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VIBRATORY ROLLERS & GREEN SPEED
The pace of golf greens has never been more central to how
the golfer views the quality a given golf course. Speed is
now demanded instead of craved and the virtue of patience
is now a distant memory of day’s gone bye. Augusta syndrome
is no longer confined to a couple of weeks in April but is
instead culpable for the entire year. Yes, speed is King and
“long live the King”.
So how do we satisfy this thirst for velocity? Lets first
look at what determines the speed of a green…
According to classical mechanics, ball-roll distance relates
to the ball's initial energy when a putter strikes it (or
when you release it from a Stimpmeter) and friction-the resistance
between the ball and the turf surface. As the ball rolls across
the turf surface, the resistance of the putting surface slows
it down. A green with high resistance decreases ball speed
more quickly than a green with low resistance and results
in a shorter ball roll (a slower green). Thus, any management
practice that modifies resistance will subsequently change
green speed (Dr. Roch E. Gaussoin 1999).
There are many ways to decrease the resistance between the
green surface and the ball and thus increase green speed.
Some examples are: Decrease Nitrogen levels which will help
fine down the grass leaf, promote a more upright growth by
regular verti-cutting, use of PGR’s to thicken the turf
canopy, top-dress greens regularly to “fill-in”
any small voids in the turf and of course reduce the cutting
height. Perhaps the simplest and historically the most used
method is to use rollers to smooth the green.
Rolling to increase green speed can be accomplished in a
couple of ways:
Basic Roller
The basic roller consist of a drum of a given weight, which
may vary in diameter, that is rolled across the green to even
out small deviations in the surface of the green. The weight
of the roller will determine the extent to which these deviations
are compressed.
An evolution of the basic roller system is to use several
rollers in train so that for a single pass over the green
the surface may be rolled in multiples determined by the amount
of rollers in use. Examples of this type of roller are the
Greens Iron and the Tru-Turf machines. These are self contained
units with an engine and transmission. They require specific
operator training as they are fairly awkward to maneuver.
The advantage of a system with multiple rollers is that less
passes over the green will be required to increase green speeds.
However, when basic heavy rollers are incorporated to work
within a greens triplex mower, there is some concern over
the strain they cause to the lifting hydraulics which are
designed to lift approx. half the weight of systems such as
the Tru-Turf rollers. Because of their weight they are also
cumbersome to install and remove. Further concerns have been
voiced about legislation concerning manual handling.
Perhaps the single biggest disadvantage regarding the basic
roller configurations is their inability to “vibrate”
top-dressing into the turf canopy. Vibration of sand into
the turf is a recent trend which helps prevent blades being
blunted when cutting through the sand by substituting rolling
instead of cutting in the couple of days after top-dressing
– a very useful compliment to normal rolling.
Vibratory Roller
A vibrating Roller system works by generating vibration through
an offset weight (or weights) placed on a rotating shaft.
As the shaft rotates, energy is transferred back and forth
from one side of the shaft to the other; it is this alternating
shift in weight that creates the vibration. The frequency
of the vibration is determined by the speed of rotation of
the shaft and the force of the vibration is determined by
how heavy the offset weight is.
Rolling greens whilst incorporating vibration has recently
gained acceptance amongst the greenkeeping fraternity. The
dual advantage of increasing green speeds whilst aiding the
incorporation of top-dressing into the turf canopy is seen
as better value for money than a basic roller alone. Another
reason for the upsurge in usage of vibratory rollers is that
their weight is similar to that of a regular greens triplex
cutting unit and therefore does not strain the hydraulic lifting
mechanism on the power unit. Operator training is also not
necessary which implies the scope of personnel able to perform
this task is equivalent to those that can cut the greens;
there bye making it easier to integrate into routine course
maintenance.
One concern of a single drum vibratory roller is the risk
that corrugation of the green surface may occur if the frequency
of vibration is too slow in relation to the speed of the mower
moving across the turf. The average operating speed of a greens
mower is approx. 3 – 4mph. A vibrating roller operating
at a frequency of 83 Hz would equate to an alternating shift
in weight of the rotating shaft at about every 15 –
20 linear mm of travel - this could lead to corrugation problems
depending on the firmness and amount of thatch present in
the green. One way to overcome this is to reduce the mower
speed to reduce the vibration interval and so reduce the linear
distance of force - but this is not maintenance friendly due
to time constraints placed on course managers these days.
A new initiative from TurfWorks International™
is the True Level Vibratory Roller™ system which transfers
its high frequency vibration rate through two rollers instead
of only one. This is the most revolutionary (excuse the pun!)
approach to the use of rollers to help maintain golf greens
in recent years. The designers of this system have cleverly
incorporated the vibration mechanism in a cassette that transfers
its vibration through the systems chassis. The vibration is
transmitted equally through the rear and front rollers which
are both 60mm in diameter. This system consistently beats
the competition at increasing green speeds because of the
dual effect of the high frequency coupled with the twin rollers.
It is also effective in working in top-dressing into the turf
and even has a brush system that can be attached to the vibratory
unit which is very efficient when the sand is slightly damp.
Possibly one of the biggest selling features of this system
is that it takes the cost saving aspect of vibratory rollers
a stage further by negating the need to purchase a separate
cassette maintenance system. The user simply removes the vibration
cassette and swaps it for a verticutter or sarrel roller etc.
The TurfWorks™ System is now available for the discerning
Course Manager who realizes the benefits of the industries
only modular greens maintenance system that incorporates vibration
rolling as part of its extensive maintenance repertoire. For
a modular system that includes a verticutter, Ultra Grooma,
Rotary Brush, scarifier and the patent pending Vibratory cassette
plus many more then contact TurfWorks International™
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