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TENNIS
TECHNOLOGY
Smashing Surfaces
By David LaSota and Sheldon Westervelt, P.E.
Global Sports & Tennis Design Group llc
Racquets aren't the only components to alter the way tennis is played.
Today, the sport's most significant variable is the type of surface
installed.
"With the exception of the tiebreaker, the rules of tennis
have hardly changed over the past 100 years. However, technological
advances in the tennis industry have changed the complexion of the
game dramatically. Advances in everything from racquets and balls
to tennis shoes and court surfacing have made the game significantly
faster and more punishing to the body. The tennis facility developer
must be aware of these changes in order to build the most attractive
and player-friendly court possible.
Today, the game's most significant variable is the type of surface
installed. The type chosen for an outdoor court will depend on a
variety of factors - the amount of play on the court, players' skill
level, the construction budget, the maintenance budget and the physical
limitations of the site. The latter might include climate, irrigation
capabilities and space. These factors should be evaluated prior
to choosing a court surface.
Outdoor tennis courts can be classified into three general surface
categories - grass, clay and hard. Indoor tennis court surfaces
include those used out-of-doors as well as carpet-type prefabricated
systems, clay-like indoor systems using rubber, and rollout playing
surfaces. Each type of surface has advantages and disadvantages,
so a court specifier must weigh the pros and cons of each. Grass
and clay courts are more comfortable for the tennis player but are
more expensive to construct and maintain. Hard-court surfaces are
more economical in both the long and short term, but are more punishing
to the player.
The grass category includes both natural and synthetic grass surfaces.
Natural grass, the original surface used for tennis play, is by
far the most luxurious and is most widely associated with Wimbledon.
Because of the natural resilience of a grass surface, this surface
is very forgiving to the body and comfortable to play. On a well-maintained
surface, glare and dust are nonexistent.
However, the grass surface is expensive to install, costly to maintain
and very vulnerable to weather. Grass courts are slow to dry after
rainfall events, and are very slippery when wet. A grass surface
may also negatively affect play; if not maintained properly, uniform
ball bounce could be compromised by imperfections in the ground.
Installation and maintenance costs are high because of the vulnerability
of natural grass to foot traffic. Tennis matches are typically staggered
on grass courts to provide time for the grass surface to recover
from damage caused by play. As a result, the amount of space (that
is, the number of courts) required for continuous play exceeds that
for other surface types.
Certain manufacturers are producing and marketing a synthetic grass
tennis surface to offer the look of a grass surface while providing
the comfort of a cushioned playing surface. This kind of surface
is typically manufactured with a short-pile synthetic fiber filled
with sand and laid over a shock-absorptive cushioning system. Because
of the artificial nature of this surface, the system can be installed
to provide relatively consistent bounce and cushioned comfort without
the slickness of a natural grass surface. While maintenance costs
are lower than those of natural grass, synthetic-grass installation
can be quite expensive and its life expectancy is somewhat limited.
The expense associated with the installation and maintenance of
traditional grass courts is what initially led to the development
of clay courts as an alternative surface. This category of surfacing
includes local natural clay, fast-dry (granulated stone) and even
ground brick. The early clay court was difficult to play on because
of glare, long drying time and lack of traction when wet However,
at optimum moisture levels, the natural clay surface is the least
demanding on the player. It will provide slide in the player's game,
thereby reducing the transfer of shock in the feet and legs caused
by sudden stops.
Over the past several years, manufacturers have developed an artificial
"quick-dry" or "fast-dry" type of court surfacing.
This surface is composed of a drainage layer under a manufactured-clay
playing surface. The drainage layer improves the drying time of
the playing surface by removing the water from the court by means
of a granular base material and drainage piping. This base course
provides moisture to the fast-dry surface during play. The surface
layer is typically composed of clay, crushed rock, marl (in France
and Switzerland) or ground brick depending on the geographical area
in which the court is constructed.
Because of the fine, granular nature of the fast-dry court, this
surface must be irrigated frequently. Many courts are irrigated
on top of the surface by hand or by above-court sprinkler systems.
New technology in fast-dry court construction provides a surface
that is irrigated from below the surface. Utilizing irrigation piping
below the badly material, the granular base acts as a controlled
water reservoir, using the principles of evaporation and capillary
action to maintain a constant and uniform moisture content in the
surface layer. The irrigation system is equipped with overflow devices
to shed excess water after rainstorms.
The fast-dry court surface is more expensive to install and maintain
than most hard-court surfaces. Regular maintenance is required to
maintain a true and consistent bounce. In some extreme climates,
the irrigation system must be drained over the winter to prevent
freezing and damage to piping.
Hard courts range from asphalt or concrete covered with a color
coating to acrylic, vinyl and rubberized hard-court surfaces. The
type of pavement selected for a hard-court surface will be determined
by evaluating local soils, the water table, cost and site conditions.
An asphalt pavement is most commonly used; however, in extreme cases
where unstable sub-soils are evident, post-tensioned concrete is
used to maintain the structural integrity and planarity of the playing
surface.
Hard courts are typically installed in public parks and other high-traffic
areas where minimum maintenance is a primary concern. They can be
the least expensive type of surface to install and require the least
amount of maintenance.
This surface is, however, the most punishing to the player's body
because of the lack of slide characteristics provided by grass and
clay courts.
In an effort to reduce the shock experienced with hard-court play,
the tennis industry has developed numerous cushioning systems that
are applied directly over the pavement surface prior to coloring
the court. These include granulated rubber, rubber mats, cork and
shredded cane fibers, the installation costs of which vary dramatically.
The advantages of a cushioned hard-court surface include low initial
cost, low maintenance cost, true ball bounce, low glare, quick dry
time and sure footing for the player. There are, of course, disadvantages
to using this type of surface. It retains heat for a longer period
of time, it causes players more foot and leg stress, and is more
prone to damage from misuse. It should also be noted that small
repairs to the surface are not easily hidden.
Indoor tennis courts frequently feature the same surfaces as outdoor
courts. In addition, one of the most predominant indoor surfaces
is the cushioned asphalt subsurface with an acrylic overcoating.
Indoor courts' protection from the elements makes other surface
systems that cannot be used outdoors viable. These are usually prefabricated
surface systems, such as a carpet-type surface that is pre-manufactured
and rolled out on the court surface. Carpet surfaces come in a variety
of styles - smooth, textured or grass-like. Because they are not
subjected to rain, snow and hot and cold temperatures, they can
be manufactured more like carpets, providing a minimal frictional
coefficient between the shoe and the surface. This type of surface
will play more like a natural grass court.
There are also indoor court surface systems that are clay-like in
appearance and playing characteristics. These are composed of synthetic
rubber granules on a carpet-like substrate that tends to resist
the sliding of the granules, thereby producing a slide rather than
a slip.
Some indoor surface systems are manufactured to permit them to be
rolled out for tournament use and then re-rolled and stored, or
moved to another site. These systems tend to be developed to have
specific playing characteristics to satisfy the needs of a specific
tournament or a particular playing requirement. Some of these courts
come already lined, making them available for a quick rollout in
preparation for play.
Many players like the feel of playing tennis on a clay court, even
indoors, and the development of subsurface irrigation systems have
made the use of fast-dry courts more practical for indoor applications.
The benefits of installing fast-dry courts inside include players'
ability to slide and a reduced friction coefficient. However, there
are some drawbacks to using this surface indoors. In an indoor environment,
this surface will react differently than in an outdoor environment.
Ventilation, air flow, heat flow and other factors that affect the
drying of the court surface can often result in non-uniform playing
characteristics on the court surface. Other disadvantages of a fast-dry
indoor court include excess humidity that tends to adversely affect
the structure of the building, the tendency of the surface material
to be tracked through the clubhouse and difficulty in controlling
the amount of moisture on the court surface.
Choosing a court surface really can be a challenge for a tennis
facility developer. Specifiers must look at so many factors - climate,
level and frequency of play, site location and player needs. For
example, if players are accustomed to the comfort and slide of a
clay court surface, a hard court will obviously not be an appropriate
surface for consideration. If water is not available for irrigating
a court, water-dependent systems like grass and clay will not be
an option.
Developers must also consider the style and frequency of play. Remember
that while some surfaces such as grass are beautiful to the eye,
these delicate systems cannot withstand the stress of constant play.
Surfaces in public spaces and parks should be able to withstand
the punishment of skateboards, bikes and in-line skates. When considering
delicate surface systems, make sure to include life-cycle and maintenance
costs in your deliberations. Ultimately, of course, budgetary constraints
will impinge on the type and quality of the system selected.
Additionally, many other details will influence your surface decision
such as court location, orientation, access, sub-surface evaluation,
drainage, lighting and player support facilities. A tennis facility
consultant can help sort through the many surfacing and materials
options, providing valuable guidance about the type of facility
best suited for the anticipated clientele, climate and playing conditions.
A consultant can provide a design that conforms to the rules of
the game while protecting the developer from litigation caused by
unsafe court installations.
It is also important to seek experienced and reputable tennis court
contractors who specialize in the application of the various court
surfaces. While site preparation and installation of support facilities
can be completed by a general contractor, a specialized tennis court
contractor should be used to ensure that court surfaces are constructed
within the tolerances dictated by the tennis industry.
by David LaSota and Sheldon Westervelt, P.E.
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