Project Story

Chapter 1

Fulfilling wishes to improve Hirara Port

Chapter 2

Gather information from a unique perspective and prove the need

Chapter 3

The key to approval lies off island. Follow the RORO ships

Taking the lead for Nishimura in the investigation on nearby ports was Aya Makino, a member of the Nishimura team then in her third year at NEWJEC. Packing a stopwatch and camera in her bag, Makino traveled the sea route along with a RORO ship from Naha Port to Hirara Port and then to Ishigaki Port. She recorded the state of each port and the time taken for cargo operations.
"Thinking it best to remove as many variables as possible to make an accurate comparison, I suggested that we take all measurements from a single ship," says Makino. "It was physically exhausting, but I think it clearly illustrated the current state at Hirara Port."
Just as Nishimura had predicted, the cargo handling delays at Hirara Port also had an impact at Ishigaki Port. Continues Makino:
"It's not uncommon in this region for a delivery originally scheduled for an evening arrival to show up the next morning, or for goods not to show up for a while if bad weather strikes, causing continued delivery cancellations. Our conclusion was that improvements to Hirara Port were necessary for stable goods transportation not only for Miyakojima, but throughout Okinawa Prefecture."
During her investigation of Ishigaki Port, Makino actually witnessed a regular ship missing its delivery.
"Even missing regular deliveries for just one day can leave convenience stores and supermarkets running out of stock. And if the quay were to get destroyed in a disaster... It felt imperative to get the project accepted, no matter what it took."
Makino aimed her camera at an empty shelf to snap another picture to add to the materials. Based on Makino's investigations and through repeated discussions with the Okinawa General Bureau, the team prepared an improvement plan. Once done, they continued to refine the plan through repeated feedback from the Council of Transport Policy Ports and Harbors Subcommittee. Finally, after about a year, the long-desired project was approved.

Chapter 4

The ground motion geek squad assembles to fix a data shortage

Once the project was approved, work on preparing a design ground motion began for designing the seismic-reinforced quay. Ground motions are ground vibrations as caused by earthquakes. Also engaged in work on dams, power generation facilities, and other critical infrastructure, NEWJEC has many engineers experienced at forecasting ground motion. Hirai is one such engineer. For many years, Hirai's work included measuring vibrations in dams and analyzing seismic response in slopes at power plants.
"We ran ground motion forecasts for Hirara Port in 2012," starts Hirai. "With the Great East Japan Earthquake occurring off the Pacific Coast the previous year, associated research unearthed many new facts on the mechanisms behind ground motion, including which parts of a fault will release strong energy. For Hirara Port, we decided to quickly take these new facts into account in preparing the design ground motion."
However, during simulations, it was found that the data from the provided boring survey was insufficient. With that, Hirai, along with two NEWJEC engineers affectionately known within the company as "the ground motion geek squad," headed out immediately to conduct a field investigation. The squad estimated the underground structure from ground surface surveys, taken with two methods: The surface wave method and the microtremor method. The surface wave method involves planting geophone sensors at regular intervals, and then striking the ground with a hammer to measure the vibrations. Meanwhile, the microtremor method is to measure naturally occurring vibrations from the wind, waves, and other sources. Hirai reflects fondly on the experience with a chuckle.
"It was fun! Normally you'd expect everyone to be in a panic if there's not enough data to go off, but we were excited. 'Yes, we get to go investigate!' It's a typical scene at NEWJEC, where engineers who love their work assemble. I doubt many construction consultants would go investigate underground structure themselves."

Chapter 5

Building a seismic-reinforced quay with locally sourced, fragile stone

Based on the Hirai team's design ground motion, design for the seismic-reinforced quay started in 2012. In the quay design, Shinichi Yoshikawa was particular about a certain aspect.
"It's common in seismic reinforcement to improve the soil by mixing in cement and such to fortify the foundation ground. But doing that would impact the environment by causing turbidity in the surrounding sea water. This design avoids the need for major soil improvements to the extent possible so as not to affect the clear ocean waters of Miyakojima."
Also, with Miyakojima being a remote island, ordering more materials and construction equipment would balloon transportation costs. Therefore, it was also necessary to choose methods that could be completed with a local construction company using only materials on the island. With these restrictions, Yoshikawa chose the caisson method. In this method, a riprap foundation is built on the sea floor. Then, huge concrete boxes called caissons are placed on the foundation and packed with gravel or other materials to stabilize them. The structure is designed to withstand external forces through the self-weight and frictional force of the quay.
"The caisson method isn't some special method and so can be completed with local resources."
But there was one problem: the white stone material, called 'shiroishi' stone, that was used for the foundation. Shiroishi stone is readily extracted on Miyakojima from Ryukyu limestone. While readily available, the stone was brittle and unsuited to the caisson method, which requires a certain weight. With that, Yoshikawa worked to increase the caisson width in order to disperse the counterforce on the underside of the caissons and limit the pressure applied to the shiroishi stone. In addition, in sections, the superstructure installed on top of the caisson extends 4 meters in toward the land. This design shifts the center of gravity in toward the land so that in the case of any strong shaking, no excessive pressure will be applied to the shiroishi stones on the sea floor. For his work on this design, Yoshikawa was awarded the Award for Businesspersons and Engineers by the client: the Hirara Port Office of the Okinawa General Bureau. An interview with Yoshikawa was also featured in a local Okinawan newspaper.
"I felt the heft of Miyakojima resident expectations for the Hirara Port improvements. I'm just happy to have made even a small contribution to the development of the region."

Chapter 6

Starting work 2 months early by completing design and land reclamation application simultaneously

With land being reclaimed to expand the terminal, this project required an application for land reclamation on public waters. Preparing this application was another task undertaken by NEWJEC. At that time, many Japanese ports were competing to attract large cruise ships, and there was a desire in Hirara Port as well to start using part of the berths on the quay by 2020 to join in the competition. Thus, while such applications are normally prepared after the design is completed, in this case the applications were prepared concurrent with the design process. Maiko Takeuchi reflects on her work at the time.
"The application must include any number of items. In addition to the design outline, it's required to explain why land reclamation is needed and what impact the reclamation work or presence of the landfill site will have on the environment in terms of water and air quality, noise, vibration, and so on. However, we had trouble finding the information needed for simulations, such as the amount of landfill soil and construction method. Also, anytime the work machinery or vehicle quantities or processes were altered, we had to rework the various items associated with each change. It was tough."
As Takeuchi tells it, they were able to complete the process concurrent with the design because NEWJEC was able to handle all the planning and design.
"For one, if you were missing a certain figure, you could simply ask the engineers to produce it as soon as possible. Also, many company members were working on Hirara Port, so if there was something I didn't know, I could just ask someone and get an answer. Members working together so closely is precisely what made it possible to prepare the applications and design simultaneously."
The application for reclamation on public waters was submitted just as the design was completed. Teamwork had shortened the schedule by almost two months.

Chapter 7

An emotional opening ceremony, looking to a full open in 2024

In 2017, 220 of the 440 meters planned for berth use were provisionally opened. The port already allows 10,000-ton class RORO ships and 50,000-ton cruise ships to dock. Nishimura was present at the provisional opening ceremony.
"This is the first time in my career that I've been invited to an opening ceremony. It was a great honor. I had a flood of emotions at the ceremony when that first RORO ship entered port and docked safely. That's not the end of the job for us though. The real sense of accomplishment will come when all the work is done and the port can provide the islanders an uninterrupted flow of supplies."
The port will be fully open for service in 2024. NEWJEC looks forward to continued involvement in the development of Hirara Port as well as other ports in Okinawa Prefecture.