Page 14 - 2024 - Q3 - Minerva in Focus

MINERVA IN FOCUS
LR2 Tankers A look into Minerva’s Newbuildings

Minerva Marine has signed the shipbuilding contracts for four 112,500
DWT oil product tankers. The vessels shall be the first dual-fuel (LNG)
LR2 tankers in the Minerva Marine fleet and will be built at the New
Times Shipyard, a leading yard in the dual-fuel shipbuilding market
in China.
The steel-cutting phase of the first vessel in the series will take place
in December 2025. The vessels will be delivered between February
and September 2027.
Key technical aspects of the newbuildings
include:
• LNG dual-fuel main engine from Man Energy Solutions,
Type 6G60ME-C 10.5 GI–HPSCR
• Pre-shrouded vanes and hub vortex fins
• LNG C-type tanks installed on deck, with a capacity of
2 x 1800 m3
• Shaft generator
• Dual-fuel auxiliary and composite boilers with free flow
The first • consumption capability of natural boil-off gas (NBOG)
High-pressure compressor for the consumption of NBOG
in order to feed the main engine
dual-fuel (LNG) • Led lights
•
Variable frequency drives (VFD) for engine room fans
LR2 tankers Main benefits of the design:
• Latest hull developed by the shipyard
• Latest main engine execution
in the Minerva • Optimised fuel efficiency
• Zero NBOG wastage
• Reduced emissions for the protection of the environment
fleet • Commercially competitive for charterers

The shaft generator refers to the electrical equipment that is con-
nected to the main propulsion engine, operating as a generator
(Power Take Off / PTO), a motor for additional power boost (PTI),
An article by or for emergency propulsion (take-me-home / PTH).
Vaia Hatzigianni, Each of our four 112.5K DWT product oil tankers will be equipped
Head of New Buildings and Projects, with one in-line type shaft generator, connected without a gearbox
Minerva Marine Inc. (low speed) with the LNG dual-fuel main engine.

The PTO system mainly consists of:
• One permanent magnetic shaft generator installed on
the propulsion shaft line (the SG rotor is mounted on the
intermediate shaft)
• One frequency converter, which supplies the generated
power from the shaft generator rotation to the vessel’s main
switchboard (producing electricity as an alternative to the
operation of the 4-stroke Diesel Generators)
For our design, the sizing of PTO continuous rated output shall corre-
spond at a minimum to the capacity of one Auxiliary Engine capacity.
Thus, during normal seagoing, the vessel’s entire electric load will
be covered without requiring the operation of an auxiliary engine,
leading to significant fuel, maintenance, and emissions savings.
The main engine maker, MAN Energy Solutions, and the candidate
PTO system makers/integrators have been contacted and a technical
evaluation is currently in progress among all relevant parties regarding:
• A potential extension of the shaft generator’s rated output to
ensure stable and continuous operation with an increased
power margin.
• The setting of the main engine’s working range (min/max
rpm & load) where the engagement of the PTO is possible.

14 ISSUE 29 / Q3 2024