ENGINEER TO ENGINEER
In brief
Enerpac jacking system constructs
world’s largest observation wheel
The Ain Dubai observation wheel, which is over
250 metres tall, almost twice the height of
the London Eye. At its simplest, the structure
comprises a wheel rim, rotating hub and fixed
spindles mounted on four support legs.
The rim is 240m in diameter
and assembled from eight
segments that are welded
together and connected to
the hub by cable spokes, each
longer than a full-size football
pitch. For the wheel assembly,
the height of the Ain Dubai
takes it well beyond the reach of
a traditional crane and so an alternative method
was needed. Enerpac proposed to use a pushpull
system for the wheel construction.
Located at the base of the wheel, a pair of
hydraulic grippers pushes the wheel forward,
effectively rotating it. The push grippers are
then released and pulled back into position using
hydraulic cylinders. The sequence is repeated.
The wheel segments are welded together
as each new segment is added. Ensuring the
welding process could be completed smoothly
relied on precise positioning of each new
segment by the Enerpac system.
Using precision hydraulic control,
the Push-Pull system was able
to bring the wheel rim within a
few millimetres of the previous
rim, and hold it there, to enable
the two segments to be welded
together.
The project imposed
rotational loads up to 2,572 tons –
the largest load ever handled by such a system,
highly accurate control of wheel rim movement,
and accommodating the system within limited
space constraints. Also, for the first six months
of the wheel’s construction the entire load of the
part-completed wheel would be borne by the
system. The system is powered and operated by
a central hydraulic power unit.
Thames Water London supply
control upgrade goes to Schneider
The project to upgrade and unify the complex
computer system controlling London’s water
supply involved moving from a 25-year-old
system, composed of multiple legacy and
obsolete sub-systems to a new, universal
SCADA platform, all while maintaining water
supply across the capital. As the facilities
operate 24/7, the team had to make changes as
quickly as possible.
The new technology provides Thames Water
with an open interface system. This means data
can be collated and processed from over 4,000
outstations and delivered to the company.
The unified system will enable Thames Water
to make operational savings through improving
the total lifespan of the systems components,
reducing maintenance and the level of control
required, while improving resilience and
efficiency.
Carly Bradburn, Thames Water’s head of
digital operations, said: “The computer system
oversees the production, treatment and delivery
of up to 2.2 billion litres of drinking water every
day. Replacing it has been a very complex and
challenging project. The old system was over
25 years old and software updates were no
longer available. The commissioning of the new
system included checking and validating more
than 700,000 data points, and around 100,000
functional, mimic, alarm and user tests to ensure
minimal operational disruption and risk. This has
been a monumental achievement. What once
seemed impossible has been done,” she added.
Rail depot equipment specialist
Mechan has provided South
Western Railway with a flexible
way to service rolling stock at two
of its key maintenance facilities.
The Sheffield-based manufacturer
delivered a set of 16 lifting jacks
to the Bournemouth and Salisbury
traincare depots, where they are
being used to look after a variety
of rail vehicles. Initially, 12 of
the jacks have been installed
at Bournemouth and four in
Salisbury; however, they have all
been constructed with an identical
moving anvil and castor wheelbase
arrangement, enabling them to be
switched between sites if needed.
When a major Chinese
manufacturer of marine propulsion
systems needed a robust clutch
to integrate into a roll-on-roll-off
ferry gearbox, it turned to Stromag.
Large ferries commonly use a
dual diesel-powered propeller
shaft propulsion, with four diesel
engines driving two propeller
shafts. In this arrangement, there
are twin diesel engines connected
to a common gearbox for each
shaft. The gearboxes reduce the
medium shaft speed from the
engine down to the low-speed
drive required for the propeller.
The two engines per gearbox
are each connected via a clutch,
which enables engagement/
disengagement to allow either
one or both engines to be run as
needed, and facilitates reversing
of the engine. For this application,
wet-running multi-disc KMS
clutches were specified, being
specifically designed for use in
marine gearboxes. The oil-cooled,
hydraulically-operated units are
used where high torques must
be transmitted reliably in tight
engine room spaces. Stromag
supplied Model KMS 18000/25
clutches which were integrated and
adapted into the gearboxes. Each
635 mm diameter clutch has a
torque rating of 240,000Nm. Along
with meeting the performance
requirements and providing a highreliability
solution, the models are
also low-maintenance, as disc wear
is compensated by piston travel.
92 www.operationsengineer.org.uk Winter 2021
/www.operationsengineer.org.uk