Carving Crazy Horse Mountain
- 1) measure Korczak’s model;
- 2) measure the mountain;
- 3) remove all the rock that doesn’t fit!
The members of the Crazy Horse mountain crew are experts in precision blasting, equipment operation and engineering. They maintain a strong emphasis on safety in all steps of the operation and are proud to have an outstanding safety record. Here's a little closer look at each of the meticulously detailed steps this team carries out to carve the mountain:
1. Measure Korczak’s modelMeasuring systems have evolved steadily during the history of the Mountain Carving. Korczak relied on artistic estimates and his incredibly practiced eye and natural feel for dimensions and scale. Measurements are taken from several scale models ranging from 1/34th to 1/300th. Today we rely on Monique’s “eye” and laser scanners. The laser scanners provide us a three dimensional computer model of Korczak’s original model.
2. Measure the MountainKorczak used a combination of his artistic eye, tape measures and a beautiful old theodolite (survey instrument) to determine the basic location of his model within the Mountain and to begin the process of removing excess rock. To complete the face, a 60-foot long measuring boom was fixed to the top of Crazy Horse's head in 1987 to direct the work on the face. A plumb bob suspended from that measuring boom was used to transfer numbers from the pointing system on the 1/34th model of Crazy Horse's face.
When work moved beyond the face in 1998, a survey control system was developed and this instrument, known as a total station, measures very precise angles and distances from known control points to calculate 3 dimensional coordinates for any point on the mountain. It uses an infrared beam reflected from a hand held prism to measure distances up to several thousand feet with accuracy to the nearest 1/1000th of a foot.
Laser scanning equipment has been used to measure the entire Mountain on several occasions over the past 10 years. This technique allows for measuring huge numbers of points very quickly and accurately to build 'digital models' of the Mountain in engineering computers. These digital models allow us to see Korczak’s model inside the Mountain, and provide measurements and coordinates for the carvers.
3. Remove all the rock that doesn't fitAll blasts at Crazy Horse are designed, drilled and executed to protect the rock that is left after the blast. This is the opposite of most blasting operations, where the main concern is the final size and location of the material being blasted away. The mountain crew prepares most blasts using a system that explosive engineers call "pre-splitting." It is similar to perforating a piece of paper to allow it to tear evenly. The rock to be removed is drilled on all sides with a series of parallel drill holes. Explosives are detonated throughout the entire length of each of the drill holes, cleanly removing the desired rock while leaving the remaining rock undamaged. Here's a more detailed look at each of the steps in the rock removal process:
- Drilling - Equipment has evolved from Korczak's use of a single-jack (sledge hammer and steel) to drill the holes for the first blast on the Mountain. Hydraulic drills are now the standard and our fleet includes three of these very efficient machines mounted on tracks or rubber tires. Most of our holes are drilled about 20 feet deep using 2 inch diameter carbide steel bits. Our largest machines approach drilling rates up to 10 feet per minute! The next generation of these drills will be faster with less vibration & remote controlled for hard to reach and delicate areas of the Mountain.
- Explosives loading - When most people think of explosives, they imagine dynamite. Dynamite is very effective at fragmenting rock, but expends all of its energy in an area equal to the length of the cartridge – a very small portion of the drill hole. Our blasts use detonating cord and pre-split products, designed to expend the same amount of energy over the entire length of the drill holes. This provides much better control of the explosive energy and does much less damage to the rock that is not removed by the blast.
- Blast timing - The typical blast is actually a carefully-timed series of smaller blasts spaced only few milliseconds apart. The vibration and damage caused by the blast can be controlled by limiting the amount of explosive detonated in each section of the blast. This is a common practice in the blasting industry which is understood and practiced by the Crazy Horse blasters. We have also used the latest technology – a system of programmable detonators, which allow nearly infinite choices in blast timing. We have also used the latest technology – a system of electronically controlled, programmable detonators, which allow nearly infinite choices in blast timing. Systems like this will play a key role in controlling blasts as we work closer to finished grade in the future.
- Mucking - Removing the blasted rock or muck from the mountain is accomplished with equipment. These rocks range in size from small gravel up to the occasional 10-ton boulder and most remain on the blasting bench rather than falling off the mountain from the force of the blast. The average dump truck on the highway is hauling about 15 tons of material. It takes 200 truckloads to haul away the rock from just one large blast on the mountain!
- Finishing - When the crew returns to finishing work it will be accomplished as it was on Crazy Horse's face by drilling to isolate small blocks of rock (100 to 1,000 pound chunks). These blocks may be blasted off using very light explosives. A jet torch running on diesel fuel and compressed air (operating at 3,300 degrees (F)) is used to finish the surface of the Mountain Carving. The jet finishing process is called spalling. The jet removes drill marks and smoothes the final surface. The final step in finishing is to seal the natural seams in the granite so that water cannot infiltrate and cause damage during freeze/thaw cycles.
So close you can see it!
Crazy Horse mountain carvers recently mapped out their future on the far side of the Mountain.
In preparing to create the artistic details, the crew painted the outline of the extended hand, using reference points transferred from computer models and checked with the latest surveying equipment. The hand will be supported by the mane atop the colossal horse’s head.
- The hand will be about 25 feet tall.
- The extended left index finger, resting on the horse’s mane for stability, will be nearly 29 ½ feet long.
- The horse’s head, when completed, will be 219 feet tall. (Taller than the statue of Liberty from base to torch)
We are currently removing the rock to craft the hand, a measuring boom similar to one used in creating the carved face has been built and installed at the end of the extended arm.
Research Results- The Next Stages-
The next stages of Crazy Horse Mountain Carving are being planned and are ever evolving. As we move forward and plans are finalized they will be shared.