Home' Work Boat World : September 2010 Contents The "μ-tug" has arrived.
The Damietta Port Authority in Egypt
needed a line handling vessel for its sea
port and a small tug to assist river barge
operations for the adjacent river port.
With the Micro-tug from Mapso Marine
and designer LOMOcean, they got both.
This small tug delivers five tonnes of
bollard pull in a compact package with a
single Scania 294kW engine.
The tug comes from the drawing board
of LOMOcean, better known for their
extremely low resistance vessels
('Earthrace', 'Planet Solar'). This low
resistance pedigree has resulted in a fuel
consumption of only five litres per hour at
seven knots, and a top speed of ten knots,
both remarkable for a short, beamy tug. On
a full tank of fuel (1,000 litres) this tug
would cover 1,400 nautical miles, an
almost trans-Atlantic range. It is expected
that she will need refueling once every two
months, based on an average of three hours
of operations per day.
The secret is below the waterline, an
innovative design featuring a substantial
box keel, multiple chines, and large chine
Thanks to the box keel, she tracks very
well, and thanks to a MacLear Thistle
rudder, she turns sharper than would be
expected from a single screw vessel. The Kort
nozzle improves the thrust, protects the
props and reduces the tendency to walk.
This tug is part of a growing trend to
build small tugs in aluminium, such as the
BRAtt mini tug delivered this year. The
advantages of aluminium are well known
for work boats; it does not rust, is durable,
low maintenance, tough and light.
A tug can be too light, however, because
the forces it is subjected to are so high.
Because the hull is so light, despite using
6mm plating all over, the box keel is filled
with 4.6 tonnes of lead ballast. The box
keel moves the pivot point of the tug
forward, which is highly desirable, and the
lead ballast is ideally located as low as
possible in the hull, much like a sailboat.
The result is an amazingly stable vessel for
its size, with a metacentric height (GM) of
1.5 metres. It is quite interesting watching
her rock still at anchor while large steel tugs
nearby dance to the tune of the waves.
The wheelhouse has a 360-degree view,
and is surprisingly spacious with seating for
four plus the master. A version with under
deck accommodation is on the drawing
board; on this particular vessel the under
deck compartment houses a work bench.
The μ-tug was designed from the outset
to be a single or twin-screw vessel, and the
hull longitudinals are spaced accordingly.
With twin Scania 335kW engines, the very
same hull would provide over ten tonnes of
bollard pull. The structure in general, and
the towing post on the aft deck especially,
are already dimensioned for ten tonnes pull.
Mapso Marine has plans to expand this
range of Micro tugs to include eight-metre
and 12-metre versions. A "mini-tug" range
will be developed with 15-metre and
Mapso Marine, established in Egypt
since 1976, describe themselves as "boat
developers". In the words of Philippe
Maari, the Managing Director, "We bring
together an operator, a yard, a designer,
and a propulsion package, and we make it
happen." They have been hugely successful
applying this formula to Voith Water
Tractors, with over thirty projects
delivered. In fact, Maari asserts that Mapso
has sold more Voith Schneider propellers
than anyone else since it was invented.
The Micro-tug is available as a completely
engineered kit for any yard in the world that
wishes to build it -- or indeed available as a
finished boat with GL survey ex-Egypt. The
kit includes complete design information,
pre-cut aluminium sheets, profiles, all
closures, all system components (bilge, fuel,
fire, etc.) and of course the propulsion
system. Mapso Marine can also provide
technical personnel to help less experienced
yards build this boat, including yards that
have never built aluminium boats. The kit is
also easily convertible to steel if desired.
For further information contact:
Mapso Marine Propulsion and Supply,
Egypt. Web: www.mapso.com
For further information contact:
LOMOcean Design, New Zealand.
PH: +64 9360 9799, FX: +64 9360 9795,
Type of vessel:
In survey to:
Maximum bollard pull:
Germanischer Lloyd, 100
A5 IN(0.6) Z Work Boat
Damietta Port Authority
Mapso Marine / ESRBC,
1 x Scania DI12
59M 400, 294kW
1 x FPP in Kort nozzle
miles at 7 knots
1,000 litres (2 x 500)
September 2010 WORK BOAT WORLD
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