An earthquake cannot be prevented. However, preventive measure are currently underway in western Japan to mitigate potential earthquake damage on the SANYO Shinkansen route.

Every day, SANYO Shinkansen transports over 600 000 passengers,m playing a crucial role in western Japan. This high-speed train connectes Osaka, the second- largest city in Japan, with Fukuoka, one of the largest metropolises in southern Japan. Given its significance, various measures are implemented along the high-speed train line to minimize potential damage and, most importantly, to ensure the safety of passengers. One such measure involves the installation of guardrails.

The installation of guardrails on the tracks necessitates the use of a new type of sleeper. Consequently, the existing sleepers are slated for replacement with the new ones, contributing to the overall enhancement of safety measures.

In 2016, the cutting-edge sleeper change system, SES170, was introduced. SES170 is an impressive machine, measuring 94 meters in length, and it seamlessly handles all tasks involved in the sleeper replacement process, from dismantling the old sleepers to distributing ballast afterward. On a chilly day, We visited one of the key operators, affectionately nicknamed "Troublemaker" in Western Japan and conducted an insightful interview.

-I understand that you have been responsible for operating SES170 since its introduction to the present day. I gather that this was your initial experience with operating such a machine. I can imagine the considerable you must have faced during that time.

Mr. Ryou ("Ryou"): I was quite anxious at first. I was 21 years old when I took charge of SES170. Having recently gained some experience in various fields since joining the company, I was just beginning to comprehend the entire process of my job. Suddenly, I found myself entrusted with this new and gigantic task. At that time, I didn't know what to expect.

--I believe you encountered numerous challenges once you commenced operating the machine.

Ryo: The SES170 is indeed a remarkable machine, and we have encountered numerous challenges. However, each time, my colleagues and I managed to overcome them one by one. After going through those ordeals, my colleagues started calling me a "troublemaker".

--"troublemaker"?

Ryo: Yes (laughs) I seem to pull off all kinds of miracles. For instance, there was an incident on the first day of working on the main line of the Sanyo shinkansen. Prior to the night shift, I meticulously ran through the work simulation in my mind, envisioning the entire process from the beginning to the end of the day. I felt a mix of excitement and nerves as I anticipated the moment of working on the main line. I distinctly recall repeatedly simulating the tasks in my mind that day, attempting to calm myself down.

On the first day of work, the initial step involves carefully rotating the sleeper by 90 degrees. Using the manipulator under his control, I lift and remove the old sleepers from the track. The sleeper shuttle then transports them to the rear of the formation for storage.

--Just hearing about the intricacies of the process already makes me nervous.  

Ryo: Night work commenced, and the machine setup proceeded smoothly. Finally, it was time to get to work. The sleeper shuttle returned with new sleepers from the rear.  "Good! Everything is going perfectly, as planned. Now it's my turn! " I thought to myself.  As I aimed to manipulate one of those sleepers downwards, an unforgettable incident occurred. I heard an unknown metallic sound. Despite having a faint expectation that it might be nothing serious, no one immediately knew what had happened.

When I attempted to lower the new sleeper, the manipulator unexpectedly failed to respond. Our historic first new sleeper would not be installed that night. Despite extensive practice with the machine at the depot, during which we had addressed many critical points, this situation had never arisen before. I felt a momentary panic – what had I done wrong? Time passed quickly, and eventually, we had to make a decision. We resorted to manually placing the emergency sleeper on the track. I felt a deep sense of disappointment as I had eagerly anticipated the first day of work.

We had already practiced a lot with the machine in the depot and eliminated many critical points. But such a situation had never arisen before. I almost panicked. What did I do wrong? Time flew by fast! Finally, we had to make a decision and manually insert the emergency sleeper on the track. I was very depressed because I was looking forward to the first day of work.

The Machines had to be returned to the depot before the first Shinkansen arrived. Fortunately, we successfully accomplished this, averting any potential issues. Upon close inspection, it was discovered that a sensor had malfunctioned due to contact with a mechanical part caused by the unexpected movement. The error was swiftly rectified, and the following night, we proceeded with our work without encountering any problems.

Later, due to problems with certain parts, errors persisted, and I found myself being held responsible for several of them. It`s interesting how sometimes, just by touching things, people inadvertently cause malfunctions in machines, isn`t it? Since then, I`ve been humorously labeled a 'troublemaker' Of course, everyone understands that I am not truly at fault. 

--I see (laughs). Ryo-san is now one become one of the central figures in the SES project.

(Senior project team member) Takayuki: That is correct. His role is very important in advancing the project. Our work cannot run smoothly unless we can share a joke or two once in a while.

--I believe there are numerous challenges, given the necessity to maneuver a large machine with a limited number of personnel.

Takayuki: Whenever a problem arises, we transform into "detectives" and embark on a search for the cause within the intricacies of the large machine. With its extensive length and numerous sensors, the machine presents its own set of challenges.

We also encounter unique challenges with the SES170. Deu to its considerable length, reproducing the entire series of operations within the limited space of the base is not feasible. Therefore, the critical aspect lies in determining the cause of the problem within the working hours at the site where the full range of work operations can be executed.

--I see, so there are such restrictions. I hadn't considered that aspect, thank you very much. The challenge indeed arises due to the organization of the long machine.

Finally, I would like to inquire about the future development of the SES project from the project manaager, Mr. Tamotsu.

Tamotsu: In 2018, we accomplished an extraordinary achievement by exchanging 198 pieces of sleepers in a single night, setting a new world record for the highest number of sleepers exchanged within that timeframe.

However, at present, our goal is not to increase the number of sleepers replaced even further. Instead, our focus is on stabilizing the quantity of units exchanged and enhancing personnel training in each region. In the short term, we may not be breaking records for the number of units exchanged per night, but our aim is to establish a solid foundation by securing stable human resources over the medium to long term. At the end of June 2021, this special team will be disbanded. In the span of five years, it has been a relatively short yet impactful period for us.

--Editor's Postscript--

The "three sacred treasures" and　the Japanese proverb  "three heads are better than one” underscore the special significance of the number "3" in Japan, symbolizing stability and harmony since ancient times. The three interviewees displayed a profound sense of trust in each other, embodying something unique that only a team overcoming numerous challenges can possess. Encountering a team of such caliber is rare occurrence, making the dissolution of the team a somewhat poignant moment.