SDevelopments in the
commercial sector, such as this
new Advanced Variable Drive from Caterpillar,
usually find their way into leisure marine.
The new hydraulic gearbox can be switched
between different energy sources to become
‘a highly optimised, lower-cost alternative to
conventional electric hybrid systems. It has
similar benefits such as improved performance,
lower noise and lower emissionsibinews.com International Boat Industry | AUGUST–SEPTEMBER 2019 73
Here are some of the developments
you will be seeing at the forthcoming
shows, with insight from leading industry
professionals as to what the future
may hold.IMPROVING THE GEAR CHANGE
Engines themselves have become far
more efficient thanks to computer control
and common rail injection, and marine
hybrids are also making an impact in the
commercial sector. But any engine is only
as good as its drive train, and here there
have been some exciting developments in
transferring more power into the water
and using it for steering.
With the exception of a water jet, which
uses a bucket system for reverse, a marine
combustion engine will require some kind
of gearbox, either attached to the engine
itself, or located within the drive leg or pod.
The big problem with marine engines,
especially as they get larger, is how to
smoothly engage the power at tick-over,
especially if swinging a large and heavy
propeller. Also, how do you bleed off revs to
run at very low speed?
Several companies have been very active
recently in making this power transfer not
only very smooth, but also available at very
low speeds to greatly aid close quarters boat
handling or trolling. This has partly been
encouraged by auto docking, which needs
seamless gear changes and an unstressed
drive train.
One solution has come from Germany-
based ZF, a leader in the field of marine
gearboxes, which launched its new ZF
400 family of transmissions for seagoing
vessels at last year’s METSTRADE. At this
year’s event, it will be revealing the latestgeneration, the ZF 400 IV, which features
Supershift 2 gear change technology. This
is described as an ‘improved clutch pack
design which negates the need for an
additional hydraulic circuit and is available
for all ZF gearboxes. This results in fast
shifting response and smooth gear changes
even at low speed.’
ZF says the new 400 model system is
rated up to 735kW (1,000hp) and covers a
wide range of ratios and configurations.
“Since it can be installed in either
a down-angle, integrated V, remote V
or parallel configuration (also available
for work vessels) customers enjoy great
flexibility when designing or retrofitting
motorized vessels, such as yachts or fishing
boats,” ZF told IBI. “With a power density of
up to 0.3195kW/rpm (0.4282hp/rpm),
the ZF 400 is the perfect fit for a broad
range of recreational and commercial
applications. The Supershift 2 system
returns a 35% faster clutch disengagement
with 30% less peak torque. It can also be
combined with ZF’s standard trolling valve
options, such as Autotroll.”
Perhaps the most striking feature, as
demonstrated in a video recorded at the
test lab, is the lack of the heavy ‘clunk’ that
a traditional transmission makes when
engaged. The ZF 400 is silky smooth.
Volvo Penta has also developed a
‘clunkless’ gearbox for its new electro-
hydraulically steered DPI outdrives, again
with an eye on the needs of the computer-
driven boat. At Gothenburg this year, the
company unveiled its re-engineered diesels
and drives, which have together logged over
40,000 hours of testing.
“We identified a number of customer
values, critical to success,” said VolvoSAdding to its 100 years of transmission
manufacture, ZF will be revealing its new
ZF400 IV generation of marine transmissions
at METSTRADE. The new gearbox features
Supershift 2 technology for seamless gear
changes in commercial and leisure applicationsKPƂPKV[NYXEQO^RCMP 300. EL
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