The problem of mowing uneven ground is an old one for turf managers. However, in some respects, it is even more serious now than in times past. As mower manufacturers have enlarged mowing decks to increase production, the machines' ability to deal with contours has decreased. Meanwhile, architects increasingly are incorporating hilly ground into their designs. This is especially true of golf-course architects, who lately seem to be fond of putting large moguls in rough areas.
The problem with many large mowers is that wide, rigid decks can bridge a valley (scalping the edges of the cutting swath) or scalp a high spot (leaving the edges of the swath too long and the middle too low). Therefore, the best way to mow highly uneven ground is with small, independent cutting units. Historically, walk-behind "trim" mowers have been a turf manager's only truly good option for the best quality of cut on uneven ground with high-cut turf. Of course, mowing turf 20 or 22 inches at a pass is a costly, labor-intensive process, so even that is not such a good option.
Compounding the problem are heightened standards of appearance for golf courses. Today, many golfers expect courses to have a "wall-to-wall" manicured look, including roughs. As Peter Whurr, director of product management at Ransomes Textron observes, "Everything else is finished out great-greens, tees, fairways-so the problems are in surrounding roughs. The customer is now looking for finished roughs. That's how high expectations are getting." This creates a greater challenge for superintendents than ever before. However, if superintendents have an effective way to mow roughs, they can "mix and match everything on the golf course to please the golfer, and manicure the rough to the same level as everything else," notes Whurr. That's the basis for an emerging new breed of machines: contour mowers.
Fairway reel mowers deal quite well with contours. As we'll see later, that ability is inherent in their design. However, it's only within the last several years that manufacturers have specifically addressed this contour mowing with rotary mowers. LasTec (Indianapolis), a pioneer in the field of contour rotary mowers, released its first model in 1990. Even today just a few manufacturers offer rotary models designed for contours. Aside from LasTec's line (which includes pull-behinds and out-front attachments that work with a variety of tractors, as well as self-contained units), Ransomes offers the AR250 and Toro's Contour 82 is available for its Groundsmaster 3000 tractors (a pull-behind unit will be available later this year). Both of these have been on the market less than 2 years.
What makes a contour mower? To some extent, any mower with multiple cutting heads or decks adjusts to uneven ground because of the movement or "play" that such designs allow. However, the primary aim of most large rotary mowers with multiple decks is to increase production, not deal with contours, and the most efficient way to do that is by adding more large wing decks. Unfortunately, wing decks have the same limitations as any other rigid deck. Therefore, multiple cutting units do not ensure that the mower will follow contours any better. For example, a mower with three 40-inch decks would handle contours better than a single rigid 120-inch cutting unit. However, it would not produce a better cut than a mower with a single 40-inch deck (though it would save time).
Rather, the width of each cutting unit is the most important factor for dealing with contours. More and narrower cutting units allow the mower to follow contours more closely for a smoother overall cut. Of course, each must be able to move independent of the other cutting units.
So why don't all multi-deck rotary mowers have this design? After all, contour mowers perform well on level ground in addition to contours. The answer is not simple. However, it's obvious that increasing the number of cutting units makes a more complex machine. Thus, in situations where contours are not a problem and high production is the primary objective, it makes sense to use a mower with fewer, larger cutting units: it's likely to be less expensive and require less maintenance (fewer blades to sharpen and fewer parts to wear out). In addition, mowers with large, rigid decks can simply be built bigger-they're more productive. But for highly uneven ground, nothing can beat the combination of cut quality and efficiency that you get with contour mowers.
Reel mowers The discussion in the previous section applies mainly to rotary mowers. However, it's important to point out that most fairway mowers, particularly the newer multi-plex reel mowers, certainly qualify as contour mowers. Exact specifications vary between manufacturers, but designs that allow for movement over uneven ground are typical of modern fairway mowers (as well as many other more general-purpose or utility reel mowers). Typical blade widths on fairway mowers are in the range of 22 to 26 inches. Somewhat larger reel widths are available but with correspondingly lower quality of cut, so these tend to be used more in turf that doesn't demand the level of quality of fairways.
Because reel mowers are intended for close-cut turf, and because close-cut turf is more prone to visible scalping than longer turf, manufacturers have always kept reel widths small compared to rotary units. Jeff Laskowski, chief operating officer of LasTec, notes, "It's always been accepted in the industry that reel mowers require smaller widths for greater accuracy. If you came in with a reel several feet wide, people would laugh." For good reason-such a mower would inevitably lead to serious problems. Therefore, as manufacturers created larger reel mowers to increase production, they simply added more reels rather than making reels larger. The net result is ideal for mowing contours: more small cutting heads that produce a good quality of cut even on contours.
Pull-behind reel mowers-"gang" mowers-though giving way to the more-popular self-contained fairway mowers, still are used on many courses and offered by several manufacturers. Many of them have the same contour-friendly qualities as their newer multi-plex relatives. (The reasons for their decreasing popularity stem from factors other than the ability to deal with uneven ground.)
Another reason reel units have been designed with smaller widths is that reels originally were driven by ground contact. This meant that each reel had to be small enough to function on the limited power such a drive could provide. Thus, the history and uses (on shorter turf) of reel mowers has steered them to designs (smaller blade widths) that inherently work better on contours.
Engineering rotaries Because rotaries are used for longer-cut turf which is less prone to visible scalping, the impetus for developing contour mowers has been less intense. Rather, the emphasis historically has been on increasing productivity. According to Laskowski, "The industry standard has been how bad a cut you could live with [for the sake of increased production] rather than how good a cut you could achieve. The largest single deck is 72 inches-three blades and a pan [deck], and just about everybody makes one." Thus, for high-cut turf such as roughs, turf managers had to choose between production and quality of cut on contoured ground.
But that's not the only reason rotary manufacturers were slow to develop contour rotaries. Each separate deck requires its own source of power, and the engineering hasn't been as simple as for ground-contact reel mowers or rigid decks. With one fixed deck you can power all the blades with a simple system of belts. Belts are an efficient way to power cutting units, as evidenced by their popularity with so many manufacturers. But with decks that change position with respect to one another, the engineering challenges are greater. Thus, it took time to develop workable belt drives for articulating decks. Currently, LasTec's line and Toro's 455-D Quadfloat (another "contour" mower, but with relatively wide cutting units of not less than 36 inches) are belt-driven units.
Ransomes' AR250 and Toro's Contour 82 drive each cutting unit with a separate hydraulic motor-which is the other cutting-drive option. Both belt and hydraulic types offer certain advantages. Belt drives are relatively efficient at transmitting power. Further, many people are more comfortable with belts from a maintenance standpoint. And replacing parts can be relatively inexpensive for a system that works with belts and pulleys.
However, driving each blade with its own motor means that each cutting unit can be more independent. The Ransomes AR250 has fully independent decks with no connections or shared chambers. Plus, with hydraulic motors providing power to each blade independently, a problem with one cutting unit does not affect others, unlike a belt problem that could, possibly, affect other cutting units.
How much flex is enough? LasTec mowers offer 12 degrees of movement up or down for each deck. Toro's Contour 82 flexes a full 20 degrees in two planes. Each Ransomes AR250 deck can float up or down as much as 18 inches. How much flexibility is really necessary depends on a number of factors. However, for practical purposes, the amount of articulation in all these contour mower designs is probably enough to accommodate most situations. Laskowski notes that LasTec's largest model, with 12-degrees of articulation up or down, has a 4-foot range of motion (2 feet up or down) at the tip of the outermost decks on its widest unit.
All dimensions are important Most large rotaries employ small, 20- to 22-inch blades so they can increase width without increasing depth. In other words, a single 40-inch blade would require a deck at least that wide in all directions, whereas two 20-inch blades allow you to have a deck that is 40 inches wide but still only 20 inches from front to back (or "bow" to "stern"). That's one reason you see two or three blades under a rigid deck. This allows it to retain some versatility with contours because it is still narrow in one dimension (front to back). This is important because, after all, contours run in all directions. Decks should ideally be as small as practical in all dimensions for the best cut.
However, Toro's Rick Rodier, senior marketing manager of grounds business, explains that another way to improve the quality of cut is to add another dimension of movement. Toro has incorporated this idea into its Contour 82. Not only does the deck flex in the side-to-side dimension, it also pivots front to back, adding still more versatility.
Productivity still matters Though quality of cut is the first aim of contour mowers, productivity still matters. How do contour mowers stack up? Ransomes' unit uses 22-inch blades for each of its five decks, for a total of 98 inches in cutting width. LasTec's blades vary from 21 to 25 inches and the units are three, four or five blades wide (for total cutting widths of 72 to 124 inches). Toro's Contour 82 uses four 22-inch blades for an 82-inch swath. Thus, all three manufacturers provide the narrow blade widths necessary for a good-quality cut with medium-sized cutting swaths. Although the overall widths of contour mowers cannot match the production of large conventional units, by design they provide a better cut than anything else on uneven ground.
According to Toro's Rodier, the industry can expect to see more options and more manufacturers offering contour mowers. Rodier feels that, "while 'revolution' may be too strong of a word, contour mowers definitely will have a significant impact on the industry." Contour mowers, in addition to improving quality on uneven ground, can save time because they can fill the roles that previously required two or three types of mowers, reducing the number of trips with different mowers required to mow a golf hole. For instance, according to Rodier, many superintendents are able to use contour mowers to cut uneven turf such as green surrounds and similar areas. Due to the low cutting height required, reel mowers were a necessity because large rotaries would scalp the turf. With rotary contour mowers less prone to scalping, lower heights are possible just by adjusting the cutting height of the same mower used for roughs.
As you can see, just three manufacturers are providing an impressive diversity of contour-mowing options. And with more options and refinements that inevitably will make their way to the marketplace, contour mowers are assured an important place in the future of the turf industry.
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