Rolls-Royce Derby birthplace of the Merlin

As a consultant I usually get to work on several diverse projects every year. It’s daunting, but always interesting to see the different locations and I always ensure I do a site visit. It’s fascinating to see the way different organisations work.

Recently I had a tour around a speciality chemical plant. It was amazing to see parts of the manufacturing site, some were like a scene from some post-apocalyptic sci-fi film. Sadly, no cameras were allowed so you’ll have to use your own imagination.

My current project is at Rolls-Royce in Derby. What an amazing place. For somebody like me, interested in architecture and military history it’s like a living in a museum. Not only that, as a Mancunian there is the obvious link (Mr Royce and Mr Rolls) but also as an aviation enthusiast it’s the birthplace of some of the greatest aero engines and in particular, arguably the most famous engine ever built, the mighty Rolls-Royce Merlin.

I was over the moon to find out that onsite there are private museums showcasing the evolution, or more appropriately revolution, in aero engines. I couldn’t wait to get in and have a look.

But before I start, a bit of an introduction to Rolls-Royce.

Everybody on this earth has heard of them, but probably most of us actually know very little about Rolls-Royce. Contrary to popular belief neither Rolls nor Royce were from Manchester.

royceHenry Royce was born near Peterborough in 1863 and worked as an engineer in his home town, London, Leeds, and Liverpool before setting up an electrical fittings manufacturers in Hulme, Manchester. The company developed into electrical crane construction with a factory in Trafford Park also in Manchester, and where he became interested in cars. He bought a couple of French cars which he improved upon before making his own cars in 1904.

rolls1Charles Rolls was an aristocrat born in London in 1877, but with a strong Welsh heritage. A keen exponent of early motor transport he bought his first car in 1896 at the age of 18 whilst still at Cambridge University. Allegedly, it was the first car based in Cambridge and one of the first in Wales. After University he worked in shipping and railways before setting up in 1903, with a loan from his father, one of Britain’s first car dealerships importing and selling French vehicles.

Royce was introduced to Rolls by Henry Edmunds, a director in Royce’s company and a fellow racing enthusiast of Rolls. The meeting famously (though perhaps historically inaccurately- see link below) took place on 4 May 1904 in Manchester’s Midland Hotel. The pair got on well, Rolls was impressed by Royce’s car and agreed to take all the vehicles Royce could produce which would be sold under the badge Rolls-Royce. The Rolls-Royce company was formalised in 1906 and within a few years were receiving accolades and winning awards for the engineering quality and reliability of their cars.

Rolls was a wealthy playboy, he’d been a cycling champion at university, as a motoring enthusiast he had broken the world land speed record in 1903, and he was an early aviation pioneer. Initially in balloons, he was the second Englishman ever to go up in a powered aeroplane on 8 October 1908 piloted by Wilbur Wright, after which he soon bought his own Wright Flyer aeroplane.

He, unsuccessfully, tried to persuade Royce to start producing aeroplane engines and by the end of 1909 had lost interest in Rolls-Royce, stepping down to become a non-executive director. He continued with his new passion for flying, in March 1910 he became only the second person licensed to fly an aeroplane and in June 1910 became the first man to make a non-stop double crossing of the English Channel.

He was sadly killed the following month, aged only 32, when he crashed his Wright Flyer while performing in a flying display near Bournemouth. He has the unfortunate accolade of being the first British fatality in a powered aviation incident and only the eleventh globally. However, his name lives on for the right reasons, it will forever be associated with quality, innovation, excellence and prestige.

Roll’s Wright Flyer wreckage at Bournemouth

In the mean time, despite ill health, Royce had overseen the development of Rolls-Royce which had gone from strength to strength. They had outgrown their site in Trafford Park and after considering alternative sites in Manchester, Bradford, Coventry and Leicester were lured to Derby. Their purpose-built factory, partly designed by Royce himself, began production in 1908. A huge office complex known as the Commercial Block on Nightingale Road in Osmaston south of the city centre was added in 1912.

During WW1 under pressure from the British Government, Rolls-Royce agreed to produce fifty V8 aero engines under licence from Renault. This was quickly followed in January 1915 by a request for the design and development of a new aero engine. Royce designed an engine based on the 6 cylinder 7.4 litre 40/50 engine of their successful Silver Ghost car. Known as the Eagle, the 250hp, V12 20 litre engine was ready for testing within 6 months and undergoing flying trials in a Handley Page O/100 heavy bomber by the end of the year. It was the start of a lineage of great aero engines that continues to this day.

Rolls-Royce Eagle (Rolls-Royce Learning and Development Centre)
Handley Page O/100

The Eagle was even developed into the successful but simpler Hawk by using a single bank of six pistons. Anyway, the Eagle went on to power a range of aeroplanes and tanks during WW1.

Rolls-Royce Hawk (Rolls-Royce Learning and Development Centre)

After the war Eagle engines famously powered the record-breaking flights using Vickers Vimys of (Mancunian) Alcock and Brown on their first ever non-stop transatlantic flight in 1919 and the Australian brothers Ross and Keith Smith who made the first flight from England to Australia in the same year.

Alcock & Brown’s Vickers Vimy

Development of the Eagle continued, evolving into ever more powerful engines and remained in production until 1928. Even by the end of WW1 Rolls-Royce were producing a range of successful engines and with the growing demand for aero engines the Derby site had to be extended to cope. By the end of the 1920’s most of Rolls-Royce’s business was for aero engines.

During this time the Eagle was re-designed into the successful inter-war 700hp, V12 22 litre Kestrel which was used for many different aeroplanes including some German prototypes. The classic profile and distinctive twin bank of pistons in the classic ‘V’ configuration,  instantly recognizable, was born.

Rolls-Royce Kestrel (Rolls-Royce Learning and Development Centre)

Further developments of the Kestrel resulted in the 800hp, V12 21 litre Peregrine, the 1750hp, X24 42 litre Vulture, which was basically two Peregrines bolted together sharing the same crankshaft. Neither engine was a success and though the Vulture powered the poorly performing RAF twin-engined bomber the Avro Manchester, engine construction for both the Peregrine and the Vulture was cancelled after a short production run. Around about the same time Rolls-Royce produced the powerful ‘R’ engine solely to power the Supermarine S6B in the Schneider air races.

Rolls-Royce Peregrine (Rolls-Royce Heritage Centre)
Avro Manchester – Note the twin exhausts required for Vulture X-24 engines (Wikipedia photo)

However, Royce’s foresight saw the need for an intermediate sized engine between the Peregrine and the Vulture and so in 1932, without any government funding, started development of the PV-12 (PV = Private Venture). Like its predecessor the Kestrel, it was a cast block inline V12 piston engine but 1100hp and 27 litres. Sadly, Henry Royce died in 1933 and neither saw the development and success of his engine nor the hugely significant place it has in England’s history.

The first engine runs of the PV-12 were just a few short months after Royce’s death and by 1935 it was undergoing flight tests. Initial problems with an evaporative cooling system was overcome by conversion to a conventional liquid cooling system using ethylene glycol and better performance was achieved using the latest 100 octane fuels. Flight tests continued, eventually using the flexible Heinkel He 70 high performance passenger aeroplane that had previously been used to test the Kestrel engine.

he rr
Heinkel He 70 engine test bed

By 1936 the Air Ministry had a requirement for a new fighter aeroplane with a requirement for speeds of over 300mph. The 800hp Peregrine was underpowered and neither was the Vulture suitable. But the PV-12, renamed to the Merlin, fitted the bill perfectly and government funding quickly followed.

merlin mk1
Cut-away Rolls-Royce Merlin mk.1 (Rolls-Royce Learning and Development Centre)

Over 30 prototype Merlins developing 1035hp were built, but the early production versions proved unreliable. Rolls-Royce introduced an ambitious reliability-improvement programme to rectify the issues. They selected engines from the assembly line and tested them continuously at full power until they failed. Each was then dismantled to find the components that had failed, which were then redesigned to be stronger. The programme lasted 2 years by which time the Merlin was one of the most reliable aero engines in the world.

merlin mk3
Rolls-Royce Merlin mk.3 (Rolls-Royce Heritage Centre)

Many of the most famous British WW2 aeroplanes were fitted with the Merlin. Most notably the Spitfire, Hurricane, and Mosquito. Interestingly, the failed Manchester bomber had its two Vulture engines replaced with four Merlins and it was turned into undoubtedly the best and most famous bomber of the Second World War – the Avro Lancaster.

merlin mk24
Rolls-Royce Merlin mk.24 (Rolls-Royce Heritage Centre)

Shortly before the war the Commercial Block underwent a major refurbishment. The main entrance was moved from the northern end of the building and the central section was replaced with a superb art-deco entrance known as the Marble Hall. Its stone frontage included a balcony and the interior was adorned with Tuscan columns and polished limestone with a magnificent double staircase leading up to the first floor.

nightingale rd
The Commercial Block, Nightingale Rd, Osmaston, Derby – The Marble Hall in the centre

Ernest Hives, the Rolls-Royce factory manager realised that a war was imminent and in order to ensure they could supply the demands for Merlin engines he created a series of shadow factories with their own Merlin Production lines in Manchester, Crewe, and Glasgow. Additional Merlins were also built under licence in America and known as Packard Merlins.

As great as the Merlin was, it wasn’t without issues. In early aerial combat there was a problem with the aeroplane when it went into a powered dive from level, or when levelling off after a powered ascent. The negative G-force of this pushing over or so-called ‘bunt’ manoeuvre caused a fuel starvation followed by a surge of fuel to the carburettors resulting in a loss of power or even engine stall. This was disastrous when attacking enemy aircraft as they could make good their escape. The same issue wasn’t a problem for German fighter aeroplanes as they had a more complicated direct fuel injection system and knowing the problem with the Merlin’s their pilots would often use a negative G evasive manoeuvre when being chased.

Rolls-Royce Merlin mk.1 Supercharger and twin carburetors (Rolls-Royce Learning and Development Centre)

However, the issue could be catastrophic when being chased by a German aircraft. The loss of power made them easier targets and reduced their manoeuvrability until power was regained. Combat pilots with Merlin’s quickly learned to do a half roll before any manoeuvre that could have induced negative G and thus maintained a constant fuel supply to the carburettors.

An interim solution (but too late for the Battle of Britain) came from an unlikely source. Beatrice (Tilly) Shilling was an aeronautical engineer who had studied at Manchester University and worked for the Royal Aeronautical Establishment (RAE). Beatrice who raced both motorbikes and cars came up with a simple restrictor or baffle that allowed just enough fuel through the carburettor. Her device, which was not much more than a washer, proved to be a low cost quick to implement solution that did not require the aeroplanes being taken out of service. It was installed in all Fighter Command aeroplanes by March 1941 and well received by the pilots who affectionately referred to the modification as ‘Miss Shillings orifice’ or simply ‘Tilly’s orifice’. Its official name was the RAE Restrictor. By 1943 the problem was finally overcome with the introduction of sophisticated pressure carburettors that enabled negative G and full inverted flight manoeuvres.

Beatrice (Tilly) Shilling (

Development of the Merlin continued throughout the war and by its end the latest Merlin’s were rated at over 2000hp. Production stopped in 1956 and around 160,000 had been produced. Many are still flying in historic Spitfires Hurricanes, and the of course in the last airworthy Lancaster in Britain. The noise they make is incomparably beautifully distinctive.

One Lancaster, 3 Spitfires, and a Hurricane but 8 Merlins: what a beautiful noise

There are also lots of static display examples and many running examples with zero pitch shortened propellers. The legend Guy Martin famously has one, and recently in conversation with my friend Pete Rowbotham he nonchalantly mentioned that he had got one as well. Joy o joy, but that’s the subject of a later blog.

Throughout and after the war engine development continued. The Merlin morphed into the Griffon which had about the same power but was slower revving. It powered later Spitfires and the iconic Shackleton, the grandchild of the Lancaster bomber.

Rolls-Royce Griffon (Rolls-Royce Heritage Centre)
Avro Shackleton MR3 – Newark Air Museum

The Derby factory had been targeted several times during the war. Although there are nine recorded air raids on the factory there was only one that hit the aero engine factory. It took place on 27 July 1942 when a solitary Dornier 217 dropped four bombs around Nightingale Road. Only one hit the Rolls-Royce factory, it went through the roof of the central stores and exploded in the adjacent steel store destroying the building. Houses in he nearby Hawthorn Street were badly damaged, and the other bombs exploded in Hawthorn Street, Abingdon Street and Handel Street. Twelve people were killed in the factory and eleven civilians in the neighbouring streets. A memorial plaque commemorates the event in a small memorial garden behind the Nightingale Road offices.

By 1946 aircraft engine production was so key to Rolls-Royce in Derby that car production was moved to the Crewe factory. It was never to move back and (though now a separate company) remains in Crewe to this day.

Marble Hall stairway

On 11 January 1949 the huge main window on the elegant stairway of the Marble Hall of the Commercial Block in Nightingale Road was replaced with a magnificently spectacular stained-glass masterpiece to commemorate the pilots who flew in the Battle of Britain (in 1940) using the engines produced in the factory. The opening ceremony was attended, amongst others, by Marshal of the Royal Air Force Arthur Tedder, M.D. of Rolls-Royce Ernest Hives, and various dignitaries including the famous pilot Douglas Bader. The succinct inscription on the window states “This window commemorates the pilots of the Royal Air Force who in the Battle of Britain turned the work of our hands into the salvation of our country”.

Marble Hall stained-glass window

The window remained in the Marble Hall until 2007 when the Nightingale Road factory site was closed. The window was removed, restored, and re-dedicated and is now displayed in the nearby Rolls-Royce Learning and Development Centre. Thankfully, the building is Grade II listed and has been preserved and refurbished and a replica windows installed in the original position. Sadly, the historic manufacturing sheds depicted in the stained-glass, that would have been behind it, have all now been demolished and will soon be a housing estate.

Rolls-Royce continued innovating with aero-engines. There was also of course the development of jet engines for which the names (initially) changed from the birds of prey used for their piston engines to rivers and using an RB designation derived from the R of Rolls-Royce and B from Barnoldswick -the birthplace of the British jet engine. Britain’s first production jet engine was the Gas Turbine Turbojet the Rolls-Royce RB.23 Welland which was a development of the engine designed by Frank Whittle (in Barnoldswick) and was used in the successful Meteor aircraft. This was followed by a succession of Gas Turbine Turbojet, Turbofan, Turboprop, and Turboshaft (helicopter) engines continuing up to the present day. The currently produced Trent range of Turbofan engines power some on the most iconic modern aircraft and it is said that a Rolls-Royce powered aeroplane lands or takes off every 25 seconds.

Jet 1

A brief historic summary of the most noteworthy aviation jet engines follows below, and this doesn’t include any joint ventures with other aero-engine manufacturers, marine, vehicle, missile, or rocket engines.

The Rolls-Royce story seems like an unbelievable fairy story of success. But it isn’t the case. The RB211 listed above almost bankrupted the company. By 1967 Rolls-Royce were offering the new and sophisticated engine which incorporated revolutionary materials and technology with a very competitive power to weight ratio.

Rolls-Royce RB211

Ballooning development costs and technical problems from changing demands and the drive for lower costs from the aircraft manufactures resulted in Rolls-Royce entering into receivership in early 1971. Devastating for the company and local communities that depended on it. But, it was also a turning point, the start of a bright new future.

Because of Rolls-Royce’s global importance the company was nationalised to safeguard the completion of the RB.211 program which was certified and in use by April 1972. The car division was de-merged and sold off by the Government in 1973 as Rolls-Royce Motors, since when it has remained a completely and un-related company passing through several owners to the present owners BMW.

Following continual development of the RB.211 it has become a reliable, economic and ubiquitous engine, the benchmark for all turbofan aero engines. In fact, the current Rolls-Royce aero-engine product line, the Trent, are all developed from the RB.211 – a staggering lineage of more than 50 years.

Rolls-Royce Trent Engines

Rolls-Royce was re-privatised in 1987 and today has around 40,000 employees in almost 50 countries. Their presence in Derby can be seen all over the town. Sadly, the original build sheds behind the Commercial Block on Nightingale Road have all gone, but apart from the Commercial Block and Marble Hall may other thought-provoking old buildings still remain in use interspersed with high-tech modern development and production facilities.

However, as I mentioned at the start of this blog, there are two internal museums showing the history of Rolls-Royce and the lineage of their aero-engines from the earliest piston-engined Eagle through the iconic and historic Merlin, to the ground-breaking turbojets like the Conway, through to the RB.211 and modern Trent turbofans.

The smaller Rolls-Royce Learning and Development Centre museum houses a range of aero, ground, helicopter, and marine Rolls-Royce engines and is the current home of the restored original stained-glass window from the Marble Hall. There are also portraits of Mr Rolls and Mr Royce.

Rolls-Royce Learning and Development Centre

The other on-site museum, the Rolls-Royce Heritage Centre contains a huge display of Rolls-Royce engines including jet engines together with other significant competitor aero-engines such as radial piston engines and WW2 German piston and rocket engines. There is also an interesting space technology display and also a beautiful little model of the Marble Hall and stained-glass memorial window.

Rolls-Royce Heritage Centre
MH model
Marble Hall stained glass window model

The Rolls-Royce Heritage Centre also contains statuses of not only Rolls and Royce but also of the managing director Ernest Hives who not only managed the company but was also significant in the development of many of the iconic aero-engines, not least of all the Merlin.


There is also a life-size statue of Henry Royce standing atop a plinth in the grounds of the Rolls-Royce Campus, part way between the museums. It contains the inscription “Whatever is rightly done, however humble, is noble.”

rolls statue

RR piston
Rolls-Royce Piston Engines
RR jet
Rolls-Royce Jet Engines

Jet 1

Jet 2

jet 3

jet 4

jet 5

jet 6

jet 7

jet 8

jet 9

jet 10


Special thanks to Rolls-Royce for their hospitality and for allowing me access and to take and use the photos in this blog.

Rolls-Royce Official site


Rolls-Royce Merlin Variants

Guy Martin’s Merlin

Another Manchester myth shattered: Mr Rolls and Mr Royce probably didn’t meet at the Midland Hotel

Ross & Keith Smith Vickers Vimy & the 1919 England to Australia Air Race

Rolls-Royce’ Marble Hall Virtual Tour

Rolls-Royce Air Raid 27 July 1942

Rolls-Royce RB Designations

Rolls-Royce Gas Turbine engines

RB211…The engine that broke and made Rolls-Royce!

Daring Aviator Dashed to Death

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