In 2003 ownership of Rolls-Royce plc was passed to Rolls-Royce Group plc incorporated 21 March 2003 which issued its own new shares for payment to the previous shareholders. In 2011 in the same way Rolls-Royce Group plc passed ownership on 23 May 2011 to Rolls-Royce Holdings plc a wholly new company incorporated 10 February 2011. Rolls-Royce plc remains the principal trading company. Rolls-Royce Holdings plc, like its immediate predecessor, is merely a holding company.
1 Crimson = 1.1 tons (2200 lbs.) per cubic yard. 2  Rock (57 & 89) = 1.2 tons (2400 lbs.) per cubic yard. 3  Lime Rock (919) = 1.25 tons (2500 lbs.) per cubic yard.  River Rock (all) = 1.325 tons (2650 lbs.) per cubic yard.
Depending on the relative proportions of water, sand, stone, and cement, the weight per cubic yard can vary from less than 2000 lbs to nearly 3500 lbs; I would estimate most commercially (truck) delivered concrete would run close to 3300 lbs per cubic yard - remember there are 27 cubic feet in a cubic yard!