N & B Switch.

[Tony Bird]

Photographs of a Switch being developed by the CMES GR group.

[Pendo Pilot]

Thats a really clever & space saving switch. I like that.

[Narrow Minded]

That's neat

[tom_tom_go]

I wish this could be done with SM32 and OO so I could run my ickle trains outside

Great job!

Cheers,

Tom
RWLR

[Tony Bird]

Hi Tom,

I wish this could be done with SM32 and OO so I could run my ickle trains outside

Think about it. It would work laying OO track inside the SM32 just use plastic cement to glue the '00' track sleepers in the middle of the SM32 ones. Having 4 rails rather than 2 won't make any difference. With this type of switch the difference in rail height wouldn't matter either.

Regards Tony.

[Pretoria]

No horrible frogs! What an interesting solution.

I see no reason why it couldn't be used for any dual guage track -- including ground level 5"/7.25" etc.

My only concern is that some check rails may be advisable to guide the wheels away from some of those open ends.

Not a concern, more an observation, but you couldn't use it as a trailing point (do you use trailing points in GR ?)
Keep us posted on the outcome!

[Tony Bird]

Hi,

No horrible frogs!

Yes but the geometry is quite critical.

I see no reason why it couldn't be used for any dual guage track -- including ground level 5"/7.25" etc.

Yes but it would have to be made like a turntable to take the weight and keep the height of the rail the same. These switches are the same length for the same radius curve as a coventional point. i.e. the length between the point of the blade and the apex of the frog are the same.

My only concern is that some check rails may be advisable to guide the wheels away from some of those open ends.

Possibly. Though the gaps between the rails on the prototype are larger than they appear on the photographs and so far no stock tried have tried to jump the rails. A curved 21' with a 6' take off switch is to be made which will be fitted to the CMES GR so it can over winter to check out any problems.

Not a concern, more an observation, but you couldn't use it as a trailing point (do you use trailing points in GR ?)
Keep us posted on the outcome!

Quite right it won't switch by the action of a train running through it or as a sprung point. The reason for the design is not so much that it is quicker and simpler to make than a conventional dual gauge point but that it will handle the different wheel profiles and back to back measurements of 'G' scale, G1, LGB etc that are used at the club.

It is intended to make the test switch from from PVC which will be cut to size on a CNC machine.

Regards Tony.

[Tony Bird]

Hi,



A production prototype switch using a PVC base has been made, which will be fitted to the CMES GR hopefully this weekend. It will be used and left to winter before making others, doing this should show up any problems. On later switches the PVC base will be cut using a CNC machine.

Regards Tony.

[Pretoria]

  Aha !!  Do I espy the addition of check rails ?  

[Tony Bird]

Hi,

Yes. Interestingly as both tracks are curved 21' & 6' there is much more clearance over 4mm between the ends of the rails. The check rails are there for appearance as the backs of the wheels cannot touch them and the wheels keep to the outside of the curve when running. The switch should be fitted on Saturday so will report results.

Regards Tony.

[Tony Bird]

Hi,







A Switch has been installed on the CMES GR to see how it will react to the rigors of winter.

Regards Tony.

[Tony Bird]

Hi,

Today the Switch that has been fitted to the CMES GR was checked out by our longest locomotive which also has the largest number of wheels. Very short video as I ran out of memory in the camera.



The results very satisfying the locomovtive both pushed and pulled its bogie stock through the Switch on both its settings
.

Regards Tony.