Tortoise Non-Derail Wiring

Hate to ask. What is the response time on a Turtle that it would prevent derailment?

swav posted:

Hate to ask. What is the response time on a Turtle that it would prevent derailment?

hopefully less than the time it takes you to throw your train into reverse.
anyone who knows how a tortoise machine works will likely understand what i mean.

cheers...gary

 Tortise switch machines are spring loaded you really don't need the electrical non derailing. 

Clem K

I understand what you're saying about the Tortoise spring mechanism.  I'm sure an engine and tender can run through a misaligned switch in the opposite direction.  What about the rolling stock and other lighter weight cars.  Would they not have enough force to slip by the points against the Tortoise spring tension?

The big issue with the Tortoise machines is that they're slow, so non-derail would require being triggered from a distance that would provide enough time for the machine to throw (dependent on operating speed). I installed what is essentially a non-derail trigger at the club in the staging yard because we kept having members forget to throw the turnout back when sending a train out of staging onto the main It uses an Azatrax MRD2 turnout controller. Basically, a slow moving train coming out of the staging yard hits an optical sensor about two feet from the turnout and at 8 SMPH, the turnout is thrown before the train gets there. Another sensor on the mainline placed farther back to allow for our running speed of about 35 SMPH will set the turnout back with the next train through. The wire on the machine is set to minimum pressure so the turnout will also spring should the train arrive while it's still throwing. To manually open or close the turnout, a member just waves a hand over the sensor. The MRD2 has been replaced by the D2T but serves the same function. The information can be found here.

good morning Patrick.........The tension is adjustable, I even run older unweighted Weaver cars through. Sometimes I forget I had the switch thrown and run through it all evening. That doesn't happen much anymore ever since I installed those little switch track lanterns that ross sells, they really look cool.     

Thanks Aghrmatt

Ill look into that Azatrax unit.  That sounds like a good idea.  

Thanks Clem K

Thats a good solution also, by adjusting the holding tension to allow lighter weight cars to open the points.

Aghrmatt

I spoke with Circuitron about this.  They suggested using their TC-3 tortoise controller and the DT-4, detection unit which is as the Azatrax is  controlled,  by a photocell.  Just another option.  

AGHRMatt posted:

The big issue with the Tortoise machines is that they're slow, so non-derail would require being triggered from a distance that would provide enough time for the machine to throw (dependent on operating speed). I installed what is essentially a non-derail trigger at the club in the staging yard because we kept having members forget to throw the turnout back when sending a train out of staging onto the main It uses an Azatrax MRD2 turnout controller. Basically, a slow moving train coming out of the staging yard hits an optical sensor about two feet from the turnout and at 8 SMPH, the turnout is thrown before the train gets there. Another sensor on the mainline placed farther back to allow for our running speed of about 35 SMPH will set the turnout back with the next train through. The wire on the machine is set to minimum pressure so the turnout will also spring should the train arrive while it's still throwing. To manually open or close the turnout, a member just waves a hand over the sensor. The MRD2 has been replaced by the D2T but serves the same function. The information can be found here.

Same Idea as Matt's..... but instead of the  Azatrax, a long insulated track section will work. The insulated track section activates  a dpdt relay . The relay  contacts (using DC current)  are wired like an 'ho" reversing switch and control the tortoise direction throw  (contacts 1 & 8)

When the  insulated section is non-occupied the turnout is in the normal position.(straight).

When the insulated section is occupied  the turnout is in the diverging route position.

The downside is,,,,, Do you have room for longer insulated track sections.

Pros     Only need to hook up one insulated section but I suggest a" stop board" before the trains enters  the insulated section to check out mainline movements. 

 It's  fun to watch a train leaving  the yard it enters the insulated track section.  The switch lines for the main and returns normal after the train departs.   I think some sort of Capacitor can delay the return to normal time.

AGHRMatt posted:

The big issue with the Tortoise machines is that they're slow, ...

still don't think there is any need for an extended track sensor.  as soon as the first car or locomotive hits the switch, the throw can begin and won't be affected by the following cars transiting the switch.  in fact the first thing that will happen is that the spring tension will immediately start becoming weaker and while the switch is completing the throw, the moving points should not be a problem.

as i said above, the only concern with transiting a sprung switch is reversing the train direction before completing the transit or in a non-derail setup, before the throw is complete (~3-4 seconds).  adding complexity to the design will only increase the risk of failure.

cheers...gary

All good observations and suggestions.  Thanks!

You can also use the Atlas # 6924  Non-Derail circuit board to control the Tortoise switch machines with automatic non-derailing feature.

Steve

the Atlas 6924 was my initial choice.  It seems they are not made anymore.  I checked a few large hobby shops and no one has them in stock.

thanks for the suggestion

Patrick,

You might want to check with Walthers I know they had recently purchased a large quantity . Also W B Klein had an inventory.

Thanks Steve, I'll check with both of them.