Having watched a few episodes of Mythbusters, I’m thinking of emailing them and asking them to test some railroading and model railroading myths. These are the ones I’ve got so far:
The current across model train rails (DC and DCC) is enough to kill someone
You can prevent a steam loco from starting by jamming quarters (I think) under the driving wheels
A diesel-electric loco can’t go through shallow water
They’ve already tested the ‘pe*ing on the third rail’ ‘pennies on the track will derail a train’ and ‘train will suck baby strollers off a platform’ myths. Are there any others that should be tested?
the current across the rails on your layout can actually kill you. All that is required is 5 mA, yes milli amp across your heart and this can cause death. The trick is to get a good conductivity in order to pass this much amperage across the heart and at these low operating voltages it is nearly impossible to do. Just to put everybody at ease, your car battery pumps out a huge amount of energy and you can touch both terminals and nothing will happen. The reason is that the voltage is not high enough, but due to the higher voltages coming out of your receptacle we have Ground Fault Interupter Receptacles that will turn the power off if they sense an imbalance of current flow by 4 mA or greater.
Can a diesel electric loco go through shallow wather? How shallow? If the water gets into the motor, then there will be one big short. So if the water stays below the motor, then sure it can go through the water. I remember in Trains magazine there was an article where a rail line was flooded. So they pushed the freight train through the flooded section of track to the diesel engines on the other side of the flooded section, hooked on and continued the journey. The water must have been very calm and no risk of washed out sub road bed, steam engines could handle water a lot better.
Interesting idea… But I don’t think the “diesel-electric loco can’t go through shallow water” is much of a myth, those traction motors are pretty low to the ground!
It doesn’t take much of a depth of water to put the traction motors of a diesel electric out of service. The same applies to many modern electric locomotives. The water will get into the moptor, short the fields and fry the motor. This is no myth. I’ve seen it happen.
That’s quite interesting - considering it even mentions in the oeprating manuals for many diesels to cut the field current before running through standing water. They might have been coasting with the reverser in neutral but that’s a long way - then again they obviously had a lot of speed up and without using the brakes it takes a long time to slow down a train. Hmmmm…
As for the suction of a train - if the Mythbusters think this is busted then they’ve never been too close to the platform edge when an express rolled through. Even standing behind the line you can feel the tug - but it’s not as much into the side of the moving train as it it behind it. Falling off the platform BEHIND the train isn’t such a big deal unless it’s a high platform or a subway and you fall against the third rail.
Thanks for the link - that video’s a classic! [:)]
However, it was shot in South America, and so it’s possible they could be using a diesel-hydraulic engine there instead of a diesel-electric - which I’m assuming wouldn’t be as affected by water.
Are there any other railroading/model railroading related myths we’d like to see tested?
AH, didn;t think of that, as diesel-hydraulic locos never really caught on here in the US. The hydraulic motors should be well sealed - and if modern diesl-hydraulic locos are set up at all liek the Krauss-Maffei units they experimented with here, it’s really bascially a differential down at the wheel and axle leve - and that wouldn’t be affected by the water. If they use individual hydraulic motors like electric traction motors, they still should be ok as the hydraulic motor pretty much needs to be sealed up to keep the hydraulic fluid inside. Possibly the shaft seal could become overwhelmed with excessive water and allow some in that would mix with the hydraulic fluid but with the extreme pressure of the workign fluid any seal failure probably blows out rather than in.
Of course, part of the reason I want to see them test these myths is because of their philosophy: “Duplicate the circumstances, then replicate the results” - which, assuming all the myths I listed are false, this means we’d also get the following questions:
Can a model railroad be souped up enough to kill you, and what are the dangerous levels/voltages?
What would it take under the wheels to stop a steam loco from moving?
How much water does it take to stop a diesel-electric?
Either way, we’ll learn something.
It is a myth that water will short out a motor (or anything electric for that matter). Rather it is the “salts” (minerals) in the water that provide the conductivity. You can run an electric circuit in pure water all day long but only for a short time in salt water. The salt increases the conductivity of the water enormously and provides and alternative path for the electricity to follow-- pretty much wherever it wants to in that case-- whereas pure water does not. When two electrodes are placed in water and electricity flows between them, you get two actions: oxidation and reduction, which are the “corrosive” (damage-causing) elements. In fact, pure water is sometimes used as an insulator. But we’re talking about very, very pure levels of water here and not just “bottled water”. Even adding a few grains of common table salt would raise “pure” water’s conductivity to dangerous levels. So the question really is-- how “pure” is the water that locomotive is rolling through?
Plastic wheels causes the track to get dirty. I converted around 200 cars to metal wheel sets, track stay no cleaner now than when they where all plastic.
Randy,
They stood Buster (the test dummy) up within inches of the track on a station platform and had one of the Arizona commuter trains whip by at 79mph. Buster fell away from the track, not towards it. They also set up a lightweight baby carridge in the same spot. The carridge went flying away from the tracks.
The myth that a train can “suck” people or things into the train or onto the tracks behind it is busted as shown on their show. Not to say there isn’t any “suction” (there is), but that reverse force is not even close to the positive force the “bow wave” puts on objects close to the track.
For myself, I have stood within 3 feet of the Acela going by me at 150mph, and the same distance from the HHP-8’s and AEM-7’s going by at 125mph (standing on the handicapped platform at Mansfield, MA). There is not enough suction to pull anything into the train or tracks. In order to do so, it would have to overcome the force applied by the bow wave to the object in question, and that’s just not possible.
IMHO, most of the so-called “suction” that people near the tracks experience is actually their own doing. When something pushes against one’s front, one tends to push back so as not to get pushed over backwards. Therefore, they lean in towards the train when the bow wave hits them. But since the bow wave is of such a short duration, by the time the person in question leans forwards, the slight force from the turbulence behind the bow wave hits them in the back. This makes it seem like they almost got sucked into the train as it passes, when really they leaned into it and then got a little pat on the back while they did so.
I do have a myth that they can try to bust, BTW. An old story was that one day in a cold, icy winter, a local steam-powered freigh
I think the funnest part would be when Mythbusters decides it’s time to make it happen. Remember the cement mixer from the loosening cured cement myth? I do, because I blinked and suddenly the truck was gone. Or the anceint wall-of-mirrors weapon thingy used to burn down ships, although they cheated on that one a bit, but fun to watch non the less. I’ve had idea’s for Mythbusters but decided to keep them to myself since I realized they probably wouldn’t let me help prove/disprove it.