Application of RPD to the Offshore Self-elevating Units
JIANG ~a-ningl, LI ~ o n ~ - t a o ~ (1. Tianjin Maritime Safety Administration, Kartjin 3002 11, China;
'PEElZig
SHIPBUILDING OF CHINA
W.51 Supplement l S i l (aa
No. 191)
Aug. 2010
# @ 3: $ft&7L$;
RPD; & & 1 % % ;
ftk WE##; BE%
A
8f )8 $ : U674.381
*fwsiiYo\E!:
-
dR&;fJ %#!!%%, &fin F&G 'L3 RPD JU-2000E P&EIBR RPD % 203rnrn[~]: GustoMSC a4 C 4 , J6 f $ffJ@RRPD % 5 ~ r n r n ~BMC375 ~&%%'T%~HF~!J%R%%~ ~~:
[6]
L Hongtao, YANG Qingxia, LI Ye. Study on general performance of jack-up under elevated condition[Jl. China Ocean I
Engineeaing, 2009,23(3): 577-584.
[I]
-4##, £&&. %A'P~%df)#7M.k@3riA~tllE&, 1992.
January 2002.
[2] SNAME. Guidelines for S i Specific Assessment of Mobile Jack-up Units[S]. Ttchnid & Research Bulletin 5-5 A,
2. Ofihore Engineering Plan Approval Center of CCS ,Tianjin 300457, China)
Abstract
The RPD represents the differential vertical displacement between each chord of one leg. The maximum allowable RPD is the value that should not be exceeded under jacking, pre-load jacking and pre-load holding conditions. Theory and method of RPD calculation are studied and suggested respectively in this paper. As an example, the maximum allowable RPD for a jack-up with truss legs is determined. This paper may be helpfi~l to he rig owners, operators and designers.
[3]
E.%. *##. $*fa#?% fiER%$[J].
m%%9%, 2007,22(6): 4-5.
[4] MSC.RPD design fix C 4 jack-up [EBIOL]. hm: J6
151 MSC. Overall Basic Design for Jsck-up[MJ. GustoMSC, 2007: 5 . 6
*ft%~%jzeT~~~-irt%%B~%BZ%~ #%e-+%%I"CBMB(InStbft%.Pe,%3PZ$ Ha*%, %Eft@fiW~E%T:)Fi!TSkW%i+ B, RPD RPD &84%%Bj2T2i!iRk9 ilifIE3 %%~3%-zmE9~M
.
RPD (Rack Phase Difference)
~X%%%8@Mm?ag#%%Rga#fl&%&#%&&@ilif?fiE
RPD = (b,
UC
-4,) +&o
I%kBBR3%B%GhS%fi, &I#MWB~%%%,W W ! J L B A ~ Z f i ~ + @ @ % f i S ~ EEBb < 1 > HJW@E~#G@KJ C o it-$$%%$US% e RPD 3 fi
K y words. Jack-up; RPD; truss leg; jacking; preload jacking; pre-load holding e