Do you think the 3 gridlines could be what the "whoever they are" are referring to when they talk about splitting the US into 3 sections?No, I do not.
a) I don't give those people that much credit and
b) the US 'grid' is already 'split' (exists operationally, for the most part) in three sections!
Years and years ago - before the "interconnection" of different areas and their loads and generating sources reliability of electrical power generation was far *worse* compared to today since any failure of the local generator due to any reason: boiler failures/prime mover failures (including brush failures), transmission failures caused by breaker or switch failures, or transformer failures ... interconnecting allowed 'neighboring' systems to be *more* reliable, not less.
Tightly tying systems together today, though, requires that safety and islolating breakers and protective devices be properly set up (one of those failed in 1965 and took down the NE US) and monitored by the "system operators" (this was the failure last year 2003, IMO, involving FirstEnergy's control room).
Do you have an opinion on whether the NY Blackout was accidental or intentional?Ahhh ... which NY Blackout - there has been, really, only one "NY Blackout" and that was in 1977. (1965 was regional, the NE area and 2003 was an even bigger regional event!).
New York has, however, been 'blacked out' to due to much larger, encompassing blackouts in 1965 and of course in 2003 ...
Last year's (2003 blackout) was primarily of a green regional system coordinator (MISO) coupled with a control room "in the blind" (First Energy) and a short, late season warm spell that stressed the system just enough such that certain lines sagged into trees (some that were on the shortlist with tree-trimming crews in the area to do just that!) ...
As always, cites references if needed but far and away the biggest, most comprehensive resource on last year's blackout (complete with news stories as well as technical papers and analysis) can he found here:
www.pserc.wisc.edu/Resources.htm - Resources for Understanding the Blackout of 2003