Achieving bunker consistency is a Herculean task

Golf Course News, Jan 2003 by Ross, Kevin J

Other than the condition of greens, bunkers are the most talked about and controversial area of the golf course. Most of the talk is from golfers, and superintendents have all heard the comments: too soft, too hard, too wet, too dry, too much sand, too little sand, too inconsistent. While bunkers are a hazard, it is up to superintendents to ensure that they are a fair hazard.

The most important part is the sand quality. There are very few places in the United States that have natural sand deposits that meet specifications for great bunker sand. Most premium bunker sand today is manufactured in a few locations across the country. These manufactured sands, along with a few rare natural deposits, make the process of finding great bunker sands very difficult and expensive.

What makes great bunker sand? The United States Golf Association considers seven factors when selecting bunker sand: particle size, particle shape and penetrometer value, crusting potential, chemical reaction and hardness, infiltration rate, color, and overall playing quality. Depending upon your location and climate, how you rank these factors may vary slightly.

However, there does seem to be one common denominator that may be the biggest factor, the fried egg test, or in testing terminology, the Penetrometer value. The penetrometer value measures the energy required to bury a ball in sand. This value shows the ability of sand to resist the golf ball from burying, or in more scientific terms, its resistance to compression.

The penetrometer, itself, is a device that some are also questioning, particularly whether or not a better device is needed. It does not factor in ball spin, which has major input on the resulting lie in a bunker. Also, particle shape is the sand characteristic that influences the penetrometer value the greatest. Highly angular sand compacts easily, and therefore has a high resistance to burying a golf ball. However, this sand would also have a tendency to become a very firm playing sand, which may be a concern to some players. On the other side of the spectrum, well-rounded sand has a high tendency to bury a golf ball, due to its inability to compact and to be very unstable on bunker faces.

Unfortunately, even though sand quality is the most important factor, it is also the most difficult to solve. According to Dr. Norm Hummel, from New York-based sand and soil testing firm Hummel Sr Co., there are probably only a half a dozen sands in the United States that meet the criteria for excellent bunker sand.

"Of all the sands we test for bunkers, we only approve about five percent that are sent, and even some of those are marginal," he said.

Do all golfers like the same sand? Unfortunately, it is not that simple. PGA Tour professionals and most low handicap players prefer a firm sand, allowing spin to be produced on the ball. Slightly softer sand is preferred by a higher handicapper who cannot develop the clubhead speed needed to get through a firm sand bunker shot. These two different types of sand also receive comments from players. If you have firm sand, disgruntled players will insist there isn't enough sand in the bunker, With soft sand, players insist there is too much sand in the bunker.

This brings us to consistency. To start with, nobody said bunkers should be consistent and most agree it's nearly impossible. Golf course architects don't clone one type of bunker to be used throughout the course. Bunkers are designed differently to offer various strategies to a hole, and various penalties to a player. Then the argument is, "Well, sure they are different in design, but the sand should be consistent."

But since there are so many factors affecting the sand condition in a bunker, even with the best bunker construction and the perfect sand, you probably won't have perfect consistency. Some of the factors that affect this consistency are sunlight, angle to the sun, shade, irrigation water, bunker depth, and drainage, along with others.

Another problem for obtaining consistency is shot trajectory into a bunker. Each hole is designed differently, and different shots enter bunkers differently. The worst angle a ball can enter a bunker is a 90 degree angle to the sand slope. This angle offers the least reaction between the ball and the sand. Also factored in should be the speed of the ball when it hits the sand.

For example, one of the worst scenarios is a par-3 that measures 130 to 150 yards, slightly downhill and has a southern exposed/angled green complex. This offers sand that stays dry, a very high golf shot trajectory, and the golf ball hitting the sand at about a 90-degree angle. This is one of the worst cases for potential fried egg lies. Even sand with decent specs can have trouble overcoming these factors. A totally different scenario could be a par-4 that measures 440 yards, with an uphill second shot. Most players are hitting long irons and fairway woods for the second shot to a green complex that faces north and has plenty of shade. These bunkers would offer little chance for a buried ball, even with poor quality sand. The playability would also be totally different (or inconsistent, as golfers say) than the above-mentioned par-3.