Sailor Well-being and Rack Curtains

Studies conducted by the Naval Postgraduate School Crew Endurance Team on United States Navy (USN) ships have shown that ambient light is a major habitability-related factor in berthing compartments. Even though the US Navy rack curtains are intended only for privacy, we postulated that they could also be used to improve sleeping conditions by blocking the light entering the rack space while the sailor is sleeping. Along these lines, we conducted a longitudinal quasi-experimental study on a Navy ship, comparing an enhanced rack curtain with the standard rack curtain in terms of sailor well-being, acceptance, and habitability conditions. Data were collected in December 2018 from 71 fit-for-duty crewmembers while the ship was underway in cold waters off the Pacific Northwest coast. Results showed that, overall, sailors approved of the enhanced curtain rating it positively in terms of light and noise reduction inside the rack. Also, regardless of the type of rack curtain, temperature inside the rack space was consistently lower than outside the rack. Compared to the standard curtain, the enhanced curtain was associated with an even larger temperature differential between the spaces inside and outside the rack. That is, in the cold environmental operating conditions in which the ship sailed, the inside of the racks with the enhanced curtain was colder than racks with the standard curtain. These findings can be explained if we consider that temperature in the rack is affected by the supply of air from the central ventilation system. When the curtains are closed (as it is oftentimes the case when sailors sleep in their racks), airflow is obstructed and the inside temperature cannot equalize to the external one. Therefore, our results suggest that the enhanced curtain obstructs airflow in the rack more than the standard curtain design.