Discussion in 'On the Road' started by KL7AJ, Dec 23, 2019.
7000 cubic inches
By the way...if you ask the average Joe Schmoe what keeps a train on the tracks, he will probably say the flanges on the wheels. ACTUALLY, if everything is aligned right, the only time the flanges touch the rails is going through a switch. What keeps the train on the tracks is that the wheels are conical cross section, so gravity keeps the train centered on the rails. (It is nice to know the flanges are there, however)
By volunteering at a railroad museum, I learned how vital track maintenance is to keeping a train on the rails. Especially on track with wooden ties, it's easy for the spikes to come loose and have the rail move. When that happens, the train will come off the rails. I've had to re-rail a locomotive several times because of this, but thankfully all of the derailings were at very slow speed and no one was injured.
Actually 10,320 cubic inches per engine (16 times 645)
Big for its time, but not any more.
The descendant of the prime movers in the DDA-40X is the EMD 710, so named for its 710 cubic inches per cylinder, and available in sizes up to V20:
which works out to 14,200 cubic inches in a single engine.
The V20 710G is used in the SD-80MAC and SD-80ACe, which are rated 5000 and 5300 HP respectively:
Very powerful but still can't work DX as well as QRP rig with wire atenna.
Oh the practical things we learn here!
TOM K8ERV Montrose Colo
Not exactly the case.
Yes, the slightly conical shape of the wheels does most of the work. But the flanges are needed even if everything is perfect, and not just for switches.
For example, on curves, tracks are often tilted/banked slightly (this is called superelevation). But there's a limit to how much superelevation can be used, because if there's too much, a train that stops on a curve will be in danger of falling off to the inside of the curve.
The result is that there is a certain speed where the superelevation is "just right. Faster than that, and the flanges on the outside rail keep the train from going off on the high side, and below that, flanges on the inside keep the train from going off on the inside.
On busy lines with sharp curves, it is standard practice to install flange greasers to reduce noise and wear.
We use graphite bars 4 inches wide and 2 inches thick 18 inches long which are spring tensioned. One bar per wheel.
These are mounted in a metal frame work and are bolted to the truck and aimed at the wheel flanges on our locomotive fleet here on CSX. These are used in conjunction with the trackside 'greasers' that squirt about a teaspoon full of grease on the rail's flanges each time a wheel passes over a trip mechanism.
Greasers are generally located at each end of curves. Not really needed on straight tangent track.
With the shape of the wheel's flange and the rail's flange, the wheel actually 'falls' back into correct centered position on the rail head when there may be a tendency to slightly climb out of the gage.
The gage (width between the rails) is the same width of two Roman Chariot horses... 4' 8-1/2 inches, I think...