in providing for rapid movement of scenery and props were considerable.
There are three common methods of transporting scenery. The first is to provide storage space under the stage and move scenery up by means of hydraulic lifts. The second method is to bring scenery from the wings by means of special trucks. Thirdly, a stage loft can be provided which. used in conjunction with a grid iron, enables scenery to be lifted and
flown into the flies.
In theatres where very elaborate stage productions are presented. a combination of any of these three methods of scene-shifting can be adopted. In addition. a rotating stage may be used to effect very rapid scene-changes.
In the Singapore National Thea. tre, both the first and second methods were found impracticable. Test bores on the site in March 1961 had shown that ground water was present only about five feet below the natural ground level. To construct an under- stage basement with hydraulic eleva. tors would therefore have been pro- hibitively expensive. Similarly, to provide space for scenery-shifting trucks in the wings would have meant extending the overall length of the building further than the site readily allowed.
ery
re-
It was decided therefore to adopt the third method - flying the scen- from an overhead grid iron in conjunction with the 50-ft. volving stage specified in the brief of requirements. In any case, it felt that the weight of the stage with the grid iron system would make it a suitable anchor for the cantilever roof over the auditorium.
Safety
was
An interesting feature of the stage is the safety devices safety cur- tain and fireproof doors which completely seal off the stage from the rest of the building in the event of fire. Sliding steel doors at each side of the stage close automatically if the air temperature around them reaches danger level. The enormous safety curtain between stage and au ditorium weighs 9 tons and the whole equipment, including the weight, 18 tons.
counter-
the
Flanking the stage are, on north side, the stage lighting control
124
room and, on the south, the televi- sion commentary room.
Seating
at
The basic problem with regard to seating was that of reconciling the two main requirements an almost unlimited informal' open-air capacity for occasional mass audiences large-scale productions (such as the much Aneka Ragam Rayat), and a smaller number of fixed seats near enough to the stage and with suf ficiently good acoustic conditions for the more intimate atmosphere of concerts. recitals and plays.
The method of resolving this pro blem has been to provide fixed seat- ing for 3,500 people on terraces im- mediately in front of the stage. As it is envisaged that most of the shows at the theatre will be in the round". a fan-shaped seating arrangement has been adopted so that the audience can be brought as close to the stage. as possible.
For mass audiences, the hillside behind the fixed seating has been cleared and graded to provided ac- commodation (standing room or por- table seating) for an additional 18,500 people, giving a total audience capa. city of 22.000. To give this addi- tional audience an unobstructed view of the stage, and yet at the same time to provide weather protection for the fixed seating. a cantilever roof has been designed. This is an- chored to the stage house and ex- tends 150 ft. over the auditorium. covering the whole fixed-seating area. The auditorium is completely open at the sides and rear.
Acoustics and Sound
was
One of the most vital considera- tions in designing the theatre that of ensuring high-quality acous- tics for every section of the audience (under cover and otherwise) and for every type of performance. To ad- vise on these problems, the services of Mr. Robert Newman of
of Bolt. Beranek and Newman Inc. of New
York. a world authority on the science of acoustics were obtained.
With the main structure of the theatre screening the auditorium from traffic noise, it was considered that, for orchestral performances, a system of wooden acoustic reflectors sus- pended above the stage would effec-
tively distribute the sound through- out the auditorium. For smaller-scale productions. however, banks of the microphones are provided on stage with 150-watt. amplifiers driv- ing multiple loudspeaker units above the proscenium.
One of the inherent difficulties in using amplified and natural sound together in a theatre is that the form- er, which travels almost instantane- ously, reaches the rear part of the audience in advance of the natural sound. producing an irritating echo effect. To eliminate this. an ingenious sound delay system, known as Delay- ed Sound Reinforcement, has been adopted. A mechanism similar to a tape-recorder inserted in the ampli- fying system. enables the amplified sound to be delayed in order synchronise it with the natural sound. The degree of delay is adjustable for cach bank of loudspeakers.
to
For the open-air area behind the auditorium, groups of weatherproof loudspeakers are provided. Both these and the whole sound amplifica- tion system of the theatre are con- trolled from a small booth situated in the middle of the auditorium. At his desk there, the sound engineer at each performance will receive exactly the same quality and volume of sound as the audience and, by a complex system of boosters, mixers, attenua- tors, etc.. will be able to balance the output of the speaker system to give optimum listening conditions for every type of performance.
Ventilation
is semi
of
As the National Theatre open-air, there was no question air-conditioning the auditorium. In- stead, a forced-ventilation system has been installed, Powerful fan units draw in fresh air from roof level and blow it into the auditorium and stage area. If. in the future. it is ever decided to enclose the open sides of the auditorium. this ventilation sys- tem can quickly be adapted to pro- vide air-conditioning.
The Structure
In general, the structure of the stagehouse and the adjacent two- storey wings is of reinforced concrete and for the short spanning beams structural steel for the longer beams, interspersed with brick. The cantil- ever roof over the auditorium is of
THE HONG KONG & FAR EAST BUILDER — VÕLUME 18. NUMBER 5
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