hit the rack

From the use of rack to mean a berth or bunk. Compare hit the sack.

hit the rack (third-person singular simple present hits the rack, present participle hitting the rack, simple past and past participle hit the rack)

1. To go to bed.
   • 2010, Herb Brewer, Chronicles of a Marine Rifleman: Vietnam, 1965-1966, →ISBN, page 171:

     By the time I had unpacked my sea bag, made my rack, and finished a good long hot shower, it was late in the evening. I decided to make it a day and hit the rack.

   • 2012, Whit Howland, The Case of the Sad Luck Dame: A Huey Dusk Caper, →ISBN:

     With that in mind, he walked off to his bedroom and shut the door. It was time to hit the rack.

   • 2012, Brewster MaCoy, A Fear of Dying: A Soldier's Story, →ISBN, page 135:

     It was around 2300 hours when I finally hit the rack, and as I always did when I thought we may enter into a combat situation, I lay on my bunk with my eyes closed and said a prayer for the safety of my squad.

2. Used other than with a figurative or idiomatic meaning: see hit,‎ rack.
   • 2015, Tom Green, The Blue Hand:, →ISBN, page 71:

     I said, “Holy old Fuck,” when the cue ball hit the rack dead on, bounced straight back, and stopped dead in the middle of the table.