Sometimes it is worthy to go into the WHY of a situation, and not just the WHAT.
In N America, unlike most of the rest of the world, we want two different voltages. 240 for "major appliances", and 120V for the rest. This then, is the reason not for a Neutral, but for the two HOT lines on a 240/120V system.
Almost the entire world uses a grounded neutral scheme, but only with a single available voltage. That voltage could be 100, 220, 240V.
The most convenient (cheapest..) way to get two voltages, if they are a factor of 2 different, is to use a center tapped secondary transformer at the utility feed. Voila, now with just 3 wires, I can get two different voltages. In N America, those are 120 and 240. Still have that grounded neutral, and when that particular wire looses its low resistance connection to that center tap, bad things will happen. Not a loss of power, but wildly wrong voltage values. That is the source of the damage, both too high, and too low.
I'll make the bold assumption, that land users started this trend, not boat users. But, you can see that N. American market boats continue the tradition of split phase 120/240 for the larger boats.
Meanwhile, Europe and Asia would have none of this foolishness, and has a simpler, single voltage available for most users. I'm going to exclude industrial users from this discussion, and also 3 phase marine is excluded; since most of the readers here don't use 3 ph for their boat/home service. When a euro 230V boat loses its neutral connection, the voltage simply drops, sometimes all the way to zero. There is no chance for an abnormal high voltage due to neutral loss.
So, that is the madness behind the neutral story.
To the comment I made on the clothes dryer. The rumor is that during/just after WWII, there is a shortage of copper, and it affected home wiring design. Again, to save money, the clothes dryer and usually the electric range wanted both 120 and 240. The safe way to do this is to use 4 wires; L1, L2, N, and safety ground. But no, many installs to this day are still using only 3 wires. L1, L2, and a combined duty N and safety ground. Since this grounded wire carries current (motor and timer), if it becomes disconnected at the source, the frame of the dryer now becomes live with 120V! All other first world countries would not allow such wiring practice. It was about 25 years ago that new installs insist on the 4 wires to any 240/120 appliance.
