Conceived as a means of loading from offshore facilities including pipeline buoys and FPSOs and FSOs in the North Sea, shuttle tankers are one of the niche sectors in the world fleet.
They are characterised by the distinctive bow mooring and hose handling systems but other than this appear similar to any other tanker type. However, because of their need to manoeuvre before and during loading, all modern tankers are also equipped with Dynamic positioning systems.
The mooring and hose handling system is an essential element of the shuttle tanker concept and usually includes a chain stopper with a quick release mechanism so that the mooring hawsers can be dropped rapidly in an emergency. Following a series of collisions between tankers and the FPSOs they were loading from in the 1990s, dynamic positioning – usually DP2 – became a standard feature of the type.
The shuttle tanker concept has expanded beyond its initial operating area and can be found in many areas where offshore oil production occurs. The world shuttle tanker fleet is currently comprised of 90 ships in service and a further nine on order including the four new Teekay LNG-fuelled ships. A little over a third of the fleet operates in the North Sea and a slightly higher number off Brazil.
In size, the ships range from 34,500dwt to 162,000dwt. Only 21 ships are under 100,000dwt with the majority being Suezmax or Aframax types. The on-order fleet has a similar composition with two small vessels of 42,000 and 63,000dwt, six vessels including the Teekay ships are 125,000dwt each and the largest 155,00dwt.
Teekay is the largest operator in the sector with a fleet of 28 vessels mostly 100% owned by the company but a small number are part owned. These ships account for 31% of the in-service fleet. The company also has a small number of vessels chartered in from other operators. The second largest fleet is owned by Knutsen with 26% followed by Russia’s Sovcomflot with 11%. The remaining 32% are owned by a variety of smaller operators.