Development of a value-engineered NOMAD buoy

Abstract

Since the mid-1970s, the National Oceanic and Atmos p h e r i c A d m i n i s t r a t i o n (NOAA) Data Buoy O f f i c e (NDBO) has used Navy Oceanographic Meteorological Automatic Device (NOMAD) buoys as p a r t o f t h e i r ocean data gathering network.These U.S. Navybuilt, 20-ft long, boat-shaped hulls, have proven t o be extremely seaworthy buoys.The h u l l s a r e r e l i a b l e , e a s i l y t r a n s p o r t a b l e , and f o r many a p p l ications, they are an a t t r a c t i v e a l t e r n a t i v e t o t h e c o n v e n t i o n a l 4 0 -f t and 33-ft diameter discus-shaped buoys.As a r e s u l t , NDBO, i n e a r l y 1979, began a c t i v e l y p u r s u i n g t h e i d e a of designing and con- s t r u c t i n g a second generation, value-engineered (VE) v e r s i o n o f t h e NOMAD buoy. A c o n s u l t i n g firm was c o n t r a c t e d t o r e d e s i g n t h e NOMAD h u l l , and i n June 1981, c o n s t r u c t i o n was s t a r t e d on a s e r i e s of f i v e new NOMAD buoys. This paper describes the design and c o n s t r u c t i o n o ft h e VE NOMAD buoy, and d e t a i l s t h e e f f o r t s o f i n d u s t r y and government working together to produce a r e l i a b l e , c o s t e f f e ct i v e d a t a buoy. NOMAD DEVELOPMENTThe NOMAD h u l l i s we1 1-documented t o have been develo ed f r o m t h e " R o b e r t s b u o y " o r " c u r r e n t r a d i o buoy."!-3The Roberts buoy was a 6.67-ft long, 400-lb, boat-shaped buoy developed i n t h e e a r l y 1940s, by t h e U.S. Coast and Geodetic Survey, t o measure s t r o n g t i d a l c u r r e n t s . The buoy's performance was s a t i s f a c t o r y , b u t i t s l i m i t e d s i z e r e s t r i c t e d t h e b u o y ' s use i n o t h e r a r e a s .The successor to the Roberts buoy was the Naval Research Laboratory (NRL) Mark 3 b u o y . T h i s h u l l was designed by NRL for housing sono-radio equipment, moored i n a s t r o n g c u r r e n t i n deep water. I t was 12.58-ft long and displaced approximately 4700 l b . The buoy resembled the Roberts buoy, but with increased dimensions to accommodate a larger payload. There were two tentative designs of the NRL Mark 3 buoy, designated Buoy A and Buoy B. The two designs had the same dimensions in plane; however, Buoy B had an a p p r o x i m a t e l y 8 -i n . g r e a t e r d r a f t t h a n Buoy A.NRL tasked the David Taylor Model Basin (DTMB) t o conduct model tests on b o t h h u l l t y p e s t o d e t e r m i n e t h e i r p e r f o r m a n c e . 2 The r e s u l t s o f t h e s e model t e s t s caused DTMB t o recommend the further development of Buoy B because of i t s g r e a t e r l o a d -c a r r y i n g c a p a c i t y .