HOW TO BUILD A LIFEBOATPAGE NAME HERE
All lifeboat refi t and repair work was
moved to the new factory in 2015,
followed by the complete Shannon class
build programme, with a target of six new
boats per year. Situated on the same site
as the offi ce and training facilities, the
crews themselves what they really needed.”
The RNLI’s stable of all-weather
lifeboats grew to include the Severn,
Mersey, Tamar, Tyne and Trent. While each
class excelled in its operation, refi t and
maintenance was a logistical nightmare so
a rationalisation programme was needed.
New technology, such as light, powerful
diesel engines linked to water jet
propulsion systems, also supported the
argument for a new generation of
all-weather lifeboat. Plans would
encompass the best of the older models
with the latest technology available.
A new project team was formed in
2007, which included naval architects,
mechanical, electronic and electrical
engineers, and CAD specialists. At fi rst the
team evaluated an ‘off-the-shelf’ hull form,
known as the Experimental Boat, which
was used for behavioural analysis in
varying sea states. Marsden recalls that
the tests were rather alarming:
“Unfortunately, in specifi c rough
conditions we encountered severe
slamming and rolling. The hull had a fl at
22° deadrise, and coming off a wave we’d
end up with a large amount of transverse
acceleration pressures on the crew, rather
than the more acceptable vertical
acceleration, which we could control with
shock mitigating suspension seats. We
were at risk of actually injuring people
during our testing!”
However, the programme did serve to
illustrate that jet drives were the most
suitable form of motive power for the next
generation of all-weather lifeboat,
especially when operating inshore.
As the Shannon class was designed to
replace the beach-launched Mersey
(known as a Fast Carriage Boat or FCB2),
the team also had to develop a launch
and recovery system to use with the
Experimental Boat.
This involved a carriage which, once the
lifeboat was aboard, could be rotated
through 180° using hydraulic power, readyBehind the scenes at the RNLI’s all-
weather lifeboat boatbuilding facility
in PooleRNLI senior engineer Marsden Butler
factory comprises two substantial
buildings: the fabrication facility – where
key components are laid up – and the fi nal
assembly and refi t hall, where these are
brought together and the lifeboats are
completed, ready for testing. Alongside,
older lifeboats are brought in for repair
and refi t before being returned to service
at one of the 238 lifeboat stations across
the UK and Ireland.
According to Marsden, the ethos to
build the new Shannon class fi rst took
root around the time that the Arun class
was designed by GL Watson of Glasgow
and went on service in 1971.
“It seemed that in designing our own
boat, we could benefi t from the RNLI’s
considerable knowledge and learn from theShannon class
boats have
an advanced
composite hull
and are water jet
powered