Spien Tsubasa: the linguistic choice for the official name of this grand structure itself embodies the friendship between Cambodia and Japan. ‘Spien’ means ‘bridge’ in Khmer, while ‘Tsubasa’ means ‘wings’ in Japanese. The long-anticipated opening of this bridge is finally realised today. The elegant silhouette of the bridge reminds its viewers of a pair of birds opening their wings wide, as if to launch themselves high into the sky above. Located on the National Road 1 between Phnom Penh and Ho Chi Minh City, the bridge connects both sides of the two kilometer-wide river at the point known as Neak Loeung. It measures 5.4 kilometres in total including the approach roads on both sides, making it the longest bridge in Cambodia. It is even longer than any bridges of the same type that exist in Japan.

SpienTsubasa was built with grant assistance of JPY 11.94 billion (approximately $127 million) from the Japanese government provided through the Japan International Cooperation Agency (JICA) – the largest grant ODA (Official Development Assistance) project in Cambodia, and one of the largest Japanese grant ODA projects in the world.

Before the opening of this bridge, the only way for people and goods to cross the river at this point was to use the ferry service. On busy days or during holidays, the queue for the ferry would be as long as seven to eight hours worth of waiting, making this river crossing a major logistical bottleneck on National Road 1.

National road 1 serves as a trunk road of the so-called Southern Economic Corridor-which runs through Bangkok, Phnom Penh to Ho Chi Minh City, an economic growth belt of the Mekong countries of the ASEAN (Cambodia, Laos, Myanmar, Thailand and Vietnam). A drastic reduction in the travel time along this corridor with the opening of SpienTsubasa is expected to bring a lot of positive contributions to economic development of the whole region.

Mr Itsu Adachi, who joined the JICA Cambodia office as its chief representative in March, has been involved in the Spien Tsubasa construction project from the very start.

“When Kizuna Bridge in Kampong Cham Province opened in 2001, Prime Minister Hun Sen expressed his wish to see another big bridge built by Japan over the Mekong. That was the beginning of our discussion for Spien Tsubasa,” he recalls.

Mr Adachi first worked in Cambodia as an advisor to The Council for the Development of Cambodia (CDC/CRDB) from 2001 to 2003, during which he participated in the opening ceremony of Kizuna Bridge. “The need for another bridge over the Mekong at Neak Loeung was being strongly felt even in those days, but nobody then expected that traffic along National Road 1 would increase to the level that we see today. Nearly 15 years after the first idea of the second bridge popped up, I am extremely happy to be able to witness the opening of this bridge today.”

The feasibility study for Spien Tsubasa started in 2004, but it was not before 2010 that actual construction work could commence. It was an ambitious, technically demanding undertaking to say the least.Engineers, mainly from Japan and Cambodia were brought in to materialise the building of this beautiful structure, while overcoming a number of hurdles that were peculiar in this construction site.

The existence of unexploded ordnance (UXO) was one of them. The area of Neak Loeung once hosted an armory of the Pol Pot army, and was also one of the major battle fields during the civil war. For this reason, prior to the start of the bridge construction, the Royal Cambodia Armed Forces (RCAF) and the Cambodia Mine Action Centre (CMAC) conducted a thorough survey of the area, which resultedin over 4,000 UXO pieces removed.

However, some war remnants had not been completely removed. The bridge construction suffered a major setback in 2012 when an anti-tank artillery shell strayed into a pipe that was pumping up sand from the riverbed and exploded. As the explosion happened underground,no one was injured but the damage to the equipment caused by this incident was serious enough to delay the on-site work by four months. Workers’ safety was the highest priority of the construction team, and it was fortunate that the nearly five years of construction work brought no casualties.

The race with nature was another particular difficulty. The flow of the Mekong is much faster than it appears, and therefore 22 pylons, 70 metres long and 2.5 metres thick are driven deep into the riverbed to reinforce and hold the bridge against the constant, mighty current. The water levels vary between the wet and dry seasons (up to seven metres) which meant that certain types of work had to be carried out only during the dry season without a day’s delay.

Spien Tsubasa has finally connected both sides of the river after overcoming such difficulties.

“Improvement in connectivity within ASEAN is important, but we hope that this bridge will also serve to reduce economic gaps within Cambodia also, by further activating movements of both people and goods inside the country, and bringing benefits that every Cambodian can cherish,” Mr Adachi says.

When the two wings of the bridge physically met in the middle above the water in January this year, Prime Minister Hun Sen announced the new design of the 500 Riel banknote with the two major bridges built by Japan over the Mekong River: Kizuna and Tsubasa. This was “to celebrate the friendship and collaboration between our two countries,” he said.

The monumental new construction over the Mekong literally serves as a symbol of the relationship between Cambodia and Japan today.