We’ve recently installed the mock-up extension of the over-stage reflector canopy to improve the acoustic performance for the extended stage area at the Concert Hall, Hong Kong Cultural Centre.
The Hong Kong Cultural Centre, located on the waterfront of Victoria Harbour in Tsim Sha Tsui, is the prime venue for a variety of cultural activities including world-class concerts, operas, dance, drama, theatre and musical productions, film screenings, conventions, conferences and exhibitions. Since its grand opening on 8 November 1989, the Hong Kong Cultural Centre has remained the premier cultural venue offering stimulating environment for arts talents and quality programmes to the public, and has since been witnessing the development of the arts in Hong Kong.
To cater for performing arts of all variety, the Centre is designed to house 3 major performing halls, namely the Concert Hall, the Grand Theatre and the Studio Theatre. There is also an Exhibition Gallery and 4 foyer exhibition areas. Other ancillary facilities include 11 rehearsal and practice rooms and 2 conference rooms.
The 2,019-seat oval-shape Concert Hall is designed for any kind of music performances. The hall is finished in high quality oak and fitted with adjustable acoustic canopy to ensure quality acoustics effect.
In order to improve the acoustic performance of the concert hall, the Leisure and Cultural Services Department, Hong Kong Special Administrative Region Government (LCSD) commissioned Ove Arup & Partners Hong Kong Ltd (Arup) as the acoustic adviser and structure adviser to study the hall’s acoustics and produce recommendations for how the hall could be improved. Arup investigated potential improvements and advised to build a mock-up extension of sound reflective over-stage reflector to cover the extended downstage area to enhance additional reflection. James Law Cybertecture International Holding Limited (Cybertecture) was appointed as the Architect of this project.
On 24 June 2013, LCSD appointed Macostar Hong Kong Ltd (Macostar) to provide system engineering, detail design and construction of the Concert Hall’s mock-up over-stage reflector with Arup and Cybertecture’s design requirements and specifications.
Macostar is a stage lighting and machinery system specialist in Hong Kong, and has been involved in a number of stage-related projects with LCSD including the Centre’s chain hoist system at the Grand Theatre back in 2011, but the Concert Hall’s new mock-up reflector canopy is a different challenge.
The Centre is well-known for being one of the busiest performing venues in Hong Kong with a wide range of performances packed all year round. Due to a very tight booking schedule, the new reflector canopy had to be ready by 14 August 2013 for the next venue user. Macostar had to work out an engineering design solution, to source all necessary components, controlling equipment and safety devices of the suspension system, and to build this motorised canopy within 52 days.
This 15m wide, crescent moon-shape acoustic canopy comprises a space frame made up of 2 layers of truss elements, attached with reflector panels and lightings. The associated lifting devices of the canopy include 8 new 1000kg steel frames and lifting hoists at roof walkway, and also 22m long lifting wires to support and stabilise the canopy. The position of the canopy is adjustable (7.5 – 12 metres) to ensure quality acoustics effect, fully covering the extended downstage area of the hall’s 290m² stage platform.
The new canopy would replace the existing downstage single bar lighting truss as well as its motorised hoisting system, which only had 4 rigging points to support its linear bar construction. Allowable load of the new canopy (8,000kg) would be 4 times that of the old system. Macostar needed to re-design the hoisting system with stronger custom-built steel frames and 4 new rigging points at the roof walkway to support and stabilise the new canopy. CM Loadstar D8 Electric Chain Hoists were chosen as the lifting devices for their great features such as precision helical gearing for quieter operation, and overload protector to prevent lifting of excessive overloads.
As the linear, permanent load structure are more commonly used for the stage lighting system in most performance venues in Hong Kong, Macostar needed a technical, stage safety solution for the canopy’s multi-point lifting structure, and selected Eilon Engineering’s Ron StageMaster 5000 Single Wire — a multi load-cell, stage safety device for load control and overload prevention. The safety system is laptop-based with a real-time monitor of load-map that can be overlaid on stage-plan layout (e.g. AutoCAD) and can enable monitoring all the loads during installation, as well as during the canopy’s intended life. The system is also connected with a Kinesys DHC-8-HC DigiHoist controller — a linkable, fixed speed digital controller with safety group halt functionality built in — and a custom-made touchscreen control pendant, which provides information on the acoustic canopy’s current position and load of each hoist along with the target position for the particular cue being displayed.
Macostar also worked with Italian aluminium truss manufacturer LITEC to make a QX30S square-type truss system for the canopy’s upper layer: the metallic space frame structure, and the lower layer: black trusses for performance lightings. QX30S was chosen for its compact size, light weight, and excellent performance with high-load bearing and twisting strength. As the Litec team could also offer tailor-made trusses and cross fittings to give the structure strength and offer versatility in the assembly of corners and joints, therefore fewer truss components were required for the intended architecture. The metallic space frame became less cluttered, and aesthetically looked even more elegant and refined.
The metallic space frame was then fitted with 16 flat wood panels and 10 15°-curved acrylic panels. These reflector panels were specially designed as they needed to be sturdy, rigid and firm, and made of materials that are non-resonant, non-combustible and shall have sufficient internal damping to avoid ringing on impact.
As the new acoustic canopy replaced the existing downstage lighting truss, the overall lighting system has been adjusted to provide better illumination for concert performances. Macostar selected 27 ETC Source Fours as the canopy’s performance lighting fixtures to provide bright white beams and clear pattern projections. 40 Starlux surface mounted downlights were also installed as architectural lighting.
This new mock-up canopy serves to collect valuable data in developing a design for a permanent extension to be constructed in later years, and remains to be the Concert Hall’s sound improving feature until September 2015.
For more photos and details about this project, visit our showcase page.
