Just wondering… Taking a turnout at speed sometimes raises havoc in the dinning car. I have seen meals dumped on passengers and myself been thrown against a wall and brused. I guess that is the price we pay to enjoy our hobby. Artisimm5 [:)]
It really depends on what speed the turnouts are designed for.
Some in Britain are designed for trains to take the diverging route at 100+ mp/h, they are like #20’s or some such, huge long things.
In this country, a #20 turnout is good for 40-45mph and a #24 is good for 50 MPH. If you have a train going 100 mph through a #20 lined for the siding, I’m outta here. Nikes don’t fail me now!
#6.5 Turnout = 5-10 mph
#8 Turnout = 10 mph
#10 Turnout =15 mph
#14 Turnout =30 mph
#20 Turnout = 40 mph
#24 Turnout =50 mph
Thanks all.
Those speeds are for standard design turnouts. The Normal position being the straight rail and the reverse position curving away.
Now, if you have a number “n” Y Switch, each rout diverges at 1/2 half the curvature of the standard design and the speed can double.
Well, it’s hard to judge the # when you are level with it, it was a huge turnout though.
Kenneo- carefull, speed is a function of radius/degree of cv. and elevation, switches for the the most part are flat…plus unbalance (in relation to centripital force)
SPEED= SQRT((E+3)/0.0007D) E=0, (flat) D=degree of curvature, 3" maximum unbalance (freight railroads use 2 or less)
Mookie’s closed book/open mind pop quiz to follow…
The proper tem for “Y” switch is equilateral turnout, and they are a relatively minority item whose geometry precludes it from many locations.
You are correct on all points, but if I had tried to explain all of that just to say that you can (within the confines of the physicis involved) double the speed with an equilateral, I would still be writing the post!
Such arrangements as I mentioned are in use on high speed lines, and yes, you can not get double the speed, but, depending on your equipment, can approach that number.
I’m talking “ball park” here. The turnout curvature for a say, #20 E is “1/2” the turnout curvature of a # 20 R or a #20 L, even though the total frog angle is the same, because instead of turning to just one side, you turn to both and “1/2” of the “curvature” is present for each side, and therefor, you have “1/2” of the frog angle. The only practical general use is in high speed rail corriders.
If I were to design something like I am talking about, and did not use the proper engineering formuli, I would indeed have the train in a heap in the middle of the track.
I was always told that you doubled the turnout number to get the safe speed.
UP has installed some #30s, with movable frogs, which have three switch machines each: one for the frog and two for the points. If you have to hand-throw both switches of a crossover (which would be thousands of feet apart, with the wide track spacing), that’s quite a bit of walking!
I also seem to remember about some new point profile that’s supposed to make things safer. How do that, and the movable frogs, affect the speed, if at all?
Heck i do it the easy way i look up in the time table what speed i am allowed to go into and out of the sidings. that way i dont haft to get the calculator out to to the math
Centripital force?
Is that sorta like catching your toe, and experiencing falloverable force, only expressed as a mathmatical equation?
Ouch = toe + rail+ rocks X2 if someone is watching.
Stay Frosty,
Ed[:D]
Excellent! The Mookie Pop-Quiz is gonna trip me up on that little gem. Centripital force is that force that puts you up against the high rail in a curve, why the train wants to go straight. Everybody else calls it centrifugal but the old Physics book points out that that is a layman’s term and not the proper term.
I am busy writing this down, since it is the only part of this entire conversation I have understood. Gotta remember that formula! That’s a goodie!
Mook
Gives “trip” a whole new meaning. Ed, does this now mean that a 5 foot person falling victim to your foumula would ge a dented forhead and a massive non-migrain headache? How would that alter your formula?
(big wide cheesy grin!)
CShaveRR: The special points are called “Samson” Points and have been around for years. They are beefier, harder to wear out and require that the stock rail that they close against to be undercut/machined so that the extra width can fit under the railhead… There are also replaceable manganeese switch point tips out there, but the rest of the rail is usually shot by the time you want to replace the tips.
Ed: We’re still amazed over the corn syrup episode and appreciate the straight-forward operating guy’s view salted with the good natured humor. (Oh yeah, is a civil engineer still a hogger out of job?)
Movable point frogs (neat things, pioneered by Britain’s Henry Boot & Co.) help frogs wear longer and are a beter solution than the old spring rail frogs. You don’t get the banging of the wheels accros the flangeway gap in the frog. Much smoother ride and you find these usually in heavy tonnage areas. (Very expen$ive)… They don’t do much for speed though…
KenEO: Not trying to “blow smoke” and can understand the “ballpark” reference 7 or so posts back…What is frightening is the people that take stuff in this forum and others and think this stuff is gospel. If I had a nickel for every time I corrected the work of a non-railroad licensed engineer or surveyor that has encountered a railroad, I could retire and live off the royalties. Some of the assumptions, misconceptions and mistakes should be published in Ripley’s. (Some still have us in stitches, they are that bizzare! Others make me concerned about my chosen profession and the public’s safety)…Like Ed, just trying to keep things “somewhere in the middle”… We all get to learn a little and have a little fun here.
Pretty cool hearing “sampson,” “stockrail,” and “springfrog,” come up again, Mudchicken. I worked for ABC Rail Prod/ABC NACO/Racor/Abex. Does any of these ring a bell?
Ken
I dont think the height of the person would make much difference. It would all depend on…
ouch= toe+ rail+rocksX2 if someone is watching divided by density of skull.
But with some of the guys I work with, it wouldnt matter how deep the dent went. Nothing in there to hurt in the first place.[:D]
Stay Frosty,
Ed
Ironken: As in Meridian Rail now?
Well, I guess we write it this way — ??
OUCH!! = (toe + rail + rocks) / Density of Skull
EMBARASSMENT = OUCH!! X Density of matter within skull X 2.
What a party at the Yard!! When do you think a new drink of Karo-on-the-Rocks with little-white-pellets will become available? What would they call it??
I’ve been to a few parties like that. Some were better than others, but I can’t remember any that were fun. But one was really funny. About 1976 or 77 we dumped several cars of a pig over into the canyon at Wildcat Creek. Two cars, one of tuna and the other of Coors in cans burst open about 700 feet down. Good old #1 Market sent the Bulls up to make sure nobody got the beer, but they couldn’t stop the bears. They would show up, open the tuna cans and scarf up and when they got thirsty, open a few brewskys and satisfy their thirst. The Bulls tried to stop them, at first. They were never able to yard the cars up. They just left them for the bears to finish off, and they are there to this day.
Eric - I read that and actually understood it! All except the # 1 Market - ?
Jen