Question about turnouts

[7Dave7]

Hello group,

Pretty much brand new to the hobby. Studying real hard, in prep for my first layout.

Question - with a given turnout, say off a mainline to a siding and a train running on the main, parallel to the siding, toward where the siding and main converge, does the setting of the turnout matter ?

Dificult to explain what I'm asking - if the train is going toward the turnout, I know with one setting, it will continue on the main and with the other setting, it will branch off onto the siding. I want to know if the turnout position matters when  the train is coming the other way, whether it be along the main, or along the siding.

 

Thank you in advance for any replies.

Dave J. 

 

 

 

[BigG]

 Hi Dave, and welcome to the hobby!   I'm not quite sure what you're asking, but let me try 2 things, and you can get back at me if I'm wrong.

 First: if a train approaches a turnout thrown the other way (against it). If the rails are not powered, the 1st wheels to hit the point rails will try to push their way through it. This will not usually succeed, as the point rails are usually firmly held in position, and there will be a derailment sooner or later. Damage to the points usually occurs in short order. If the tracks are powered, the point rails will be in position to short through the wheels and axles.

 Second scenario: if you mean what side to place the switch stand. It usually doesn't matter, except that the safety of the switchman is uppermost. Usually you don't want him to have to cross tracks much. If there are busy tracks nearby or if this is the mouth of a ladder of switches, Put the stands all on the same or quiet side. In a lonely setting, it is good if the engineer can see his man for safety reasons. Before walkie-talkies, the switchman used hand signals or a lantern to tell the engineer what to do.

 Hope this is what you're asking,     George 

[loathar]

People have put light springs in their turnouts so if the train approaches the point rails from the wrong direction, the springs allow the point rails to move and NOT derail the train. I forget the term for this type of turnout. Most commercial turnouts are rigid through the use of a switch stand or turnout control and would cause a derailment.
What your describing can be made, but is kind of a touchy mechanism due to train cars being light weight and not being able to hold the turnout points open.

[7Dave7]

 

Hello George,  thank you for your reply.

As I said, difficult to explain myself, or rather, my question. I think you and the other poster have answered it. Basically I wanted to know if there was any scenario when a train could pass through a turnout without it mattering which way the turnout was thrown.

I was so busy wondering if this would work, I forogt to consider the turnouts are, of course, powered and you have to consider this.

 

 

[7Dave7]

 

Hello Loathar,  thank you for the reply to my post.

Between you and big G, I've got my answer.

[tomikawaTT]

Howdy, Dave,

First, a little nomenclature:

• Points - those sharp-ended things that determine which way a train will go when it encounters a turnout.  The two of them, and the throwbar that connects them, constitute a switch.
• Facing-point movement.  Movement which causes the train to take one route or the other at the switch.
• Trailing-point movement.  This is what you were trying to describe.  The train comes onto the switch from the 'back' side.

Now, unless a switch is specifically designed to allow trailing-point movement through a closed point (switch lined for the other route,) the usual result is a derailment as the wheel flanges are pinched up and out of the wedge-shaped space between the stock rail and the closed point.  As a general rule, you should always throw the switch to the route being used for a trailing point movement.

What Lothar was describing is a 'spring' switch, which is designed to allow a trailing-point movement through a closed point.  I believe that some 'toy' turnouts will allow spring switch action, but most spring switches are deliberately designed to send all facing-point moves in one direction while allowing trailing-point moves from either direction.  (My hand-laid spring switches look like trolley switches, with only one point.)  The vast majority of scale turnouts do NOT have spring switch capability.  Even if the points will allow a trailing point movement to force the blades, doing so is a very bad idea.  All it takes is one wheel to get pinched out and you will have something derailed and possibly damaged.

Spring switches have another problem.  If you get a trailing point movement part-way through a spring-loaded point and then try to back up, all the cars which have already cleared the points will take the favored route.  Having one truck go one way and the next truck go the other way is a recipe for catastrophe.

Chuck (modeling Central Japan in September, 1964)

[7Dave7]

 

 Hello Chuck,

Thank you for thr reply to my inquiry and the information you provided. Good to know the facing / trailing  movement terminology. Makes it easier / better to describe things.

Just to let everyone know, I was mostly curious if I had to make sure my turnouts were switched the correct way at all times. Clearly, I DO indeed have to do this. No problem, now that I know.

Thanks again to Chuck and the others who helped out with my question.

Dave J. 

 

 

[mobilman44]

Hi!

No doubt about it, you should have the points lined up to receive the train, be it coming into the "curved" portion or straight portion of the turnout.  HOWEVER - isn't there always a "however" - locos and heavier cars will often go thru the turnout no matter which way its turned.  But of course lighter cars will derail and make for a messy situation.

ENJOY,

Mobilman44

[Railway Man]

Hello group,

Pretty much brand new to the hobby. Studying real hard, in prep for my first layout.

Question - with a given turnout, say off a mainline to a siding and a train running on the main, parallel to the siding, toward where the siding and main converge, does the setting of the turnout matter ?

Dificult to explain what I'm asking - if the train is going toward the turnout, I know with one setting, it will continue on the main and with the other setting, it will branch off onto the siding. I want to know if the turnout position matters when  the train is coming the other way, whether it be along the main, or along the siding.

 

Thank you in advance for any replies.

Dave J. 

 

In the prototype, the "straight rail" side of the turnout will be for the main track and the "diverging route" for the siding or industry spur about 99.99% of the time.  There are exceptions but they are rare because they create very high maintenance costs, greatly reduce the maximum speed that is allowable on the main track, and turnout-caused derailments almost always happen when the switch is "reversed", that is, aligned for the diverging route instead of "normal" for the main track.

On the prototype, maximum speed on the diverging route is usually approximately twice the frog number, though different railroads have slightly different ideas about this.  For example, a #9 or #11 is allowed 20 mph, a #14 or #15 30 mph, a #20 40 mph, a #24 50 mph, and a #30 60 mph.  The smallest turnout regularly in use on the prototype is a #8.

RWM

[NeO6874]

[

The smallest turnout regularly in use on the prototype is a #8.

 

Really?  I thought it was larger -- on the order of 12+.... but then again I might be thinking for more heavily used areas rather than the secondary or tertiary routes in an industrial complex (eg, that one track that gets one car every month or two to supply the <whatever>)

[Railway Man]

[

The smallest turnout regularly in use on the prototype is a #8.

 

Really?  I thought it was larger -- on the order of 12+.... but then again I might be thinking for more heavily used areas rather than the secondary or tertiary routes in an industrial complex (eg, that one track that gets one car every month or two to supply the <whatever>)

There are smaller sizes than #8 in use but they are not common.  For industrial track, some railroads will accept #8s as the minimum size while others require #9s.  I've seen a few #8-1/2s but they are not common.

Generally in industrial trackage we use #9s, while for yards and terminals #11s are preferred.

RWM

[tomikawaTT]

[

The smallest turnout regularly in use on the prototype is a #8.

 

Really?  I thought it was larger -- on the order of 12+.... but then again I might be thinking for more heavily used areas rather than the secondary or tertiary routes in an industrial complex (eg, that one track that gets one car every month or two to supply the <whatever>)

21st century industrial track in North Las Vegas, NV, was laid with #7 turnouts (castings dated 2000.)  Somewhat older industrial district on the other side of I-15 uses #8 turnouts.

FWIW, the Army Corps of Engineers training manual for railroad maintenance (circa 1960) was filled with references to #8 turnouts for new construction - no mention of anything smaller or larger.

Chuck (modeling Central Japan in September, 1964 - on mostly #5 turnouts)

[majortom]

The South bound departure track onto the main in the Centralia yard on the IC had a spring switch the train could go through onto the main no matter how it was lined.

 

majortom

[wjstix]

Kato HO manual switches are sprung in such a way that a locomotive going thru the points it will push them out of the way, like on a spring switch in the prototype. Cars in my experience have trouble however because they're too light.