The Evolution of Testing Experiments for New MT7 Marine Gas Turbine

Transcription

1 The Evolution of Testing Experiments for New MT7 Marine Gas Turbine The Authors of the Paper Corresponding Author: Sang-Pil Lim (Naval Marine Engineer, Rolls Royce Marine Korea) Postal Address: 197, Noksan SanEop Buk-ro, Gangseo-gu, Busan 46753, Korea. Tel: Pratik Chanhoke (GT Product manager, Rolls-Royce Marine North America Inc.) Postal Address: 450 S. Meridian Street, Indianapolis, IN 46225, USA. Tel: Abstract Many Navies continue to keep a strategy emphasized power projection and employment of naval forces from the sea into the littoral regions of the world in quickly changing dynamic threats. The need to be able to rapidly deliver large quantities of Marine hardware and/ or personnel, as performed by Landing Craft Air Cushioned (LCAC) vessels, is key to establishing beachheads and bringing the seaborne military force into operation ashore. In response to the US Navy s desire to replace the aging LCAC fleet, the new Shipto-Shore Connector (SSC) has been developing and designing recently. Textron Marine and Land System with L3 Communication, which is the prime contractor for the Rolls Royce Ship-to-Shore craft program, won the competition and selected the MT7 as their main propulsion gas turbine in 2010 even though faced immense competitions. Consequently the MT7 and the Textron design brings to the US Navy a much lower-risk solution for SSC program but also high mission capability which driven the need for a 25% increase power, reducing 11% fuel consumption and enhanced payload. The MT7 is the newest engine to be developed to support the growing fleet of gas turbine engines offered to the naval market. This paper takes the new MT7 gas turbine engine from its aero roots with the AE1107 engine that powers the V-22 Osprey aircraft, through the engine s development phase and its ABS NVR Type Certification to become a released production marine engine for the SSC and future LCAC applications. The paper also details the technical challenges of adapting the aero engine into a fully marinised gas turbine for an LCAC application and explores the impact of the changes in the operating environment on the engine design. Authors Biographies Mr. Sangpil Lim is Naval Marine System Manager at Rolls-Royce Marine Korea. He graduated from Pukyung University in Korea with Bachelors of Engineering Degree in Mechanical Engineering, and graduated from Naval Officer Candidate School in Republic of Korea Navy. Mr. Sangpil Lim has over sixteen years of experience with Naval Marine Engineering in a career. He has been working in the company since 2014 and involved on a variety of the Rolls-Royce equipment in the recent Korean projects including the FFX-II Frigate / PKX-B Fast Attack Craft and Korea Coast Guard Programs etc. He had worked for the 4-stroke diesel engine manufacturer as a propulsion system integrator between 2007 and 2013, and prior to that, spent seven and half years as a Marine Engineer Officer in the Republic of Korea Navy, including four years on-board serving at Frigate. He is a member of Society of Naval Architecture Korea as well as Affiliate Member of IMarEST. Mr. Pratik Chandhoke is the Naval Marine Product Manager for aero-derivative gas turbines at Rolls-Royce Marine North America. He has attained a Bachelors of Science in Mechanical Engineering degree and an Executive Masters of Business Administration degree in Management both from Purdue University, United States. Mr. Pratik Chandhoke has worked in Rolls-Royce for ten years in product management, program management, project engineering, systems and hardware engineering of various projects involving Rolls-Royce T56 and AE series engines. In his current role, Mr. Pratik Chandhoke owns the US gas turbine product line strategy which includes the MT7 engine for the US Navy SSC application, AG9140 and AG9160 generator sets that currently support the US, Korean and the Japanese Navies.

2 1.0 The Introduction Rolls-Royce s MT7 engine has been selected to power the US Navy s Ship-to-Shore Connector (SSC). This new engine is the latest derivative to the Rolls-Royce AE common core family that has been operating for over 50 years. The MT7 s development is highly critical to the success of the SSC which is required to deliver 25% more power in a small space envelope. The MT7 faced immense competition to be the prime power provider on the SSC program. Ultimately, the MT7 succeeded due to the overall value that the MT7 and the Textron design brings to the US Navy. Compared to the competition, the well-established core of the MT7 made for a much lower-risk solution for the SSC program. The MT7 also delivers the high level of power density that is required on the hovercraft. All of this, coupled with the high reliability of an engine with over 67 million operating hours in the air made the MT7 the clear, best value solution for the US Navy. This paper takes the reader through the evolution of the MT7 from concept, to a production solution for the SSC and future LCAC application with proven marinalization through ABS NVR certification testing. 2.0 Replacing the Landing Craft Air Cushion (LCAC) 2.1 Program Background/ History The concept of the US Navy having a capability that permits sea-to-land deployment of weapons systems, cargo, and marine personnel to form a marine surprise assault task force has been around since the early 1970 s. Development of this concept led to the first of type craft that in turn evolved into the production craft Landing Craft Air Cushion (LCAC). This craft started production in the mid-1980 s and after over 20 years of operation a Service Life Extension Program (SLEP) was initiated to keep the craft in service until the 2020 timeframe. The LCAC s replacement program resulted in the LCAC-100 series craft being initiated and eventually contracted. 2.2 Replacing the LCAC In the beginning stage, it was changed to the Customer Furnished Equipment (CFE) finally nevertheless the US Navy asked to be Government Furnished Equipment (GFE). The program when contracted was a fixed firm price, incentive fee offering. In 2005 the US Navy commenced with research and development into the Heavy Lift LCAC Program. LCAC¹ LCAC SLEP SSC Length 27.97m 27.97m 27.99m Breadth 14.73m 14.73m 14.55m Weight 87.2T 87.2T 88.6T Payload/ 60T/72T 60T/72T 74T Overload Crew Max Speed (Knot) Engine 4 x Lycoming/Allied Signal TF-40B 4 x Vericor Power Systems ETF-40B 4 x Rolls-Royce MT7 Gearboxes Power Output(hp) 16,000 16,000 20,900 Range 200NM 200NM 200+NM Life(years) Notes Introduced FADEC Control System Craft 10 year life extension program [Table 1: Operational changes introduced by the SSC over legacy LCAC s]

3 The operational changes introduced to the Ship-to-Shore Connector (SSC) over the initial LCAC product are listed out in Table 1 above. The number of reduction gearboxes was highlighted in particular as a major change from the LCAC to the SSC. The LCAC had 8 gearboxes and these were reduced to 2 for the SSC. The simplification with the new configuration helps eliminate many of these early developmental problems with a reconfiguration of the engine arrangement and introduction a single gearbox each side of the craft. In addition, the SSC can give an increasing payload capability compared with the original legacy LCAC with similar ship particulars. The LCAC replacement program, the SSC, calls for the introduction of a total 73 craft. With four engines per craft, the anticipated number of engines required, with spare engines totals over 300, a high volume program for Marine applications The installation of MT7 engines on the SSC can be seen in Figure 1 below, together with a fundamental overview of the SSC craft. [Figure 1] - SSC Craft Improvement Overview 3.0 MT7 for the Ship-to-Shore-Connector (SSC) 3.1 MT7 s AE Family Heritage The AE family of engines has logged more than 67 million flight hours and operates on more than a dozen military and commercial applications including the C-130 transport, the ShinMaywa sea plane, the Global Hawk reconnaissance plane, Embraer 145 passenger jet, and the unique V-22 Osprey Program tilt-rotor aircraft. Figure 2 illustrates the various applications that are powered by the AE engines, all of which are currently in production. More than 6,100 engines have been manufactured to date and regularly demonstrate industry leading reliability and time on wing. The average time-on-wing (TOW) of the AE2100 turboprop regularly exceeds 5,000 hours, and some applications of the AE3007 turbofan regularly exceed 10,000 hours. In October 2009, a AE3007 engine was removed from an Embraer 145 regional jet after having logged over 18,000 hours since its last removal. The engine had to be removed to replace an individual time expired component.

4 [Figure 2] Application of the Rolls-Royce AE Common Core Family of Engines Although the marine environment is very demanding, the specifications and requirements laid down for the Ship to Shore Connector are met or exceeded by the current AE1107C engine, this engine has been built to and meets MIL- E-8593A standard. Furthermore, the AE1107C has already performed on shipboard operations with the US Marine Corps on the Wasp Class vessel, USS BATAAN and USS NASSAU. 3.2 MT7 - Rolls-Royce Engine Offering The MT7 engine is the marine application of the battle-proven AE1107C engine used on the successful V-22 Osprey Program aircraft, with over 600 engines delivered to Naval Air Systems Command (NAVAIR). The MT7 engine offers engine performance that exceeds the requirements of the SSC program as demonstrated under combat conditions together with reduced life cycle costs. Changes to the originating core engine the AE1107C are depicted in Figure 3, and includes; a new PTO torquemeter shaft, AE2100 pneumatic starter, new marine full authority digital engine control system (FADEC). Additionally, there is a customer requirement whereby the bleed system from any engine can be used to enable cross engine starting, i.e. with engine 1 running, starting of engines 2, 3 and 4 is available; similarly with engine 2 running starting of engines 1, 3, and 4 is available, etc.

5 [Figure 3] MT7 Engine Configuration Changes introduced to the MT7 The MT7 planned for use on the SSC has over 95% commonality with the AE1107. Components that are new to the MT7 configuration are listed below: o o o MT7 output shaft This shaft is also used to determine the power output of the engine. Monitoring parameters from the torque-meter and engine, the power can be reliably calculated. MT7 FADEC Hardware and Software the engine control system is new for the MT7. The configuration of FADEC hardware is developed specifically for the marine environment and to withstand the shock test requirements. The software is developed to suit the hardware configuration and to meet the SSC requirements. Integrated Pneumatic Starter the starter is an off the shelf unit from the AE2100 engine, part of the AE family. It meets the customer requirement for starting the engines with pneumatic air. Components that are specific to the SSC MT7 configuration are listed below: o Customer Bleed Manifold and Interface Valve this is a specific customer requirement, permits the engine, once started to bleed compressed air in order to start any of the other 3 engines. Additional components that were added to the scope of the SSC program were: o Craft Engine Air Inlet System this is usually part of the engine scope in order to minimize losses in the intake and to ensure the incoming air is evenly distributed in the engine. o Craft Engine Exhaust Gas System this is also usually part of the engine scope to ensure that the gas turbine exhaust gases are efficiently returned to the atmosphere with minimal losses. 3.3 AE1107C Reliability - A Leader in Sand Ingestion Damage Resistance Given the aggressive operating environment of the Ship to Shore Connector, the MT7 engine with its AE1107C heritage is already a leader in sand ingestion damage resistance. This reinforces the MT7 as the low risk, battleproven engine of choice for the craft. To most accurately quantify this fact, results from engine-only tests were collected. This allows for a direct comparison of the AE1107 engine s ability to generate power while ingesting sand compared to other engines in its class. These engine-only tests remove the platform to platform differences and as a result, remove variability of platform specific filtration devices such as the engine air particle separators utilized on the V-22 platform.

6 There is however a distinct difference between the AE1107 and the MT7 s operational working conditions. The AE1107 working on the original concept V-22 Osprey Program craft is open to atmosphere and has the ability to pick-up all that is sucked into the intakes. The SSC on the other hand treats the MT7 gentler with robust intake filtration system added to the normal operation of the engine. The level of filtration anticipated will remove much of the erosion and corrosion elements from the incoming air to engine. Comparison conditions of operation for the V- 22 Osprey and LCAC are provided in Figures 4 and 5 below. [Figure 4] - V-22 Osprey Operation with Dust, sand and salt water ingestion [Figure 5] - The Original LCAC, demonstrating the aggressive working environments of the engine has to sustain, with sand, dust and salt water ingestion 3.4 Reduced Life Cycle Cost With its NAVAIR application in the V-22 Osprey Program, the MT7 engine is well-developed in the Navy support system. The ability to leverage the existing support system allows significant cost avoidance for the SSC program. The MT7 engine provides industry leading life cycle costs for the SSC application where the primary drivers are acquisition, maintenance and support infrastructure. The MT7 has over 90% commonality with existing National Stock Numbers (NSN) in the US Navy supply system. The volume of parts usage from the combined programs allow for economical buys and logistics efficiencies. Special tools, test equipment and parts common to the engine applications are already carried on the ships that will embark the SSC craft as a result of provisioning for the V-22 Osprey Program. The AE1107C engine contract with NAVAIR includes a Power by the Hour maintenance agreement under which Rolls-Royce is incentivized and authorized to maintain a continuous improvement program for increased time on wing and as a result, reduction in Life Cycle Costs (LCC). The MT7 and SSC program will capture these improvements at no additional cost. In addition a Rolls-Royce service engineer is available to deploy with embarked V-22 Osprey Program squadrons and may provide technical support to the embarked SSC craft.

7 A depot overhaul facility for the V-22 Osprey Program at Rolls-Royce Engine Services Oakland (RRESO) is in full operation and presently overhauling approximately 80 engines per year. The engines from the SSC program will be overhauled at the same facility and will have cost reduction benefits from the economies of scale. The MT7 engine will reap the benefits of 80% parts commonality with a population of over 6,100 engines in the AE family. This large population of engines assures a strong supply chain well into the future. 3.5 MT7 Weight Benefit The MT7 has the lowest weight of any engine considered for the SSC program. The engine dry weight is 441 kg (973 lbs.) and a wet weight of 453 kg (999 lbs.). The craft-set weight of four MT7 engines is less than 1,812 kg (3,995 lbs.). This weight advantage provides the craft builder an opportunity to increase range or payload and if necessary provides a way to mitigate the risk of craft weight growth during construction. The compactness of the aero derivative engine includes a fuel cooled oil cooler that is installed on the engine and fits on its underneath side. Even the most seasoned marine engineer still expect large infrastructure to cool oil, taking additional weight, system requirements and valuable deck space, when compared to the small compact aeroderived system installed on the MT Lower Program Risk The Navy SSC Ship Design Manager has publicly identified his top three areas of program risk Engine marinization and qualification: this is the US Navy s top risk. Since the AE1107 is the base engine, the MT7 is not a developmental engine. For the V-22 Osprey Program the lead engine already has the equivalent of 30 years of SSC experience. The MT7 engine is a mature engine that has some minor ancillary changes introduced. Rolls-Royce has applied proven methods to qualify more engine models for more marine applications than any other engine manufacturer. In the past ten years these engines include the MT30 (US Navy LCS and DDG 1000; Korean Navy FFX; UK Royal Navy Queen Elizabeth Class Carrier and Type 26 Frigate), MT5S (DDG 1000) and WR21 (UK Royal Navy Type 45). These engines range in power from 4-40 MW and are operating successfully in service, or soon to be in service. For the SSC program, Rolls-Royce will apply these same proven technologies and methods to the successful MT7 qualification. Rolls-Royce was the first company to qualify an engine to American Bureau of Shipping (ABS) Naval Vessel Rules (NVR) and plan to do the same for the MT7 engine. Discussions between ABS and NAVSEA have led to the mutual initial assessment that based on V-22 Osprey Program experience the MT7 should only require a 500 hour test. As a part of the risk reduction plan, Rolls-Royce is investing in the qualification process of the MT7. Rolls-Royce has direct control of the entire supply chain for the MT7 engine. Rolls-Royce Marine North America Inc. management is able to prioritize the supply chain to meet program requirements Mechanical System Integration: The Navy s second highest risk concern is the integration of the mechanical propulsion system. The use of a Dynamic Response Analysis (DRA) was cited by the Navy as the primary mitigation tool for this risk. Rolls-Royce Marine North America based in Annapolis Maryland has created the DRA tool for the LCAC program and has performed the DRA s for every recent US Naval ship including LCS designs. In addition to this unique DRA resource, Rolls-Royce employs over 100 marine engineers and naval architects whose talents can be drawn upon to support the SSC program.

8 3.6.3 Control, Communication, Control, Computers and Navigation (C4N) System Software Development: The Navy s third highest risk concern is the integrity and operability of the C4N1. The interface between the gas turbine engine and the C4N system is the Full Authority Digital Engine Control (FADEC). Rolls-Royce has recent, successful development of engine controls and monitoring development as evidenced by the LCS program. 3.7 Reliability Maintainability Assessment The lead AE1107C engine on the V-22 Osprey Program has already operated the equivalent of 30 years of SSC operation. By virtue of aircraft hours and operating profiles the V-22 Osprey Program will drive a Reliability Maintainability Assessment (RMA) program that will directly benefit the SSC program. In sand ingestion testing completed for the V-22 Osprey Program, the AE1107 engine performed 25% better than the T64 engine when tested for the CH-53E. Experience on the V-22 Osprey Program, coupled with the incentivized Power by the Hour program, has driven engine improvements which have increased engine reliability by over 100%. This engine reliability program, funded by Rolls-Royce with NAVAIR endorsement, will benefit the MT7 engine for the life of the SSC program. Engine maintenance is a driver for SSC engine Life Cycle Cost. Commonality between the AE1107 and MT7 will enable lowest possible parts pricing. Cost effective maintainer training and development of efficient maintenance procedures further improves lifecycle cost. The MT7 engine uses titanium in key components for weight optimization and increased durability. The MT7 also utilizes individual rotor and stator blades and vanes which provide flexibility and opportunities for cost optimization during planed engine overhauls. This architecture provides clear cost benefits over Integrally Bladed Rotors (IBR) or blisk or BLaded disk technology where it is currently not possible to replace individual blades and vanes adding to the total cost of ownership. The factors of reliability and maintainability drive availability and as described above the MT7 engine offers the leading program for not only today s success but also a program for continual improvement. 4.0 MT7 Testing Experiments and Completion of ABS NVR Type Approval 4.1 Performance Experiments A host of experimental testing activities were performed on the AE family, and thereby the MT7, through the development of the parent T406-AD-400 gas turbine. This already completed development program conducted experiments to assess performance of the below important parameters: Start/Acceleration Corrosion Susceptibility Sand and Dust Ingestion Exhaust Gas Emission Foreign Object Damage (FOD) Demonstration Application specific experimental activities were designed to test parameters important to the mission profile for SSC operation. These are Endurance Durability Tests, Structural Tests, Engine Environmental and Ingestion Tests, Subsystem/component environmental tests, Stand-alone tests, fuel type qualification and engine type certification. Critical experimental testing focused on fuel type qualification and engine type certification. 4.2 Fuel Qualification Experimental Testing A fuel qualification experimental test was performed on the MT7 materials to include F76 as an approved operational fuel type. The experimental evaluation included the following measurements:

9 Bulk chemical/physical properties through laboratory analysis Lean burn-out and ignition combustion operation measurements Combustion emissions, including smoke, Oxides of Nitrogen (NOx), carbon monoxide (CO), and unburned hydrocarbons (UHC) Component durability (combustion liner, fuel nozzle flow characteristics, combustor exit profiles Hot section material compatibility evaluation for oxidation and composition Three main test rigs were used for this experimental test program. The first is a three (3) fuel nozzle sector of the AE3007 annular combustor, see Figure 6 for an inside view of the Sector Rig. This rig is used to measure performance parameters such as ignition and LBO characteristics, gaseous emissions and smoke, and liner temperatures [Figure 6] - Internal View of Sector Rig [Figure 7] - AE Combustor Rig Test Configuration Testing in the full annular combustor rig adds the capability to obtain representative radial temperature profiles. This test configuration allows assessment of turbine durability, liner wall temperatures, and nozzle-to-nozzle interaction. Figure 7 shows the AE combustor rig used for this experiment at the Rolls-Royce Test Facility. 4.3 Engine Performance Experimental Testing with Result of Type Certification⁴ American Bureau of Shipping (ABS) provides governance for engine performance and operation against a specified mission profile through the use of Naval Vessel Rules (NVR). Part 2, Chapter 3, Section 1 provides a list of tests required to obtain engine type certification. A summary of type certification activities is listed below. These items are fully addressed in the Design Assessment submitted to ABS by RR. Engine piping was subjected to normal operating pressures with no leaks during testing. Full compliance to the ABS requirement for 150% of max working pressure will be demonstrated by vendor pressure test data Pre-Endurance Cycle Testing Visual and Dimensional Pre-Examination: The equipment is subjected to a visual and dimensional examination to confirm that the materials, workmanship, and construction of hardware are in accordance with the physical requirements and assembly/part drawings. Provide engine configuration baseline for component evaluation after endurance test - Compliance: All engine hardware was subjected to standard build-up procedures and inspections. Additional inspections and measurements were taken on specific hardware, as agreed upon and approved by ABS.

10 Performance Calibration: Performance calibration testing is conducted at the prevailing ambient test cell conditions and the data is corrected to sea level static conditions to establish the pre endurance engine performance levels. The performance calibration will be run with increasing power settings and performance data is recorded at each power condition. - Compliance: A performance calibration was performed to establish engine baseline performance prior to the start of ABS certification testing. Raw data collected during the calibration was adjusted reference conditions via an in-house data reduction program. The performance calibrations used was the standard AE 2207C test used for production. Second-order-curve fits were used to adjust performances parameters to MT7 rated targets. Specific Fuel Consumption: The Pre Endurance Specific Fuel Consumption (SFC) is determined from data collected during pre-endurance performance calibration run. - Compliance: Baseline SFC was calculated prior to the endurance test using performance parameters described above pre-endurance performance calibration. Piping Integrity: Piping integrity for the MT7 was satisfied through the Quality Assurance portion of ABS NVR Type Approval. Pressure check compliance is demonstrated using existing vendor test data and the Rolls-Royce quality processes in place. Additionally, leak free piping is verified after the completion of each endurance test cycle. - Compliance: Parts were purchased through Rolls-Royce approved suppliers and met print requirements which include pressure tests. In addition, the parts successfully completed endurance testing with no leaks. Alignment: Engine-to-dynamometer alignment can be measured and recorded prior to the type approval test. - Compliance: The MT7 pre-endurance engine to spindle alignment was measured in Test Bed. The alignment procedure consisted of inserting temporary spacers between the torque meter aft flange and air inlet housing forward flange until gaps on all sides were equivalent. Overspeed Governor and Engine Protective Devices: the FADEC overspeed protection capability is tested during this experiment. All other engine protective devices are tested to ensure proper operation per the requirements. These protective measures include automatic shutdowns for overspeed, low lube oil pressure, loss of flame, excessive vibration, and excessively high turbine temperatures. Starting system safety is also tested. - Compliance: All shutdown conditions were successfully demonstrated by adjusting parameter thresholds in the EEC logic. For each demonstration, the engine was brought to idle (Np=7500 rpm) and the EEC shutdown value was manually adjusted to induce a shutdown. The values were then manually adjusted back to the original values by the controls engineer. An aborted start attempt was performed to demonstrate automatic fuel shutoff the seconds after no light was identified. Following the no light off, the control system automatically performed dry motoring to clear unburnt fuel and vapors Type Approval Endurance Cycle Testing During the endurance cycle testing, the MT7 was operated at specific performance conditions indicated within the NVR for low usage, category IV gas turbines. The test profile defines the operating points in a single cycle and this cycle was repeated to conduct the prescribed 500 hours of engine operation and checked shown Figure 8 as an example. During the cyclic operation, the following measurements were taken: Observed load, as corrected by ISO 2314 to the standard conditions specified The type approval endurance test was run with a total of 167 cycles with the requirement. A spreadsheet was created to document time at condition, temperature and power, to determine cycle validity

11 Lubricating oil consumption was measured and monitored through the certification test activity. Average oil consumption as a function of engine run time was periodically provided to Rolls-Royce. All additions or removals of oil were recorded in the test stand data log book. Fuel and Lubricating oil samples were taken both before and after performance calibrations in test bed. Two samples were taken at each point in approved bottles and were labeled with the corresponding test time and date. One sample was provided to ABS and the other was provided to Rolls-Royce to be sent to the laboratory for analysis. Engine vibration was measured with Engine Monitoring Unit (EMU) sensors provided with the engine and by test stand supplied sensors. Vibration limits were set by Rolls-Royce technical team and if exceeded, the engine was shutdown. There were no shutdowns due to vibration during the test. Additionally any discrepancies between the two sets of sensors were reported to Rolls-Royce. Pre-endurance Heath Check run (Speed Np, Ng) Mid-endurance Heath Check run (Speed Np, Ng) Post Endurance Cycle Testing Post-endurance Heath Check run (Speed Np, Ng) [Figure 8 : Endurance Heath Check run: Pre, Mid, Post] Following cyclic testing, the post-endurance experiments and measurements were conducted and recorded at the prevailing ambient test cell conditions. The ABS requirement for low usage, CAT IV gas turbine engines is no more than 3% power loss. Engine starting was re-assessed including time-to-start and the conduction of ten (10) consecutive starts. A post-test performance calibration was conducted in identical fashion to the pre-test calibration and results were compared to ensure power and specific fuel consumption (SFC) degradation is within acceptable limits. Finally, engine alignment was measured to ensure it is within acceptable limits. The results were compared to the pre-endurance test alignment values and showed little to no change in engine alignment. The next step was to dis-assemble the engine to assess the condition of its hardware. It was dis-assembled to its component and sub-system levels permitting the relevant assessments to be carried out. These assessments included; visual inspection, dimensional verification, non-destructive test (NDT) crack investigation and engine alignment

12 measurements. The report containing the findings was submitted to ABS, rounding out the submissions to gain ABS NVR Certification. The inspection resulted in all hardware passing the relevant measurements and tests were successfully carried out to the satisfaction of ABS and Rolls-Royce internal procedures and policies. Listed below are the MT7 brochure performance and technical specifications. Power output Rotational Speed Rotation Length Diameter Weight(unpackaged) Fuel Specific Fuel Consumption(SFC) Specification 4 5 MW(6,000~7,000 SHP) 15,000 RPM Anti-clockwise when viewed from exhaust 1,500mm(59.1 ) 877mm(34.5 ) 441kg(971lb.) Marine diesel, kerosene and F76 Military Diesel g/kw/hr(0.4 lb./hp/hr) The tests completion supported the USN Program Milestone C for craft production readiness. The engines supporting the first-of-type Test and Training Craft have now been successfully factory tested and accepted by Textron. The next step is for these engines to support craft installation and testing. Testing of the craft at Textron will include installation checks, system integration testing, and first article operational and acceptance tests. This will support craft test and evaluation trials to follow in late 2017 or early Full rate production will follow the successful completion of these trials in parallel with retirement of the existing USN-LCAC s. 5.0 Future work on MT7 5.1 Improved Lifecycle Cost & Enhanced Maintainability The MT7 will naturally lower its lifecycle cost and increase maintainability through adapting operational experience from the AE engine family wherever possible and practical. To support the thousands of AE family engines produced, Rolls-Royce is continually developing new repair-schemes, enhancing maintenance procedures, engineering solutions to increase engine life, and developing modifications to make engines more fuel efficient. Many of these developments will naturally progressively be adopted by the MT7 engine range and made available to MT7 operators. These changes include significant durability improvements introduced to the AE1107 to improve combat operations and configuration changes that increase the output power by 17% from the baseline configuration ² 5.2 MT7 Developing Adaptable Solutions Rolls-Royce recognizes that there are a variety of future applications of the MT7 beyond the USN Ship to Shore Connector. Future customers will require custom solutions that are unique to their programme. Rolls-Royce is working to make the MT7 highly adaptable for future applications. Rolls-Royce can offer highly customized MT7 options for its customers in the following areas and beyond: Engine start system (electric, pneumatic, hydraulic) Baseplate (shock resistant, hard mounted) Bleed Manifolding (Customer Options) Intake Plenum (Vertical, horizontal)

13 Exhaust Ducting (vertical, horizontal, transom) Local Operating Panel (Customer Option) 5.3 Future MT7 Applications Many of the world s navies are interested in developing or replacing amphibious craft (LCAC/ Hovercraft), fast patrol boats and, fast attack vessels. As these opportunities emerge, Rolls-Royce believes that the MT7 is likely to be an attractive option for propulsion. At a power density value of approximately kw/kg, the MT7 offers class-leading power density that offers strong system-and platform-wide benefits on these vessel types. This level of power density will provide a more meaningful multifunctional capability than has previously been available to these type craft. When combined with continually improving power, maintainability, and low lifecycle cost, the MT7 a strong contender for these future applications. 6.0 Conclusions The MT7 already has a rich heritage that has powered many platforms and the future is certainly positive as well. Strongly supported by the further improvement and evolution of the AE core, the MT7 engine is one that will continue to improve in reliability and maintainability. MT7 can meet naval requirements driven by the need for increased power density, whilst dropping fuel consumption and allowing an enhanced payload to be carried by the vessel. In the longer-term, there are many opportunities to ensure the MT7 remains a most competitive engine through technology insertion and as a result of a positive design spiral through which low-cost, optimized weight, reliability and affordable solution can be continually improved. Rolls-Royce continues to develop flexible solutions to make the engine easy for its customers to incorporate in their designs. The compact size, and highly-customizable options positions the MT7 to power fast conventional hull designs and amphibious craft well into the foreseeable future. 8.0 The Acknowledgements The authors of this paper would like to show their appreciation to the following personnel for their support in the preparation of this paper; Sam Cameron, David J Kemp, Matt Waters, Damian Whatmough, Ed Wright, and Richard Partridge. 9.0 Citations / References 1. Navy.Mil Web Page, 2. Aero & Defense Intelligence Report Optimisation of Propulsion Systems for fast Naval Craft, by E F Wright, J W Collins, O J Rath 4. Rolls Royce Engineering Department Report, EDNS /001 MT7 ABS Certification Test Report 5. In-Ha, Hwang, The Way in Developing Characteristics of the Future ROK Naval Ship : The 17th Naval Ship Technology Seminar, 2014