, its extremely easy to change something when
necessary.

Having designed logic circuits in the past, I can say that using a
microprocessor instead is better all around.

Mike

------
Mike Dodd - Montpelier, VA
Modeling Virginian Railway, 1957
http://www.mindspring.com/~mdodd/vgn_frame.htm

All,

The mailing list for the Layout Design SIG is now hosted by Onelist.
David Zuhn and I are still the administrators so if you have problems
send David mail... ok, you can send mail to me too. ;-)

Messages to the list should be sent to ldsig@onelist.com. To subscribe,
unsubscribe and change to digest mode please visit

     http://www.onelist.com/subscribe/ldsig

I was not able to subscribe digest users in digest mode. Each of you will
need to visit the URL above and change your subscription mode. Sorry.

Messages to ldsig-request@... will return a note telling you about
the new list server. Messages to ldsig@... will be forwarded to
ldsig@onelist.com. At some point in the future both aliases will go away.

Mike Davison

Hey am I there? Everone is gonna want to check there mailout. So lets
all have a little patience. JonC