Road Hole Shorts

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Archive for September 18, 2010

The hazards of sand bunkers

By Mary Armstrong/For the Sun-News

Posted: 09/17/2010 12:00:00 AM MDT

Cat box, traps, the beach, kitty litter, whatever you might call them, we all have a love/hate relationship with these pervasive golf hazards. To be accurate, the correct term is sand bunker or just bunker. They’re beautiful, dramatic, strategic and in the final analysis a pain in the you-know-where.

Despite the fact that the prescribed method of playing a greenside bunker shot is precisely to be imprecise — that is to hit the shot “fat”, 99.9% of all novice players struggle to extricate themselves in a single swing.

On the original golf links of Scotland, bunkers were sandy blow-outs. It has been asserted that these blow-outs were the result of over-grazing or repeated bedding by sheep left to roam the links commons. In environs such as the Scottish links lands, these sandy areas were unstable and often “migrated” with the prevailing breeze.

As time passed, the game and the playing surfaces became more organized and it became desirable to maintain a constant layout. As a result, it became desirable to attempt to control these sandy areas. At first, earthen berms or stacked sod walls were tried. If these proved ineffective, wooden bulkheads were installed. But whatever their beginning, they have developed into intricately designed features, requiring careful and sophisticated grading, soil preparation and at times manufactured sand meeting demanding specifications. What you find on the course today aren’t your Grandfather’s bunkers (or your grandmother’s either).

Bunkers are sand-filled depressions. Seems simple enough doesn’t it? And bunkers are hazards. There’s no penalty assigned as there is for hitting into a water hazard. Yet historically, bunkers presented a more difficult playing surface than turf. Today’s Pro’s will often tell you they prefer the predictable lie of a bunker. Nonetheless, as the game has matured, there have been changing attitudes about what constitutes a “fair” bunker. I know, it seems kind of oxymoronic, doesn’t it?Anyway, as far back as the late 1940’s the United States Golf Association (USGA) began advising course managers on the types of sand that would afford a fair test as well as provide a stable, manageable surface.

In 1974, the USGA released bunker guidelines that were based upon their experience, laboratory testing and hands-on efforts.While there are some interesting tidbits I could share on other elements of the design and construction of bunkers I’m going to focus on selecting the proper sand. Fortunately, sand is plentiful. Since the USGA has gone to all the trouble to come up with guidelines, you might have surmised that just any old sand won’t do. How a sand plays — that is, how the material reacts to a shot landing in it and how it performs when a shot is played from it — is perhaps the most critical issue. Particle size is particularly important. When particles are not “graded” — that is, when they are all of similar size — the ball is more likely to plug or produce a “fried egg” lie depending upon the incoming trajectory of the shot. Conversely, properly “graded” sand will have a particle size distribution that will produce a more desirable firmness that can yield a sensation of feel and finesse for skilled players. Properly “graded” bunker sand will also fall into the range specified for the greens construction as well. This will mean that sand blasted onto the green surface will quickly migrate into the green rootzone and won’t overly damage mowing equipment.

Another important factor to the material functioning well within its design is its purity. A sand that is “dirty” contains silt or clay. In sufficient amounts the silt and/or clay will reduce the permeability of the sand, causing it to drain slower, eventually irreparably damaging the bunker drainage system. A course that has a number of bunkers exhibiting this problem probably has “dirty” sand. On the other hand, sand that has excessively large particles or gravel may drain just fine, but is otherwise undesirable to players.  You might think that sand particles are largely round. Think again. True, much of the common desert sand of the world and sand in dunes are round. But the round shape also means that they are relatively unstable and they don’t react well in playability tests. So, an angular sand is most desirable for bunkers. They tend to shift less and also exhibit a sort of “interlocking” characteristic that helps to keep them in place even in windy conditions.There are sands that will come out of the ground suitable for bunkers, but they are rare and some processing — usually in the form of screening or washing is necessary. Because sand is plentiful it is fairly inexpensive as natural resources go. The real cost is in the trucking or shipping of the material. Costs upwards of fifty dollars per cubic yard and sometimes beyond are not unheard of.

With the average course needing more than 1,000 cubic yards just for bunkers you can see that the cost could be substantial.So the next time you curse the course for the inadequacies you perceive in their bunker sand, you might consider that purchasing the proper material, trucking it to the site, removing the old sand, installing new drainage and installing the new sand might well elevate your green fees by more than a few dollars.

A golf architect in New Hampshire for over 20 years, Armstrong brought her craft to Las Cruces last January. She is the founder of Armstrong Golf Architects, which provides planning, designing, permitting and construction monitoring services for golf course projects. You can comment on her writing and view past articles at her blog: https://roadholeshorts17.wordpress.com/.