Slow steaming

Slow steaming ( English for " slowly" ) is a strategy of reducing fuel costs in liner shipping ( container shipping ), which was previously pursued only by tankers or bulk carriers. Reduced fuel costs, the Slow steaming are doing extended travel times compared to that you may have to compensate by using more ships. This capital commitment increases for both the shipping company as well as for suppliers and customers. When weighing capital tie-up, compliance with delivery times and energy costs, the latter playing an increasingly important role in container traffic.

Causes

While in the container shipping the fuel consumption of new buildings permanently increase until about the year 2000, the cruising speed of tankers and bulk carriers has been lowered due to the lower charge value per ton and less critical delivery dates for a long time up to 11 knots. By 2008, the average fuel costs for container vessels had risen to seven times the cost of the year 2000. With a 10,000 - TEU ship, fuel costs amount to about 45 % of the total cost. With increasing size of vessels, their share is increasing. Only the lubricant costs for the largest motors can amount to $ 800,000 per year. As a result of this cost explosion and the financial and associated shipping crisis in 2008 kept the slow steaming strategy in the liner shipping feeder. It led to short-term cost savings and a reduction in capacity due to longer journey times.

Technical Realization

The slow steaming concept is mainly used in the ships mainly used in the liner shipping with low-speed two-stroke diesel engines. A lowering of the engine power up to about 50 % is applied in technical terms generally unproblematic. However, at lower engine loads, the retention of the lubricating oil increases in the cylinder while the cylinder temperature falls. Due to the dew point and condensation to form sulfurous acid, so that the cylinder drain oil more iron particles may apply. Therefore, fuel oil should be used with low-sulfur lubricating oil or with a higher base number ( 70-80 KOH / g).

In place of the mechanical cylinder lubrication is in the partial load operation in some cases worked with an electronically controlled lubrication, which will produce a thin but sufficient lubricating film in the can be dispensed over a third of the lubricant. The Wärtsilä shipyard delivered in 2010 to Maersk 34 retrofit packages for electronic optimization of engine lubrication in the low -load operation. Maersk led reentry into profit in 2010 back to the Slow steaming.

The savings are particularly large when the ships have been (including the hull shape ) from the beginning designed for slow steaming as 2011 took place first at the Maersk Conakry. The hull is shorter and wider, which means less ballast water must be carried. Due to the lower rotational speed increases, the propeller diameter and the bulbous bow has to be optimized .. The hull form of the ship, the slow speed to be adjusted. So at speeds of around 15 knots plays a greater role of the friction resistance in the water as the wave refraction resistance. Therefore, a straight back Steven is often used, as is known from classic ocean liners.

It also experimented with underwater bubble carpets to reduce the water resistance that at the AIDA newbuildings 2015/16Vorlage first time: to come tomorrow / In 2 years used. Also provide ports in the future to more cold ironing facilities.

Also grows with Slow steaming the incentive, ocean currents and tides to use by route optimization.

Economic and ecological effects

By consciously slow approach and scrapping of less energy-efficient ships, the excess capacity in the container shipping industry could be attenuated. In certain segments surged after the recovery in 2010, even back to bottlenecks. Because yet another ship approaches were always recorded to the market, Slow steaming increased the cost pressure on older and smaller ships that had to move into niches or were launched.

Another side effect is the scarcer and more expensive Leihcontainern due to longer orbital periods. Thus, the utilization of the leased container parks is from large suppliers between 2009 and 2012 increased from about 85 to about 95 %, so that today rather than invest some investors in funds for returnable container in ship funds.

Clearly positive environmental consequences are evaluated. By reducing the amount of fuel used and emissions are reduced. The metallic impurities contained in the heavy oil is reduced, which are bonded to the highly condensed aromatic compounds, - in addition to the emission of carbon dioxide, sulfur and nitrogen oxides are - in combination with the use of suitable lubricants.

Some analyzes say the loss of importance of vessel traffic ahead due to its lower speed for short distances and its replacement by truck and rail. An upgrading of the Trans-Siberian railway for mass container traffic between Asia and Europe appears neither economically nor ecologically sensible.

Examples

Germanischer Lloyd calculated that falls on the route Hamburg -Shanghai on a container ship, which takes only 26 knots 18 knots fast driving, the fuel consumption of 6210 to 3700 tonnes - a savings of 40 percent. If the speed is reduced to 12 knots, the saving effect is as high as 50 percent.

The shipping company Maersk sat in the crisis year 2009, the standard rate of their container vessels of 24 knots down to 12 knots. 2010, thus saving 20 percent of fuel. The slow speed, against the many marine engineers initially recited technical concerns, requires an improved cleaning of the turbocharger and increased maintenance of the valves. Customer side may need to be increased slightly in buffer storage inventories. For security has increased in complying with the delivery, as the earlier closely calculated timetables were often disrupted by unforeseen events.

Hapag -Lloyd went on the slow speed concept and retains it in even after the end of the crisis. Since 2009, a turbocharger from the ship's engine ever developed to reduce their performance. For the boost pressure of the turbocharger remaining elevated.

The Hamburg-Süd set the speed of their ships in Latin America Service 20 down to 16 knots and reported 40 percent fuel savings. The rotational speed of the ships increased from six to seven weeks and which another ship had to be used.

As ultra - slow steaming lowering the speed is referred to seven or even five knots. Bureau Veritas and Wärtsilä lead in association with other partners to a pilot study.

Legal Aspects

2012/2013 there was a first successful action brought by a charter company for breach of contract against a ship owner who had reduced the speed of its ships. However, most contracts exempt the carrier from any responsibility for meeting deadlines. The shipping association BIMCO has developed 2011 types of contract that should govern the admissibility of the Slow steaming between charterers and ship owners.