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Tube ProducTs InTernaTIonal March 2014
developments
products &
Acoustic positioning technology
A new acoustic positioning technique
to improve the quality and accuracy
of pipeline touchdown monitoring
has been successfully utilised by
project management, engineering and
construction company Technip.
The company has installed a Sonardyne
GyroUSBL transceiver on the stinger
of its rigid pipe S-lay and heavy lift
construction vessel
G1200
. Used in
conjunction with Sonardyne’s Ranger 2
USBL tracking system, the technology
is used to acoustically track an ROV
positioned at pipelay touchdown to
ensure the pipe is being accurately laid
in the permitted corridor.
Ranger 2 is a survey grade USBL
acoustic positioning system designed
for long range tracking of underwater
targets and position referencing for
dynamically positioned (DP) vessels.
The system calculates the position of a
subsea target by measuring the range
and bearing from a vessel-mounted
transceiver to an acoustic transponder
fitted to the target.
Typically, the transceiver is deployed
through the hull or over the side of the
vessel; this enables targets to be tracked
below, to the side and far behind.
However, on a large pipelay vessel a
transceiver cannot reliably ‘see’ through
the thruster wash created at the rear.
By fitting the transceiver on the end
of the
G1200
’s pipelay stinger, it was
positioned well away from thruster noise
and in direct line of sight of the ROV
behind it.
GyroUSBL combines a 6G high
performance HPT transceiver with
a Lodestar attitude and heading
reference/inertial navigation system in
the same assembly. This combination
eliminates alignment errors and allows
users to monitor the dynamic motion of
the stinger’s tip.
“We’ve been incredibly impressed with
the accuracy, precision and repeatability
provided by Ranger 2 GyroUSBL,”
commented Iain Miller, subsea
intervention manager for Technip USA.
“The success with the stinger-mounted
transceiver means that we’re now
looking to adopt this novel technique
for future pipelay projects here in the
Gulf of Mexico and elsewhere.”
Ralph Gall, technical sales manager
at Sonardyne Inc, said, “Locating a
transceiver on the stinger is a great
solution for ensuring that vessel noise
disruption is rejected. The time-saving
features of the pre-calibrated GyroUSBL
also result in reduced operational costs
with the ability for users to move it from
vessel to vessel with minimal downtime
whilst maintaining the highest levels of
positioning performance.”
sonardyne International ltd
– UK
Sonardyne’s GyroUSBL transceiver was mounted on the end of the G1200’s 105m-long stinger
