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April 2012 www.sname.org/sname/mt that, in the majority of cases, it exceeded the criteria for passenger vessels (in terms of area and space) given its dimensions and proportions. erefore, it was decided to only address the habitability in terms of physical environment. e assessment consisted of preparing all the information required as if the hab- itability notation were to be requested for the RPSV. With this in mind, the spaces in the layout of the RPSV were classied as shown in Figure 1, and a test plan for each aspect to be assessed was developed, tak- ing into consideration: the measurement locations; the procedure for data acquisi- tion and the instrumentation to be used during this activity; the methods for data analysis; and the test schedule. For the purposes of this exercise, all the accommodation spaces and the combat spaces were selected as the locations where measurements were to be taken. Due to the relatively small size of the vessel, mea- surements were not restricted to potential worst-case locations. Ergonomic risk was defined at this stage by the degree of nonconformity of the design in terms of percentage, where the sites with deviations greater than 25% from the value dened by the rules to receive the habitability notation were identied as loca- tions with high ergonomic risk. Each of the three aspects of physical environment was assessed in the RPSV as follows. LIGHTING . Adequate illumination lev- els are important because they allow the execution of specic tasks onboard, includ- ing movement within and through spaces. Lighting together with the adequate selec- tion of color schemes and materials can make the di erence between a boring and an exciting environment, which plays an important role in personnel morale. The fact that the majority of the spaces onboard a ship need to be articially illuminated facili- tates the task of providing adequate levels of illumination; however, factors such as brightness, contrast, reectance, and size, among others, need to be taken into account to guarantee adequate levels of comfort. The objective of the lighting systems assessment is to determine compliance with minimum standards required by the crew to eciently perform the daily tasks onboard. For the RPSV, 60 measurement locations were decided, 48 of them related to general illumination and the remaining 12 to task illumination. e measurements were taken with the vessel in port at noon. SOUND QUALITY ENVIRONMENT NOISE. According to the ABS guide, Noise criteria have been selected to improve crew performance and to facilitate communication and sleep in appropri- ate vessel spaces. An additional goal is to enhance crew comfort.? For the case study, 43 measurement locations were decided and distributed in three deck levels. e measurements were taken with the vessel sailing on protected waters at its maximum speed (85% maxi- mum continuous rating). THERMAL ENVIRONMENT. Thermal Comfort is largely determined by the interac- tion of thermal environmental factors such as air temperature, air velocity, relative humid- ity, and the personal factors of activity and clothing. ermal environment factors?spe- cically temperature, relative humidity, and air speed?were measured in accordance with the identied requirements in every- thing but horizontal gradient. A total of 48 measurement locations were decided span- ning the 3 deck levels. Data was collected at the time of the day with the highest and low- est temperatures (noon and midnight) with the vessel at port and underway. RESULTS The different measurements taken to evaluate the physical environment were tabulated and plotted in order to iden- tify the zones of the RPSV where the crew was at ergonomic risk. e following para- graphs summarize the ndings in the three aspects of physical environment evaluated, together with the actions taken in order to correct the deviation from the norm, when it was found that this action was required to minimize ergonomic risk or to reduce it to an acceptable level. LIGHTING . The measurements showed that lighting was insucient in the sick bay, the galley, and in the cabins designed to transport soldiers and marines. In order to minimize the ergonomic risk in the sick bay, it was recommended that direct specialized lighting be installed in the area where the surgical procedures take place. In the case American Bureau of Shipping, Guide for crew habitability on ships,? (2001); and Guidance notes for the application of ergonomics to marine systems? (2003). ASTM F-1166, Standard practice for human engineering design for marine systems, equipment and facilities? (2000). International Maritime Organization, Code on noise levels onboard ships? (1981). International Maritime Organization (IMO), Recommendation on methods of measuring noise levels at listening posts,? IMO Resolution A.343 (IX) (1975). ISO 2923, Acoustics ? Measurement of noise onboard vessels? (1996). ISO 8468, Ships bridge layout and associated equipment? Requirements and guidelines? (2007). ISO 11399, Ergonomics of the thermal environment? Principles and application of relevant international standards? (2001). Royal Institution of Naval Architects, Comfort with regard to noise,? RINA Rules 2004, Pt. F, Ch.6, Sec 1 (2004). United States Navy, Shipboard habitability design criteria manual? (1995). United States Navy, Naval Ship Technical Manual?NSTM,? Chapter 330, Lighting (1999). O. Tascon and J. Carreño, Evaluation of an OPV design for the Colombian Navy: Lessons learnt? in proceedings of the 10th International Marine Design Conference, Norway (2009). Deeper Dive To learn more about the issues and challenges examined in this article, check out the following resources.