Heave Compensation Introduction
HC 1 Sheave Arrangement
HC 2 Sheave Alignment Correction
HC 3 Double Sheave Box
HC 4 Double Sheave Box Incorporated in Structure
HC 5 Lift In of Heave Compensation Cylinders
HC 6 Heave Compensation Cylinders in Place
Ram Rig Single, Rams and CrossbeaM
Ram Rig Single, Rams and CrossbeaM
West Navion Is a Twin Ram Rig Drillship, in this photo sitting in the yard awaiting the lift in of the twin derrick
West Navion, a Dynamically Positioned Drill Ship
which can maintain position whilst drilling (when
not drilling It can also move from one location to
another easily). The picture on the left shows the
upper works of a RamRig drilling derrick. The
Rams either side of the dilling station have a long
stroke and can move with consistant force from
end to end of stroke. It also has a system for
heave compensation which againg accomodates
the small heave movements of the ship whilst
maintaing a consistant drilling rate. Finally West
Odin had two such rigs interconnected. This
allows a hole to be drilled by one drill station whilst
the other station is making up dounle lengths of
pipe. Muck of the pipe handling and drilling is
automatically controlled to minimise manual
handling. This type of rig was the step change
around 2000, subsequently rigs have been made
more automatic and other derrick designs and Box
Girder style structures are used. The main
emphasise of this type of rig is that it was
constucted as a Module in one location ,
transported and lifted in in situ. Its foundations are
slightly different to other modules in that the loads
from drilling are large and transmitted into the
ships frame via haunches which spread the loads
into adjacent frames. West Navion had other
conventional modules for Power Generation which
were box like and similarlry lifted in by floating
Shear Legs.
Level 3
a general understanding of Modules 
C2V Where you see this, Click too View
Level 3
Level 2
Level 1
The string of pictures below show some of the elements of the installation of various pieces of the drilling compensation system.