Stopping a Train

Hi Folks,

I am considering the idea of placing some dead track sections [controlled by an ON-OFF toggle switch] at high risk locations [crossings, tunnel exits, etc.] to safe guard against a collision between a continuous running train [unmonitored] and any other train. I am thinking that it would be ideal to have the ability to stop the unmonitored train by cutting the power ahead of its engine(s). For example, within a continuous loop, a train exits a tunnel in a high traffic area on the layout. On most occasions, that's not a problem. However, there may be times when I would like the option to stop that train just as it exits the tunnel given my uncertainty as to what may be taking place at that location. Once all concerns have been dismissed, I would then start that unmonitored train on its continuous run, once again.

My questions:

(1A) If you have these dead track sections [as described above] and an engine pulling a train hits this section when the power has been cut [toggle OFF], is this bad for the engine and/or the cars and their couplers?

(1B) If so, how do you safely stop an unmonitored train with one or more engines?

Many Thanks! Matt

Reply to
Matt & Kathleen Brennan
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Mechanically it doesn't seem to cause any major damage or wear. Physically it is probably better for a loco than hitting another loco at speed.

It can cause derailments if the loco is of the type that locks it's wheels.

Use a contact section and a latching relay to switch off a longer section of track, preferably a full train length to deal with banking locos, modern high speed (passenger) trains which use a loco at each end, or push/pull trains where the loco might be at either end. The contact section can be a quarter inch (or a two sleeper/tie length) separate isolated piece of rail on the common rail which will ground the relay coil. Preferably the latching relay will have end off switching so that only the first (metal) wheel will operate it.

Normally (until recently) the prototype will separate it's trains by use of blocks and signals.

Reply to
Gregory Procter

: : My questions: : : (1A) If you have these dead track sections [as described above] and an : engine pulling a train hits this section when the power has been cut : [toggle OFF], is this bad for the engine and/or the cars and their : couplers?

Sudden stops are chancy but probably won't damage things unless the train is traveling fast and/or on a tight curve - then you might have a derailment. I wouldn't advise it if you were running a looong train however. But, the sudden stop would probably do much less damage than a crash into another train or a run off an open drawbridge. I'm using stopping sections to protect a diamond "just in case" and they satisfy that objective.

: : (1B) If so, how do you safely stop an unmonitored train with one or more : engines?

IIRC, you are considering DCC operation; Digitrax has an approach that I have had reasonable success with; unfortunately it requires a second booster. The advantage here is that the stopping section also takes advantage of the momemtum set into the DCC decoder. You can see it at:

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all your decoders can be programmed to Analog Mode Conversion Off, you should be able to do a stopping section with DC instead of the DCC Braking signal and the momemtum will still work.

Reply to
KTØT

Thanks you guys.

I am pleased to read that a simple ON-OFF toggle approach, though not ideal, seems safe for the engine(s). The Digitrax option looks very nice. As usual, budget will dictate the final choice. But, utilizing the momentum feature in DCC sounds ideal. It is especially appealing for a passenger station. We're definitely going with DCC though we are not prepared to buy into a system quite yet [cost].

Sincerely, Matt

Reply to
Matt & Kathleen Brennan

M&KB> Hi Folks, M&KB> M&KB> I am considering the idea of placing some dead track sections M&KB> [controlled by an ON-OFF toggle switch] at high risk locations M&KB> [crossings, tunnel exits, etc.] to safe guard against a collision M&KB> between a continuous running train [unmonitored] and any other train. I M&KB> am thinking that it would be ideal to have the ability to stop the M&KB> unmonitored train by cutting the power ahead of its engine(s). For M&KB> example, within a continuous loop, a train exits a tunnel in a high M&KB> traffic area on the layout. On most occasions, that's not a problem. M&KB> However, there may be times when I would like the option to stop that M&KB> train just as it exits the tunnel given my uncertainty as to what may be M&KB> taking place at that location. Once all concerns have been dismissed, I M&KB> would then start that unmonitored train on its continuous run, once again. M&KB> M&KB> My questions: M&KB> M&KB> (1A) If you have these dead track sections [as described above] and an M&KB> engine pulling a train hits this section when the power has been cut M&KB> [toggle OFF], is this bad for the engine and/or the cars and their M&KB> couplers?

Generally no. Model RRs are not especially 'heavy'. Unlike real trains, model trains can safely 'stop on a dime'. Various 'tricks' are used to 'simulate' a real train's behavior (flywheels, power packs that simulate inertia, etc.), but the reality is that suddenly cutting the power will result in an (unprototypical) sudden stop. Assuming that the train was not running at an excessive speed, there should not be any damage. Make sure that the 'dead' section is at least as long as the longest engine consist you expect to use. It sort of defeats the purpose if a second engine 'pushes' a leading engine past the dead section or if you have an engine long enough to span the dead section.

M&KB> M&KB> (1B) If so, how do you safely stop an unmonitored train with one or more M&KB> engines?

Your plan will work fine, at least as a quick-and-dirty safety hack.

M&KB> M&KB> Many Thanks! M&KB> Matt M&KB> M&KB> M&KB>

\/ Robert Heller ||InterNet: snipped-for-privacy@cs.umass.edu

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Reply to
Robert Heller

There are ways to achieve momentum using off the shelf analogue DC components also at a considerably lower cost than DCC. DCC is geared to driving individual locos whereas obviously DC is geared to track sections. If you want automated control of one or more locos while driving another, analogue DC is obviously the way to go. If you want to drive each individual loco then DCC is the way to go.

(now we've opened up the dreaded DC vs DCC debate again )^8

Regards, Greg.P.

Reply to
Gregory Procter

Greg, I use both DC and DCC on my layout; DC is used on the automatic lines and (has been) used for the automatic stopping sections on the DCC layout. Works fine.

I've changed approaches on the DCC part of the layout though - now I wait until the engines are completely in the stopping section and then switch from normal DCC to a braking signal (a DC signal would work just as well if all decoders could have analog conversion defeated).

No debate - we each use what we are comfortable with... I appreciate your experience and insightful comments on this NG!

73, Bob Schwartz
Reply to
KTØT

Matt,

People who use block control (like me) probably know this situation all too well. If you're running single locos with flywheels then the stop shouldn't be all that sudden as the loco will/might coast to a halt. If you're running multiple locos then you run the risk that the lead locos (and the train) will stop while the trailing locos are still receiving power. In that case they'll just sit their spinning their wheels until either you rectify the problem, or 'bad' things happen.

ALSO - if you're running passenger trains with 'lighted' coaches that pickup up track power through both bogies, it is possible for the coaches to electrically bridge the gap between the powered and non-powered track sections. If the loco has flywheels then the train might not stop until after the last coach enters the 'dead' section. This happened to me at an N-trak exhibition many years ago. When I saw that a very long, very fast passenger train in an adjacent block was gonna run up the back of a slow moving freight train in my block, I killed the power on my block thinking that both trains would stop. The freight train did - but the passenger train just kept right on moving until it slammed into the caboose.

Ron

Reply to
RonMcF

"RonMcF" wrote in message news:41a84c69$0$21876$ snipped-for-privacy@news.syd.swiftdsl.com.au... : Matt, : : People who use block control (like me) probably know this situation all too : well. If you're running single locos with flywheels then the stop shouldn't : be all that sudden as the loco will/might coast to a halt. If you're : running multiple locos then you run the risk that the lead locos (and the : train) will stop while the trailing locos are still receiving power. In : that case they'll just sit their spinning their wheels until either you : rectify the problem, or 'bad' things happen. : : ALSO - if you're running passenger trains with 'lighted' coaches that pickup : up track power through both bogies, it is possible for the coaches to : electrically bridge the gap between the powered and non-powered track : sections. If the loco has flywheels then the train might not stop until : after the last coach enters the 'dead' section. This happened to me at an : N-trak exhibition many years ago. When I saw that a very long, very fast : passenger train in an adjacent block was gonna run up the back of a slow : moving freight train in my block, I killed the power on my block thinking : that both trains would stop. The freight train did - but the passenger : train just kept right on moving until it slammed into the caboose. : : Ron : Good input Ron; I hadn't run into the wheel bridging situation before. My stopping sections are long enough for a complete set of engines plus some amount for the momentum - determined experimentally. I switch power for the entire section by detecting the engine at the location I want the deceleration to start. May have to extend the switching back another block.

Reply to
KTØT

I have a few DCC fitted locos and a DCC controller wired as a selectable cab, but I doubt that I'll ever fit all my (100+) locos with decoders. The number of locos is so that I can represent any combination that appeared in my modelling region and era, not because I have a layout that needs so many :^(

I'm still hunting for the decoder that will give me speed mapping and feed-back control on DC.

Regards, Greg.P.

Reply to
Gregory Procter

Greg,

I assume that you mean that by throwing a switch, individual track blocks can be hooked up to either a DCC system, or a DC throttle. This is what I'm hoping to do some day, but I haven't tried it yet. I'm curious about what happens when you overshoot blocks, etc.. Have you found this to be much of a problem?

Regards, Ron McF

Reply to
RonMcF

I don't find it a problem in as much as blocks extend beyond the natural stopping point as far as possible. The layout is being signalled and a train reaching a stop signal turns off the entire block the train is on plus the one behind. With PC block control there is normally a dead block between controllers.

A DC loco over-running a DCC block halts and buzzes. A DCC loco over-running a DC block reverts to DC running, either continuing, or stopping and reversing

Regards, Greg.P.

Reply to
Gregory Procter

Thanks Greg.

No plans for signalling or automatic stopping on my layout.

Accidentally running into a DC block (controlled by another throttle) produces the same result, regardless of the type of loco/throttle. My concern was that the smoke might get out of some component somewhere, but that does not seem to be the case. So it looks like I can probably do what I'm wanting to do.

Ron

Reply to
RonMcF

Any DC loco with a small motor (N gauge size) is going to be in trouble on DCC in a very short time! (hey, I never realized that loco had a smoke unit! :^)

Regards, Greg.P.

Reply to
Gregory Procter

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