• pic1
  • pic2
  • pic3
Ship Management
Chartering
Oil tankers chartering
Technical Management
Ferrying of Vessels
Ship repair and modernization
Sale and Purchase of Vessels
Survey Services
Thickness measurements
Diesel Diagnosis (DDS)
ISM, ISPS, MLC

Modernization of tankers with installation of double bottom

In accordance with MARPOL 73/78 convention, that fully entered into force on 01 Jan 2008:

  • oil tankers of dwt of 600 t an above must have cargo tanks, protected along the full length by the bottom ballast tanks or compartments, that are not designed for carriage of oil or bunker fuel;
  • oil tankers of dwt below 5000 t, equipped with cargo tanks of capacity below 700 cbm, must have cargo tanks, protected along the full length by the wing tanks or compartments, that are not designed for carriage of oil or bunker fuel;
  • oil tankers of dwt of 5000 t or above must have cargo tanks, protected along the full length by the bottom and wing ballast tanks or compartments, that are not designed for carriage of oil or bunker fuel.

By now we have the unique situation — the majority of river-sea tankers does have double hull and double bottom, but nevertheless are non-compliant with reg. 21 of MARPOL 73/78 for the carriage of oil and oil products of density of 0,900 mt/cbm and are not eligible for the carriage of such cargoes.

The river-sea double-bottom tanker concept was brought up in 1950s, therefore almost all tankers were built with double bottom and double hull. The international requirements for double hull were adopted much later, therefore the double bottom height of major part of domestic tankers is less than required by reg. 19 of MARPOL 73/78.

Domestic river-sea tankers mostly belong to the following projects (build at Soviet and Bulgarian shipyards):

  • Volgoneft project 550, 550А, 558, 1577, 630;
  • Lenaneft project Р77;
  • Lenaneft project 621, 621.1, 621.2;
  • Oleg Koshevoy project 1677М;
  • Nefterudovoz project 1570, modernized dry cargo carriers project 05074М, 1565, 507B and others.

Compliance with the double bottom height regulations of MARPOL convention of river-sea tankers and tankers with restricted area of operation of Lenaneft project.

Type and project Double bottom height, mm. Conclusion
At double hull В ДП Required by MARPOL
Lenaneft, 621, 621.1 1000 800 987 Non-compliant
Lenaneft, 630, 630.1 1000 800 1100 Non-compliant
Lenaneft, Р77 0 0 987 Non-compliant

 

The possible long-term solutions under consideration:

  • scrapping of old vessels and construction of new MARPOL-compliant tankers;
  • carriage of light oil products only, i. e. cargoes with density of 0,900 mt/cbm and below;
  • conversion into dry cargo ships;
  • installation of double bottom and double hull without change of year of built (modernization);
  • installation of double bottom and double hull with change of year of built (conversion).

Some possible solutions were developed taking into account these principles:

  • two tankers (MT Mekhanik Voronkov and MT Volgoneft 228, owner Volgoneft) were modernized with replacement of cargo compartments, taking into account requirements of all international conventions;
  • project 630 tankers were modernized by raising the double bottom to the level as per MARPOL requirements;

Modernization of oil tankers “Tiksi” and “Yana” as per MARPOL 73/78 regulations.

The modernization including installation of double bottom plating was ordered by the ship owner and performed by our company in dry dock and at repair berth of Sevastopol shipyard.

 

Photo 1. MV Yana sailing from dry dock, MV Tiksi at the shipyard berth

Photo 2 Photo 3
Photo 4 Photo 5
Photo 6 Photo 7

Installation of double bottom plating

Due to the vessels’ hull construction — corrugated bulkheads — the steel plates were cut and replaced. The stripping pipelines and tank shutters were moved to the level above the double bottom plating.

 

Photo 8. Tank shutter before the double bottom plating installation Photo 9. Tank shutter before the double bottom plating installation
Photo 10. Stripping pipeline before the double bottom plating installation Photo 11. Stripping pipeline before the double bottom plating installation
Photo 12. Steel plates cut from the corrugated bulkhead Photo 13. Steel plates cut from the corrugated bulkhead
Photo 14. New steel plates Photo 15. New steel plates
Photo 16. Pipes cut to fit the raised bottom level Photo 17. Construction of the double bottom plating
Photo 18. Construction of the double bottom plating Photo 19. Construction of the double bottom plating
Photo 20. Construction of the double bottom plating Photo 21. Construction of the double bottom plating

Cross section of Lenaneft-type tanker (project P77) before (a) and after (b) modernization as per project RST006

The following equipment was installed during modernization:

  • bilge pumpls,
  • sewage transfer pumps,
  • contents gauges,
  • tank degasation fans,
  • watertight covers, manholes and hatches,
  • ladders.

Midship section plan of MT Tiksi after modernization.

During the process of modernization the repair works on vessels’ hulls and equipment were performed with installation of new machinery and presentation to Class surveyors.

 

Photo 22 Photo 23
Photo 24 Photo 25
Photo 26 Photo 27
Photo 28 Photo 29

Modernization of MT Tiksi (ex Palflot-1, project P77) and MT Tiksi (ex Palflot-1, project P77) was performed by our company.

Both tankers were under full operation of Trans-Service Maritime Agency during the whole modernization period from February until end of June 2014.

Beside the general modernization (upgrading of double bottom plating to comply with MARPOL regulations) the following machinery and equipment was repaired: main and auxiliary engines, generators, power plants and automation systems, cargo and supply pumps, auxiliary mechanisms, radio, lifesaving and navigating equipment.

Several kilometers of cargo pipelines as well as ballast, air, stripping and general pipelines were repaired and replaced on both vessels.

The vessels were dry-docked with extraction and repairs of tail shafts, rudders and fittings. Upon completion of modernization the vessels were surveyed by RS Class inspectors for compliance with ISM, ISPS, MLC Conventions.

The vessels sailed from Sevastopol (MT Tiksi on 15 June and MT Yana on 19 June) heading for Rostov-on-Don. Then both tankers will be going through the inland waterways of Russia to their operation region in the Lena river (port Tiksi) as a part of program of supply of fuel to Yakutia. The vessels are manned by crews from Sevastopol and Nakhodka.