Ship Handling & Ship Safety Articles

16.05.2024
Why Do Not Ships Have Headlights?

Every now and then we hear yet another story about a nighttime collision at sea, maybe between a ferry and a yacht or even between two large ships. Either way, the same question always comes up – why did not they see each other?

Sure, if it is nighttime, it is harder to see things, as you must have noticed it yourself when driving at night, you need headlights to stand a chance of seeing anything. Yet, when you look at a ship at night, they do not have headlights.

But why? If the headlights work fine for car, why not for ships? Well, think about what a headlight actually is. It is just a source of light, designed to emit photons which can bounce off objects and return to your eyes. Your brain then interprets them and tells you what you are seeing.

Simple enough but you need a light powerful enough to illuminate the area you are looking at. The power from the light is dispersed across the full width of its beam. Then, when the light hits an object, small bit of its beam that hits the object is reflected back, but it is again dispersed, meaning that only a tiny fraction of the original light gets back to you.

That is fine in a car, you want to narrow the area right ahead of you extending out far enough that you can take action to avoid the things that you see. Even at motorway speeds around 100 meters should be enough. You are probably starting to see where I am going with this.

With a ship 100 meters may not be enough to see your own bow, let alone to see far enough ahead to take any action. A large cargo ship, for example, needs more than a mile to stop. With two such vessels approaching each other, you are looking at needing at least two miles visibility to take action in time. You know how bright a car’s headlight is. Just think how much brighter a ship’s headlight would need to be to have the same effect!

Imagine two ships approaching each other at night. We have already established that they do not use headlights to see each other. So, what do they use? Well, they still use lights, but they are called navigation or nav lights instead. Every seaworthy vessel is fitted with nav lights the idea is that they are arranged in a standardized distinctive way so that other vessels can not only see you, but also identify how you are moving. As nav lights are fitted to the target vessel, their power only needs to be sufficient to be seen by other vessels.

If you have a light fitted as shown on the picture, rather than just relying on a tiny portion of reflected light, you can see howWhy Do Not Ships Have Headlights 2 much easier it will be to see compared to using a headlight.

But what about identifying their movement? Let us take this cargo ship as an example. She would show two masthead lights, the aft one being higher than the forward one. These immediately tell other ships in which direction she is moving. But she also shows sidelights. These are the colored lights that you probably know about – red for port and green for starboard. Again, it reinforces, which way she is traveling.

But the lights can tell us even more than that. If we are looking at the vessel’s port side and she turns towards us – as the masthead lights come in line, you can start to see both sidelights. You know the other vessel is heading straight for you. Take the look from above and you can see that the only angle where you would see all those lights is from right ahead. The observant among you will spot that these lights do not go all the way around either. Instead, we have a single white light filling in the sector of the stern, as shown on the picture. What this means is that if you spot a single white light, one of the things it could be is a power-driven vessel viewed from a stern.

If she turns a bit you can come on the cusp of viewing her sidelights and mast headlights, too. Looking from above, the only thing where this is possible, is along the white line shown – it is two points of 22.5 degrees above the beam – the very definition of overtaking we took straight from COLREGs.

Of course, we just looked at a power-driven vessel here but there are countless variations on this arrangement. You can Why Do Not Ships Have Headlights 3add extra mast headlights to indicate you are towing or show only side lights to indicate you are sailing. You can even modify your status by adding two all-round red lights to show you are not under command, or three all-round red lights to show you are aground or make the middle one white to show that you are restricted in your ability to maneuver.

See, nav lights tell you so much more that headlights ever could. They accomplish the basics making the vessel show up against the dark sky. But, in addition, they allow you to identify the vessel type, work out its aspect, and see which way she is moving – all vital information when it comes to applying the collision regulations, and working out which of you needs to give way to the other.

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15.04.2021
Effective Communication On Board

It is very important to understand the importance of the shipboard communications at all levels in order to achieve safe and efficient ship operation. What is communication? Here is one possible definition – transferring signals and messages from one person to another with the purpose of creating an understanding, a particular meaning or a certain reaction from the other person. If no reaction is received, we are talking about one-way communication.

According to statistics, as much as 70-80% of incidents and accidents at sea can be traced back to some kind of communication problem including those between personnel on the bridge because of different culture, native language, age, experience etc., between bridge and engine personnel, ship and tugs, ship and VTS, ship and ship owner/operator, ship and authorities.

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28.02.2021
Why Are Ships Painted Red Below the Waterline?

Have you noticed how boats, both large and small, tend to be painted a different color under the water? Most often, it is red but actually nowadays you can get any color you like. The reason for it goes back to the earliest days of sailing ships. Back in those days wooden sailing ships would slowly plot around the world. A combination of their slow speed and rough hull made them an ideal breeding ground for underwater growth. Just take a look under a pier and you will see the sort of marine growth these ships used to suffer. We are talking barnacles, worms, seaweed, and things like that, so that is the issue.

Well, all of these things have negative impacts on ships over time. You get the obvious of things like damage to the hull itself due to worms and the actual growth; then you get issues like the additional weight that they have to carry around and reduction in maximum speed due to the extra drag. Of course, on sailing vessels that drag-on weight would impact their ability to sail upwind which would yet further reduce their efficiency. What you need is a way to stop marine life from growing on the bottom of the hull andWhy are ships painted red below the WL 2 this is where antifouling comes in.

Antifouling is just a system designed to reduce fouling by animal and plant life on the underwater sections of a boat or a ship. Early solutions were to place copper sheets on the hulls of ships. The “Cutty Sark” is a great example of this. The primary purpose of the copper sheets was actually to stop worms eating their way through wooden hulls. A secondary benefit is that the copper would reduce the growth of plant life.

Of course, as wooden hulls were replaced by iron, worm issue did reduce but they have never been eliminated. Just look at the leisure industry today and you will still see a plenty of wooden hulls around, and of course regardless of its construction materials we still have the same old issue of drag caused by the growth of plant life is probably more important now to keep that under control, considering the costs of fuel and efficiency savings on long passages.

We still need antifouling to stop a combination of worms, barnacles and weed from growing on the underside of the hulls but instead of using the old technique of copper sheets we now use a form of paint. The subject paint works on the same principle and actually still uses copper as a biocide though it is mostly cuprous oxide mixed with the paint rather than copper sheets.

It is the natural red color of those copper oxides that has led to the traditional red color of antifouling. Modern antifouling systems can be broken into two broad categories – hard and soft. Soft coatings are designed to wear off over time continuously exposing Why are ships painted red below the WL 3fresh biocides as the outer layer of the paint wears off. Hard coatings, on the other hand, are designed to be lot more durable. They are meant to last a lot longer. As the biocides are released the durable layer of paint remains but the biocides contained in the outermost layer do get used up.

Both systems work on the same principle. They gradually release biocides commonly based on the chemical element copper. The difference is that the soft coatings allow the paint to flake off as well. As you can imagine, there are environmental considerations – antifouling releases biocides and possibly paint into the environment. That is one reason a lot of ports do not allow cleaning the hulls. They do not want the extra dose of biocides and paint released by the rubbing process.

One of the other options is to use the normal hardware and paint on the other side of the hull but that will result in a lot of aquatic growth. That is fine on a small boat that you can pull out of the water and clean quite often, but is not so great on a container ship running around the world. What would happen if, for example, container ship picked some weed in Asia and carried it into the Baltic Sea where it takes hold and overtakes some of the native species? Similar things have happened and do actually continue to happen though it is not so much from hull growth because antifouling is more of an issue for the ballast water.Why are ships painted red below the WL 5

So, aside from just using no antifouling, what could you do? There is a talk of systems that slowly use some sort of jelly from the hull. The theory is that as the growth attaches to the hull, the jelly seeps off and takes the growth with it. There are also some silicon based paints that make it hard for barnacles to stick to the hull. Unfortunately, these do not actually stop the growth but it makes it easier to clean off.

As said above, most ports do not allow cleaning anyway not only because of the historical antifouling issues but also they do not want to clean off species that are not native to the harbor itself. The last thing they want is to be overcome by some sort of invasive weed from the other side of the world.

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03.12.2020
Personal Safety On Board — The Shipboard Management Role

Safety must be essential factor in all ship operations. Ship owners need to make a profit, but the best way to do that today is by operating safely. The senior management team on the ship needs to put the health, safety, and security of their crew above everything else. To achieve that, safety must be managed effectively.

The ISM Code makes safety management essential. But safety management makes good sense in both human and commercial terms. For all shipping companies, a history of shipping incidents and accidents damages their reputation and leads to the loss of business and further financial consequences.

It may seem that accidents happen at random, but the researches show that there appears to be a relationship between near misses and serious accidents. The more near misses, or hazardous occurrences that happen, the more minor or serious accidents occur. Proper evaluation of a near miss or hazardous occurrence reports and making appropriate changes in procedures will reduce accidents and contribute in managing safety on board.

There are many components to successful safety management and obvious one is good training and familiarization with the company’s safety management systems. Another one is proper maintenance, including making sure that all maintenance is correctly carried out and logged. Motivation and leadership is also vital. If safety matters to the senior officers, everyone on board will notice that; they will then make safety a high priority in their own activities.

This leadership is an essential part of another component – the development of the safety culture. The senior officers must make Pers Saf On Board - The Shipb Mant Role2it clear that they are committed to the company’s safety procedures for it is their attitude to safety that determines the safety culture of the ship.

Finally, there are the safety management procedures themselves – these shall be developed by the shore office in consultation with the shipboard management team based on their experience, risk assessment, and legal requirements. But the shore office’s responsibility does not end with creating good working procedures. They also have a responsibility to employ personnel of a suitable standard both at sea and ashore.

Most important of all, there shall be open communication and trust between the ship and the shore. The Designated Person Ashore under the ISM Code must ensure that everyone ashore and on board works together to manage safety. For safety management systems to be effective, they must be regularly reviewed to ensure continuous improvement.

Standards must be established and then implemented. The progress of this implementation must be followed and measured so compliance can be checked. The situation must be reviewed and changes made if the objectives have not been met.

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24.11.2020
Bridge Resource Management

Bridge resource management is such a vital part of the ship safety that it is requirement of the STCW convention and the ISM Code. It is a method which uses all resources available to conduct safe and efficient vessel bridge functions. These resources include both equipment and personnel. It takes both traditional skills to operate the equipment as well as managerial skills to use personnel resources to their potential. In order to best utilize personnel o board your vessel, you must understand the human factors involved. These include communications, situational awareness, stress, fatigue, leadership and decision making, and group dynamics and integration.

The NTSB has determined that human factor contributed to 75-80% of all marine casualties. That is why the STCW has made a requirement that all shipboard officers must demonstrate an understanding of the concepts which constitute effective Bridge Resource Management. Note that it is important to establish good vertical communication including making sure to includeBridge Resource Management 2 unlicensed personnel.

The bridge personnel’s performance is essential to the safety of the vessel. In order to achieve a sound and efficient bridge organization, defined procedures including Master’s standing orders are essential. Procedures shall be established to ensure duties are clearly defined and assigned to certain individuals. Effective procedures will minimize the risk that an error by one person will have disastrous and irreversible consequences. No one should be assigned more than they can handle, and no duty should be re-assigned without notifying the watch officer.

A visual lookout should always be maintained. In good visibility, it is good practice to periodically undertake collision avoidance routines in order to be fully prepared if difficult situations subsequently arise Bridge Resource Management 3and reduce visibility.

To cope with the workload and risks, specific watch conditions should be established for restricted visibility, heavy traffic, and pilotage conditions. It is important to make sure that all equipment needed is available and functioning. If equipment is not functioning, its limitations and errors should be correctly applied. Pilots are valuable addition to the bridge team; there must be a good exchange of information between the pilot and the bridge team so each is aware of the other’s intentions.

In assigning duties, careful consideration should be given to the ergonomic layout of the bridge. The concept of the zones and responsibility takes this into consideration and duties are assigned so that personnel are not interfering with each other but can share critical information. Checklist should be used but not treated as a substitute to the thorough knowledge of the ship or procedures. Checklists have many benefits, such as focused attention at the task at hand, helping to establish priorities, serving as an aid against failure of human memory, helping to balance the workload, and eliminating guesswork by instituting standard procedures. The STCW convention requires that new crew members be given familiarization training prior to assuming any duties, and Masters and mates have knowledge of Bridge Teamwork Principles.

 

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22.11.2020
Lifeboat Drills — Preparing for Safety

In this short article we will have some talk about the lifeboat drills that are supposed to be carried out on board ships on the regular basis in order to make sure that the ship crew members are duly aware of the lifeboat arrangement of their vessel and are able to launch the lifeboats in a safe way.

Lifeboats save lives and that is a known fact. The lifeboat will get you to safety except that occasionally, through poor design and maintenance, lack of training, lack of familiarity with their equipment, communication failure or simply operator’s error, lifeboat drills have actually taken lives or caused serious injury. That is why it is critically important that the drills are carried out with all participants focused on the safety.

So, what are the most important things you need to know here?

Firstly, you should know that whatever job you have on board a ship, anything that threatens the safety of your vessel, could put you in the position of having to know how to operate a lifeboat. As a professional mariner, you know that any lifting operation has its hazards, especially if you are launching or recovering a heavy lifeboat.

Look at this video showing what had actually happened during one of the lifeboat drills – there is no scenario, the case is real.

The on-load release mechanism failed because the cables controlling the hook release were not adjusted properly so the lifeboat was free to fall into the sea. The crew did everything correctly. The lifeboat was actually being recovered and luckily there was no one on board the lifeboat. If there had been, there is a high chance they would have been badly injured.

It is been claimed that as many as sixteen percent of the seamen who have been killed on merchant ships, died during lifeboat drills, and eighty percent of the fatalities are claimed to have been due to the hook release mechanism.

Let us look at the example how you would launch and operate a lifeboat. It may not the same as that on your ship but you can find details of lifesaving equipment and procedures for holding safe drills in your company ship’s safety management system.

One should never enter the lifeboat without checking that release hooks are fully closed and that the fall prevention devices are in place if they are used. However, there is one particular control that you must be very clear about – the release handle. Check that the release handle is in the closed and locked position and that the safety pin is installed in place.

It is this release handle that was operated in error in our real life example above, resulting in the lifeboat falling down to the sea. It should be understood that it is not always easy to know from the inside of the lifeboat how far it has been lowered or how high it is above water. For that reason, the system has been devised and used in some lifeboats that should ensure the lifeboat is in the water by using a hydrostatic sensing system.

So, we can say that deploying lifeboats in drills should always been undertaken in a professional and seamanlike way ensuring that full attention is paid to the significant risks that are inherent in getting you away from your ship if the worst happened. Please ensure that all crew members participating in the lifeboat drills in any role have thorough understanding of the safety aspects. This understanding may eventually contribute into the provision of the safety of human life at sea. We all know that the regular and properly conducted shipboard drills are the pre-requisite for provision of the safety.

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18.11.2020
Distress flares

Distress flares are the essential item of safety equipment. Flares are one of the most effective and rapid means of both signaling distress and indicating your exact position. It is imperative that flares are stored in a water-proof container. Flares can play a key role in assisting early rescue and also reducing a heavy cost of search and rescue operations.

In Tasmania, for example, 48 % of boats are used outside smooth waters, in sheltered or open waters, and are therefore required to have flares on board. Of course, many areas of smooth water can get rough, so the subject recommendation should be applicable to those boats, as well.Distress flares

The general area of operation of your motor boat determines firstly whether they need to be carried and, secondly, the type of flares and number required. For sheltered, partially smooth waters the requirement is two red hand flares and two orange smoke flares. For open and coastal waters the requirement is two red hand flares, two orange smoke flares, and two red parachute rocket flares.

As various brands of flares have different methods of ignition, it is important to carefully read the instructions to ensure your familiarity with a method of operation. Prior to leaving, it is vital that all your passengers also know how to activate the flare. Your instructions may well save your life.

It is important to check the expiry date and replace any out of date product. Flares generally have three-year expiry from the date of manufacture. Such products can be returned to manufacturer. Be advised that it is an offence to activate a flare unless doing so for rescue purposes or when authorized by Master.

Distress flaresWhere possible, hand-held flares should be activated on the downwind side of the vessel. Your arm should be fully extended above your head. Make sure that all other passengers and a vessel superstructure is well clear of this operation. Hand flares, particularly red flares, emit extreme heat, and so do be careful when using them.

The parachute rocket flare is a hand-held self-contained distress rocket which ejects a parachute with a suspended red flare at around three hundred meter altitude. It burns for forty seconds at a brilliant thirty thousand candela. It can be seen from fifteen kilometers by day and forty kilometers or more by night. Rocket flares must not be activated when a helicopter or aircraft is overhead.

Orange smoke flares are the most effective device for daytime use. They emit a vivid expanding cloud of dense orange smoke visible for sixty seconds and can be seen at a distance of up to four kilometers at sea Distress flareslevel and even further from an aircraft.

Red flares are most effective at night but may be used during the day, as well. Red hand flares burn for over sixty seconds with an intense fifty thousand candela red light. They can be observed from a range of up to ten kilometers at sea level on a clear dark night and up to twenty kilometers from the air. They can be seen at day light over a shorter range.

Remember, you can be fined for not having the required safety equipment. Always check to ensure your compliance with the applicable requirements before you go boating. Needless to say that having all required safety equipment on board and maintaining it in a good working condition may one day save your life and the lives of your passengers.

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14.11.2020
Ships in Shallow and Restricted Waters

Narrow passageways and fairways in rivers and canals with a navigable depth and width comparable small in relation to the draft and the breadth of passaging ships are called restricted waters. The maneuverability of ships navigating through such restricted waters will be affected by high hydrodynamic effects that are different from those when ships navigate in broad and deep waters. These peculiar hydrodynamic effects are the shallow water effects, ship squat, interaction and bank effect. Let us have a look into the shallow water effect and ship squat.

When a ship proceeds, the surrounding water is displaced toward the sides and bottom, making a relative flow against the ship’s advance. Advancing hull submerges deeper compared to when she is dead in the water; this changes the trim because the water Ships in Shallow and Restricted Waters - 2around the hull flows a little faster compared with the ship’s speed and the hydraulic pressure decreases. This phenomenon is called ship squat; but why does this take place?

In shallow water, when the bottom clearance is comparatively small, the ratio of the horizontal flow along both sides of the ship increases because the current towards the bottom is restricted. The hydraulic pressure along both sides of the hull decreases, as the nearer hull is to the surface flow, the faster the rate accelerates and the water level around the ship drops considerably. For this reason, sinkage of the bow and stern and subsequent trim change become larger in shallow water than in deep water. We should be careful that sinkage of the bow and change of trim become greater when a ship Ships in Shallow and Restricted Waters - 3runs in shallow water.

Now let us see how the depth of water affects the turning capability of the ship in shallow water. We will have a look at the data of the turning capability of the large ships. Every curve indicates the tactical diameter of a specific ship by the multiples of the ship’s length. There is another graph illustrating how the turning track of the ship differs as the depth of the water changes. Note that in both cases, the ratio of the water depth to draft is changed with all other parameters remaining same. Thus, we can estimate the tactical diameter of a ship running in restricted water as the multiples of its length, although the presented data are taken from the test results of the large ships, this method can also be applied to smaller ships.

Ships in Shallow and Restricted Waters - 4In view of the maneuverability of a ship, the depth of water also affects course stability like the effects on turning ability. We shall study the difference of the effects on course stability in deep water and in shallow water from the results of the zigzag maneuver tests. In the zigzag maneuver test a ship’s rudder starts to swing alternately to port and starboard when the ship is set on the steady straight course. At first, the rudder is put to starboard ten degrees until her head swings starboard ten degrees from her original course. Immediately after the ship’s head swings ten degrees starboard, the rudder is changed to port ten degrees until her head appoints ten degrees port from her original course.

This alternate rudder operations are repeated several times making a ship run in a zigzag course. On the picture you can see the results of the zigzag tests conducted in deep and shallow water. The required time to turn a ship’s head port or starboard to a settled angle in shallow water become shorter with a smaller overshoot angle than that in deep water. This means that we can expect quicker rudder effect in shallow water compared to that in deep water.Ships in Shallow and Restricted Waters - 5

A well-remembered case among several cases reported in the past is that of a large passenger ship navigating in shallow water without reducing the speed that hit her bottom severely on the rocks. When running in restricted water, it is essential to keep enough underkeel clearance to avoid the deterioration of the maneuverability and touch bottom damage.

Underkeel clearance means the space between the ship’s bottom and the sea bed. It equals the value when the ship’s draft is subtracted from the sum of chart datum and Ships in Shallow and Restricted Waters - 6height of tide at that time. To maintain enough underkeel clearance, we have to consider the factors affecting the sinkage of the hull such as squat allowance, wave response allowance, possible error of chart datum, meteorological and oceanographic conditions, and other environmental conditions, and secure a safety allowance that eliminates ship handling difficulties.

The effects of sinkage and change of trim when a ship navigates in shallow water greatly affect the ship’s maneuverability. Enough knowledge of these effects in restricted waters will prevent accidents.

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