Barry,
just intrigued where you get your info..."not suitable for a B777"...do you have any basis for this. I'm sure a 777 can make a 90 deg turn, even if tight-ish. Looking at GoogleEarth, the taxiway looks more than wide enough. I know for a fact, ac as large as the 777 have been involved in such a manoeuvre without incident.
How are you qualified to make such a statement?