User Manual for the Type 8300 Compatt 6
(and Variants)
UM-8300-Compatt 6
Issue B3
4.2.4 Strops
The suspension rope or strop between the anchor weight and the shackle in the release mechanism
should be long enough to allow ‘line of sight’ between the transponders in the array, and any
topographical features in between. The minimum strop length should be 1.5 metres to ensure the
momentum of the falling transponder does not carry it down onto the weight when the weight reaches
the seabed, and possibly damaging the release. Allowance should also be made for any currents
which may deflect the transponder from floating straight above the anchor weight.
If a wire strop is used, particular attention should be paid to the materials used. Electrolytic action
between dissimilar metals could result in the strop breaking and the transponder drifting away.
The eye of the wire strop must be electrically insulated from the release mechanism to minimise
corrosion.
4.2.5 Mounting Guidelines for Endcaps with an Inclinometer
The following guidelines should be followed for mounting transponders with inclinometers.
Note
Inaccurate Equipment Operation. Realignment of the inclinometer orientation when re-installing
the unit, following removal, is important. Small tilt angle differences can be zeroed out when the
system is calibrated during lowering, however incorrect orientation will result in the system giving an
incorrect Course to Steer.
a.
Orientation
– It is important to install the unit on a structure with a known orientation. The flat
bottom endcap has a label next to a vertical groove which reads BOW/Forward. This must be
facing North.
b.
Levelness
– Although the inclinometers will be calibrated for levelness during structure lowering
care should be taken to ensure it is mounted as near to vertical as practical. The sensors have a
±90° range.
c.
Isolation
– To minimise corrosion of the aluminium pressure housing, contact with structure
metalwork should be avoided at all costs. Clamps around the tube should only be in contact with
the housing sleeve. The flat bottom face should be insulated with an insulating material such as
neoprene or nylatron.
d.
Acoustic masking
– The position on the structure should be such that the transducer is well
away from reflecting surfaces above it, especially flat areas.
e.
Installation mounting kit
– An inclinometer installation mounting kit, CPN 650-2559; see
.
f.
Stab mounting kit
– A stab mounting kit (641-0434) with 0° 90° 180° 270° directional control
can be used to mount a Compatt 6 ensuring repeatability when required; see
.
g.
Endcap mounting
– To mount the bottom endcap onto an adaptor plate, a custom mounting
plate must be used. The plate must contain two dowels to give a datum line to which the endcap
can be abutted to. The plate is mounted using four bolts; see
. An electrical isolation
layer between the mounting plate and the endcap should offer corrosion protection.
Note
The locking sleeve on the endcap connector protrudes from the port side face of the endcap.
h. DPT base mounting bracket – For Riser monitoring (620-7168); the transponder is held by one
or two clamp rings around the tube which are stood off the Riser by approximately one metre.
Section 4 – Installation
18