Dickens said: "It was the best of times; it was the age of wisdom." The development of modern networks is so wonderful that writing a few short articles has allowed friends who have not been in touch for a long time to reconnect, and I have also made many new friends; thanks to this era, we are in the same village; thanks to this era, information flows so freely.

I originally thought that the articles I wrote for comfort had no market, but unexpectedly, an article about hydraulic drilling rigs was appreciated by thousands of friends. I thank Mr. Jia Jingchen from Jinhua for our late-night communication and all the friends for their attention; through feedback from friends, I learned that everyone has various connections with drilling rigs, including complete machine manufacturers, users, and parts suppliers. This also indirectly shows how deeply hydraulic drilling rigs have penetrated our industry and lives; hydraulic drilling rigs are now more commonly used in underground drilling rigs, while open-pit drilling rigs are gradually decreasing.

In fact, even earlier, hydraulic drilling rigs used in top hammer open-pit drilling rigs also shone brightly. Regarding the Three Gorges Dam, there are various statements now, but we will set that aside. However, during the construction of the Three Gorges, Atlas Copco's top hammer open-pit drilling rigs were absolutely indispensable. At that time, Atlas Copco had more than 30 top hammer drilling rigs including ROC742 and ROC748 at the Three Gorges, and the drilling rigs were basically COP1238, which belonged to the era of COP 1238.

To ensure the construction project, Atlas specifically arranged for the company's handsome brother Lu Jianyi to stay on site for a long time, providing services and ensuring the supply of spare parts. It should be said that the completion of the Three Gorges Dam included the hard work and dedication of countless ordinary workers like Brother Lu; including Zeng Qing from Zhigao Company.HuiBrother, at that time I was working in Xuanhua and also shed sweat at the Three Gorges. Later, when he talked to me about those times, he was also filled with emotion.

Next to the lady, leaning towards the middle, is Mr. Lu Jianyi.

I don't know if it was the government department that disagreed or if Atlas did not pursue it. Later, when I went on a business trip to Yichang to visit the Three Gorges construction monument, I thought, if a ROC 742 drilling rig had been left there at that time, how meaningful that would have been!

Speaking of the ROC742 drilling rig, I think many people may not have a concept of it now. In a certain sense, it is the predecessor of the current ROC D7, but there are also significant differences; I remember it was around 1998 when Lafarge was building a cement plant in Dujiangyan. Initially, we participated with the ROC742 model. In fact, at that time, ROC742 had basically stopped production in Sweden, preparing to launch the ROC D7, but it was still being produced in the Nanjing factory. I relaxed while communicating with Mr. Shi Ming from Lafarge in Chengdu, and I really felt that Chengdu is a great place to relax and live comfortably. Later, Brother Lu Jianyi left the company due to company adjustments, and that was also the last time I saw him as a colleague of Atlas, and I felt quite low and melancholic at that time.

The drilling rig for the Lafarge Dujiangyan project, later we switched to the ROC D7 model because ROC 742 was no longer in production. It may be for this reason, or perhaps for other reasons, that they ultimately chose another top hammer drilling rig from Tomrock, the predecessor of Sandvik; of course, this drilling rig did not perform very well there. The reason for the poor performance is not that the drilling rig is bad; to be fair, Sandvik's drilling rigs have quite good performance, but the application target was not suitable. This actually brought some negative impact on the later promotion of Sandvik drilling rigs in China, and their market share has always lagged behind Atlas. Atlas should feel fortunate, as the old saying goes, "Disaster is a blessing in disguise."Blessing is hidden in disaster. This also brought me more thoughts when recommending drilling rigs later.

We know that the drilling method for open-pit drilling rigs is basically the top hammer type of hydraulic drilling rigs; now, the three types widely used in limestone mines are the down-the-hole hammer type and the rotary roller type used in large mines, plus Atlas's unique COPROD, which combines top hammer and down-the-hole methods. Each method has its applicable working conditions. For example, in the Three Gorges project, the rock is very hard and intact, and at the same time, high drilling efficiency is required, and the impact of blasting vibrations should be minimal. Therefore, the top hammer type is undoubtedly the best choice; for most limestone mines, the rock is relatively developed, and the top hammer drilling rig is difficult to exert its advantages; as a production drilling rig, it requires a relatively large diameter and flexible movement, which is also the main reason why Sandvik's top hammer drilling rig did not perform well in the Lafarge project. Therefore, later in the limestone industry and some coal industries, we mainly recommended down-the-hole drilling rigs, which indeed played to their advantages in practical applications. This has also led to the current situation where down-the-hole open-pit drilling rigs almost dominate the market, especially in the cement mining industry, and has created many domestic down-the-hole drilling rigs, such as Zhejiang Zhigao, Xuanhua Taiye, etc.; in fact, specific problems should be analyzed specifically. From what I understand, there are several limestone mines where using top hammer drilling rigs would actually be better, but sales personnel and purchasers may not want to have any issues, following the crowd. Whatever others use, I will use too, and the final effect can be said to be very unsatisfactory.

COPROD is a unique drilling method created by Atlas that combines the advantages of top hammer and down-the-hole methods. It is indeed very unique and highly efficient. Huanggang Yadong Cement has a ROC F9 COPROD drilling rig, which has been used for a long time and meets their mining production needs with just one unit. This form is unique to Atlas, and the requirements for drilling tools are extremely high, and the price is relatively high, so it is rarely used in practical applications.

Roller drilling rigs were once essential drilling equipment for medium and large mines. With the development of down-the-hole hammer technology, the hole diameter of down-the-hole drilling rigs has become larger and larger, and their market has been greatly impacted. Except for particularly large coal mines that are still purchasing, there seems to be basically no market now. The best roller drilling rig manufacturer in China used to be Jiangxi Mining Machinery Factory. The first time I went to Lushan was to attend their order meeting (this term is basically no longer used now). Later, it was renamed Nanchang Kaima, and then acquired by Hengtian Group. It seems that they no longer produce it now. Shougang Mining Company also once produced it, but now it seems there is no news.

Times have changed. Dickens also said: "It was the worst of times; it was the age of foolishness," and my feeling is just as people say, when the times abandon you, they don't even say goodbye.