when the unit is started

Pairing tradition with technology, groundsmen combine their experience with the latest industry trends to maintain a picturesque turf. Education is a must to keep up with the latest research findings in the business. And, as groundsmen adapt to new turf and grass recommendations, equipment manufacturers try to stay par for par by incorporating new technology in their latest designs of turf maintenance machines.

Of all these turfcare trends, topdressing is one that has been evolving since the early days of golf. What began as a generous aTopdresser1pplication of sand, which was applied only a couple times each year, has developed into a process that is practised much more frequently with a very precise amount of material. Proper equipment is needed to adhere to these recommendations and, fortunately, manufacturers have adapted with the times to maximise the accuracy of their machines, whilst minimising the physical footprint and eliminating unnecessary maintenance. One could say they have the design of topdressers down to a science.

Whilst several types of topdressers are available - from large units capable of tackling par-five fairways to small walk-behind machines - we'll focus on the small towable units. These are large enough to vastly improve efficiency over walk-behind equipment, but are gentle enough to handle topdressing applications on the most precious areas: greens and tees.

On Target

The United States Golf Association (USGA) has been recommending lighter applications of topdressing material and, over there, some groundsmen are spreading sand at less than 1mm. To maintain such a light depth in a uniform application, a topdresser's feed system, gate, spinner and controller all must work together to achieve results that are on target with individual needs.

The traditional method of feeding material to the spinner is a conveyor system. Just as the name hints, a conveyor is used to move material from the hopper, through the gate and onto the spinner. This system works well in high-capacity units, where a wide belt is capable of moving large amounts of material from the hopper. But, where conveyors excel in quantity, they lack in consistency.

Recently, manufacturers have developed auger systems, which feed a more accurate amount of material onto a precise spot on the spinner. With the help of a digital readout, the operator is able to see exactly how many pounds of material he is spreading per minute according to his auger speed setting. This technology has increased in popularity, not only for its consistent, measurable material flow, but also for its ability to handle diverse materials, rather than just pure sand. Since the auger diameter used in these units is typically 150 to 180mm, they don't have the capacity to deliver as much material as large conveyors, though.

Material waste is another important consideration in many new designs. Again, auger feed designs excel in this category, as conveyors have a tendency to drag sand underneath the machine and spill it onto the ground. But, in order to reduce material waste upon startup and shutdown, some manufacturers have developed an automatic procedure for when the unit is turned on and off.

When all topdresser components are shut off at the same time, a build-up of material is typically left on the spinner. Then, when the unit is started, the operator experiences a sudden rush of material that leaves a clump of sand on the ground. To prevent this occurrence, and keep the system cleared at all times, some machines will automatically power up the spinners before the feed system starts, and then shut the spinners off a few seconds after tTopdresser2he material flow stops.

Next, a few spinner enhancements have been developed to help accommodate personal preferences. These include tiltable spinners, which help control how material is propelled into the turf canopy. Also, some designs incorporate spinners with adjustable paddles for further fine-tuning the spread pattern.

Even the gate plays an important part in the feeding process. It helps regulate material flow and, in some topdressers, it can be electronically actuated from the seat of the towing vehicle. The positive locking feature on these electronic units is especially handy for quickly closing and opening the gate when moving from one green to the next. This prevents material from bouncing out during transport.

Regardless of the feed system used, any topdresser can be inhibited by material that lumps together - especially wet sand. This occurrence prevents a consistent flow of material to the spinner, reducing the accuracy for which greenkeepers strive. However, many units now contain vibrators to eliminate the problem by breaking up such material.

Finally, to manage all of these components, controllers have started to become more sophisticated. Like the topdressers themselves, controllers come with varying abilities - from basic to more advanced. The simplest machines may require the operator to make adjustments on the machine itself, which becomes difficult for pinpointing the desired settings. But, by using the latest technology, the operator can mount electronic controls in the towing vehicle and manage each of the components independently from the cab. The industry is beginning to trend toward the technology of independent controls, which allows a topdresser to spread accurately and helps to prevent material waste.