I had long heard of SANY rotary drilling rigs and seen the star product SR280R at various exhibitions. Now, after having the chance to sit in the cab and truly feel its sharpness—and after learning about the trials it has endured—I realized that behind every star product there is also hardship.

At the northernmost subway station in Beijing, I took a bus westward for 30 stops and arrived at a place surrounded by mountains on all sides, billed as a tourist attraction—Huata Village in Nankou Town. Apart from the introduction mentioning the village's thousand-year-old temple, "Heping Temple," and an ancient bell from the Qianlong era preserved in the temple, I found nothing worth touring. Perhaps I came at the wrong time!

Our destination was a well-hidden valley behind Huata Village—the Beijing SANY Heavy Machinery Huata Test Site. Before we even arrived, we could hear the sound of steel colliding in the distance; it must have been the rotary drilling rigs. Sure enough, after a while we saw the typical SANY red. More than a dozen rotary drilling rigs were working simultaneously in the valley, a rather spectacular sight.

Led by Director Chen of the test institute, we entered the site and began this test drive. Because the rock formation beneath the Nankou Huata test site has a hardness of 80–120 MPa and drilling starts directly into rock, drilling is extremely difficult, so we gave up the idea of personally drilling a 10 m deep pile hole. However, with the cooperation of the on-site staff, we still conducted a simple test drive of the SR280, using a core barrel to continue drilling 1 m deeper in a 30 m deep pile hole. Unfortunately, our skill was limited and we failed to bring the drilled rock fragments out of the hole, but we did truly feel the sharp rock-drilling capability of the SR280R.

Behind the "R"

Outsiders may think the letter "R" in the rotary drilling rig model merely represents an improved version, but insiders know that "R" stands for rock drilling, and this "R" is not something just any machine can carry. The SR280R adopts SANY's original winch pressurization method, which raises the power head's pressurization force to 45 t while also extending the rig's pressurization stroke. It can perform economical and efficient construction in rock formations with uniaxial compressive strength not greater than 100 MPa and drillability less than grade 8. The SR280R has a maximum drilling diameter of 2.5 m and a maximum drilling depth of 84 m. Thanks to the use of a parallelogram luffing mechanism and five-stage vibration reduction technology, its anti-vibration capability is increased by 30%, providing strong structural support for rock drilling. Automatic pressurization control technology and stepless adjustment of pressurization force are efficient rock-breaking pressurization technologies developed on the basis of rock fragmentation theory, increasing average rock-drilling efficiency by 50%. According to formation conditions, the power head offers three drilling modes—standard mode, rock-drilling mode, and economy mode—so you can choose between fuel savings and drilling speed.

A veteran that keeps learning

Although the SR280R is already a veteran in the SR280 series, this veteran has not forgotten to learn new tricks. The all-new SR280R rotary drilling rig has several changes. Anyone familiar with SANY rotary drilling rigs knows that most SANY rock-drilling rigs use a truss-type mast, and the previous SR280R did too. Although this structure improves the mast's deformation resistance, because there are many welded parts, the mast is prone to weld cracking under long-term high-intensity vibration. Today's SR280R has been equipped with a reinforced box-type mast, which ensures the mast's deformation resistance while solving the weld-cracking problem. The tensioning hydraulic cylinder for the pressurization wire rope has also been moved from the upper part of the mast to the lower part for easier adjustment.

Worry-free and comfortable

The verticality adjustment of the SR280R rotary drilling rig's mast can be completed fully automatically with one touch. From the mast lying flat to standing upright, the operator only needs to turn on the automatic mast-raising function on the display, and the entire process requires no manual intervention. The operator can take this opportunity to pour a glass of water or call a loved one. But if you want to smoke a cigarette, you probably will not be able to, because the entire mast-raising action is controlled by electro-proportional valves, making automatic mast raising as precise and fast as manual mast raising.

The biggest problem that used to trouble operators was "messy rope" on the wire rope. Now SANY has solved this problem—which previously required experience and concentration—with a small automatic program. So-called messy rope occurs when the drilling bucket has already reached the bottom of the hole, but because the drill pipe is lowered too quickly or the operator is distracted, the drill pipe continues to be lowered; the wire rope then comes out of the rope groove and stacks on the main winch drum. When the drill pipe is lifted and the wire rope is tightened again, a "pop-pop" sound of rope biting occurs, seriously affecting the service life of the wire rope. SANY's R&D personnel added a bottom-touch protection function to the control program: the control program automatically judges the wire rope tension, and when the drill pipe touches the bottom of the hole and the tension is less than the set value, it automatically stops releasing the rope, preventing the equipment from developing "messy rope."

The whole machine has more than ten limit switches. When the position of each component reaches the limit position, it automatically alarms and stops that action to prevent accidents, so even novice operators do not need to be nervous.    

Enjoying the drive

I have to say that operating the SR280R from its cab is a pleasure. Early cabs had two displays, one showing data for various chassis indicators and the other showing data for various upper-structure indicators. Now these two screens have been combined into one stylish, minimalist high-definition color large screen. If the video playback function had not been deliberately removed to keep operators focused on construction, I would really have wanted to use this display to watch a high-definition movie. On it you can see how deep the current pile hole has been drilled, where the drilling bucket is currently positioned, and how deep the current bucket has drilled. You can even know the GPS coordinates and altitude of your current location.

The angle of the left and right armrests of the cab seat is adjustable, the seat base and cushion can be adjusted forward and backward, the backrest angle is adjustable, and even the firmness of the seat can be adjusted, so operators of any body shape and weight can obtain the best comfort. The cab is fully equipped with heating and air conditioning, high-power audio, a radio, a cigarette lighter, a fire extinguisher, and other facilities. There is also an ashtray below the cigarette lighter, reflecting SANY's attention to detail everywhere. The radio and air-conditioning control panel are integrated; you can save your favorite stations to shortcut keys and listen with one touch. If the air conditioner malfunctions, you can also read the fault code directly from the panel.

Like all SANY rotary drilling rigs, the SR280R reflects humanized design everywhere. Inclinometers are installed on both sides of the bottom of the mast, so even if the mast inclination sensor fails, construction can continue through this "clumsy" but reliable method. A level gauge is also installed inside the cab. When the rig is positioned before drilling, the level gauge can be used to check whether the chassis is too tilted, so as to avoid tipping accidents during slewing.

How can rock-drilling efficiency be improved when drilling hard rock? SANY has put considerable effort into this area. High-frequency pulse control of pressurization pressure is used to achieve jog breaking and efficient rock drilling. A dedicated SR280R-LH rotary drilling rig, commonly known as the SR280R short-and-stout model, has also been developed for the Yunnan-Guizhou-Sichuan region and is more suitable for drilling in the rock formations of that area. Today's SR280R series includes the SR280R, SR280RⅡ, SR280RC, SR280RⅡC, and SR280R-LH, and has become SANY's flagship product in the pile machinery industry. SANY is still continuously improving and developing new models. What surprises will the SR285R, soon to be put into testing, bring? We will continue to follow it.