Thread by @ChrisO_wiki

1/ The two oil tankers that have sunk in the Kerch Strait were specialised river-sea vessels that should not have been operating at all, according to Russian sources. They were supposed to have ceased operating at sea in 2008 under Russian and international regulations. ⬇️

2/ The tankers Volgoneft-219 and Volgoneft-239 sank today in a severe storm near the Kerch Bridge, killing at least one person and spilling 4,500 tons of heavy fuel oil (mazut) into the sea. They were operated by the Samara-based company Volgotanker.

3/ This is not the first accident to have befallen the Volgoneft tanker fleet. A very similar disaster happened during a storm on 11 November 2007, when Volgoneft-139 broke apart in the Kerch Strait, spilling at least 1,300 tons of fuel oil into the sea.

4/ The ships were designed to deliver oil and fuel products along the Volga river to Russian ports on the Black Sea. They are single-deck twin-screw tankers with double bottom, double sides, forecastle and poop, a superstructure and an engine room in the stern.

5/ They were laid down in Volgograd in 1969 and 1973 respectively and were among the 131 Project 1577 river-sea oil tankers built between 1967 and 1982. By 2017, two of the class had been lost in accidents and nine more had been scrapped.

6/ The Project 1577 tankers now have an average age of nearly 50 years and do not meet the requirements of the International Maritime Organisation (IMO). In particular, their cargo tanks are excessively long and they lack settling tanks or sufficiently high double bottoms.

7/ Under the IMO's International Convention for the Prevention of Pollution from Ships (MARPOL), the tankers were supposed to have stopped operating at sea transporting heavy oil and oil products (i.e. cargo with a density of 0.900 t/cu. m. and greater) since 2008.

8/ While Russia has sought to replace and modernise older tankers, many continue to operate unmodified. Implementation of the MARPOL requirements is reported to have been deferred several times.

9/ Operators of vessels that do not meet the requirements have continued using them under 'temporary' certificates issued by the Russian Maritime Administration. These have been issued repeatedly since 2008, keeping the vessels in service long after they should have been retired.

10/ Russian inland and mixed river-sea navigation vessels are in general very old, with an average age of at least 40 years. This is far older than equivalent foreign ships. /end

Sources:
🔹 morvesti.ru/analitika/1692…
🔹 morvesti.ru/analitika/1690…
🔹 korabel.ru/news/comments/…

threadreaderapp.com/thread/1868395…