The Royal Festival Hall

The Royal Festival Hall was inaugurated in 1951 as part of the Festival of Britain. The building was widely hailed as a standard-bearer for the new, collective, social Modern architecture. its near-symmetrical massiveness and stand-alone situation linked it still to the nineteenth-century tradition of the grand public building, unlike the frothy exhibition pavilions around it. Alterations and refurbishments have changed the building and its surroundings since then. We present another preview of the book “Modern Theatres”.

The.

Queen’s Hall that had been opened in 1893, seating an audience of 2.500. Located in Langham Place, it became London’s principal concert venue and was home to the Promenade concerts. The hall allegedly had drab décor and cramped seating but superb acoustics; it became known as “the musical centre of the British Empire”. On the night of 10 May 1941, however, just after London Philharmonic Orchestra and the Royal Choral Society had given a concert, there was a heavy air rai, in which the House of Commons and many other buildings were destroyed. An incendiary bomb hit the Queen’s Hall and the auditorium was completely destroyed.

Ion 1943, at the height of the Second World War, Britain’s Royal Society of Arts suggested that an international exhibition be held in 1951 to celebrate the 1851 centenary of the great Exhibition. The post-war Labour government decided to organise an event “as a tonic to the nation”, and the event became known as the Festival of Britain. Festival projects took place throughout the UK but the central focus was London’s South Bank Exhibition near Waterloo. A number of buildings and structures were constructed on the South Bank of the River Thames including the Dome of Discovery, the futristic Skyon  an the Royal Festival Hall. The Festival was regarded as a symbol of the Labour government and the succeeding Conservative government orders the demolition and scrapping of the structurees and displays, all except the Royal Festival Hall.

The Royal Festival Hall was built between 1949-51 by the London County Council and designed by the LCC Architect’s Department, headed since 1946 by the progressive young Scottish architect-planner Robert Matthew. The hall comprised a reinforced concrete frame structure containing a concert hall with over 2,900 seats, raised above the ground, with an open foyer and stairs flowing around and below. The 2,901-seat auditorium at the core of the Royal Festival Hall had been conceived as an egg-in-the-box by the architect and acoustician. The hall could also accommodate a 120 strong orchestra, and a choir of 250 singers as well as an organ. Its prime purpose was for symphony concerts, which is to say that other uses such as speech or amplified music were subordinate to the acoustic requirements for symphonic music.
Unfortunately, the hall became known from its very opening as generally too dry and lacking warmth of sound with a weak bass tone. In retrospect, it seems that the original acoustic designer, Hope Bagenal, had not adequately considered several crucial acoustic design parameters such as an appropriate volume per seat V/N required for a modern concert hall and underestimated the absorption factor provided by an audience. Musicians on the platform also had difficulty hearing themselves and others.

Difficult acoustics

Initial discussions envisaged a reverberation time target of 2.2 seconds matching that of other contemporary successful concert halls and recommended back in 1931 by Bagenal and Wood who were then the established authorities in acoustic design of concert halls.  The hall also suffered mistakes during the construction phase. The original ceiling, which followed a line designed to reflect sound toward the rear of the audience, was initially intended to be of solid plaster 50mm thick which would have provided a considerable mass for the low frequency reverberance, hence giving good bass tone and warmth to the sound. Unfortunately, this thickness was reduced by mistake to 10 to 20mm thickness of plaster. Once completed, the thickness was brought back to the specified 50mm by using lightweight vermiculite plaster instead of the specified material. This mistake was unfortunate as it made the ceiling more absorbent at low frequency than originally intended. Finally, acoustic absorption was scattered across the hall. There was a risk of echoes from the back walls and, consequently, the rear walls of the auditorium also included additional mid-to-high frequency acoustic treatment in the form of cushions stuffed with glass wool on 100mm battens with rockwool in the cavity. On stage, the side wooden screens separating the orchestra from the choir consisted of 10mm thick wooden panels on 100mm battens with acoustic absorption in the air space, making this surface a very good low frequency absorber. All these factors resulted in the notoriously dry acoustic conditions with a reverberation time with an audience down to 1.5 seconds at mid-frequencies and lacking bass tone and warmth.

A noisy surrounding

Reverberation is only one aspect of acoustics: other factors need be considered, such as clarity of sound, loudness and self-hearing for the orchestra.  These factors were also not resolved satisfactorily, further contributing to the poor acoustics of the hall. The original canopy above the orchestra was designed not to obstruct other use requirements, such as the organ for example. The organ consultant required an unobstructed opening for the organ of 18m horizontally by 9m vertically, which meant that the platform (including the choir seats) had to be wider than desirable for orchestral or choir purposes. The other consequence was that the canopy was located partly too high above the orchestra (15m high, above the conductor) and was chiefly designed with the intention to reflect sound towards the audience rather than to the orchestra providing the latter with little feedback. The orchestra therefore did not benefit from early reflections from the canopy, which are required for self-hearing. 

The other important acoustic design consideration in a concert hall is the sound insulation from external noise and vibration events. The egg-in-the-box concept was also influenced by the idea of limiting noise and vibration emanating from the nearby underground and surface railway lines. However, although the hall might be an ‘egg-in-the-box’, it is not a fully-fledged ‘box-in-a-box’ construction, like most modern concert halls located close to railway lines (such as the Bridgewater Hall in Manchester or the more recent Milton Court Concert Hall in London). The proximity of two major sources of noise with above-ground trains on the Hungerford Bridge and underground trains running directly under the building, posed a challenge. The noise from the above-ground trains was measured, resulting in the conclusion that a double leaf concrete envelope construction would be necessary. Walls consisted of two 250 mm thick concrete walls separated by a 300mm air space with absorption in the cavity.  The roof itself consisted of a 150mm thick inner leaf of concrete carried by 600 to 1200mm high sleeper walls (i.e. depending on the camber of the roof) and covered with a 100mm thick reinforced concrete external roof with 50mm glass wool in the cavity. The ground vibrations were also measured and results concluded that the hall did not require modern anti-vibration box-in-box construction. Extra precaution was given, however, to reduce the risk, and the hall was built as high as possible above the ground.

Alterations and Refurbishment

The Hall was substantially altered in 1964 with major changes to the river façade, entrance and foyers. This renovation also introduced an “assisted resonance” system to try and improve the acoustics.  Additional foyers and terraces were added to the building which effectively extended it by 9 m towards the river. An entirely new façade and main entrance were created facing the river. During the first thirty years of its existence the Royal Festival Hall operated in a very traditional manner with the upper level of the foyers opening shortly before the evening performance and closing immediately after the audience departed. In 1983 the Greater London Council (the successor organisation to the London County Council) introduced a radical ‘open foyer’ policy where the foyers were opened to the public all day, every day with exhibitions, lunchtime concerts, informal evening concerts, bars, shops and buffets.   Shortly after that, in 1988 the Festival Hall was designated as a Grade 1 listed building by English Heritage – one of the first ‘post-war modern listings’ in England - in a recognition of its ‘exceptional’ architectural and historic interest.  

The building closed in 2005 for another major (£91 million) refurbishment under architects Allies and Morrison. The river side of the building was changed again with a series of restaurants and cafes being created at low level. For this 2007 refurbishment, the American acousticians, Kirkegaard Associates, were selected to provide the acoustic design input. The ambition was to improve the acoustic conditions of the Royal Festival Hall whilst not altering the architectural effect of the original building. Even so, there were protests, led by the Twentieth Century Society, which objected in particular, to the removal of the original canopy, claiming that the “the architectural consequences of this will be disastrous”. Kirkegaard’s work focused therefore on what was possible, namely to remove the low frequency absorption provided by the lightweight ceiling, strip off any surfaces susceptible to absorption of sound (i.e. absorption on the rear walls, carpet in some areas) and replace it with sound diffusing finishes while redesigning the platform and the canopy. These replacements made the renovation work more difficult due to the presence of asbestos.
A new auditorium ceiling, heavier and denser than the original ceiling, was installed. The ceiling consists of an internal wave form consisting of lightweight glass-reinforced gypsum shells with a 250mm thick layer of plaster and bricks above.  Warm wood panelling was also installed across the hall, rejuvenating the feel of the auditorium and providing the hard surfaces required to increase the reverberance. The original teak floor was reinstated and any carpet replaced by hard floor. The stage was remodelled with a slightly less fan-shaped design and the original canopy was replaced by a small wing-shaped canopy made of modern Nomex material (a flame resistant material used by the US Army during the second Iraq war) stretched over a frame. This contributed greatly to the improvement of the acoustic conditions for the musicians on stage, providing them with self-hearing but also reopening the available volume above the old canopy and hence improving the reverberance thanks to extra volume. The organ itself was also refurbished by its original maker, Harrison & Harrison, its depth reduced by 1.1 m to satisfy architectural and acoustic requirements. A variable acoustic system was also introduced which reduced the reverberance for amplified music events.

Despite all these efforts, however, the reverberance was merely increased to 1.65 seconds, still below the 1.7 originally intended by Hope Bagenal and far from the 2.2 seconds that a modern symphonic concert hall requires. The hall also presents balance problems in some parts while crispness is at more of a premium than warmth. But there was nevertheless a discernible improvement, and the press and musicians hailed the new acoustics, acclaiming the clear amelioration of the sound quality of the hall which now possesses a new bloom and sound clarity and gives the music room to breathe, providing a fluid procession of solos in the Birtwistle to the dynamism and richness of colours in the Firebird.

Royal Festival Hall - Conclusion

Over 65 years the Royal Festival Hall has grown to be one of the world’s most significant concert halls largely thanks to its geographical location in London. As a hall it has hosted most of the world’s leading orchestras and music ensembles. Musicians and orchestras need to be seen and heard in London; it is important for their reputation to be reviewed by the London critics (alongside those in New York and some other cities).

But the Festival Hall has always been an acoustically flawed hall with too dry an acoustic caused by too short a reverberation time; and even now, despite the many attempts to improve its acoustic performance, it will never be an acoustically great concert hall.  Accordingly, today, in 2017, plans are afoot to create a new Centre for Music for the capital, under the co-sponsorship of the Barbican Centre, the London Symphony Orchestra and the Guildhall School of Music.  The site would be 140-150 London Wall – the Barbican site which currently houses the Museum of London – and at the heart of the new Centre would be an acoustically perfect 1,900 seat concert hall, rectifying at last a deficiency that has weighed on London concert-goers since the loss of the Queen’s Hall in 1941.