And to the folks poo-pooing the new warp core because "it doesn't look anything like the warp cores we've been used to since the movie era first began" and whatnot:
The original TOS engine room and warp core didn't look anything like the warp cores we became used to starting in December of 1979. Trek is entitled to change how starship engine systems look every now and then to keep pace with the changing times, tastes and developing scientific and mechanical knowledge. The TOS warp reactor system from 1966-69 was a product of that era just as the vertical and horizontal, pulsating warp core with glowing plasma was a product of increased budgets and more daring set designs in the wake of high-tech blockbusters such as Star Wars.
The warp core and engine room of Archer's 22nd century NX-01 took elements from both TOS and the shows and films of later generations and created a cramped, clunky engine room with a relatively low ceiling, lots of ladders and metal railings and a swinging door that opened and closed with a manual handle.