When Rolls Royce went into receivership in 1971, it was like a hammer blow to british
industry and was almost as unthinkable as the fall of the monarchy or the Chruch of
England, and yet one single project caused more damage than the combined forces Hilter
and the Luftwaffe in the darkest days of world war 2 to bring down one of the most famous
engineering names in the world. However, in a twist of fate worthy of any
great piece of fiction that same project was also the salvation of Rolls Royce and turned
it from a mid-sized engine maker into a global leader. This is the story of the RB211 high
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To find out how Rolls Royce got in to such a position we have to go back a few years
to America and the introduction of a new type of large wide-bodied aircraft that airlines
were looking to buy which would allow them to move more people more efficiently and over
longer distances. Part of this had been driven by the crossover
of military programs like the US defence competition for the Heavy Logistics System which saw the
developments from Boeing, Lockheed and Douglas, which went on to create the Lockheed C5- Galaxy
and the much more successful loser that became the Boeing 747.
Other new wide-bodied aircraft developed in the late 60’s and driven by demand from
the airlines were the Douglas DC10 and the Lockheed L-1011 Tristar, these also required
three engines instead of the usual two for redundancy for long flights over water.
With such large aircraft, there was a need for large engines with GE supplying the CF-6,
the larger civilian version of the TF39 from the C5 Galaxy and Pratt & Whitney supplying
the JT9D developed for the Boeing 747. Key to these new engines was the newly developed
High Bypass Concept which used a much bigger fan. This provided extra thrust by completely
encircling and flowing around the outside of the engine core. The large fan also ran
at a higher pressure ratio of about 1.5 which acted like a supercharger for the core too.
These new engines needed to be both powerful and lightweight for their size with thrust
outputs in the 43,000 lb range. Rolls wanted a part of this new and expanding
market and thought they had an advantage over the others because they had been developing
the worlds first 3 spool High Bypass Engines. In this configuration, 3 sets of turbines
spin on three concentric shafts which drive the compressors sections at different speeds,
allowing each one to be more efficient than a typical 2 spool engine.
Rolls had also been developing carbon fibre “Hyfil” fan blades, the combination of
this and the 3 spool design would give them a greater power to weight ratio than anything
on the market. Rolls developed the first turbofan engine
to enter service, the Conway in the early 1950’s and in 1961 they started work on
a high bypass engine to replace the Conway. This led to the development of the RB178 but
they were in a more difficult position with smaller budgets than their US counterparts.
The development budget for the RB178 being just £2.6 Million compared to the $20 Million
development funding that GE and Pratt and Whitney received from the US Dept of Defence.
Instead of designing a finalised engine, rolls developed their engines in stages so there
would be varying power outputs up to the specified final product. This continuous development
work meant that a large number of people were involved with the project as it went on and
at its peak, 770 people worked on the design. This also created lots of expensive stock
and spares which had to be managed and stored as changes to any part could happen at almost
anytime during the development process. The US firms also had much greater running
experience with the US airline, something that Rolls normally got with Military contracts
and testing programs first but these engines would go straight to the civilian sector.
In the UK the RAF didn’t get their first RB211’s until 1983 and they were secondhand
ones from British Airways. Rolls lost out to Pratt and Whitney when Boeing
refused to use the RB178 for their Boeing 747. This led the cancellation of the RB178
but in its place they came up with the A.T.E or Advanced Technology Engine family that
would go from the RB203 with 10,000 lb thrust to the RB207 at 60,000 lbs of thrust for the
Airbus A300. But another blow came when the UK pulled out
of the Airbus programme leading to the cancellation of the RB207 which was dropped in favour of
the smaller RB211 and it was this engine that Rolls targeted the Lockheed Tristar with.
Lockheed could see that the RB211 would be a superior engine and give them the edge over
the very similar Douglas DC-10. In 1968 Rolls agreed on a performance guarantee with Lockheed
that the new engine would be delivered by September 1971 and would produce a stated
42,000 lb thrust even though the new engine only existed on paper and they knew the issues
around launching a new engine with untried technology.
Rolls soon found themselves in a difficult position, everything about the RB211 was bigger
than they had ever dealt with before, the fan was over 7ft or 2.1M across, as were the
casings and rings on an equally large size. The operating temperatures and pressures were
also higher than anything they had done before. One of the main features of this engine was
the Carbon-fibre Hyfil fan blades, these would be considerably lighter than titanium ones,
this also translated into a lighter hub, bearings and frame. But this new technology had cost
a huge amount of money not only to develop but also to make the tooling for mass production.
In tests, the new blades worked well but when it came to the obligatory birdstrike test,
when 4lb chickens from the local supermarket were fired at high speed into the blades at
takeoff speed, the resin on the thin leading edge of the blades failed.
In a stroke, the power to weight ratio advantage against the competition that the Hyfil blades
gave was wiped out and so was the time and money that had been invested.
As a fall back, Rolls had also developed titanium blades for such an eventuality but even here
there here problems. The Derby factory where the RB211 was being developed had pioneered
air-cooled turbine blades for the Conway bypass jet in the mid 1950s.
These were forged from nimonic high nickel alloys which would keep most of their strength
up to 900C. In the Conway, peak gas temperature was 1100C so the cooling holes would need
to keep them 200C cooler than the surrounding gas but in the RB211 the gas temperature would
be 1250C, which at first doesn’t look much of an increase but the strength of the blade
decreased by 25% for each 25C over 1100C. Making the blades was also very costly and
an engineers nightmare. Each blade would be made from a rough bar which then had many
small but long cooling holes drilled in them. This rough blank would then be heated till
it was white-hot and squeezed between two dies to achieve the final shape.
They would then be machined to the precisely correct size and profile but microscopic variations
in the cooling hole size between different blades would cause uneven cooling.
At Bristol Siddeley, they had stopped making forged blades in 1960 in favour of cast ones
using materials that were stronger than nimonics and too hard to be forged or machined. They
could produce blades with mirror finish that only required machining of the root using
lost wax casting , a technique for making precision casts that dates back thousands
of years. This is where the top engineers come in, these
highly skilled people sometimes moved from one company to another and were in great demand
like Stanley Hooker. Hooker had started at Rolls in 1938 and worked on all of the major
Rolls engines of the war. He then went to Bristol Siddeley before retiring but he was
coaxed out of retirement when Rolls bought out Bristol Siddeley to help sort out the
RB211. However, things at Rolls were about to get
a lot worse, the 3 spool design had problems with oil leaks and bearing failures but it
was when the RB211 was first run they came into sharp focus. The performance was way
down on from what it was expected to be coming in at just 34,000lb thrust instead of the
guaranteed 42,000. When Hooker looked at the engine he found
that the HP turbine efficiency was very low at 65% and the speed of the three spools was
way off the design values. These are things that should not been allowed to happen but
in 1967 Rolls had lost one of the best troubleshooting engineers in the world with the death of Alan
Lombard, without his leadership the project was coming apart at the seams.
Development costs had doubled to £170M from the original estimate and the cost of making
each engine was more than their sale price of £230,000.
Hooker set to work at fixing the issues and within a matter of weeks had not only regained
the missing performance but been able to go way beyond it.
In February 1971 just before the engine could be put on test, the shock announcement came
that Rolls Royce was insolvent. After years of huge outgoings on the RB211 and no sales
because of delays, it had broken the company. As Stanley Hooker said, for once the British
government moved at lightning speed to buy Rolls Royce overnight before the creditors
could claim its assets and because of it’s strategic importance but they wouldn’t buy
the RB211 and neither would anyone else but the engine itself well on its way to achieving
its stated performance and more. Lockheeds boss, Dan Haughton, who had refused
to change the contact before to help out Rolls was now in a bad situation himself because
if they couldn’t get the engines, the Tristar project and Lockheed itself was in danger
of collapsing. The UK government put pressure on the US government
to guarantee bank loans to Lockheed to keep it from going bust. A new contract with Lockheed
was negotiated with the penalties for late delivery dropped and the price per engine
went up by £110,000 each Hooker was appointed technical Director and
brought in a team of retired engineers from Rolls Royces past including Cyril Lovesey
and Arthur Rubbra both of whom were over 70 to use their vast experience which dated back
to the Merlin days to make the RB211 reliable and producible in numbers and keep the cost
under control. Hooker was also given the power to bring in
the best engineers as he saw fit from other engine projects which totally transformed
the RB211 program. The first RB211 was certified on April 14th
1972 and the first Tristar entered service on April 26th 1972, the initial engines still
had teething issues but within a few years a programme of mods made things much better
and the engine became highly reliable. Hooker knew the limitations of the RB211 and
to keep up with the competition started work in 1973 on the RB211-524 with 50,000lbs thrust
and greater fuel efficiency The efficiency of the new engine was shown
in 1980, when Qantas who had access to all three of the big fan engines said that when
used with the Boeing 747 that it used about 7% less fuel than the JT9D a saving of about
$1 Million per year per aircraft. This was the turnaround for Rolls Royce, the
Engine which had very nearly sunk the business was now becoming a world leader in power and
efficiency. The RB211-535E4, the last of the RB211 line
was the first to be used on the launch of the new Boeing 757 and going into service
in 1983. Many of the RB211-535E4s are still in service
having clocked over 40,000 hours over nine years, more time on the wing without removal
than any other engine, equal to over 18 million miles flown and accounting for 58% of all
the engines fitted to the Boeing 757. From the basis of the RB211 come its spiritual
successor the Trent range of turbofans launched in 1988 which today ranges from 61 to 97,000
lb of thrust. Rolls made the decision to offer an engine
for every large civilian airliner using a common core to keep costs down and they also
became masters of titanium blade manufacturing and now carbon fibre blades, the technology
which let them down at the start of the RB211. Rolls Royce is now the second-largest maker
of turbofans in the world after GE and next up from Pratt & Whitney, a success that was
built on the RB211 and the trials and tribulations that came with its difficult birth, and all
that was down to the determination of the engineers brought back from retirement and
in some cases who spent their final day still at Rolls Royce to make it happen, quite turn
around indeed. So I hope you enjoyed the video and if you
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