List of reused codes/names for norwegian ordinary research vessels.
Other groups of vesssels, like naval vessels, ships of oportunity and
commercial fishing vessels, are not dealt with.

58GS : G.O.Sars
       1.       1950 - 1970/03
       2. LLZG  1970/06 - 20030209  (renamed Sarsen 20030210)
       3. LMEL  20030425 - active
	   
58JH : Johan Hjort
       1.       1922 - 1931
       2.       1932 - 1956 (renamed Oscar Sund (58OS) 1957)
       3.       1958 - 1982
       4. LDGJ  1991 - active
	   
58OS : Oscar Sund
       1.       1957 - (1957 only?) (former Johan Hjort)
       2. JXNI  1993 - 20061103
	   
58MS : Michael Sars
       1.       1900 - 1931 (rarely used after about 1914) 	   
       2. LHUW  1979 - 20031218
	   
58GD : G.M.Dannevig
       1.       1950 - 1986
       2. LINW  1987 - active
	   
58DR : Dr. Fridtjof Nansen
       1. JWVN  1974 - 1993/09
       2. LGWS  1993/10 - active
	   
58SD : H.U.Sverdrup/H.U.Sverdrup II (military research vessels)
       1.       1960 - 1989
       2. LCMO  1990 - active