Evaluation of the LEP centre-of-mass energy above the W-pair production threshold by Blondel, A, Boege, M, Bravin, E, Bright-Thomas, P, Camporesi, T, Dehning, B, Heemskerk, M, Hildreth, M, Koratzinos, M, Lancon, E, Mugnai, G, Muller, A, Peschardt, E, Placidi, M, Qi, M, Quast, G, Renton, P, Sonnemann, F, Torrence, E, Weber, A, Wells, P, Wenninger, J, Wilkinson, G, Grp, L