Slip Switch Track

A double slip has four sets of points in addition to a centre crossing, even though it has the same routing functions as two turnouts toe to toe.

Regards, Greg.P.

No - the double slip necks down to two closely spaced parallel tracks plus a crossing - four tracks all impinging on a common loading gauge. The double slip can be sub-divided into two distinct families, those where the two curved tracks interlace, and those where the two curved tracks pass without touching.

Regards, Greg.P.

"Consist" is in itself an incorrect term as used by US railways.

So we won't go in to how yanks shoot their guns?

Nope. You'd be astonished and amazed at how well and how often it works. I would guess better than 90% effective.

Not exactly. A true torus has only one surface, there is no side, inside, outside, or any of the traditional three dimendional surfaces there is only "the surface". It's sort of like a Mobius ring on steroids, except that a Mobius ring has a surface AND an edge. The torus lacks the edge. A ring torus cannot be used as a coffee cup because it has a hole with no inside wall or floor. If one were constructed from open-cell foam, it could serve somewhat as a device to contain liquids, but only in the manner of a sponge. Not an effective, or particularly useful, coffee cup. Sucking coffee from a saturated sponge is not my idea of having a large time. Not only that, but people will talk about you if you are observed doing that.

Greg Procter said that any shape can be referred to as a grossly deformed torus. I agree. A stricter definition and/or description differentiating torii and cylinders is needed.

One interesting thing you can do with a ring torus is turn it inside-out to form an identical torus. Every time you turn it inside-out it will be exactly the same as it was before. Sounds like fun, eh?

Please elaborate. This should be interesting.

Hunh? Who?

That would be a Tardis.

As a 1st LT in an infantry unit, we used to regularly run NUGs (New Useless Guys) around looking for: cans of squelch; left handed monkey wrenches; skyhooks (a classic); left hand vibration dampers (for M113 cupolas), and more.

Had my driver going all day between me, the PSG, and the motor pool one day during an exercise in Florida.

You didn't have them get an aerosol can of slack?

Paul

No, just prop wash.

Dear folks,

The doughnut-coffee cup case is a good one. The mistake that is being made is in thinking the doughnut hole becomes the inside of the cup. It doesn't. It becomes the hole in the handle! (The cup has to be the kind with an ear).

If you carve a wooden model of a torus, it does indeed have only one surface, because there aren't any edges where you can say one surface ends and another begins. A sphere is the same way, though.

Cordially yours, Gerard P.

Hey - I rode a bus in from the country, and I was never late for class.

Hello, I'm the Doctor. Doctor who? Yes, that's right.

Yes and in the same way that the above torus becomes a coffee cup, a bowl is merely a deformed sphere.

I can't really subscribe to that in either case. I think the whole idea of the torus morphing into a coffee cup exceeds the limit of elasticity of the torus. I could say that Rodan's "Thinker" was a deformed torus with the hole being a passage from the mouth to the ear. Such reasoning would permit virtually anything with a hole through it to be called a deformed torus

I don't think that will work.

An parabolic or hyperbolic coffee cup with a recurved handle stretches the limits of acceptability even further.

How all this relates to model railways is absolutely a mystery to me.

That would be the half imploded sphere style coffee cup!

What limits? The donut shape of the torus is just it's energy conservation state.

Worked for Rodan *8-}

Remember that simple oval track years and years ago? That was a slightly deformed 2-D torus!!

Paul

OK, well here's another question. It occurred to me while I was thinking about torii and spheres.

In deep space where, for all intents and purposes, there is zero gravity-- ( there is actually no such place, but this is a hypothetical problem anyway so we can pretend)-- and zero atmosphere, will a volume of water left unrestrained or contained form a perfect sphere? Will it form into its shape of greatest density per unit volume, or will it simply blob, amoeba-like and drift through the void?

For ease of thought and uniformity of replies let's use a volume of 100 liters of pure water.

Think about it. While you are doing that, I'm going to go out into the workshop and mess around with my trains for a little while.

Nope, he's right. Actually, a cylinder is a torus is a donut. If you took an infinitely elastic donut and pinched and squeezed it, you could shape it into a coffee cup without adding or subtracting holes. You could also mold that same donut into a cylinder...

But into what would you dunk the donut?

Jeff Sc. Flatland, Ga.

Don't bother to reply via email...I've been JoeJobbed.