almost never modeled?

M.U. cable racks

It's sunday

It's sunday here.

Sunday?

Patience, Grasshopper!

My Guess

Self-guarding frogs.

worms, not frogs

Eww, that's a can of worms.

Don't get me wrong, I'd love to model self-guarding frogs, but if I did, I would want to model them to scale, since an oversize one would be more of an eye sore than anything else. The trouble is that if you use regular code 110 wheels, you would have to make it twice as wide as it should be.  And if you have a mix of code 110 and code 88 wheels, they wouldn't work reliably with the narrow tread wheels.  If you want to get serious about that, you would need to convert everything to either code 88 or proto-87 wheels.

I know...

Retarders (rail brakes)

Do I win?

First a quick movie . . . .

There are two frogs set up as a crossover in order to get the worst case "reverse curve" sideways forces for testing. The frogs are produced from AAR drawings and are scale length and "scale" in every other way, except for the usual NMRA HO flangeway. They do meet all the NMRA standards. In addition, to the NMRA standards, they do work with code 88 wheels as well. The cars shown running have a mixture of code 110 and code 88 wheels. Although technically only safe for slow speed, (10 mph or so) , we thought we'd test them a bit faster as well. It is April 1, after all

Why ...

Why the apparent difference in railhead height and large gaps?

Just loose parts posing for first photos.

The picture was taken when the frogs were first made and just rested loosely in the also loose rails, before we finished the crossover and stuck everything down. I tried to get the angle to match the prototype picture.

Rail height and rail position after that is just about perfect. Hence the safe crossing at the "fast" speed in the video.

Front "gap" between the rails is as per the prototype.

I don't think I can make these in N scale.

different tread widths?

Since the principle of a self-guarding frog is that it incorporates guard rails into the frog which work on the tires of the wheels, how is it that they will work on wheels with different tread widths?  Since the tires of code 88 wheels can't come anywhere near the guard, this frog would be no different than building a normal NMRA frog and not installing separate guard rails (functionally.)  I know from experience that a well-built NMRA frog will work without guard rails 99% of the time, but the derailments will usually occur when pushing a heavy train, which induces side forces through turnouts--that's when the truck will side-thrust and find the wrong route and derail.  What is there about this frog which will prevent this from happening with code 88 wheels?

N scale not available ? How sad

Thank you, Andy - understood - just for display.

I really like that you have such good HO products, this item included, and good N scale product also. I probably will never do HO (but who said "never say never"?). I am sad that you say:

Oh, well - guess I'll just have to suffer. Currently my track is Atlas Snap Track, including Atlas flex track, code 100 80 (as Irv reminds me below) (and a little bit of used Bachmann - not the EZ-Track kind) - it will be "good enough" for starting. Maybe someday I'll have hand-laid, but not in the near future.

Atlas flex track

While Atlas fles track in HO is code 100, N scale version of flex track is code 80.

Irv

In the interests of . . .

.. . .keeping the funding for the Proto:87 SIG R&D part of the Stores going, I'm not going to disclose any trade secrets about why these work so well. So for the sake of the thousands of modelers who depend on our unique products, please don't push me on that.

Just please understand these are professionally engineered to work 100% of time. With the different wheel sizes (as shown above) taken into account. They are not some happy fluke of trial and error, or a misunderstanding of statistics. As a long-term ex-Silicon Valley VP of Engineering, I am qualified to do what I do as a hobby.

I would like to re-emphasize for those with exceptionally wonderful otherwise field experience, these are two SG frogs specially set in a crossover.  I.e. They are ALWAYS FORCING the cars to move in two opposite diverging directions, one after the other.  If left to their own devices, all these cars would ALMOST ALWAYS DERAIL at normal frogs with the guard rails missing. That's what Newtons Laws of Motion would predict and cause. The first car in the sequence is not being pulled around the curve by a leading locomotive. It's free to try and keep on traveling in it's last straight line.

Similarly, the very fast motion in the second part of the video makes those diverging forces effectively much larger.  (F=M x a) and is a fair simulation of longer heavier train forces. So, while it will be a while before videoing the 30 car ballast train reversing through this particular test crossover, I have no concerns about that situation either.

Engineers Cab View of the Crossover

I thought I'd add an engineers view of the crossover frogs, to show both frogs and the reverse curve effect that the cars traveled through as well. It is a  #6 size for a fairly typical model yard size of crossover and turnouts.

Last but not least, the frogs are part of the Stores "interchangeable" "88-safe" universal HO frog range. So you can just swap out existing number #6 frogs and just "drop-in" these as upgrades any time in the future. And of course they can be used to upgrade any existing RTR or handlaid turnouts already in place.

So you wany something like Proto 160?

I am all for it but we'll need someone with very good eyesight to do it. I can't do it as I already wear glasses for seeing and driving. I take them off when I read or do work like writing or putting stuff together.

Irv

Proto:220 works OK

And here's a link to avoid copyright problems: http://www.rmweb.co.uk/forumimages/Z4.jpg

So he did it dual gauge!!!

Perhaps I should have put this on the "innovators" thread?