An explanation to the mystery of cargo ships that sink when their cargo liquefies

Solid bulk cargoes are typically “two-phase” materials as they contain water between the solid particles.
Solid bulk cargoes are typically “two-phase” materials as they contain water between the solid particles.

Think of a dangerous cargo and toxic waste or explosives might come to mind. But granular cargoes such as crushed ore and mineral sands are responsible for the loss of numerous ships every year. On average, ten “solid bulk cargo” carriers have been lost at sea each year for the last decade.

Solid bulk cargoes – defined as granular materials loaded directly into a ship’s hold – can suddenly turn from a solid state into a liquid state, a process known as liquefaction. And this can be disastrous for any ship carrying them – and their crew.

In 2015, the 56,000-tonne bulk carrier Bulk Jupiter rapidly sunk around 300km south-west of Vietnam, with only one of its 19 crew surviving. This prompted warnings from the International Maritime Organisation about the possible liquefaction of the relatively new solid bulk cargo bauxite (an aluminium ore).

A lot is known about the physics of Continue reading “An explanation to the mystery of cargo ships that sink when their cargo liquefies”

Flexible mobdock repair method for underwater shaft seal repairs developed by Hydrex

Diver/technician re-welding the rope guard after shaft seal replacement
Diver/technician re-welding the rope guard after shaft seal replacement

Hydrex has developed a flexible mobdock repair method that enables the underwater replacement of all types and sizes of shaft seals. This technology has been successfully used by Hydrex diver/technicians for over a decade. It allows ship owners to keep their vessel sailing, saving precious time and money.

Damaged stern tube seals will cause an increasing amount of oil leaking or water ingress as the damage worsens. By replacing the seals when the damage is first discovered, Hydrex keeps the down time low. The ship can keep its schedule as seal repairs can be performed during cargo operations. This is done by creating a dry underwater working environment around the shaft.

It is not always straightforward to replace seals, because there can be quite a bit of variation in the configurations of the stern tube itself. There can also be complications with the liners, which can be worn down and show ruts. All this is routinely handled by Hydrex teams on the jobs.

In this article you can find a short summary of some of the recent Continue reading “Flexible mobdock repair method for underwater shaft seal repairs developed by Hydrex”

Ethylene vapors activate carbon monoxide alarm says safety alert

A certified marine chemist traced the source of the vapors to an eight inch crack on a cargo vapor line
A certified marine chemist traced the source of the vapors to an eight inch crack on a cargo vapor line

The USCG has published a safety alert informing marine inspectors that ethylene vapors on LNG carriers can activate Carbon Monoxide alarms. Specifically, during an examination of a LNG carrier whose cargo tanks contained ethylene vapors, PSC Officers (PSCOs) received alarms on their portable four gas meters giving a reading of 60 to 100 parts per-million (PPM) Carbon Monoxide (CO).

A certified marine chemist traced the source of the vapors to an eight inch crack on a cargo vapor line. PSCOs initially thought the alarm was related to a combustion event and did not suspect the ethylene vapors were the source, because they did not get a Lower Explosive Limit (LEL) reading on their monitors.

The chemist indicated that the LEL most likely never alarmed because of high winds on deck. He further explained that the molecular weight of Ethylene (28 g/mol) was identical to the molecular weight of CO which accounted for the CO PPM readings. USCG personnel contacted the manufacturer who confirmed that Continue reading “Ethylene vapors activate carbon monoxide alarm says safety alert”

INTERCARGO Bulk Carrier Casualty report published

INTERCARGO has published its Bulk Carrier Casualty report that analyses bulk carrier casualties over the period from 2008 to 2017
INTERCARGO has published its Bulk Carrier Casualty report that analyses bulk carrier casualties over the period from 2008 to 2017

INTERCARGO has published its Bulk Carrier Casualty report that analyses bulk carrier casualties over the period from 2008 to 2017. The report revealed that 53 bulk carriers over 10,000 dwt have been identified as total losses over that period with cargo shift and liquefaction remaining a great concern.

In 2017, the tragic losses of ‘Stellar Daisy’ carrying an iron ore cargo and ‘Emerald Star’ with a nickel ore cargo raised questions of structural integrity and safety condition of high density cargoes carried onboard. These two bulk carrier casualties caused the loss of 32 seafarers, the highest annual loss of lives since 2011.

As the report reveals, 9 casualties of suspected cargo failure consisted of 6 bulk carriers carrying nickel ore from Indonesia, 2 vessels with Continue reading “INTERCARGO Bulk Carrier Casualty report published”

London P&I Club reveals key causes of recent container loss claims

Photo credit: London P&I Club
Photo credit: London P&I Club

A recent run of container loss claims by the London P&I Club has highlighted some of the common contributory factors that emerge as part of the investigation process. The Club noted that the subject of misdeclared container weights continues to be a problem. But with this particular run of claims it was the attending surveyor’s observations about cargo securing equipment that caught the eye.

In these cases, it became clear that several manual twist locks were not correctly locked at the time of the incident. The causes for this were considered to be two-fold – some twist locks were damaged (specifically with locking levers either bent or missing), or the units in service were a mixture of right and left-hand locking units, leading to confusion over the observed status of the twist lock.

Upon investigation, a number of container corner castings and container foundations showed no signs of having a locked twist lock forcibly removed during the collapse, the natural conclusion being Continue reading “London P&I Club reveals key causes of recent container loss claims”

Recent court ruling found cargo insurer not liable for general average contributions

Recent court ruling found cargo insurer not liable for general average contributions
Recent court ruling found cargo insurer not liable for general average contributions

A recent UK court decision has concluded that a cargo insurer was not liable for general average contributions as the owner had failed to exercise due diligence, which led to the breakdown of a vessel’s main engine.

The crude oil tanker, “Cape Bonny”, was sailing between Argentina and China when the number 1 main bearing failed catastrophically. The breakdown happened when the vessel was trying to avoid a tropical storm and towage assistance was needed. The shipowner declared general average and contributions were sought from the parties to the common maritime adventure, which naturally included cargo interests. The cargo’s contribution was assessed at about US$ 2.5 million.

General average is governed by the York-Antwerp Rules and is included into charterparties and bills of lading. However, parties to the maritime adventure are not liable to contribute if they can successfully prove a breach of contract.

A breach of contract is possible if the vessel was not fit to sail before and Continue reading “Recent court ruling found cargo insurer not liable for general average contributions”

A plan for a digital twin to develop Blue Denmark is announced

Digital Tvilling
Digital Tvilling

Danish Maritime Authority has prepared a report on “the digital twin”. A digital twin presents a ship digitally throughout its lifetime.

Imagine having access to every bit of information on a ship – from engine performance to hull integrity – available at a glance throughout the full lifetime of the vessel?

A digital twin is a ”digital presentation” of a vessel with associated processes and systems, based on continuous data collection. And these processes or systems are presented digitally. Rather than arranging for a physical test cycle, the processes can be followed easily and quickly.

Mogens Schrøder Bech, Senior Consultant of R&D at the Danish Maritime Authority:
“The potential of the digital twin is huge because it is possible to make a number of decisions on optimisation digitally rather than by means of physical tests. And this potential will increase along with the development of digital tools.

“This enables us Continue reading “A plan for a digital twin to develop Blue Denmark is announced”

Possible new cure for diesel bug

Possible new cure for diesel bug
Possible new cure for diesel bug

A new product that removes water from the bottom of diesel tanks is expected to end all diesel bug problems.

The Diesel Dipper is a self-contained system independent of the engine. Fitted with a 12-volt pump, it is designed to suck water from the floor/bottom of a fuel tank below the fuel suction and by doing so, makers Marine 16 say it eliminates or prevents diesel bug and engine failures.

Marine 16 said: “Water and sludge lying on the bottom of the tank is drawn up into a ‘tank separator’ where it separates from the diesel and collects on the bottom. This accumulated water and sludge is then periodically drained off into a container.”

The clean diesel exits the top of the separator and flows through a Continue reading “Possible new cure for diesel bug”

Partnership formed to study the safe use of lithium-ion batteries in shipping

Partnership formed to study the safe use of lithium-ion batteries in shipping
Partnership formed to study the safe use of lithium-ion batteries in shipping

DNV GL has announced a joint partnership to study the safe use of lithium-ion batteries in shipping. The class society’s partners in the effort include flag states, research institutions, battery and propulsion suppliers, fire system manufacturers, shipowners, vessel operators and yards. DNV GL says that the hope is to identify improvements not just for the batteries themselves, but for the associated systems, procedures, and approval processes.

“We put a great deal of effort into ensuring the safety of these new alternative systems, but the cost of the present safety and approval methodology is cumbersome. This collaborative effort gives a chance for an even greater level of safety,” said Rasmus Nielsen, a naval architect and officer at project partner Scandlines.

The project’s deliverable’s are focused on safety. Tasks include the development of Continue reading “Partnership formed to study the safe use of lithium-ion batteries in shipping”

Deck water spray failure highlighted as one of the main deficiencies on LNG carriers

Deck water spray failure highlighted as one of the main deficiencies on LNG carriers
Deck water spray failure highlighted as one of the main deficiencies on LNG carriers

The US Coast Guard has published an information bulletin about the ongoing issue regarding inadequate deck water spray systems on LNG carriers. US Coast Guard has noted that inadequate coverage of the required areas by a deck water spray system is one of the main deficiencies identified when certificate of compliance inspections are undertaken on these vessels.

The Deck Water Spray system is required by the IGC Code 1993, Regulation 11.3. This requirement text has remained nearly identical back through the GC Code 1983 and to the EGC Code. The new 2016 edition of the IGC Code incorporates the amendments adopted by the IMO MSC at its ninety-third session (May 2014) by resolution MSC.370(93).

These amendments, which entered into force on 1 Jan 2016, consist of a complete replacement text of the IGC Code and will apply to ships whose keels are laid or are at a similar stage of construction, on or after 1 July 2016.

Across the industry, vessel operators and crews have struggled to keep these simple systems operating properly. Ineffective operation of the deck water spray appears easily managed by periodic removal of the Continue reading “Deck water spray failure highlighted as one of the main deficiencies on LNG carriers”

Revolutionary design of harbour escort tug launched

Revolutionary design of harbour escort tug launched
Revolutionary design of harbour escort tug launched

Dutch towing group, Muller Maritime, has taken delivery of the harbour escort tug Multratug 32. Despite the high number in its name, it is both the first in its class and the first vessel of its kind.

Designer Robert Allan Ltd. calls it a “Carrousel RAVE Tug,” or CRT, and it integrates two features into a novel new package. First, it has two Voith cycloidial drives arranged fore and aft (the Robert Allan-Voith RAVE design). Second, its towing winch is mounted on a giant circular bearing – the “Carrousel Towing System” – which sits around the entire wheelhouse. With these design elements the tug can rotate with a load on its line, without fouling the towline on its own superstructure or girting. It is designed to pivot relative to its direction of travel, creating drag with the width of its hull.

Robert Allan says that it is the tug’s relative heading that determines the magnitude of the towline force. At speed, large forces can be generated by applying a small amount of thrust to change the tug’s orientation to the escorted vessel. The propulsion system is primarily used to control the tug’s heading, position and speed – not to generate bollard pull. Continue reading “Revolutionary design of harbour escort tug launched”

Ships carrying heavy fuel oil cargoes subject to ongoing condition surveys

Libya releases tanker carrying fuel to rival government
Libya releases tanker carrying fuel to rival government

In order to improve ship standards, the International Group of P&I Clubs has said it will continue to conduct survey triggers for seagoing vessels of 10 years of age or more carrying heavy fuel oil cargoes.

As a result, all sea-going vessels that are 10 years old or more and have carried heavy fuel oil as cargo within the previous 12 months will be subject to condition survey, unless:

– The vessel has undergone a P&I club condition survey during the previous 12 months.
– The vessel has undergone a Special Survey during the previous 6 months.
– The vessel has a valid Condition Assessment Program (CAP) rating of 1 or 2 with a classification society having membership in the International Association of Classification Societies (IACS).

Operators should have in mind that a declaration is now required so that Continue reading “Ships carrying heavy fuel oil cargoes subject to ongoing condition surveys”

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