Rolls-Royce Trent

Trent
Rolls-Royce Trent 900 on A380 prototype
Type	Turbofan
Manufacturer	Rolls-Royce
First run	1990 (Trent 700)
Major applications	Airbus A330 Airbus A340 Airbus A350 Airbus A380 Boeing 777 Boeing 787
Developed from	Rolls-Royce RB211
Developed into	Rolls-Royce Marine Trent

Rolls-Royce Trent is the name given to a family of high bypass turbofan engines manufactured by Rolls-Royce. All are developments of the RB211 with thrust ratings of 53,000 to 95,000 lbf (240 to 420 kN). Versions of the Trent are in service on the Airbus A330, A340, A380 and Boeing 777, and variants are in development for the forthcoming 787 and A350 XWB. The Trent has also been adapted for marine and industrial applications.

The Trent has achieved significant commercial success, being the launch engine for all three 787 variants, the A380 and A350. Its overall share of the markets in which it competes is around 40%.^[1] Sales of the Trent family of engines have made Rolls-Royce the second biggest supplier of large civil turbofans after General Electric.^[2]

Singapore Airlines is currently the largest operator of Trents with five variants in service or on order.^[3]

Design and development

Origin

When Rolls-Royce was privatised in April 1987, its share of the large civil turbofan market was only 8 per cent.^[4] Despite increasing sales success with the RB211, General Electric and Pratt & Whitney still dominated the market. At that time, the aircraft manufacturers were proposing new planes that were going to require higher levels of thrust than before. Furthermore the Boeing 777 and Airbus A330 were to be twin-engined, and their airline customers were demanding that they be capable of operating in the extended twin-engine operations environment (ETOPS) at the time of their initial introduction into service.

Rolls-Royce decided that to succeed in the large engine market of the future, it would have to offer engines for every large civil airliner. In view of the enormous development costs required to bring a new engine to market, the only way to do this would be to have a family of engines based on a common core. The three-shaft design of the RB211 was an ideal basis for the new family as it provided flexibility, allowing the high-pressure (HP), intermediate-pressure (IP) and low-pressure (LP) systems to be individually scaled. Recently freed from the restrictions of state ownership, Rolls decided to launch a new family of engines which was formally announced at the 1988 Farnborough Airshow. Reviving a name last used thirty years previously, the new engine was named the Trent. The Trent name had been used for two previous Rolls-Royce engines. The first Trent was the world's first turboprop engine. The name was reused again in the 1960s for the RB203 bypass turbofan which was designed to replace the Spey. Rated at 9,980 lbf (44.4 kN) it was the first three-spool engine, and forerunner of the RB211 series, although it never entered service.

Rolls-Royce has obtained significant sums of 'launch investment' from the British government for the Trent programmes, including £200 million approved in 1997 for Trent 8104, 500 & 600 and £250 million for Trent 600 & 900 in 2001. No aid was sought for Trent 1000. Launch investment is repaid to the government by a royalty on each engine sold.^{[citation needed]}

Design

Like its predecessor RB211, the Trent uses a three-spool design rather than the more common two-spool configuration. Although inherently more complex, it results in a lighter, shorter, more rigid engine which suffers less performance degradation in service than an equivalent twin-spool.

Although all the engines in the Trent family share a similar layout, their three-spool configuration allows each engine module to be individually scaled to meet a wide range of performance and thrust requirements. For example, the large 116 inch diameter fan of the Trent 900 keeps the mean jet velocity at take-off at a relatively low level to help meet the stringent noise levels required by the Airbus A380's customers.^[5] Similarly, core size changes enable the (HP) turbine rotor inlet temperature to be kept as low as possible, thereby minimising maintenance costs. The overall pressure ratio of the Trent 800 is higher than the 700's despite sharing the same HP system and IP turbine; this was achieved by increasing the capacity of the IP compressor and the LP turbine.

The core turbomachinery is brand new, giving better performance, noise and pollution levels than the RB211. So significant were the improvements that Rolls-Royce fitted the Trent 700's improved HP system to the RB211-524G and -524H,^[6] creating -524G-T and -524H-T respectively.

When the RB211 programme originally started, it was intended that none of the compression system would require variable stators, unlike the American competition. Unfortunately, it was found that, because of the shallow working line on the IPC, at least one row of variable stators was required on the IPC, to improve its surge margin at throttled conditions. This feature has been retained throughout the RB211 and Trent series. Although the original intent was not met, Rolls-Royce eliminated the need for many rows of variable stators, with all its inherent complexity, thereby saving weight, cost and improving reliability.

Variants

Trent 600 - First proposal

The initial variant, Trent 600, was to power the McDonnell Douglas MD-11 with British Caledonian as the engine's launch customer. However, when British Airways bought British Caledonian in 1987, they cancelled the MD-11 order. With the collapse in 1991 of Air Europe in the aftermath of the 1990 Gulf War, the only other Trent-powered MD-11 customer was lost. As the MD-11 was itself suffering poor sales due to its failure to meet its performance targets, the Trent 600 was downgraded to a demonstrator programme, engine development being switched to the Trent 700 for the Airbus A330.^{[citation needed]}

Trent 700

In April 1989, Cathay Pacific became the first customer to specify an Airbus aircraft powered by Rolls-Royce engines when it ordered ten A330s powered by the Trent 700. The following month TWA followed suit with an order for twenty A330s.

The Trent 700 first ran in August 1990, and certification was achieved in January 1994. 90 minutes ETOPS approval was achieved in March 1995, and this was extended to 120 minutes in December 1995 and 180 minutes in May 1996.^[7]

Trent 800

At the same time, Boeing were investigating an enlarged development of its 767 model dubbed the 767X, for which Rolls-Royce proposed the Trent 760. By 1990 Boeing abandoned its planned 767X and instead decided to launch a new, larger aircraft family designated 777 with a thrust requirement of 80,000 lbf (360 kN) or more. The Trent 700's 2.47 m (97 in) diameter fan would not be big enough to meet this requirement, so Rolls proposed a new version with a 2.80 m (110 in) fan diameter, designated Trent 800.

Testing of the Trent 800 began in September 1993, and certification was achieved in January 1995.^[7] The first Boeing 777 with Trent 800 engines flew in May 1995, and entered service with Cathay Pacific in April 1996.

Initially Rolls-Royce had difficulty selling the engine: British Airways, traditionally a Rolls-Royce customer, submitted a large order for the competing General Electric GE90 engine. The breakthrough came when the company won orders from Singapore Airlines, previously a staunch Pratt & Whitney customer, for its 34 Boeing 777s. The Trent 800 has a 41% share of the engine market on the 777 variants for which it is available.^[8]

On 17 January 2008, a British Airways Boeing 777-236ER, operating as flight number BA038 from Beijing to London, crash-landed at Heathrow after both Trent 800 engines lost power during the aircraft's final approach. The subsequent investigation found that the cause was ice released from the fuel system which accumulated on the fuel-oil heat exchanger leading to a restriction of fuel flow to the engines.^[9]

Trent 8104

In 1998 Boeing proposed new longer range variants of the 777X; taking advantage of the Trent 800's growth capability, Rolls-Royce designed and built an improved engine designated Trent 8104 which was later scaled upwards to the even larger 8115. This development was the first engine to break through 100,000 lbf (440 kN) thrust and subsequently the first to reach 110,000 lbf (490 kN). However, Boeing required that the participating engine developer assume a risk-sharing role on the overall 777X project. Rolls-Royce was unwilling to do so, and in July 1999 Boeing announced that it had chosen the development of the GE90, the GE90-110B and GE90-115B to be the sole engines on the long-range 777s. This resulted in the 8104 becoming just a demonstrator programme, despite setting further industry firsts for thrust levels achieved and the first to demonstrate the use of a fully swept wide chord fan.

Trent 500

In 1995, Airbus began considering an engine for two new long-range derivatives of its four-engined A340 aircraft, designated A340-500/-600. In April 1996, Airbus signed an agreement with General Electric to develop a suitable engine, but decided not to proceed when GE demanded an exclusivity deal on the A340. After a contest with Pratt & Whitney, Airbus announced on 15 June 1997 at the Paris Air Show that it had selected the Trent 500 to power the A340-500 and -600.^[10]

The Trent 500 first ran in May 1999 and achieved certification in December 2000. It entered service on the A340-600 with Virgin Atlantic Airways in July 2002 and on the ultra-long range A340-500 with Emirates in December 2003.

As of January 2009 a total of 15 customers had placed firm orders for 139 A340s powered by Trent 500s; Lufthansa is the largest operator with 21 currently in service.^[11]

Trent 900

Rolls-Royce Trent 900 on test

In the early 1990s, Airbus had begun development of a larger successor to the Boeing 747, an aircraft designated A3XX, which was later to be formally launched as the A380. By 1996, its definition had progressed to the extent that Rolls-Royce was able to announce that it would develop the Trent 900 to power the A380. In October 2000, the Trent 900 became the A380's launch engine when Singapore Airlines specified the engine for its order for 10 A380s; this was quickly followed by Qantas in February 2001.

The Trent 900 made its maiden flight on May 17, 2004 on Airbus' A340-300 testbed, replacing the port inner CFM56-5 engine, and its final certification was granted by EASA on 29 October 2004 and the FAA on 4 December 2006.^[12][13] Rolls-Royce announced in October 2007 that production of the Trent 900 had been re-started after a twelve month suspension caused by delays to the A380.^[14]

On 27 September 2007, British Airways announced the selection of the Trent 900 to power 12 A380 aircraft,^[15] helping to take the engine's share of the A380 engine market to 52% at the end of February 2009.

Trent 600 - Second proposal

In July 2000, Rolls-Royce signed an agreement with Boeing to offer the Trent 600 engine on developments of 767 and 747 aircraft.^[16] The 767 variant was to be a new longer-range version of the Boeing 767-400ER to be powered by the Trent 600 and Engine Alliance GP7172, although in the end this aircraft was never launched. When Boeing finally launched the 747-8 in 2005 it announced that the General Electric GEnx would be the only engine available for the 747-8.

Trent 1000

On 6 April 2004 Boeing announced that it had selected two engine partners for its new 787: Rolls-Royce and General Electric. Initially, Boeing toyed with the idea of sole sourcing the powerplant for the 787, with GE being the most likely candidate. However, potential customers demanded choices and Boeing relented. For the first time in commercial aviation, both engine types will have a standard interface with the aircraft, allowing any 787 to be fitted with either a GE or Rolls-Royce engine at any time as long as the pylon is also modified.^[17]

In June 2004, the first public engine selection was made by Air New Zealand who chose the Trent 1000 for its two firm orders. In the largest 787 order, that of Japan's All Nippon Airways, Rolls-Royce was selected as the engine supplier on October 13, 2004. The deal is valued at $1bn (£560m) and covers 30 787-3s and 20 787-8s. The Trent 1000 will be the launch engine on all three current 787 models, the -3 and -8 with ANA and the -9 with Air New Zealand.^[18] On 7 July 2007, Rolls Royce secured its largest ever order from an aircraft leasing company when ILFC placed an order worth $1.3 billion at list prices for Trent 1000s to power 40 of the 787s which it has on order,^[19] and on 27 September 2007 British Airways announced the selection of the Trent 1000 to power 24 Boeing 787 aircraft. Trent 1000's share of the 787 engine market was 40% at the end of August 2008.

The first run of the Trent 1000 was on 14 February 2006,^[20] with first flight on Rolls-Royce's own flying testbed (a modified Boeing 747-200) successfully performed on June 18, 2007 from TSTC Airport in Waco, TX.^[21] The engine received joint certification from the FAA and EASA on 7 August 2007^[22] (7-8-7 in the UK). Entry into service has been delayed by more than two years to the last quarter of 2010 following a series of delays to the Boeing 787 programme.^[23]

Trent 1500

A Trent 500 replacement engine, known unofficially as the Trent 1500, has been proposed for the Airbus A340-500/600, to help the aircraft compete with the Boeing 777-200LR/300ER.^[24] However, the announcement of the A350 XWB, which covers the A340 market, will most likely prevent the Trent 1500 from ever becoming a reality.

The Trent 1500 would retain the 2.47 m (97 in) fan diameter of the current Trent 500 engine, as well as the nacelle, but incorporate the smaller, more advanced, Trent 1000/XWB gas generator and LP turbine, suitably modified.

Trent XWB

By 2004, Airbus was facing pressure from customers to develop a competitor for Boeing's 787, and in October 2005 formally launched the new aircraft designated A350, which was to be essentially an updated A330. Rolls-Royce offered a variant of the Trent 1000, dubbed Trent 1700 which would have been similar to the Trent 1000, but with a throttle-push to 75000lbf static thrust. Unlike the Trent 1000, the Trent 1700 would have been a conventional bleed-air engine,^[25] and would be developed in partnership with Kawasaki. After a lukewarm response from the airlines, Airbus reviewed their A350 proposal, and on 17 July 2006 announced that they would be offering instead an all-new aircraft called the A350 XWB (Xtra Wide-Body), with a fuselage diameter slightly greater than that of Boeing's 787, to compete with both the 787 and the 777.^[26]

Rolls-Royce has reached an agreement with Airbus to supply a new variant, currently called the Trent XWB, for all versions of the Airbus A350 XWB.^[27] Originally announced with a static thrust range of 75000-95000lb_f, by September 2007 Airbus had revised their requirements down to 74,000–92,000 lbf (330–410 kN).^[28] Certification is planned for 2011, with the 83000lb_f Trent XWB-83's entry into service on the A350 XWB-900 expected in 2013. This will be followed by the 74,000 lbf (330 kN) Trent XWB-74 in 2014 on the A350 XWB-800, and finally the 92,000 lbf (410 kN) Trent XWB-92 on the A350 XWB-1000 in 2015.^[29] General Electric has yet to confirm that it will offer a GEnx variant for the A350 XWB. Flight International magazine has suggested that the GE/Pratt and Whitney Engine Alliance GP7000 may be the second engine option for the aircraft, at least on the smaller variants.^[30][31]

On 18 June 2007, Rolls-Royce announced that it had signed its biggest ever contract with Qatar Airways for the Trent XWB to power 80 A350 XWBs on order from Airbus worth $5.6 billion at list prices.^[32] On 11 November 2007, another large contract was announced at the Dubai Airshow from Emirates Airline for Trent XWBs to power 50 A350-900 and 20 A350-1000 aircraft with 50 option rights. Due to be delivered from 2014, the order is potentially worth up to 8.4 billion US Dollars at list prices, including options.^[33] By the end of February 2009, Rolls-Royce had secured orders for engines to power a total of 420 A350 aircraft. By November this figure was up to 500 aircraft. ^[34]

Non-aircraft variants

MT30

The Marine Trent 30 is a derivative of the Trent 800, (with a Trent 500 gearbox fitted), producing 30 MW for maritime applications. The current version is a turboshaft engine, producing 36 MW, using the Trent 800 core to drive a power turbine which takes power to an electrical generator or to mechanical drives such as waterjets or propellers. It will power the Royal Navy's next generation of aircraft carriers.

Industrial Trent 60 Gas Turbine

This derivative is designed for power generation and mechanical drive, much like the Marine Trent. It delivers up to 58 MW of electricity at 42.8% efficiency (http://www.rolls-royce.com/Images/b_trent_tcm92-10920.pdf). It comes in two key versions DLE and WLE. The WLE is water injected, allowing it to produce 58 MW in ISA conditions instead of 52 MW. It shares components with the Trent 700 and 800 (http://www.rolls-royce.com/energy/products/powergen/trent/default.jsp). In power generation roles the heat from the exhaust, some 420'c (http://www.rolls-royce.com/energy/products/powergen/trent/apps.jsp) can be used to heat water and drive steam turbines, improving efficiency of the package.

Applications

• Airbus A330
• Airbus A340
• Airbus A350
• Airbus A380
• Boeing 777
• Boeing 787

Specifications

Trent 8104/8115

Originally designed for the 777-200LR and 777-300ER (both part of the 777X project), this engine comes in two thrust ratings, 104,000 lbf (460 kN) and 114,000 lbf (510 kN), and has been tested up to 117,000 lbf (520 kN). As Boeing's thrust requirements increased, Rolls-Royce began developing the 115,000 lbf (510 kN) 8115 which was to be an enlarged version of the 8104, with a 3.05 m (120 in) fan and a core scaled up 2.5 percent from the 8104. It featured swept-back fan blades and a host of new technologies such as contra-rotating spools.

The 8115 was never built, as Boeing signed a contract with General Electric to be the sole supplier of engines for the 777X aircraft, owing to GEs willingness to risk-share on the airframe part of the project, and sales of the aircraft to GECAS.

Trent XWB

The Trent XWB family is designed to power the Airbus A350. The engine has been optimised for the 84,000 lbf (370 kN) A350-900, with a derated 75,000 lbf (330 kN) version for the A350-800. The 93,000 lbf (410 kN) version for the A350-1000 will maintain the same core and 3.0 m fan size; the additional thrust will be achieved by running the fan at higher speeds which will require stronger blades and a strengthened casing. In addition, the core's operating temperatures will be increased using new technology currently under development, taking advantage of this model's later launch date.^[35]

• Three-shaft high bypass ratio: 9.3
• Take-off thrust: 75,000–93,000 lbf (330–410 kN) (flat-rated to ISA+15C)^[36]
• Fan diameter: 3.0 m (118 in)
• Fan: single stage, swept, low hub:tip ratio
• Airflow: approx. 1,440 kg (3,200 lb) per second
• IP compressor: 8 stage axial
• HP compressor: 6 stage axial
• Combustor:
• HP turbine: single-stage, aircooled
• IP turbine: 2-stage
• LP turbine: 6-stage, cooled

Trent series specification table

See also

Related lists

• List of aircraft engines
  

References

Notes

External links

Wikimedia Commons has media related to: Rolls-Royce Trent

• Rolls-Royce plc
  • Trent 500 series
  • Trent 700 series
  • Trent 800 series
  • Trent 900 series
  • Trent 1000 series
  • Trent XWB
  • Trent 60
  • MT30