The Home Machinist!

This looks wrong.... Most diagrams of this switch have the points inside of the frogs but I can't seem to work this one out. I tried reducing the cross-over angle then reducing the radius to 23' but would rather have it closer to 30'. What can be done for a proper single slip switch?

This is 7 1/2" gauge aluminum rail.... The radiused portion of the rail is 30 feet but reduced to 23 inside of the switch.

Perfectly OK to have the points outside of the frogs- Great Western Railway (UK) did it all the time. I'm not sure if you could use TEMPLOT to figure out the dimensions or not- http://templot.com/companion/templot_home.php (it's not an easy program to use, but it has some good support).

http://www.templot.com/forum_img/double_outslip.jpg

James

James Powell wrote:Perfectly OK to have the points outside of the frogs- Great Western Railway (UK) did it all the time. I'm not sure if you could use TEMPLOT to figure out the dimensions or not- http://templot.com/companion/templot_home.php (it's not an easy program to use, but it has some good support).

http://www.templot.com/forum_img/double_outslip.jpg

James

Thanks very much James - yes this will be a welcomed tool. I am using a CAD program - cumbersome for this sort of work.

BC

Found on the net.

lrdg2150 wrote:Found on the net.

Yes, very good example. This one has gone from a single to a double too - and wow are there lots of parts to that 'intersection'. We are joining two
ovals - front yard and back yard. About 1000 feet total. This is big a project as the locomotive....almost.

I need to research casting concrete ties...maybe with a wire 'rebar' strengthener included. Silicon mould....??? And is it worth it?

BC

The WB&S has a double slip switch in operation.

I believe the Engineering Handbook sold by
Railroad Supply has a diagram of how one is built.

The C&IG has had mixed results with concrete ties over the past decades. Yes, rebar in the casting is critical. We have some that even have two bars. Screw inserts are placed in the tie as the concrete sets. The concrete mix is critical. Many have broken over time.

Currently we are installing plastic ties for tangent and curved track and treated wood ties for all switches. No new concrete ties are being installed at this time.

Thanks for that info. Concrete ties also look like a consideral amount of piddeling to make. Making track in panels looks like another drawback with concrete ties - would probably require a fork lift to handle.

RR supply - thanks for that too! But don't see that on the web site.....

BC

OK, I found the book on Amazon for $135.00... Oh well...

Call Mike after 6:00 pm Eastern.

It's not 135.00 from him.

I can tell you all about concrete ties, my entire Railroad is concrete ties (except for the switches). Like anything there is good and bad. Bad: they are very time consuming to make, that do break, when wet the are conductive and make signaling a pain, but possible, too heavy for panel type construction. Good: don’t rot, they are heavy (track does not move or float when flooded), gauge is set in concrete, building the track on the ground allows joints to be staggered by five foot, and also allows for rolling the radius into the rail which keeps track in place better. I love my concrete but it was a lot of work.

Bill Fitt had some articles about making them in his Modeltec magazine. As I recall, he used an orbital sander to vibrate the mold to eliminate voids.