No matter how well designed the rig or how well supervised the crew, only careful, conscientious conduct by everyone can assure safe operations. Each person should receive instructions on the proper way to perform their work and the use of personal protection equipment (PPE). Safety standards prohibit the wearing of rings or other jewelry, loose clothing, or long hair on a drilling rig. All these things are subject to being caught in moving machinery.
The mandatory personal protection items worn by each crewman should include hard hat, safety boots, gloves, and safety glasses. Proper clothing is also important.
Safety hard hats must be worn by all personnel, including visitors, when in the work area. Hats must be of nonmetallic, nonconductive material. They must meet prescribed standards of strength and protection from impact, flying objects, or electrical shock. A bright colour increases visibility.
Safety Shoots and Boots
Steel-towed footwear made of heavy leather or neoprene construction is mandatory on drilling rigs. They greatly decrease the number and severity of toe injuries. Soles and heels should be of nonskid material (rubber is too slippery). They should be discarded when the metal begins to show.
Gloves protect the hands from minor injuries and improve the hold on slick or wet surfaces. They should be of heavy cotton construction, short and close fitting. Large gauntlets are apt to get caught in something so gloves of this type should not be worn. Rubber gloves are needed when handling caustic or corrosive material.
Safety Glasses, Goggles, Face Shields
Eye protection is of utmost importance. If an eye injury occurs, prompt medical attention is critical. Personnel should always wear approved safety glasses, goggles, or face shields when engaged in the activity where flying material is generated. These should be readily available on every rig. The risks to eyes are numerous, whether engaged in routine maintenance chores or a major activity like pulling the drill string. Any action involving a hammer can produce flying chips. Wire brushes, grinding wheels, scraping, compressed air or steam cleaning operations all present dangers to vision.
Approved splash-proof goggles or face shields should be worn when handling hazardous materials, such as caustic, cement,cleaning solutions, molten metal, or chemicals of any kind.
Electric arc welding operations should be shielded to prevent damage to the eyes of observers. The welder should always have a helmet on and helpers should be furnished special goggles.
Contact lenses are discouraged because they can hinder attention to the eye if immediate action is required.
Only close-sitting, clean clothing should be worn. Long-sleeve shirts, with shirttails tucked in, are recommended. Cuffless trousers help prevent tripping. Each crewman should have available a fresh change of clothing should their work clothes become oily or soaked with chemicals. Aprons should be worn when handling chemicals.
In cold weather, dress as lightly as possible considering the weather and activity level. It is better to be a little cold than too warm. Overheating can cause sweating, dehydration, and chilling when activity stops. Keep clothing as dry as possible and wear the clothing in layers. Sweaty or wet socks can lead to frostbite or trench foot; change them often.
Hearing protection gear should be worn around any high noise area, such as around the rig engines.
Respirators are required for spray painting, mud fixing, or working in heavy dust. Special breathing equipment and instruction are needed if hydrogen sulfide is, or may be, present.
Falls cause a significant number of injuries; therefore, a full-body safety harness is required for anyone working or climbing aloft six feet or more above the derrick floor.
In the previous article we have talked about the common sources of fire and now let’s talk about fire extinguishing. The key to extinguishing any fire is first to control it, then the flame area can be minimized and finally the fire extinguished. It is important to understand the four components that sustain the fire – fuel, air, heat, and the chain reaction. If any of these can be removed, the fire will cease. As a result, there are four ways to fight fire. The most important is to starve the fire of fuel by shutting off supply; next is to choke off the air supply. Cooling through evaporation is essential to limit the spread of fire. Once the other elements are in place, it is possible to break the chain reaction at the source of ignition.
There are four technologies available to fight the fire. To starve the fire of fuel, there are emergency systems to shut valves and stop pumps. There are passive systems, such as melt plugs on deck which activate shutdown systems at around 100 C, there is remote control through the product management system and there is ability to shut off fuel by closing valves manually. Enclosed cargo machinery spaces are provided with the fixed fire extinguishing systems suitable for the cargo carried to smother the fire. However, it is important to evacuate spaces before they are used. CO2 released at pressure can cause ignition through static electricity so it must only be used to extinguish fires and never be used to inert spaces not on fire.
Outside, the key to smothering is high expansion foam. While rarely successful in extinguishing liquefied gas fires unaided, foam is invaluable in reducing the rate of burning of pool fires in drip trays and bounded areas. Once again, if the fire is to be got under control, it is essential to reduce the radiant temperature rapidly. Foam acts to reduce the vapor emission. And, if the vapor is unignited, helps minimize the risk of ignition. Large amounts of foam are required. For LNG and LPG the foam, if available, should be optimized to create a blanket to minimize vaporization through insulation and by reducing contact with air. By its nature, foam is ineffective against jet fires.
Water is the most effective medium for cooling. Gas containers are deluged to reduce the evaporation rate due to the heat of the fire. Large volumes of water may be supplied by firefighting tugs. Water is used to reduce damage to pipes and valves, to protect personnel operating valves, or to create a barrier to prevent the fire spreading from vessel to shore. Water can also be used to disperse gas, but it does not normally extinguish the fires unless the gas can be dispersed by water spray at high volume and pressure. However, water must be used with care, especially where liquid gas has pool – in such case its effect may cause liquid to boil faster and make the fire more difficult to control.
Gas - LNG, LPG, methane, propane, butane - all valuable products compressed, or cooled, into liquid to make it hundreds of times smaller. It is transported safely in more than a thousand vessels around the world. It is safe when contained. But, when it escapes, it mixes with air with such low flash points and all it takes is a small source of ignition. It the fire is not contained rapidly, the results are potentially catastrophic.
Fire - four letters to describe very serious problem, four letters to describe the solution. Find It - Inform - Respond - extinguish. Finding a fire is relatively simple. But better still to detect escaping gases before they ignite. The problem is that both LPG and LNG are odorless and colorless. However, as the vapor is cold, it will cause a visible mist and will flow downhill like water. But the flammable gas cloud, especially with LPG, may extend well beyond what can be seen, and any flame will travel back to the source.
There are important differences between LPG and LNG vapor. LPG is heavier than air so it flows downhill and stays on the ground. LNG initially flows downhill and then rises as it heats up. So, the ignition risks for each may be different.
The IMO IGC Code specifies that vessels must have fixed detection alarms set at no more than 30% of the lowest flammable limit in the enclosed areas such as cargo, machinery rooms, accommodation blocks etc. Some systems are designed to shut down automatically at 60% LFL. Terminals also have vapor and fire detection systems and their firefighting and mitigation systems will be installed according to local requirements.
Vessel crew and terminal staff should keep each other fully informed about any fire or potential hazard. If you find a fire or ignited gas, it’s important to raise the alarm immediately. The ship’s master or terminal manager will then inform those who need to know, such as the fire brigade and the port authority. Most vapor emissions and liquefied gas spills do not result in fire. On both terminals and vessels electrical equipment is suitable for use in hazardous areas and should not cause ignition.
Should these mitigation measures fail to prevent ignition, there are two main types of fire that could result - pool fires, which are often in contained areas, and jet fires, which are often caused by a failure of a pressurized valve, a pump or a pipe. Pool fires are normally tackled first as these can cause the failure of pipes and valves, and re-ignite extinguished jet fires.
Respond quickly – time is of the essence in firefighting. Both vessel and terminal start their fire pumps. Deluge systems, water curtains and foam generators are brought into action to restrict the effects of the fire. Water spray can be used for boundary cooling, create a flame barrier or to disperse the vapor cloud.
If one tank is on fire, nearby tanks will be protected with the deluge system. The source of the gas is located and cut off remotely, if possible. Firefighting teams are mustered and correct PPE including BA’s is prepared. Hoses are run out and crew is moved to the firefighting positions. Now comes the crucial decision, whether to extinguish or control burning and then extinguish.
The decision taken will depend on individual circumstances such as whether the fire is heating vulnerable machinery, pipes, valves, or storage. Will heat damage these and create further gas or liquid escapes? Which is the greater danger – extinguishing and allowing unignited gas top escape, or allow the fire to burn? Often unignited gas is more dangerous than fire as in rare instances it could lead to a vapor cloud explosion. How much gas is likely to escape and where will it? This depends on wind strength and whether it will flow over open water or industrial land. Is it likely to disperse harmlessly or pool somewhere? Potential ignition sources downwind should be considered, such as vessels, port facilities, and houses. Often, a decision is taken to allow the gas to burn off while the source is isolated. A jet fire in a fractured pipe is likely to provide a different set of challenges and pose different questions about the risks.
If the valve is damaged and vapor cannot be controlled immediately, the water jet can be used to deflect the flame up to ninety degrees away from the vulnerable systems. Care must be taken not to extinguish the flame. Although ignited gas is often safer than unignited gas, deliberately igniting gas can be very hazardous. There is no knowing how far it is spread and where it has pooled. Every second counts - as containment vessels heat up, liquid gas boils creating ever higher pressures. But LNG and LPG boil in different ways - LPG boils off faster making it harder to control.
If, due to flame impingement, the vessel is weakened and the pressure builds within the tank beyond the point where the pressure release valve can cope, it’s possible to have a boiling liquid expanding vapor explosion. When unignited vapor is confined, or contained, it is also possible to have a vapor cloud explosion.
There are other important differences between these gases. LNG is stored at -162 degrees – it is so cold it can crack steel plates and cause severe frostbite. It can also reduce the effectiveness of protective clothing. It also burns very cleanly, with less visible flame. Its greater radiant heat makes to more difficult to get close to the source of the fire.
Whether the fire is caused by LNG or LPG, the surfaces heat up beyond 200 degrees Celsius and water droplets are deflected by the steam layer and so become less effective. The longer the fire has to create heat, the more difficult becomes controlling it. So, all firefighting equipment and clothing should be stowed for rapid access, and staff must be aware of its location…
To be continued...
This article is continuing the one giving brief introduction to the immersion suits. Practice makes perfect. If in doubt, the manufacturer's instructions are printed on the bag or the labels attached to the suit. To put on, or don, the immersion suit, as an exercise first take your safety boots to avoid any damage. Take a suit out of the bag. Check its condition. Then, insert one foot first. In an emergency, boots can be left on to save time and keep heat in. it is also advisable to wear as much warm clothing as you can. The suit is designed for both these purposes. The regulations stipulate that the person should be able to enter into an immersion suit within two minutes. This will need practice. If there is another crew member nearby, it is a good idea to help each other as it will save time and energy.
Once the suit is on, the wearer must get rid of any excess air inside it. Place a couple of fingers inside the face seal and squeeze the suit to express the air. Remove fingers before standing upright, otherwise air will re-enter. If the legs and feet have air in them, it could affect the wearer's balance when in the water and this could result in drowning.
Most suits are not floatation approved so a life jacket will be required.
Over-mittens should be worn if the hands are not expected to operate machinery or assist with evacuation. Getting off a sinking ship into the sea is dramatic. The temptation to jump must be avoided as any remaining residual air within the suit could cause it to rupture as it rapidly becomes immersed. The wearer should either use disembarkation ladder or wait for the water to rise to such level that would allow to safely step off the vessel. Be aware of other people in the water and take note of any sharp objects that might tear the suit.
The sea has always been a hostile environment and the decision to live and work upon it takes courage, skill, determination and good training. Occasionally, things do go wrong and in extreme event ship's crew may have to abandon their vessel and that could lead to person being immersed in water which could be very cold water. Under most conditions, the body maintains a healthy temperature. When more heat is lost than your body can generate, hypothermia can result. Hypothermia may develop within minutes of being exposed to cold weather conditions or it may take several hours depending on the water and wind temperatures.
Wearing the immersion suit could make all the difference - the difference between life and death. Immersion suits, also known as survival suits and abandonment suits, are intended for use in ship evacuations when rescue could be some time arriving. They are designed to save your life and since 1st of July 2006 it has been mandatory under SOLAS to provide immersion suits for every person on board cargo ships trading outside 20 deg. north or 20 deg. south. Understanding the correct procedure to put on, or don, the immersion suit, is extremely important. Hypothermia is a condition that is triggered when your body' temperature drops by just two degrees Celsius grade. As this happens, the body tries to protect itself. Circulation concentrates blood flow around the central part of the body and away from the arms and legs.
A person will start to shiver and then shake. This is the body attempting to heat itself up by muscular activity. As the temperature drops another couple of degrees, this muscular activity starts to fail. In northern latitudes, when the waters are colder, this can happen in just fifteen minutes to an unprotected person. By that time you will lose muscular control and start to lose the ability to think patiently - this could be irreversible and result in death. This situation need not arise if you know how an immersion suit works and are able to get into it correctly. It is very clever piece of kit that needs to be looked after. The suit is a one-piece item that is stored in a bag for easy access.
Let us continue to talk about shipboard lifeboat arrangements. Most passenger ships carry partially enclosed lifeboats and the types of release gear are similar to those used for totally enclosed boats. The winch operator lowers the lifeboat to embarkation deck where it must be securely bowsed. The methods used for that can vary very widely so you should consult SOLAS training manual for detailed instructions. Before anybody enters the lifeboat on an exercise drill, you must confirm that the fall preventing devices are in place and have been checked for security.
Only then can the person in charge enter the boat, turn on the main battery and manually disconnect the external power supply. At this point the lifeboat will be swung into the embarkation position and boarding can begin. The passengers will board the lifeboat through the ports and directed to their seats to ensure an even distribution of weight. The first to board will be placed furthest from the entrance. It is the person in charge's role to take command of the evacuees as good leadership is an important factor in survival situations.
It is rare for ships to find themselves in serious trouble and even rarer for the crew to abandon ship. In fact, the first principle of safety at sea remains as true today as ever - the ship is your best lifeboat and should not be abandoned until there is no alternative.
We need to be familiar with different types of lifeboats and how to use them. Detailed information about the lifesaving equipment and appliances carried on board the ship can be found in the SOLAS training manual which, in turn, would normally be found on the navigation bridge, in the engine control room, and in accommodation areas such as mess room and recreation room. The information in the manual is provided in the working language of the vessel and is vessel-specific.
Take time to familiarize yourself thoroughly with the ship's survival systems. If you wait until there is an emergency, it could be too late. The ship's muster list states which lifeboat you shall use. It also identifies the signal that initiates the abandon ship procedure and specifies individual's duties and responsibilities in an emergency - these should be familiar from regular drills. Once the crew is mustered and headcount has been taken, the bridge must be informed. Never board the lifeboat until the person in charge gives the order.
When boarded, designated members of the lifeboat crew will bring the vital safety equipment collected during the mustering procedure, such as the satellite EPIRB, the radar transponder, or extra water supplies - in fact anything that would make survival and rescue a little bit easier. If this is your role, make sure you know where to find these items. Lifeboats should only be launched when the order is given by the Master. If you work on a ferry or cruise ship, you may have to help passengers board the lifeboats. Many of them may feel nervous, coping with the emergency situation in an unfamiliar environment. If you are confident with the lifeboat launching procedure, you will help to calm their nerves and ensure a swift and safe evacuation of the ship. Let us look first at the davit launched lifeboats.
An accident can happen at any time while you are serving on any ship. If an unexpected event does happen, crew members shall always be ready and know what is expected of them. Drills are a mandatory part of shipboard life; they shall help build teamwork and confidence. But eyewitness reports from port state authorities have discovered that too often crew members are unfamiliar, hesitant, unconcerned or use poor techniques when forced into this kind of situation.
That is why holding effective drills is so important. If drills are carried out realistically, the knowledge obtained will enable crew members to handle real situations promptly and ensure a positive outcome. Crew members should remember that holding effective drills is not just a task undertaken to conform to regulations - effective drills are designed to save lives. Of course, simulating real situations to obtain knowledge is difficult and can be dangerous.
But these trainees are obtaining first-hand knowledge before setting out to sea. A drill is a way of testing your knowledge. A review of that test will indicate any areas for further training. With the number of new stories of accidents involving vessels, it has become evident that drills have not always been effective; crews were not responding quickly enough, they used poor techniques and they lacked the knowledge and understanding of their role in the real life incident.