At the heart of QEC’s power and propulsion system sits two Rolls-Royce MT30 36MW gas turbine alternators, which combine with four medium speed diesel generators.
Back in 2004, MT30 was new to naval markets and QEC became its second successful selection for a naval programme; it’s first being to power the US Navy’s Littoral Combat Ship Freedom class.
Having such powerful gas turbines available was unprecedented in the marine environment in 2004. If you consider the two WR-21 marine gas turbines which power the Type 45 integrated electric propulsion system – it would take six or seven WR-21s to provide the power required for the Queen Elizabeth Class aircraft carrier. This reduction in the number of gas turbines delivered huge design benefits to the ship and was made possible by the advancements in marine gas turbine technology.
Through this innovative electrical propulsion system arrangement, the MT30 gas turbine alternators provided the power needed to turn the propellers and drive these huge vessels through the water at speeds in excess of 25 knots. The combination of the gas turbines and diesel generators generate 109 megawatts of electrical power - plenty to meet the constant demands from the ship’s propulsion, as well as the weapons, radar and hotel requirements consistent with the demands of a small town.
The MT30 marine gas turbine has been specifically designed for 21st century naval ships. It surpasses its predecessors in that it packs a mighty punch of power and uniquely guarantees that power throughout the life of the ship. This is important for the QEC programme with a 50 year service life expectancy; a guarantee that the engine will be able to deliver the power demands of tomorrow such as increasing requirements from upgrades to weapon and radar systems.
In addition to the marine gas turbines, both the shaftlines and the two enormous nickel aluminium bronze propellers were provided by Rolls-Royce in Sweden.
At almost seven metres diameter and weighing in at a massive 33 tonnes each, they combine to deliver up to 80MW of power into the water – enough to power 50 high-speed trains.
These are the most powerful propellers ever to have been produced by Rolls-Royce AB.
Rolls-Royce also supplied the thrust blocks, shaft brake, bearings, shaft seals, steering gear and rudders as well as the stabilisers which perform the essential role of steadying a ship during various operations such as refuelling or during the launch and recovery of aircraft.
Our Electrical team also made a massive contribution, supplying the low voltage electrical distribution system that delivers the electrical energy supplies throughout the vessel. For each ship, this consists of 13 main switchboards, 34 electrical distribution centres, 27 group starter boards and 415 distribution panels. This system distributes enough electricity to power the equivalent of 5,000 family homes.
Rolls-Royce also designed and provided the Heavy Replenishment at Sea reception points which allows the aircraft carriers to receive loads containing ship consumables such as munitions and food in conditions of up to Sea State 5 for up to six tonne loads.
A retractable sliding highpoint is located at each of the hangar deck lift openings and incorporates a variable speed electric drive. They are retracted up into the hangar deck when not in use to allow clear movement of aircraft from the hanger deck onto the aircraft lift.