Not too many bearings.
Each shaft has one and only one ball (thrust bearing) and as many roller bearings as are required for shaft stability (shaft whip or whirl). So the slender inner shafts have a centre bearing as well as one near each end. In this case the centre bearings are thrust bearings.
Very good article in Flight International about the Trent 800 September 1996 can be downloaded free, gratis and for nothing from flightglobal.
Last edited by firstfloor; 26th Nov 2010 at 20:18.