Voith Water Tractor as
a Towboat for a Drilling Rig
Case Study
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Advantages of the Voith Schneider
Propeller (VSP):
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Reliable and safe
Maximum maneuverability
Suitable for different power classes
Versatile use for offshore supply
vessels and workboats
From Tunisia to Malta
in just three days
Taking no more than three days, a Voith Water Tractor (VWT) operated by Tug
Malta transferred a drilling rig from its operating site to port for repairs together
with another towboat. In November 2011, the tow move started in the Didon oil
field located in the Mediterranean between Tunisia and Libya and covered more
than 300 kilometers to the Grand Harbour of Valetta, Malta’s most important port.
Built in Spain in 2009, the VWT Spinola has been maneuvering in the ports and
territorial waters of the Maltese Islands ever since. A very special assignment sent
the harbor tug far out into the Mediterranean: To the Didon oil field approximately
75 kilometers off the Tunisian coast. Here, PA Resources produces oil from a total of
five wells in a depth of 75 meters below sea level.
One of the rigs used is the Ensco 85 from Ensco PLC with a maximum drilling
depth of 7 620 meters. The self-lowering jack-up rig has a width of 61 meters and a
length of 91 meters including the helideck. Vertically movable legs with a length of
120 meters securely anchor the rig to the sea floor and hold the hull well above the
water. The Ensco 85, which is generally staffed with 50 engineers, technicians and
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1 The Voith Water Tractor Spinola with an
output power of 5 280 kW is not just used
as a harbor tug by the operating company
Tug Malta.
2 Within just three days, the Spinola (shown
in the foreground) and another towboat
safely brought the Ensco 85 rig to Malta’s
main port, the Grand Harbour of Valetta.
seamen, can be used for the drilling of exploration wells as well as for well sinking.
In November 2011, the rig had to be transferred to the Grand Harbour of Malta for
maintenance and minor repair work. This was the fifth time that Ensco PLC contacted
Tug Malta regarding a tow move of this magnitude.
Over 300 kilometers in no more than three days
With its 5 280 kW (7 180 hp) the Spinola is particularly suited to this task. The
Voith Water Tractor can accommodate 14 staff. Together with another vessel from
the Tug Malta fleet, it only took the Spinola three days to tow the Ensco 85 jack-up
rig from the Didon oil field to the Grand Harbour of Valetta in Malta, more than
300 kilometers away.
VWT Spinola impresses with a bollard pull of up to 81 tons
The Spinola has a breadth of 13.6 meters and a length of 36.65 meters and is one of
seven tugs operated by Tug Malta. She is equipped with two 32 R5/265-2 Voith
Schneider Propellers delivering 2 640 kW each and has a bollard pull of up to 81 tons.
Her maximum speed is 14 knots.
Over 85 years ago, Voith developed the
Voith Schneider Propeller (VSP), a vessel propulsion system unique in the
world, which allows thrust of any magnitude to be generated in any direction
quickly, precisely and in a continuously
variable manner. It combines propulsion
and steering in a single unit. On the
VSP, a rotor casing which ends flush
with the vessel’s bottom is fitted with
a number of axially parallel blades and
rotates around a vertical axis. To generate thrust, each of the propeller blades
performs an oscillating motion around
its own axis. This is superimposed on
the uniform rotary motion. Blade excursion determines the amount of thrust,
while the phase angle of between 0°
and 360° determines its direction. Thus
the same thrust can be generated in
all directions. Magnitude and direction of
thrust are controlled by the kinematics,
a mechanical transmission.
Voith sets standards in the markets
energy, oil & gas, paper, raw materials
and transportation & automotive.
Founded in 1867, Voith employs more
than 40 000 people, generates
€ 5.6 billion in sales, operates in over
50 countries around the world and
is today one of the biggest familyowned companies in Europe.
Media Contact
Voith Turbo GmbH & Co. KG
Central Advertising / PR
Adela Trstenjak
Alexanderstraße 2
89522 Heidenheim, Germany
Phone: +49 7321 37 2594
[email protected]
voith.com
PR 0022 e 2012-08 WA 500 Dimensions and illustrations without obligation. Subject to modifications.
Voith Turbo, the specialist for hydrodynamic drive, coupling and braking
systems for road, rail and industrial
applications, as well as for ship
propulsion systems, is a Group Division
of Voith GmbH.