Note: Not sure if that's the actual name of it.

In the myth, it was tested as to whether or not a person (obviously male in the myth) urinating on a third rail would electrocute that person to death. Ultimately, it was determined that doing so would only electrocute a person if they were directly above the rail at a distance of maybe six inches.

However, there are some problems with this myth. Primarily in the manner in which it was tested, but also technical issues in regards to it.

Problem one: When testing the myth, a portable generator was used. These generators, due to their use with construction sites and various machines used there in (in particular computers, air conditioners, and temporary office modules) produce alternating current.

However, there are only a small number of third rail systems, all of which exist outside the united states, which utilize AC. Rather, the majority of third rail systems utilize Direct Current. Due to the voltage drop over distance, the Direct Current used in these systems is far higher than found in other applications. This Direct Current being more likely to "ground" if an alternate route to the negative pole is provided.

Problem Two: When electrifying the third rail, only the rail itself was electrified, with the two "running" rails being left unwired. This goes in direct conflict with the wiring method of third rail systems and their operation. In practice, third rail systems are a two pole operation, with the powered third rail being the positive pole, and the two running rails being the negative return. When the train takes power from the third rail, it converts it to AC, uses it in the traction motors, then converts it back to DC, and in turn returns it to the running rails where it is then later recollected to the power house. Thus completing the circuit. By not providing a negative return on the running rails, and thus no way for the power to reasonably ground out, you created instead an incomplete circuit. While yes, this could still ground out, it was less likely to do so.

Problem Three: When you tested the Urine stream itself, you failed to take into account that human urine is under pressure when it comes from the bladder. Specifically, the bladder squeezes the Urine from it when a human evacuates it. This added pressure makes the stream stay in one contiguous part until about two feet below the point of evacuation from the urethra. From that point to the point it strikes the surface being urinated on, the stream breaks into several small droplets with microns of distance between them. Given the size that a third rail typically is, and the fact that they are raised above the running rails themselves, it means that there is a high probability that the stream would still be in one piece and not having broken into droplets by the time it strikes the rail itself.