Cooling
Water
Intake
Structure
(
CWIS)
Information
Data
Required
Rig
Information
Rig
Name
Glomar
CR
Luigs
Glomar
Jack
Ryan
Rig
Type
Drillship
Total
Installed
Power
Generation
Capacity
46320
BHP
Number
of
Cooling
Water
Intake
Structures
(
CWISs)
8
(
4
high
&
4
low)

Brief
description
of
each
CWIS
(
e.
g.,
sea
chest,
simple
pipe)
Seachests
Rough
dimensions
of
each
CWIS
and
indicate
whether
onboard
CWIS
has
an
existing
flange
62"
x
47"
plate
with
slots
½
"
x
4".
NO
flange
845
square
inches
clear
 
upper
seachests
975
square
inches
clear
­
lower
Screen
type
(
e.
g.,
strainer,
wedge
wire)
with
mesh
size
Grating
Total
Design
Specifications
for
Daily
Maximum
Water
Intake
Volume
of
each
CWIS
12.5
million
gal
(
297,000
bbls)
Includes
Ballast
&
Fire
Total
Daily
Water
Intake
Volume
of
each
CWIS
(
Set­
up/
Drilling)
5.9
million
gal
(
140,389
bbls)

Design
Specs
for
Through
Screen
Velocity
of
each
CWIS
(
i.
e.,
Q=
V*
A)
(
Set­
up/
Drilling)
1.33
fps
Rule
of
thumb
traditionally
has
been
to
have
the
clear
area
through
each
grid
to
be
at
least
twice
the
total
suction
area.
List
of
Purposes
of
Cooling
Water
Intakes
(
e.
g.,
cool
crude
oil,
produced
water,
power
generators,
drill
pipe
brakes)
Cooling:
Engine,
Brake
Water,
Thrusters,
Air
conditioning,
Mud
pumps,
HPU
(
High
Pressure
Unit),
Compressors,
flare
boom.
List
of
Purposes
of
Non­
cooling
Water
Intakes
(
e.
g.,
fire
water,
hotel
loads)
Mud
system­
pits,
cement
unit,
water
Makers,
fire
main,
ballast,
sanitary
Total
Volume
of
Water
Intake
for
Ballasting,
Duration
of
the
Ballast
intake,
and
the
Through
Screen
Velocity
of
the
Ballast
intake
2.55
million
gal
(
60,879
bbls)
Duration
=
not
frequent.
Through
Screen
Velocity
=
1.75
fps
 
combined
with
cooling
water.

Mitigation
Measures
for
reducing
Exotic
Species
Migration
through
Ballast
water
The
rig
does
not
carry
much
ballast
water
from
location
to
location.
It
is
taken
on
and
dumped
at
the
same
location.
Mitigation
Measures
for
reducing
Impingement
and
Entrainment
of
Aquatic
Organisms,
as
well
as
Bio­
fouling
Prevention
Measures
Sea
chest
screens,
duplex
and
simplex
baskets,
cathodic
protection,
chlorine
injection
system
in
sea
chest
to
prevent
growth
in
piping.
Is
the
Rig
equipped
with
a
Radiator
Cooling
System
for
the
Main
Engines?
No
