10. Safety and Maintenance Work Onboard 

Every dangerous part of a ship’s machinery or other equipment should have guards or protection devices to prevent access to danger zones or to halt movements of dangerous parts before the danger zones are reached. 

Dangers can be reduced to a minimum by 

• following safe working practices 

• taking protective measures 

• wearing safe working clothes – Personal Protective Equipment (PPE). 

Particular care and attention is needed when carrying out work in machinery space as 

• communication is often difficult and sometimes impossible 

• warning shouts may have no effect 

• the work task may distract the person involved. 

To reduce the likelihood of personal injury occurring whilst working in the machinery spaces, the following precautions should be taken

• work must be carefully planned and those involved or carrying out such work must be familiar with the plans made 

• the working environment in the machinery spaces must always be kept clean and free from oil, oily residues and oily rags, to prevent slips and falls 

• communication by hand signals or similar means should be agreed beforehand 

• devices should be installed on machineries, undergoing maintenance or repair, making it impossible to run them and warning signs should be displayed 

• areas of open casings, open bilges or similar should be clearly fenced off and warning signs displayed 

• beware and kept clear of running machinery while working.

The ship's safety management system should provide safe practices in ship operation and a safe working environment, with safeguards against all identified risks in compliance with the ISM Code. In addition, deck equipment and machinery should be: 

• Suitable for the work to be carried out 

• properly adapted for that purpose; and 

• capable of being operated without any risks to the health or safety of any worker 

For safe operation of deck machineries, the deck crew shall have 

• has working knowledge of the different types and basic function principles of various deck machineries. 

• has working knowledge of emergency procedures and is able to assist the OOW with testing emergency shutdown of various deck machineries. 

• has working knowledge of the use of portable winches and pumps 

• has working knowledge of the different types and function principles of hoists, cranes and booms 

• is able to perform basic visual checks of hoists, cranes and booms and related equipment 

• knows the importance that any failure, damage or malfunction has to be reported to OOW immediately 

• understands that derricks and guys have to be moved in a combination

• understands and uses the basic signals for the operation of the different deck equipment

• understands that various equipment have limiting parameters 

• able to identify the safe working load (SWL) or working load limit (WWL) of equipment 

• understands that a load greater than SWL shall not be lifted 

• able to identify SWL of shackles, chains and slings correctly that used joint with various deck machineries.

Causes of corrosion in ship’s structures  

Ships are primarily exposed to atmospheric corrosion, caused by a combination of high moisture and salt-laden sea spray, both of which directly attack the steel through the smallest deficiencies of the pain layer.  

Ships also suffer from fretting corrosion, caused by the repeated relative surface motion between loaded metal surfaces, typically induced by vibration (caused by machinery) and structural flexing (caused by sea currents and wind).  

Simple method of prevention of corrosion  

One of the most effective ways to prevent and control ship corrosion is to apply coatings to parts that are most susceptible to corrosion, such as the hull.  

The deck is also susceptible to corrosion, especially during adverse weather conditions. During storms or strong tides, seawater can wash up on the deck and lead to surface damage. Repainting the deck can help to remedy the damage, but it’s best to apply high resistance coating to ensure protection from seawater and everyday wear and tear.  

With the proper maintenance procedure, ships are less likely to suffer from corrosion. 

Following a maintenance plan will help you to spot any early signs of damage and take the steps needed to fix the issue before the amount of damage escalates.  

Proper surface preparation is essential for the success of any marine coating system. 

The performance of any paint coating is directly dependent upon the correct and thorough preparation of the surface prior to coating.  

The Base Material (Steel Surface) can be cleaned in the following ways:  

• Manual Cleaning (Hand Tools), 

• Mechanical Cleaning with machines (Power Tools), 

• Chemical Cleaning, especially degreasing (Pickling), 

• Thermal Cleaning, 

• Flame Cleaning, 

• Blast Cleaning (Sandblast/Grit blast), 

• Water-jets

Chipping and painting including related cleaning and housekeeping jobs are major jobs of deck crew on board. The result of the jobs will be obvious in a few months and it depends on seamen's skills. In order to work well and for safety, the important matters are;

• To use equipment properly 

• To wear protectors in accordance with rules 

• To keep your good position away from direction of rotation of the equipment 

• To be a good balanced posture

Rust scale removal by chipping, hammering and scaling, and painting constitute the major portion of hull maintenance and requires labor and costs.  

It is important to do chipping with the determination "not to allow rust again in the place where chipping was carried out once". You should carry out operations to avoid such results as may be criticized by saying, "It is better not to remove rust than chipping halfway through."

There are varieties of tools from hand tools to pneumatic, hydraulic or electric driven equipment. 

(1) Hand tools 

• chipping hammer 

• scraper: Goose neck type, long handle type 

• wire blush: oval type, handle type 

(2) Electric tools 

Electric tools are handy but have problems on deck. You may not use on tankers, LNG, LPG or when carrying combustible/inflammable cargos. It is dangerous when a working crew is splayed. 

(3) Pneumatic tools (Air tools) 

This type of tools and machines are very common on board because we can compress air from engine room and less problem with water. Cleaning and applying lubricant oil are important. 

Procedures of Chipping

(1) Before chipping 

• Meeting about the job 

• Confirm protectors 

• Confirm tools and equipment. Fit attachments such as disks, needles, air hose firmly and properly. Wrong fitting of a disk paper may cause removal of it and injury. 

• Apply lubricant oil if it is not enough 

(2) During chipping 

• Electric tools are handy but have problems on deck. 

• Avoid using the same tools for long hours. Avoid working with the same posture. For example, after using an air hammer, sweeping for a while and then use air sander. 

• Keep enough safe distance each other. Rust or pieces of iron from others might hit you. 

• Be sure to disconnect air hose when a sander paper is changed. 

• Be sure to keep your body away from direction of rotating. 

• Plane off corners and edges of remaining paint. If edge of paint remains, there might be made air hole after painting.

(3) After chipping 

• Especially after grinding by dick sander, clean the surface to prevent rusting by pieces of iron dust. 

• Chipping area is decided considering enough for painting.

• Cleaning and securing tools. Do not leave tools without cleaning. 

• Keeping work places and tool stores in order is important not only for increasing work efficiency but also for preventing accidents. "Train yourself to become clean and tidy." 

• Put tools in specified places so that they can easily be taken out. 

• Protectors and detectors shall be stored so that they can rapidly be used on emergency.

• Unnecessary facilities shall be removed; unnecessary goods be early disposed of.

Electric descaling machine (Deck scaler) Using the descaling machine can achieve the quick and effective operation of de-scaling and power brushing the ship decks, hatch covers, tank tops, and other wider areas, etc. The scaling machine can be driven by both electrical and pneumatic power sources. Other electric power tools commonly used onboard are drills, hammer drills, sanders, grinders and cut off machine, etc.

Pneumatic power tools commonly used onboard are pneumatic scaling hammer, pneumatic jet chisel, pneumatic grinder, pneumatic greasing pump, air spray painting and water jet cleaner, etc. 

Maintenance 

Regular maintenance of pneumatic power tools shall be carried out as per manufacturer’s instructions and manual. Generally, the following points shall be paid attention as below;

• Keep all your hoses, air tools and accessories clean and in optimal condition wipe off grease and oil every time after usage. 

• air pressure rubber hoses condition 

• Check each component for free movement and be sure to tighten all cap screws and bolts. 

• Be sure there are no air leaks in the tools, air lines, trigger valve. 

• Clean feed systems daily with a clean cloth to remove debris and lubricate as recommended by the manufacturer. 

• Make sure it is free of dirt, grime, debris or saw dust and lubricate. 

The following safety rules are common to all power tools. In addition, each type of tool has its own unique hazards, which must be taken into account. 

• Read the manual to understand the tools proper applications, limitations, operation and hazards; 

• Do not use electric power tools in the proximity of flammable vapors, dusts or construction materials. Also avoid using electric power tools in wet environments; 

• Protect yourself from electric shock by insuring your tools are properly grounded; use a Ground Fault Circuit Interrupter for corded tools; 

• Always check for hidden wires that may contact bladed tools; 

• Select a tool based on the task for which it is designed; 

• Only use attachments specifically recommended for your power tools, and ensure their proper installation; 

• Inspect tools for damage including the cord, presence of guards, correct alignment, binding of components, or any condition that would affect the operation of the tool; 

• If a tool is damaged, or a condition develops while a tool is in use, have the tool fixed before using it again; 

• Avoid excessive force to make cutting tools cut faster; feed material only as fast as the tool is designed to accept to prevent excessive wear and decreased control; 

• Keep others away from the work area, or provide shields to stop flying debris and other distractions; 

• Do not operate a power tool if you are under the influence of medications or alcohol, or if you are tired or distracted; 

• Verify that all tools are unplugged or that the power source is removed when changing blades, performing maintenance or when tools are not in use; 

• Keep tools in a secure location when not in use; 

• Avoid unintentional tool start-up by keeping your finger off of the power switch.

Paint consists of Binder, Color pigment, Extenders, Solvents and Additives. 

Oil paint 

This type of paint was manufactured about a decade ago, but with the advent of synthetic resin paints, it is now nearly out of use. Application of this type of paint with a brush is easy but it takes time to dry up. 

Alkyd paint (Phthalic acid resin) 

Even though they are synthetic resin paints, they are similar to oil paints in nature and handling and easy to use. Beautiful finishes can be obtained without chalking or discoloration.

Chlorinated rubber paint 

They are obtained by dissolving, in a solvent, natural rubber decomposed by chlorine, as a base; they are paints of quick-drying type as they dry up when the solvent evaporates. 

Vinyl paint 

They are mainly composed of copolymers made from vinyl chloride and vinyl acetate. It has excellent properties for water resistance and chemical resistance. However, only thin dry films can be obtained. Since it quickly dries, it is possible to apply more coats at short intervals to build up an adequate thickness. Adhesion to steel plates is poor. 

Epoxy paint 

They harden as epoxy resins and various types of hardeners react with each other; they have extremely good performance with good adhesive, anti-corrosive, shock-proof, antiabrasive and chemical resistant qualities. On the other hand, they are subject to chalking, and discoloration to a yellowish color and the loss of gloss are inevitable. It is expensive, too.

Tar epoxy paint 

Bitumen contained in coal tar or asphalt is low priced and excellent in water resistant qualities. While tar epoxy paints are excellent anti-corrosive paints containing coal tar, which is cheap, as a filler and equipped with properties of epoxy resins, they have the following disadvantages: 

• Tar will cause dermatitis in the case of skin contact.

• The paint colors are restricted as tar is contained. 

• when a different type of paint is applied over tar epoxy paint, it may bleed. (Uniproof is an epoxy paint using asphalt in place of coal tar.)

Non-bleeding type tar epoxy paint (Color tar epoxy paint) 

They are heavy anti-corrosive paints of an ambient-temperature hardening type produced by improving the defects of tar epoxy paints. 

Generally, denatured epoxy paints or denatured-urethane paints are available. This type of paints is used almost exclusively for painting weather decks and superstructures. 

'Non-slip Paint' 

Heavy anti-corrosive paints are very slippery when they get wet. The passageways on deck and steps of the stairways and accommodation ladder should be provided with non-slip surfaces. 

'One Component Paint' 

For one component paint, be sure to stir the paint using a mechanical mixer for minimum two minutes, until the paint is homogeneous before use.

‘Two Component Paint' 

When part mixing a pre-calculated volume, measuring can be done by using a scoop/cup or a measure stick. Consult the TDS for the correct mixing ratio. Stir both component-A (base) and component-B (curing agent) separately before adding them together in a clean tin. 

Then stir the two components together for minimum two minutes, until you have a homogeneous mixture, using a mechanical mixer. If stirring is done manually, more time is needed. 

Hazards of paint 

• since paints generally employ solvents with a low flash point, they emit flammable vapors at ambient temperature, and are in a state which combustion is liable to occur at all times. 

• The vapor of solvents is heavier than air and accumulates at deck level. 

• solvents have a property to irritate the skin or mucous membranes, and cause headaches. They also cause intoxication. 

• since solvents dissolve fats, they may cause dry skins or dermatitis.

Stowing Paint 

• Paints have their shelf lives. 

• Paints should be consumed within 6 months as pigments deposit or resins proceed with polymerization during the storage period, depending on the type of paint. 

• Mark the date of receipt on the can with a felt-tipped marker.

• when stowing paint in the paint store, the older cans should be placed on the door side and the new ones on the far side so that the older ones may be used first. 

• sometimes turn cans topsy-turvy so that pigments may not be left as deposited at the bottom.

Types of brush 

Brush Application 

• Brushes should not be applied into the paint more than half the length of their bristles, the aim is to load the brush with enough paint to get some work done, but not too much so the paint drips and splatters. 

• The applied paint should spread evenly using smooth, steady strokes then be smoothed by light parallel strokes to eliminate irregularities. 

• Particular attention should be paid in ensuring that the applied paint is brushed into the bottom of pitted areas of steel and that the edges of nuts, etc. are well coated. 

Roller painting 

• Roller painting is a suitable method for coating places where it is not so wide for spray painting or it requires excessive time by the brush painting. 

• A roller with a length of 200mm is easy to use. 

• A mini-roller is convenient for those who are not good at brush painting.

Roller painting 

• Roller painting is a suitable method for coating places where it is not so wide for spray painting or it requires excessive time by the brush painting. 

• A roller with a length of 200mm is easy to use. 

• A mini-roller is convenient for those who are not good at brush painting. 

The painting sequence should be as follows 

"From the far side to the near" 

"From the far side to the near one" 

"From top to bottom" 

"The complicated places should be painted first." 

Paint can for roller brush 

Make a convenient container out of an empty can for thinner, etc.

Masking Tape 

• When painting white lines to mark walkways use masking tape to keep the lines straight, be sure to remove the masking tape before the paint dries, otherwise it could have a distorting effect. 

• The piping systems should be painted for identification by using masking tape in a proper manner.

• The heavy doors at entrances to accommodation spaces should be painted after applying masking tape to the portion of packing.

Prohibited Area from Painting 

There are many places in a ship where it must not be painted at all or not be painted out. Painting out for movable parts, name plates and safety marks brings about various problems. To avoid this "painting out", use various sizes (from small to large) of brushes which match the place to be painted properly. Using a masking tape is also useful. 

Rotating parts shall be greased after being painted. Samples of prohibited place for "painting out": 

Treatment of Brush and roller after painting 

• Wash out remaining paint from the brush and roller with its thinner. 

• Wipe the thinner with rag and soak the brush and roller in water. 

• If paint remains on the brush, the brush cannot be used again. 

• Brush/roller using for white paint should not be soaked together with brush/roller using for other colour.

Lubricating Moving Parts of Deck Equipment 

All deck machinery and equipment must be lubricated properly to ensure protection against wear and weather elements. All moving parts of the system must be working freely, and sufficiently greased or oiled. The maintenance and lubrication of heavy deck equipment, such as winches, cranes, and anchor windlasses, should be carried out regularly. 

There are many different types of machinery and equipment exposed on the open deck, such as windlass, mooring winch, cargo gear, accommodation ladder, life boat and heavy door, etc. which all have built-in moving gears of parts, the purpose of greasing is not only to keep them in a good condition, but also to protect them from the elements.

• Do not apply excessive grease This causes an increase in temperature in high speed rotating machinery, also causing grease to drop off. 

• where a grease nipple is located in a different access area, it should be marked so as not to miss it. 

• An appropriate grease nipple suitable for narrow access should be used. 

Wire rope is a flexible, tough, complex, and versatile mechanical power transmission member made up of numerous individual wires. Good lubrication offers protection against corrosion and minimizes metal-to-metal contact between individual wires while reducing wear on the rope and on the drum and sheaves over which it operates. 

For proper wire lubrication, 

• grit, sand, old lubricant layers are considerably removed using wire brushes, compressed air, or relevant solvents 

• applied new lubricant must be allowed to penetrate the inside of a wire rope. 

• Avoid excessive wet ride 

Brushing, painting and swabbing are the most common application techniques used onboard and using of these methods ensured that provide adequate penetration to the wire rope core.

The loose gears of cargo handling equipment such as all rings, hooks, links, shackles, swivels and blocks shall be visually inspected before operation and properly maintained as per ship’s Plan Maintenance Schedule. 

The followings shall be done for care and maintenance of Cargo Blocks and Sheaves, but not be limited to; 

• Check for proper rotation of sheaves and swivel parts. 

• Check the clearance of sheaves and swivel parts. 

• Check for any abnormal sounds while running. 

• Check for any deformation, wear and tear, scoring, corrosion 

• If necessary, would strip the blocks down and clean off any old grease and clear the grease recesses in the bush and the inside of the sheaves. 

• The ‘bolt’ would be extracted and the bush bearing would be withdrawn. Inspection would take place and any signs of corrosion; hairline cracks or excessive wear and tear would be monitored. 

• If the steelwork is found to be in good working order without any visible defects or signs of deterioration it would be re-greased and re-assembled for continued use. 

• Keep proper grease application at all time. 

The snatch blocks and chain blocks need to be also cared and kept proper maintenance in order to operation ready at all times and to prevent accidents arising from these.

Valve and valve shaft stick 

In ships many pipeline systems are installed, for the transport of various kinds of liquids, gases, and energy. In those systems valves are necessary and fitted in large numbers to stop or regulate flow, to connect numerous spaces or items to a system, or to isolate the system from open air or outside connections. 

Function of Valve 

A Valve is a device that Regulates, Directs or Controls the flow of a fluid by Opening, Closing, or Partially Obstructing Various Passageways. In an open valve, fluid flows in a direction from Higher Pressure to Lower Pressure. 

Types of Valves 

Valves are quite diverse and may be classified into a number of basic types. Valves may also be classified by how they are actuated:  

• Hydraulic 

• Pneumatic

• Manual 

• Solenoid valve 

• Motor 

There are some types of valves; butterfly valve, sluice valve, globe valve, swing valve, etc. being used. Valves are operated by human hands, hydraulic oil, electric motor and compressed air. Valves sometimes become stuck or too hard to turn. 

Causes of deterioration (airtight, watertight and malfunction)

• Exhaustion and stiffening of gland packing 

• Foreign particles and rusts in caught 

• Damages of a thread 

• Adherence between seat ring and valve disc 

Measures for protection of deterioration 

• Grinding of face of seat ring or replacement of gland packing 

• Tightening the bolts 

• Rasping (filing) 

• Repeat of open and shut motions

Gland Packing 

(1) Put valve position on "shut” 

(2) Remove split pin, nuts, washers, name plate and handle in order of top to down. 

(3) Remove indicator plate of "open" and "shut". 

(4) Remove an indicator collar. 

(5) Remove nuts of control weight. 

(6) Remove gland weight collar from the handle rod. 

(7) Remove gland packing using a special tool or a needle for canvas sawing. 

(8) Fill new packing into the trench. (Usually, 4 to 6 pieces of packing fitted.) 

(9) Restore in order of the above reverse (5) to (1). 

Procedure of replacement 

(1) Confirm the valve position on "shut" 

(2) Release the connecting part 

For a hand valve: Remove the valve handle 

For a hydraulic valve: Remove the hydraulic pipe which is connected to the actuator (cylinder)

(3) Preparation of suspending the valve 

When it is not available to find a proper place from which to suspend a valve body with a wire rope, it is usual case to set up a steel or wooden tripod. 

(4) Release the bolts which connect the flanges of main pipe

(5) Decide which direction to extract (pull out) the valve, i.e., upward, downward or sideway. It depends on the working space and also the shape of valve. 

(6) Extraction of the valve 

It is common to use a flange-opener to release and extract the valve part from the both end flanges. 

• Two flange-openers to be placed at symmetrical positions between the flanges after all bolts are removed, and then start the hydraulic jack in operative. 

• when two flange-openers aren't enough to evenly separate the flanges due to the largeness of its diameter, place " stud bolt with nuts "between the flanges. This makes a help to separate the flanges easily. 

(7) Lift the valve by a chain block. 

(8) Take out the damaged seat ring and insert a new one after cleaning the groove completely.

Restoring 

(1) Hoist the valve body and insert it between the flanges. 

(2) Insert a gasket on the side of the seat ring and then press it to the flange surface with stud bolts fast to place it in position. (this gasket is used to prevent the rubber lining from being stuck to the flange surface) 

(3) Insert a gasket into the gap created on the opposite side. (this work is a little bit hard to be done smoothly. Various measures should be devised, such as adding more pulls on a gasket) 

(4) When the position of the valve body is fixed, return the flange to its origin. 

(5) Tighten the stud and the through bolts in position. 

(6) Fit hydraulic pipes. 

(7) Purge air out of the hydraulic branch line and conduct an operational test. Driving Mechanism of Butterfly Valve