CEAC-2022-05-May

News
Pioneering Welding Technology Enables
Underwater Ship Hull Repairs
The development of a world-first underwater robot which
can repair a damaged ship’s hull using pioneering friction stir
welding technology is at an advanced stage after a concept
design for the system was finalized.
In a project funded by the European Commission, 13 project
partners from nine countries are currently collaborating on
a scheme which will result in the creation of a working machine
with the potential, with further development, to allow
a hull of a ship to be repaired at sea, removing the costly
requirement for it to travel to the nearest dry dock.
The innovative RESURGAM (Robotic Survey, Repair and Agile
Manufacture) Project will allow a responsive repair to be carried
out, from a remote distance, anywhere in the world, and
will save industry a substantial amount of time and money as
well as making it safer by taking away the need for specialist
divers to work in often hazardous conditions.
A team of engineering experts at UK company Forth was appointed
as the technical managers of the project due to the
company’s 20 years of experience in working in hazardous
environments and previous experience of building bespoke
friction stir welding tools, such as the recent development
of the FSWBot machine — an innovation robotic crawler
devised for internal repair and refurbishment of oil pipelines.
The team has successfully completed a Functional Means
Analysis to establish all functions of the new tool, and carried
out a full optioneering process to decide on the concept
model.
A first concept design for both the welding head and frame
mechanics has also been completed, and it will be developed
in the coming months.
Chris Downham, Forth’s operations manager, said: “The RE-
SURGAM Project is such an exciting initiative to be involved
with and having so much input from companies from across
Europe shows the true power of collaboration with each representative
bringing a unique set of skills to the project.
The challenge for Forth is to design a bespoke friction stir
welding tool that can be mounted to the side of a ship’s hull
and can conduct a friction stir weld, underwater, in a vertical
plane, between a repair patch and the defective area of the
hull.
One of the biggest obstacles to overcome is securing the
machine to the hull. The team has designed a circular track
frame to hold the weld head which will be secured to the
hull via a frame using four R1000 electromagnets which each
need to produce 7.5 tonnes of force and enable the weld
head the required Z-axis force to continue to weld.
The system will be tested in the company’s Deep Test Pond,
one of the largest facilities of its kind in the UK, as it measures
22.5 meters long, 10 meters wide and six meters deep
— holding up to 1.2 million liters of water.
Now a concept design has been completed, Forth’s engineers
will now start a detailed design program using analysis from
the design risk assessment to explore the functions the robot
requires and to also identify early design and functional complications.
On completion of this process, the design will be reviewed
for a final time to progress the project on to the final stages,
which include the manufacturing of the system for use on
active ships.
Forth is working with the following partners on the RESUR-
GAM Project: The Welding Institute; University of Lancaster’s
Joining 4 Innovation Centre; Element Six (all UK); ACLUNAGA
(Spain); AISTER (Spain); European Welding Federation (Portugal);
University of Limerick (Ireland); TU Delft (The Netherlands):
STIRWELD (France); Engitec Systems International
(Cyprus); GISBIR (Turkey).
“Being involved as the technical manager of the project is
a huge feather in the cap for Forth, and it is proof of how
advanced we are becoming as a company by being invited to
share our expertise on such a groundbreaking innovation.
“We are thrilled to have reached a major milestone in
completing the concept design and our team of extremely
talented engineers look forward to taking the project to the
next level as we play a key role in developing this innovative
technology which will significantly boost the industry.”
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| Chief Engineer