Container Shipping Companies reduce capacity by 7.4 % - longer port laytimes also helps
Along with longer port laytimes and evermore lower voyage speeds container shipping companies reducing continuously the transport capacities. In order to tone down, to increase the round-trip time and to lift the rate level vessels reduce their speed. Since beginning of 2009 a total of 1.27 million TEU capacities have been taken off the market, says the actual market report of the branch service Alphaliner. During the last twelve months alone it has been 260 000 TEU. A further instrument played an important role: shipping owner extended their port laytime, inter alia because the meanwhile larger vessels need more clearance times. Together with the longer round-trip times it was possible to absorb 7.4 % of the existing fleet. According to Alphaliner it has been 6.2 % last year.
Speed will be reduced evermore. After Slow Steaming with speeds around 18 knots came Extra Slow Steaming and Super Slo... [More]
What to do when the tanker markets are depressed? Maersk Tankers has taken a hard look at bunker fuel consumption, which on their Very Large Crude Carriers (VLCC) makes up about 85% of the voyage costs. They found that the key to improve earnings is super slow steaming, which they’ve taken to a whole new low with giant VLCC’s ambling over the oceans at speeds as slow as 8.5 knots.Super slow steaming requires engine load to be decreased down to 10%, which is equivalent to 50% speed, but the company recently decided to further economise on fuel consumption (and not by reducing the speed of its ships yet more) with the retrofit of a Variable Turbine Inlet system (VTI) onboard the 318,000 dwt crude oil carrier Maersk Ingrid. Manufacturers, Mitsubishi Heavy Industries Marine Machinery & Engine (MHI-MME) say that their VTI turbocharger system has been been fitted to more than ten new buildings, but never before retrofitted to an existing unit, a job that took just four days d... [More]
De-rating of prime mover reduces fuel consumption
In today’s environment of slow steaming, a permanent engine reduction can increase remarkably the economy of existing vessels and reduce the fuel consumption under these new engine load conditions. Main engines are normally designed for a specific high speed. However, for Slow-Steaming another Power-Speed-Course is decisive. A throttling of the engines reduces the engine specific maximal continuous power (MCR) and with this, the designed maximal speed of the vessel permanently. This leads to a higher economy with lower specific fuel consumption (sfoc).
MV Cap San Nicolas (9.600 TEU) in service since May 2013
Measures for throttling include the modification of the injectors, plates between crosshead and piston rod as well as a new set-up of the turbo charger. This means, that always the engines technical data have to be changed. In addition also cylinders can be cut-off - this has to be done in connection with a new torsional vibr... [More]
At slow steaming cold corrosion can occur – Castrol sees concerns by specifications given from the engine manufacturers confirmed.
Many shipping owners go for slow steaming. But to avoid long term damages by slow steaming particular adjustments must be done. One aspect is the use of optimized lubricating oils. A possible problem is cold corrosion. The lubricating oil manufacturer, e.g., Castrol Marine assumes that, during slow steaming, cold corrosion can happen if lube oils with lower base numbers (BN) come together with fuels with higher sulphur content. “We always point out that oils with lower BN are unsuitable for slow steaming with modern diesel engines. Both market leading OEM’s have now created specific guide lines, which go along with our experiences”, says Castrol manager Paul Harrold. They recommend their customers to coordinate the use of lube oils with engine type and working conditions. Last May Castrol presented some case studies. These figures un... [More]
DNV has gathered before and after operational-performance data which indicate that redesigning the bulbous bow of slow-steaming container ships can produce fuel savings of 5 per cent or above. These ‘nose jobs’ can have a payback time of less than a year.
Hyundai Merchant Marine (HMM) operates a series of 8,600 TEU container vessels which were designed and built for high speed. These vessels are actually able to operate at 27 knots. However, today the vessels are “slow steaming”, operating in the range of 15 to 18 knots. At these speeds, the existing bulb is not efficient.
In order to quantify the possible savings potential, DNV carried out a comprehensive study to develop a new bulbous bow shape optimised for the expected trading conditions. A cost-benefit assessment was conducted based on the estimated savings and this created the basis for HMM to go ahead with a conversion.
Based on input from DNV, Daewoo Ship Engineering Company (DSEC) carried out the struc... [More]
Ocean-going ships, presently in an excess for the amount of cargo to be lifted, increasingly steam at slower speeds in order to save expensive fuel oil bunker costs; better that than to be laid up reckon shipowners.
Photo courtesy of Maersk Line
The problem is that large marine diesel engines are not designed to operate below 85% power for long periods without harmful effects; effects best ameliorated by getting lubricating oil of the right specs. After a quick look at lubricating oil solutions, a handy little device to check cylinder performance is spotlighted.Marine Diesel Engines & Slow SteamingExperts at Castrol Marine drew on OEM reports and their own engine performance tests to analyse the effects of slow steaming on engine performance, finding that the oil-feed rate as well as a lower engine operating temperature had a bearing on the amount of corrosion caused on piston rings and cylinder liners.At lower loads, the cylinder oil’s feed rate is reduced, making ... [More]