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October 2011www.marinelink.com 35have been developed that apply to nu- merous applications, from furniture tospace craft. This data is often readily available. However, there are still differ- ing definitions, conventions and levels of accuracy. The designer must compare data from different sources with care to be sure that the data reflects the appro-priate measurements and the populationof people who will be crew or passengers on board the vessel. Typical measurement categories include the following (MoD Std 00-25-17):Height (stature) Sitting eye height Standing eye height Sitting elbow rest height Functional reach Foot breadth Foot length Head circumference Waist circumference Hip breadth Weight Significant amounts of anthropometric data exist, particularly for military per- sonnel, both male and female. Exampledata is presented in Table 1 presents height data for ten international regions of the world. The data is for the 50th per- centile, that is, half of the population ofthe region is taller than these values and the other half is shorter. Data of particu- lar value to the marine designer is found in American Bureau of Shipping ?Guid- ance Notes for the Application of Er- gonomics to Marine Systems? (ABS2003a). This data is from US and inter- national sources. WHO TO INCLUDE IN YOUR DESIGN RANGEWhen using anthropometric data, thedesigner must determine which portionof the population will be accommodated.This is necessary because designing forevery member of a population is often impractical. For example, a designer may decide to include 90 percent of a popula-tion and select a range between the 5thand the 95th percentiles. In practice, larger people may be able to squeeze into a tight spot, and smallerpeople may be able to reach a bit furtherthan their comfort zone, but the idea is that specifying a data range within spec-ified percentiles provides the designer with a dimensional framework that will result in a practical, cost-effective design. Whether to use a 5th or 95th percentileor an inclusive range depends upon the design situation. For example, when de- signing for maintenance access behindinstalled equipment, access clearance isimportant. The shoulder width of the 95th (larger size) percentile may be specified. This ensures that only a small 5 percentof the population will have possible prob- lems with access. On the other hand, when designing thelocation for a valve, reach can be impor- tant, and the designer may select a 5th(smaller size) dimension (Figure 1). As a result, all but 5 percent of the population can easily reach the valve (Panero 1979). Figure 2 shows another valve-related ex- ample in which all but the smallest per- son would find two adjacent valve placed Table 1 50th Percentile Height Data (cm) for Ten International Regions(Estrada 1995, ABS 2003b) RegionMaleFemale Sri Lanka163.9152.3 Colombian Workers168.6155.6 Japan168.7155.7 China169.0155.4 France171.9160.4 Germany173.3161.9 Sweden174.0164.0 UK175.5162.0 US176.0162.6 Netherlands179.5165.0 MR Oct.11 # 5 (34-41):MR Template 10/5/2011 12:45 PM Page 35