middle siding signals

Thu Apr 20 09:17:19 EDT 2017

I’m not aware of any interlocking or control point where a dispatcher can’t set a route into an occupied track because when setting a route, there was no knowledge (in the interlocking equipment) of intended direction nor would the equipment know if the track was occupied by a cut of cars or an actual train with power on it. So for all it would know, the dispatcher or operator was lining it up for a move out of the occupied track.

Clearing the signals was a second step. Once the route was aligned, he then told it to clear the signals. Generally, when a dispatcher or operator clears a signal, he’s telling it to display a signal in what is essentially automatic mode - display the signal you would display if it were an automatic signal. If the track is clear two blocks ahead on the normal route, then that’s a Clear. On the diverging route, a Diverging Clear. And so forth. And if the track is occupied (which is what you’re asking about), then it varied. Sometimes, it would (if capable of displaying it), display Restricting automatically. At others, it would stay at Stop and Stay and if a move into the occupied track was desired, he had to take an additional step that essentially said “I know Stop is what you want to display but trust me on this, put up Restricting instead”.

I’m not familiar with where Villamont is. Is it a place where helpers would be cut off? I know of one place where it was common to cut off helpers on the fly and then let the caboose (which was behind the helpers) catch up with its train by gravity. After topping the hill, the helpers and caboose would be cut off, then the caboose from the helpers with everything still moving. Once the train cleared the siding switch, the operator lined the helpers into the siding (probably a Diverging Approach came up). Once the helpers were clear, the switch was restored to the main and the signal cleared again. With the rest of the train ahead (either stopped or moving slowly), the block was occupied but the signal displayed Restricting allowing the caboose to keep rolling until it caught up with the train and coupled on (if the train was still moving, the next time the train stopped, they’d then cut the air back into the caboose). Having Restricting available on the signal expedited a common move at that location.

If the bi-directional signaling was a late addition at that location, it’s entirely likely it was determined it was not worth the expense of adding Restricting to the signal. A dispatcher or operator can always talk a train by an absolute (Stop and Stay) - the only difference is the train must stop first and not just keep rolling.

-- 
Larry Stone
lstone19 at stonejongleux.com

> On Apr 20, 2017, at 6:45 AM, NW Mailing List <nw-mailing-list at nwhs.org> wrote:
> 
> Grant,
> Once again you have my thanks for sharing from your wealth of operational knowledge.  Allow me to confirm my understanding of your statements.  In cases where both the dispatcher and the engineer knew exactly why a movement would be entering an occupied block (to pick up a previously set off cut of loads or to get behind a drag to help shove it), the dispatcher could "override" the Stop and Stay that would normally be set automatically by the occupancy detection, with a Restricting/Call On to facilitate the movement.  This makes good sense and since the preponderance of such movements would have been from the East-bound main in the case of Villamont, it also stands to reason that the extra expense of allowing for such movements from the West-bound main may not have been justified.  Did all/most middle track storage sidings have this arrangement?  You mentioned that "The Pocahontas Division was littered with these where pushers would routinely get on."  I assume that Farm would have been one such location where pushers were routinely added for the climb into Bluefield, so they would have to enter occupied track to get behind the caboose for shoving.  What were some of the other locations for regular pushing?  And now to expose more of my ignorance, I believe the dispatcher could establish a route through a control point by "throwing levers" on his machine to set the turnouts and signals.  I assume that occupancy detection would try to prevent him from setting a route for the pusher into the occupied track, so how was able to 1) set the appropriate turnout and 2) cause the appropriate signal to show the Restricting aspect?  My assumption would be that there were special controls on the board for these locations that would allow the dispatcher to set the signal to Restricting overriding the occupancy signal.  If this is the case does anyone have/know of photos/diagrams of boards showing this facility?  I would further assume that the signals governing movements for pushers out of Boaz siding would have needed this same capability for the same reasons and I will track down my photos of these signals to have a look.
> Thanks again,
> Jim Cochran
> 
> On Wed, Apr 19, 2017 at 10:39 PM, NW Mailing List <nw-mailing-list at nwhs.org> wrote:
> Jim,
> 
> I would suggest that the Restricting aspect is for a call-on signal.
> 
> One would be looking downgrade when looking east at Villamont, so grade signals would not apply, plus grade signals are automatics, these are controlled (but note lack of "S" plate). They have a full compliment of diverging aspects at point-of-switch to govern middle track pull-in, so the middle track is bonded and signaled. A dark middle track would rate hand-thrown turnouts and no signals.
> 
> Actually, note that the track layout is not exactly symmetrical, but favors an easier alignment/higher speed pull-in off of the eastbound and standard crossover for pull-out to the westbound. One exception to above is if a spring switch is on the pull-out, it must be installed using the easier alignment and the signal would lack diverging aspects. 
> 
> Before the Virginian merger, I believe a train's worth of eastbound loads were set off here (and further east?) to fill tonnage for subsequent eastbounds. That is a whole lot of back and forth thru controlled signals displaying Stop and Stay into occupied blocks of the middle track and EB Main, so to cut down on       phone traffic and expedite matters, the dispatcher can override the Stop and Stay indication with Restricting, called a "call-on" signal. The Pocahontas Division was littered with these where pushers would routinely get on.
> 
> Grant Carpenter
> 
> On 4/19/2017 10:44 AM, NW Mailing List wrote:
>> Mr. Powers,
>> Thank you for your response.  I understand your comments on geography.  My remaining question is why would it be advantageous to allow an Eastbound movement to proceed at restricted speed on the East-bound main and not be advantageous to do so for an Eastbound movement on the West-bound main?  The layout of the middle siding appears to by symmetrical with respect to both mains and I am trying to understand why the signalling should be different.
>> Thanks for your help,
>> Jim Cochran
>> 
>> On Wed, Apr 19, 2017 at 8:26 AM, NW Mailing List <nw-mailing-list at nwhs.org> wrote:
>> Jim,
>> 
>>     A restricting signal indicates the right to proceed at a restricting speed. That aspect does not deal with geography, it deals with trains ahead and track circuit continuity. It sits one position above "stop and proceed", which only deals with trains ahead - you must stop and then proceed at a restricting speed. Below that is "stop and stay". If there is a yellow plate with the letter "G" on it below the signal head displaying "Stop and stay" on the mast, a train on an ascending grade can pass the signal without the stop, ready to stop short of a train ahead. All the above very fine delineations of                 keeping your speed safely in check.
>> 
>>     From the photo, I cannot tell what track the furthest EB signal controls. If it has a dummy mast to one side of it, it may control the center siding, and most likely be like an interlocking home signal and not have any aspect allowing a stop and proceed.
>>     Wm J Powers
>> 
>> On 4/19/2017 6:54 AM, NW Mailing List wrote:
>>> I believe the attached photo may show the West end of the middle siding at Villamont (confirmation would be appreciated).  My question concerns the East-bound signals that are visible.  The signal for the East-bound main is capable of displaying the RESTRICTING aspect while the one for the West-bound main is not.  In my understanding, one reason for the RESTRICTING aspect was to allow a train to proceed without coming to a complete stop on  a grade where it might have been very hard to start again.  Since this stretch is signalled for bi-directional running, why would the signal for the West bound main not also be capable of showing RESTRICTING?  It seems like the grade would have been the same for East-bound movements regardless of which main they were using.  Any thoughts?
>>> Thanks, Jim Cochran 
>>> 
>>> Moderator:
>>> http://www.nwhs.org/mailinglist/2017/20170419.midpasside.jpg
> 
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