What does the Royal Australian Navy do with its LM2500 gas turbines after their ships have come in for the last time? When two LM2500s recently became surplus due to the phased retirement of the Royal Australian Navy’s Adelaide Class frigates, GE and the RAN recognised a maintenance opportunity—the engines would provide hands-on familiarisation and training for RAN crews ashore.
Propulsion is critical to RAN responsiveness, effectiveness and safety at sea, and the ultra-reliable LM2500s (with a collective 15 million operating hours in the marine environment) have been powering RAN ships since 1986. But the first exposure RAN personnel have traditionally had to the engine is aboard in-service ships.
The installation of the surplus engines at naval training bases at HMAS Cerberus in Victoria and HMAS Kuttabul in Sydney represents a significantly enhanced training capability, equipping maintenance staff to meet the challenges of working at sea before they push off from the dock.
“I was most impressed with the enthusiasm of the Fleet Support Unit staff and GE personnel in providing the best service they could to gas turbine maintainers in HMA Ships,” says Captain John Metzl, Director of the Maritime Cross-Platform Systems Program Office, which manages an existing LM2500 in-service support contract between the Commonwealth and GE.
“This is an innovative win-win situation and I congratulate those involved for their patience, perseverance and long-term vision to make an idea reality,” adds Capt Metzl, a Senior Navy Logistics Officer.
GE customised a multi-year agreement to support the RAN’s LM2500 marine gas turbines on its eight Anzac Class frigates, the remaining three Adelaide Class frigates, and the two Canberra Class Amphibious Assault Ships (also known as Landing Helicopter Dock or LHD ships).
The various aspects of the agreement are designed to ensure the RAN’s optimum fleet readiness and to lower the total cost of ownership of the LM2500s. The agreement covers onsite field-service support, warehousing and inventory management of spare parts, and depot-level maintenance provided in partnership with Air New Zealand Gas Turbines.
“Our focus is to perform as much maintenance as possible, but also to continuously upskill the Navy to maintain the engines while they’re on operations and at sea,” says Steve Burdick, Program Manager for GE Aviation-Marine in Australia.
Recommended maintenance procedures are programmed into the Navy’s Asset Management Planning System, and carried out onboard, wherever the ship is located, says Burdick. “Although higher-level tasks are assigned to us at GE, we always try to perform them together with ship staff, so that their knowledge and experience of the engines is continuously developed.”
Among the shipboard tasks of the RAN maintenance crews is water washing the engine after approximately every 75 hours of operation. The turbine of the LM2500 consumes about 100 cubic feet per second of air.
“The more air you can compress, the more power you have and the more efficient the engine is going to be,” says Burdick. Although incoming air to the engine is filtered, over time sea salt, diesel fumes from nearby systems, and other particulates gather on the blades, vanes and airflow surfaces of the compressor, creating resistance and reducing efficiency and power. Periodically flushing the parts with a detergent solution while the engine is running at 2000 rpm helps maintain optimal performance.
Learning how to carry out such tasks in a controlled, onshore environment will give maintenance crews greater confidence and understanding of the requirements of their ships’ propulsion systems, which operate differently in each ship-class design.
Lightweight, compact, power dense and fuel efficient, the LM2500 was adapted for marine use from the highly successful CF6 aircraft engine.
The Anzac Class frigates each have one LM2500 in a combined diesel or gas turbine arrangement; a secondary engine to the diesel motors used day to day, it’s fired up when high speed is required. The Canberra Class LHDs also each have one LM2500, but in this design the gas turbine drives a shaft that powers an electrical generator, which propels the ship—more like an electric car.
A large part of the success of GE’s support of the RAN’s gas-turbine engines is due to its relationship with the Commonwealth representatives, says Burdick. “There’s a lot of give and take, a lot of mutual helping. As the OEM (original equipment manufacturer), we have several initiatives underway right now that will improve maintenance and ensure ultimate mission readiness of the RAN in the ever-demanding and evolving maritime environment.”
Among these, warehousing of spare engines and crucial inventory control of spare parts have been centralised in Rockingham in Western Australia, and in Sydney; and the deployment of the two surplus engines at key Navy training facilities represents another significant advance in the GE-Commonwealth collaboration.