Motor Boat & Yachting - July 2018

(C. Jardin) #1
NAVIGATION
Mel Bartlett

PRODUCTS
Nick Burnham

The latest marine engines and innovations


NEWTECH

DMS’s new stabilisation fi ns could
become a staple for motor boats

Flapping


marvellous


Dutch company DMS Holland is
hoping to revolutionise the market
for stabilisers with a new design of
flapping fins specifically designed
for fast-planing motor boats. The
company originally made a name for
itself with its cylindrical MagnusMaster
rotating stabilisers for displacement
boats, and last year it launched the
AntiRoll ‘flapping’ fins for superyachts.
Now it plans to develop this AntiRoll
technology into a smaller, cheaper,
more effective package for fast
production boats.
The key to this new design of high-
aspect ratio fin is that they attach
to the transom of the boat rather
than being fitted through the main
section of the hull. This makes
them easier to install (the hydraulic
actuators of traditional fins often
have to be tucked under the floor
of the master cabin) and ensures
that all the internal workings can
be kept in the engine bay, reducing
noise disturbance at night. It also
has a number of interesting dynamic

benefits. Because the fins rotate
on two different axes, they can be
swivelled all the way round so that
they tuck in behind the transom. This
not only reduces drag to negligible
levels at high speed, but also enables
them to double up as active trim tabs,
tilting up and down to correct both
roll and lean in much the same way
as Humphree’s Active Interceptors.
This means that instead of installing
separate trim tabs and stabilisers,
customers will soon be able to specify
one set of AntiRoll stabilisers that
should cover every eventuality from
trim and lean to stabilisation at high
speed, low speed and at anchor.
Although DMS Holland won’t yet
reveal the full details of how the new

system works across such a wide
range of speeds, the illustrations
appear to show three different
operating modes: high speed, low
speed and zero speed.

HIGH-SPEED MODE
At high speed, the fins tuck in along
the trailing edge of the transom
using small rotations of the fins
to deflect the water down and
create the lift on one side or the
other, much like an oversized trim
tab. The large surface area of the
fins and high pressure of the water
running over them at speed means
tiny movements will generate
substantial lift. When combined with
fast-acting electric actuators linked to

MY TAKE The market for stablisers
is developing so fast it’s hard to know
who’s winning the race, but the idea of a
one-stop system that replaces stabilisers and
trim tabs on fast boats is a tempting prospect. Hugo

Boats like this Fairline Targa
53 could benefi t from the new
high-speed stabilisers

By adapting its wing-like stabilisers
to fi t on the transom they work at
high speed, low speed and at rest
Free download pdf