TENNIS COURTS Their origin, history, testing and description of various types There are many theories as to the origins of tennis but many believe that the early form of tennis can be dated back to the 11th century when monks used to play hand ball around the cloisters of monasteries. The game gradually evolved to the game of Real Tennis, the precursor of the modern game, and became very popular with the French and British nobility. Henry VIII was a keen player and had the original Real Tennis court built at his Palace at Hampton Court but Charles II later re-modelled the court in the 17th century to the court that exists today which is the oldest in Britain. Real Tennis was and still is played on hard surfaces, wood or stone, and it was not until the late 18th century that “Field Tennis” or “Long Tennis” began to evolve on grass courts. It wasn‟t until the Victorian era that the game of Lawn Tennis as we know it today became popular. Major Walter Clopton Wingfield patented his version of the game in 1873. His design of the court was much the same as it is today in terms of marking but the shape of the court was in an hourglass design. The shape of the court was modified in 1875 to today‟s design and official rules of Lawn Tennis were drawn up by Marylebone Cricket Club. Wimbledon‟s All England Croquet Club adopted the sport in 1880 and subsequently changed its name to the All England Lawn Tennis & Croquet Club, home of the Wimbledon Championships. Until the early 1970‟s, the majority of tennis tournaments were played on grass, including three out of the four Grand Slams – Wimbledon Championships, Australian Open and the US Open. Wimbledon is now the only Grand Slam event played on grass, whilst the majority of professional tennis events played on grass take place in England. Clay In 1956 the Gallia Tennis Club in Cannes, France, became the first place in the world to construct a clay court. Clay courts are mainly found in Europe and South America and up until the 1980‟s, virtually all the courts in Spain and Italy were clay courts. The French Open championships at Roland Garros is the only Grand Slam event to be played on clay. Acrylic/Asphalt/Concrete There are two types of hard court: porous and non-porous. They utilise a wide variety of surface textures, colours and names. It was not until the 1940‟s that hard courts were used in official tournaments. The Australian Open and US Open are both played on acrylic courts. Carpet „Carpet‟ is the term used for most synthetic indoor surfaces and the first carpet surface was called „Sportsface‟. In the 1970‟s, „Supreme‟ became the first rubber mat surface to become widely accepted. Synthetic turf is also a surface used in tennis as well as other sports such as hockey and football. The pace of the court can be made faster by adding sand or rubber granular material and the pace depends on the quantities added. SPECIFICATIONS The descriptions in the table below can be cross-referenced with the classified court surfaces to identify the generic court surface type associated with each product in the list. The descriptions relate only to court construction, and not to performance characteristics. Surface code A B C D E F G H J Type Acrylic Artificial Clay Artificial Grass Asphalt Carpet Clay Concrete Grass Other Description Textured, pigmented, resin-bound coating Synthetic surface with the appearance of clay Synthetic surface with the appearance of natural grass Bitumen-bound aggregate Textile or polymeric material supplied in rolls or sheets of finished product Unbound mineral aggregate Cement-bound aggregate Natural grass grown from seed e.g. modular systems (tiles), wood, canvas Notes: All surfaces may be porous or non-porous, with the exception of „Clay‟, which is always porous. Acrylic Normally forms only the uppermost few millimetres of a court. Artificial Clay, Artifical Grass “Appearance” relates only to the form of the surface material and not other characteristics (e.g. colour). Ashphalt, Concrete Used only when the material itself forms the playing surface. When used as a base for other surfaces (e.g. acrylic), reference will be made only to the playing surface. Clay This term denotes a class of surface that is constructed from naturally-derived materials, and include a fine gritty material as the uppermost (playing) layer, e.g. fast-dry. The following tennis court surface products have been classified by the ITF and awarded pace ratings which fall into five categories: - Slow - Medium-Slow - Medium - Medium-Fast - Fast The importance of the court surface to the nature of tennis is the very reason for the proliferation of tennis surface types, which have developed from the early days of the garden lawn. The court influences how the players move around and how the ball bounces. Of all the equipment, it is primarily the court surface that the player must adapt their game to. The limitations provided by varying climate, the seasons and the maintenance demands required to produce a natural turf surface of acceptable quality soon led to alternatives being sought in the form of clay (originally crushed brick), followed by other granular mineral surfaces, cement, asphalt, macadam, and timber. As polymer and material technology has developed in the twentieth century, the introduction of new man-made, synthetic surface types has accelerated: hardcourts with polymer coatings, cushioned coatings, rubberised shock pads, textiles, artificial turf, plastic modular systems, etc. The ITF Court Pace Rating (CPR) measures the effect of ball-surface interaction. This concept includes: friction, which primarily determines the reduction in the horizontal component of post-impact ball velocity; and vertical restitution, which determines the time between successive bounces. CONSTRUCTION A typical South African Tennis Court Excavation The site is surveyed, the court set out, the soil excavated and compacted to the required SABS1200 standards. Edging Lay surrounding drainage channels to define the tennis court edge and lead water off the surface. Sand buffer layer A 100- to 500mm thick sand buffer laid over existing soil, designed to reduce soil movement in soil containing clay properties. Base layer A 100mm thick SABS1200 gravel base, consisting of crushed stone, sieved to specific sizes, providing the structural strength in preparation of the asphalt and latex system. Asphalt surface A 25mm thick SABS1200 hot, premixed asphalt with the same expansion and contraction properties as the latex system. Factory premixed, continuously graded asphalt, designed to seal the base and improve the strength even further. TESTING OF COURTS Apparatus Test apparatus consists of: A means of projecting a ball at the specified speed and angle onto the surface without imparting spin of greater than 3 revolutions per second, such as a compressed air-powered ball cannon. A means of monitoring the trajectory of the ball before and after impact such that its horizontal and vertical speeds can be measured with a maximum uncertainty of ± 0.05 m/s (see figure 2). A minimum of three high-specification balls (see table 1). Note: Angle of travel can be deduced from the vertical and horizontal speeds. Figure 2. Test apparatus for measuring court pace.