Richelieu-class battleship and more broadly the proximity between the two main artillery magazines (one for each turret), was the greatest risk: one hit could potentially neutralize the entire main battery, or even cause the ship's loss from an ammunition explosion. On "Dunkerque", to avoid this risk the forward turrets had been positioned apart from each other, further apart than on the "Nelson"-class battleships. The French also studied three-turret designs, such as one quadruple and two double, two triple and one double, or three triple. In every case, three turrets would have increased weight vs two quadruple turrets, reduced propulsion to and speed
Double beta decay or double beta decay are predicted to be very long; hence, quadruple beta decay is unlikely to be realized. The eight candidate nuclei for quadruple beta decay include Zr, Xe, and Nd capable of quadruple beta-minus decay, and Xe, Ba, Gd, and Dy capable of quadruple beta-plus decay or electron capture. In theory, quadruple beta decay may be experimentally observable in three of these nuclei, with the most promising candidate being Nd. Double beta decay In nuclear physics, double beta decay is a type of radioactive decay in which two neutrons are simultaneously transformed into two protons, or vice versa,