I think,but am not sure,that the ORR quote is referring to a desktop exercise in which weighted statistics were used,so the adverse conclusions about DC safety appear to come from a subjective valuation of likely hazards,not real statistics. The only time a close friend of mine got reprimanded by his BBC bosses was when he wrote a national BBC1 TV 10pm bulletin which included the lines:
'2 Liverpool youngsters are fighting for their lives in a Merseyside hospital tonight after trespassing on railway sidings close to the city's Edge Hill station. The 14 year olds had walking on top of carriages & were electrocuted after coming into contact with railway high voltage cables.'
He was shown the dictionary where 'electrocuted' means killed by electricity. It happened in about 1995.
I just wonder if people don't have it in for third rail because it appears so dangerous. The ORR research justifying third rail containment seems selective.
I urge people to carefully read the ORR research quote that a poster put up. One needs to know how & why the stats were weighted. Third rail seems such a cheap & environmentally friendly way to electrify.
I know experienced posters have raised extra DC track side transformers,but they are offset by ac needing extra rail borne transformers.
They have also raised extra time preparing for track possessions,but that could be managed down & there are benefits,cranes don't have to dodge the overhead line. Power losses,well wet ballast is often piled up against the third rail,leaking vast currents to earth. Take a look next time you are held at a signal in third rail territory.
If NR had a regime for eliminating this sort of third rail earthing the only extra power loss would come from the low voltage of dc,& that could be partially mitigated by low resistance aluminium conductor rail.