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
Quadruple-precision floating-point format implement nearly quadruple precision using "pairs" of double-precision values is sometimes called double-double arithmetic. Using pairs of IEEE double-precision values with 53-bit significands, double-double arithmetic can represent operations with at least a 2×53=106-bit significand (actually 107 bits except for some of the largest values, due to the limited exponent range), only slightly less precise than the 113-bit significand of IEEE binary128 quadruple precision. The range of a double-double remains essentially the same as the double-precision format because the exponent has still 11 bits, significantly lower than the 15-bit exponent of IEEE quadruple precision (a range of for double-double versus for