The Tragic Saga of Koho Maru 5, A.K.A. Pak-1

Japan imports huge amounts of gas and does so using her own vessels rather than vessels registered to the country of origin of the imported fuel. Indeed, the ‘supertanker’ was developed to enable Japan to import increased amounts of crude oil when she expanded her refining capacity in the 1950s. Japan receives shipments not only crude oil but also liquefied natural gas (LNG) and liquefied petroleum gas (LPG).

A vessel for LPG transport called the Koho Maru-5* was manufactured and commissioned in Japan in the early 1970s and, with Japanese registration, was used for its intended purpose until it was purchased by a Thai company, re-registered to Thailand and renamed Pak-1. It was therefore as Pak-1 that she sank in the Gulf of Thailand in the mid 1990s after a collision with a Thai Navy vessel. The exact date of the incident is not known and Lloyd’s Register have no record of it, nor is it certain whether the vessel was actually carrying LPG at the time of the collision. There have been suggestions – no more – that the tanks were empty or that they were in fact holding liquid fertiliser. Information from apparently authoritative sources is conflicting and in preparing this brief account the author has had to tread warily.

On sinking, the vessel settled initially in vertical orientation with the LPG tanks uppermost a few metres below the water surface. The wreck became a major attraction to divers, vertical wrecks being few and far between. They observed and reported leakage of diesel, the vessel’s own fuel. In 2001, about five years after sinking, Pak-1 moved to horizontal orientation and, with about 6 metres of her structure visible above the water, began to drift. The drifting wreck was obviously a danger to other vessels, and the Thai Navy set about sinking Pak-1 once and for all.

It was towed to a part of the Gulf of Thailand away from shipping lanes and high explosives were applied. It now reposes in a horizontal position at the bottom of the sea about 10 miles from the mainland and continues to be an attraction to divers.

The most serious aspect of this matter has been left until the end for mention: there were fatalities amongst the crew of Pak-1 when she sank, seven such according to one report.

* Koho Maru means ‘Light of Japan’: many Japanese Navy vessels have had the same name with different numerals to distinguish them.