Semi Submersible Design

We where involved in the design and deliveries of one
of the first Semi Submersible named Amethyst build in the Netherlands end 70 .
Since then the Semi model has been used manytimes,
ST and Deutag where together for delivery
of all drilling equipment, a summary of all equipment
is show on sketch 20.03. and the Drilling package on sketch 20.01.

Note : Same as for the new generation Jackups the
question how many Riser Pipes can you handle per hours,
the Riserpipes ,length abt.90ft (27mtr) are the vertically
interconnection between BOP stack and the Drill ship.
The water-depth can be up to 3000 mtr.(10.000ft),
a day-rate is mainly based on the figure of the handling 
frequency which is for a modern drillship 2.9
riser pipes per hour ,acc.ST latest design 3,5 RP hours is possible.