Propulsion

Question 1

What type of gearbox do we use onboard?

Answer 1

Dual tandem, Double reduction, single helical, articulated gearbox.

Question 2

Where is the gearbox located?

Answer 2

Aft of the main turbines and sits on the main machinery raft.

Question 3

Where does drive from the main turbines enter the gearbox from?

Answer 3

It enters the gearbox via 2 self shifting synchronous (SSS) clutches.

Question 4

Where does drive from the turbines exit from?

Answer 4

It exits the gearbox at the FWD end of the gearbox to a large flexible coupling. Drive from this coupling is then through the centre of the gearbox via a Cardan shaft to a similar flexible coupling in the after end of the gearbox.

Question 5

How are shafts within the gearbox supported?

Answer 5

On journal bearings with axial movement prevented by thrust bearings.

Question 6

Where does the gearbox lubrication come from?

Answer 6

The main lubricating system (MLS)

Question 7

What is the purpose of the dehumidifier in this system?

Answer 7

Removes moisture from the gear case and EPM drive shaft chamber when shutdown.

Question 8

What is the benefit of a propulsive over a propeller?

Answer 8

Allows for a massive reduction in noise and physical signatures.