What exactly are you asking here? Do you mean why can you touch a neutral conductor which is in operation without feeling anything noticeable?
If you have a TN supply (supplier provides an earth connection) then the neutral and earth are within a few volts of each other in normal conditions. So touching the neutral will only result in a potential difference of a couple of volts across your body, this cannot cause enough current to flow to be noticeable.
Under normal operating conditions you have a load connected between the live and neutral, this forms a 3 way potential divider between the live conductor, load and neutral conductor.
The live and neutral conductors have a very low resistance and the load has a higher resistance,so the majority of the voltage is dropped across the load and only a few volts are dropped across the conductors (This is also why voltage drop in cables occurs). In this situation the neutral will only ever be a few volts above earth, if at all.
However if a short circuit occurs between live and neutral then the same situation as the earth fault I described earlier will happen, the live and neutral form a potential divider and the neutral will effectively rise up to a higher voltage until the protective device clears the fault.
Assuming the live and neutral conductors have exactly the same resistance then the neutral will rise up to 1/2 of the supply voltage.
So under fault conditions you don't want to be touching the neutral either!
If you have a TT supply (your earth is via an earth rod not connected to the suppliers network) the there can be a greater potential difference between the neutral and earth. Occasionally this can be enough to cause a noticeable tingle if you touch neutral and earth at the same time, this is one of the reasons there are additional requirements for isolating the neutral in this type of supply.
I can't make your numbers add up , the highest I could get with a fairly reasonable 50m loop ring main is 34.5v
I hope my diagram is not to messy. I have drawn both halves of the ring for clarity.
Where am I going wrong ? I realise that the ballance of Ze would be higher for the Live conductor and less for the N+E (the earth shroud is quite large area) but I have just done them half and half as some would also be the transformer secondary and so I just used the 0.4 ohme for each leg.
Also I have only allowed for the return path using the 1.5mm2 earth in the cable, where we were talking about bonded pipes becoming live which would reduce the resistance and thus the voltage at this point and shift it back to the higher resistance parts of the circuit.
The calculations for current through wet and dry bodies is also with the best possible conduction to an earth point that isn't at the same potential as the earth point that you are currently touching.
dry 34.5v/10kohme=3.5mA
wet 34.5v/1kohme=34.5mA
Thanks for your input.
Stu