Cosmology with Phase 1 of the Square Kilometre Array Red Book 2018: technical specifications and performance forecasts by Bacon, DJ, Battye, RA, Bull, P, Camera, S, Ferreira, PG, Harrison, I, Parkinson, D, Pourtsidou, A, Santos, MG, Wolz, L, Abdalla, F, Akrami, Y, Alonso, D, Andrianomena, S, Ballardini, M, Bernal, JL, Bertacca, D, Bengaly, CAP, Bonaldi, A, Bonvin, C, Brown, ML, Chapman, E, Chen, S, Chen, X, Cunnington, S, Davis, TM, Dickinson, C, Fonseca, J, Grainge, K, Harper, S, Jarvis, MJ, Maartens, R, Maddox, N, Padmanabhan, H, Pritchard, JR, Raccanelli, A, Rivi, M, Roychowdhury, S, Sahlen, M, Schwarz, DJ, Siewert, TM, Viel, M, Villaescusa-Navarro, F, Xu, Y, Yamauchi, D, Zuntz, J, Square Kilometre Array Cosmology Science Working Group