912 



HYDRODYNAMICS IN SHIP DESIGN 



Sec. X1.5 



BG — Pendulum stability height, as of a sub- 

 marine, when the surface waterplane area is 

 ne gUgi ble and CM coincides with CB 



BM, BMx — Metacentric radius for transverse 

 inclination 



BMl — Metacentric radius for longitudinal incli- 

 nation 



BR — Bilge radius at section of maximum area 



BDI — Bilge-diagonal intercept, measured be- 

 tween (1) the intersection of the bilge diagonal 

 with the centerline at the designed waterline and 

 (2) the intersection of this diagonal with the floor 

 h ne, wh en extended to the vertical at Bx/2 



BKW — Bilge-keel width, measured at mid- 

 length or w herever this width is a maximum 



BD/BDI — Ratio, bilge-diagonal offset to bilge- 

 diagonal intercept, at any station 



BKW/Bx — Ratio, bilge-keel width to designed 

 water line beam at the section of maximum area; 

 Blew is measured at midlength because it is 

 usually greatest there 



BR/Bx — Ratio, bilge radius to designed water- 

 line beam, at the section of maximum area 



PR — Dea drise; see last part of definition forRF 



GM, GiMx — Metacentric height, transverse, 

 from CG to CM, for transverse inclination 



GMl — Metacentric height, longitudinal, from 

 CG to CMl , for longitudinal incUnation 



HS— Half siding at flat keel, wherever it is a 

 maximum 



HS/Bx — Ratio of the greatest half -siding at 

 flat keel, wherever it occurs, to the beam at the 

 section of maximum area 



KB — Center of buoyancy above baseplane 



KG — Center of gravity above baseplane 



KM, KMt — Distance of metacenter above 

 baseplane for transverse inclination 



KMl — Distance of metacenter above baseplane 

 for longitudinal inclination 



KS — Sheer height at side, minimum, above 

 b asepl ane 



KB/H — Ratio of height of center of buoyancy 

 above baseplane to draft 



LCB — Longitudinal center of buoyancy abaft 

 FP, in fraction of L; alternative Lcb 



LCF — Longitudinal center of flotation abaft 

 FP, in fraction of L; alternative Lcf 



LCG — Longitudinal center of gravity abaft FP, 

 in fraction of L; alternative Lea 



LM A — Longitudinal position of section of maxi- 

 mum area abaft FP, in fraction of L; alternative 

 Lma ■ If a vessel has parallel middlebody, this 



position is taken as the midlength of the middle- 

 body. 



MCT — -Moment to change trim, followed by 

 appropriate unit 



PWL — Length of the parallel or straight-sided 

 portion of the designed waterline 



RF — Rise of floor at shell at section of maximum 

 area, reckoned as a height above the baseplane 

 when projected to Bx/2; also called "deadrise" 

 and abbreviated DR 



RF/Bx — Ratio, rise of floor to beam. 



XI .5 Abbreviations for Units of Measurement. 



For convenience these abbreviations are placed 

 in natural groups involving length, area, volume, 

 weight, pressure, power, time, and the like, 

 rather than in alphabetic order. 



The same abbreviation applies to both the 

 plural and singular of the word(s) it represents. 

 Periods are not inserted after any abbreviation or 

 part thereof. 



Trigonometric abbreviations are well known 

 and are not listed here. 



Length Area 



in — inch sq in, in" — square inch 



ft — foot sq ft, f t^ — square foot 



yd — yard sq yd, yd^ — square yard 



fm — fathom sq mi, mi^ — square mile 



mi — mile; nautical mile unless 



otherwise indicated 

 mm — millimeter sq mm, mm^ — square millimeter 

 cm — centimeter sq cm, cm" — square centimeter 

 m — meter sq m, m" — square meter 



km — kilometer sq km, km^ — square kilometer 



Volume 



cu in, in^ — cubic inch 



cu mm, mm^ — cubic millimeter 



cu ft, ft' — cubic foot 



cu cm, cm' — cubic centimeter 



cu yd, yd' — -cubic yard 



cu m, m' — cubic meter 



gal, U.S. — gallon 



gal. Imp. — gallon. Imperial, equal to 1.201 U.S. 



gal 

 bbl — barrel 



Weight 



oz — ounce kip — a thousand pounds 



lb — pound kg — kilogram 



t — ton (to be further specified) 



