MARINE AUXILIARIES

M a lr ai example of rotary vane steering gear yn se iA au nx Ii nl si ta ir ti eu ts e/ oW fA MS a/ rJ ia n e2 E0 n2 g1 i n e e

M a lr cont' ai yn se • These chambers will vary in size as the rotor moves and can be pressurized since sealing strips are fitted on the moving faces. iA au nx Ii • The chambers either side of the moving vane are connected to separate pipe systems or manifolds. Thus by supplying hydraulic nl si fluid to all the chambers to the left of the moving vane and drawing ta ir fluid from all the chambers on the right, the rudder stock can be ti made to turn anti-clockwise. ue ts e/ • Clockwise movement will occur if pressure and suction supplies are reversed. oW fA MS a/ • Three vanes are usual and permit an angular movement of 70°: the rJ vanes also act as stops limiting rudder movement. ia n e2 • The hydraulic fluid is supplied by a variable delivery pump and E0 control will be electrical, as described earlier. n2 g1 i • A relief valve is fitted in the system to prevent over pressure and n allow for shock loading of the rudder. e e

M a lr ai Figure 9 “IMO” steering gear – rotary vane type yn se The steering gear arrangements illustrated in Figure 8 iA and Figure 9 are permissible for tankers of 10 000 au GT and upwards, provided that a single failure (i.e. loss nx Ii of oil) in any of the two identical power actuating nl systems may be detected and automatically isolated, si leaving the other power actuating system fully ta ir operational. ti ue Automatic isolation is initiated upon detection of loss of ts e/ hydraulic oil (low oil level). oW Isolation must be followed by shut down of one power fA MS unit in case both systems are running simultaneously. a/ A low-low level alarm must be followed by shut down of rJ the power unit supplying the failed system and startup ia n of a stand-by power unit in case only one power unit is e2 running. E0 n2 g1 The systems fulfil the capacity requirements for main i steering gear when operating together n e e

M a lr ai yn se iA au nx Ii nl si ta ri ti ue Figure 12.9(a) Rotary vane steering gear ts e/ oW fA MS a/ rJ ia n e2 E0 n2 g1 i n e e

M a rl ia ny es Ai ua xn iI ln is at ri it eu st /e Wo Af SM /a Jr ai n 2e 0E 2n 1g i n e e

M a rl ia ny es Ai ua xn iI ln is at ri it eu st /e Wo Af SM /a Jr ai n 2e 0E 2n 1g i n e e

M a lr ai yn se iA au nx Variable delivery pumps can run continuously in one direction but have the capability of an infinitely changeable Ii discharge from zero to a maximum either way. The principle of operation is based on altering the stroke of the pump nl pistons in radial or axial cylinders, by means of a floating ring or swash plate respectively, to change the amount of oil si ta displaced. ir ti Generally variables displacement pumps are used to supply the oil / any other working fluid to the steering system ue ts connected to rudder. Theses pumps are used in steering system as they are well suited for applications that require e/ continues change in fluid flow. It works on the principle of changing the pump stroke to change the output with parts oW such as floating ring and swash plate. The flow direction depends upon the location of floating ring; either left or right fA MS of the center. a/ rJ While the discharge rate depends on the amount of displacement for the floating ring from its mid position. These ia n pumps can be easily classified into two major types: e2 E0 • Hele-Shaw pumps n2 g1 • Swash Plate pumps i n e e

Swash Plate Type Pump Marine Auxiliaries / WAS / Jan 2021 • Pump with the axial piston arrangement which works on the principle that “A reciprocating piston draws in liquid during retraction and discharge while it extends”. • It consists of the following main parts Casing, Cylinder block, Piston, Drive shaft, Swash plate, Adjusting valve, and Inlet & Outlet ports. • Here the reciprocating motion of the axial piston is obtained by using a swash plate. A swash plate is a device used in variable displacement pumps to change the motion of rotating shaft to the reciprocating motion of the axial piston. • Due to swash plate arrangement in the pumps, piston rotates around the shaft along with the piston barrel assembly. • During the one half of the rotation, piston moves out leading to increase in the volume inside the cylinder; while in the other half leading to decrease in the volume. This continuous phenomenon leads to the suction and discharge of the pump. Malaysian Institute of Marine Engineering Technology (MIMET)

Example of swash plate operation GIF animation Components of swash plate pump Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

Hele-Shaw Pump • This pump is connected to a motor for rotation of the shaft at a constant speed to which Cylinders are connected. • The Floating ring is actuated/Moved by mechanical linkage (Such as Hunting gear) and this movement cause eccentricity of the concentric Floating ring and piston(Cylinders). So, now the Suction and discharge occur as the pump rotate in the eccentric state. • The eccentricity of floating ring determines the stroke of the piston, floating ring accommodates slippers. • As long as the concentric state is maintained no suction or discharge occurs, as eccentricity occurs the suction and discharge starts. The direction of flow depends on the location of the floating ring. Malaysian Institute of Marine Engineering Technology (MIMET) Gif animation of a hele-shaw pump Marine Auxiliaries / WAS / Jan 2021

Example showing operation of heleshaw pump by adjusting the floating ring Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

Hunting Gear In Steering Gear System Hunting Gear is a feed back mechanism of steering gear which re positions the floating lever of hydraulic pump as the tiller moves to the desire position. Hunting: Due to piston and cylinder wear, there will be slippage of oil through. Rudder can not be kept in helm as the pump can not provide effective hydraulic locking. So, rudder can be easily displaced from the required position by the action of waves etc. Hunting gear will take action to return the rudder in ordered position. Purpose of Hunting Gear: 1. Hunting gear floating lever mechanism is required to bring the rudder to the ordered position. 2. Also this mechanism is required to position the rudder in its ordered position when the action of water, waves or propeller force displaces the rudder from its ordered position.The hunting gear brings the rudder to its ordered position against the water, wave etc. 3. It is feed back mechanism of steering gear which re positions the floating lever of hydraulic pump as the tiller moves to the desire position. Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

Operation of hunting gear Marine Auxiliaries / WAS / Jan 2021 1. The pump delivers oil, only when the steering wheel is moved. The hunting gear returns the pump control rod to mid position as soon as the rudder received the position relative to the wheel and remains there the wheel move again. 2. The telemotor moves the end of the floating rod A to A1 and the pump control rod moves B to B1. Pumping of the hydraulic oil causes movement of the tiller arm, through rams and the end of rod C moves to C1. These movements cause the pump control to pull back to the neutral position B. 3. If the rudder is rotate by the heavy sea through lifting of the shock valves, the hunting gear is moves by the tiller. This put the pump to work and the rudder will be restored to its previous position. Malaysian Institute of Marine Engineering Technology (MIMET)

Animation showing hunting gear operation Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

Buffer Spring Marine Auxiliaries / WAS / Jan 2021 Why spring links are incorporated in the hunting gear? 1. The spring called buffer spring is incorporated in the hunting gear links to take up any excess movement beyond the maximum stroke of the pump. 2. This extra movement is stored by the compressed spring and reset when hunting gear approaches the no- effect point to prevent the mechanical damage of the pump. 2. Also buffer spring will take up the shock movement of rudder due to heavy sea, thus preventing excessive hunting action of pump. Malaysian Institute of Marine Engineering Technology (MIMET)

END OF SLIDES Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

An oily water separator (OWS) (marine) is a piece of equipment specific to the bilge water in bilge well shipping or marine industry. It is used to separate oil and water mixtures into their separate components. This page refers exclusively to oily water separators Marine Auxiliaries / WAS / Jan 2021 aboard marine vessels. They are found on board ships where they are used to separate oil from oily waste water such as bilge water before the waste water is discharged into the environment. These discharges of waste water must comply with the requirements laid out in Marpol 73/78. Bilge water is a near-unavoidable product of shipboard operations. Oil leaks from running machinery such as diesel generators, air compressors, and the main propulsion engine. Modern OWSs have alarms and automatic closure devices which are activated when the oil storage content of the waste water exceeds a certain limit(15ppm : 15 cm3 of oil in 1m3 of water). Malaysian Institute of Marine Engineering Technology (MIMET)

Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

The bilge well The bilge area is the lowest area on a ship. The bilge water that collects here include drain water or leftover water from the boilers, water collecting tanks, drinking water and other places where water can not overflow. However, bilge water doesn't just include water drainage. Another system that drains into the Bilge system comes from the propulsion area of the ship. Here fuels, lubricants, hydraulic fluid, antifreeze, solvents, and cleaning chemicals drain into the engine room bilges in small quantities. The OWS is intended to remove a large proportion of these contaminants before discharge to the environment (overboard to the sea). Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

cont’ The primary purpose of a shipboard oily water separator (OWS) is to separate oil and other contaminants that could be harmful for the oceans. The International Maritime Organization (IMO) publishes regulations through the Marine Environment Protection Committee (MEPC).On July 18, 2003, the MEPC issued new regulations that each vessel built after this date had to follow. This document is known as MEPC 107 and it details revised guidelines and specifications for pollution prevention equipment for machinery space bilges of ships. Each OWS must be able to achieve clean bilge water under 15 ppm of type C oil or heavily emulsified oil, and any other contaminants that may be found. All oil content monitors (OCM) must be tamper-proof. Also whenever the OWS is being cleaned out the OCM must be active. An OWS must be able to clear out contaminants as well as oil. Some of these contaminating agents include lubricating oil, cleaning product, soot from combustion, fuel oil, rust, sewage, and several other things that can be harmful to the ocean environment.[ Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

For a ship with 400 GT and above, discharge of oil mixture can be done under Marine Auxiliaries / WAS / Jan 2021 the following conditions: 1. The ship is en route; 2. The oily mixture is processed through an oil-water separator filter meeting the requirements of regulation 14 of this Annex 3. After passing the oil-water separator system, the oil content of the effluent without dilution does not exceed 15 parts per million; 4. The oily mixture does not originate from cargo pump-room bilges on oil tankers 5. In oil tanker ship, the oil-water mixture is not mixed with oil cargo residues When the ship is plying in the Antarctic area, any discharge into the sea of oil or oily mixtures from any vessel shall be prohibited. Malaysian Institute of Marine Engineering Technology (MIMET)

Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

Annex I- Regulations for the Prevention of Pollution by Oil, Chapter 3 - Requirements for machinery spaces of all ships, Regulation 15 - Control of discharge of oil C- Requirements for ships of less than 400 gross tonnage in all areas except the Antarctic area In the case of a ship of less than 400 gross tonnage, oil and all oily mixtures shall either be retained on board for subsequent discharge to reception facilities or discharged into the sea in accordance with the following provisions: 1. The ship is proceeding en route; 2. The ship has in operation equipment of a design approved by the Administration that ensures that the oil content of the effluent without dilution does not exceed 15 parts per million; 3 The oily mixture does not originate from cargo pump-room bilges on oil tankers; and 4 The oily mixture, in case of oil tankers, is not mixed with oil cargo residues. Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

1. Oil Content Monitor and Control Unit (OCM) OCM • This unit functions together in two parts – monitoring and controlling. • The ppm of oil is continuously monitored by Oil Content Monitor (OCM); if the ppm is high it will give an alarm and feed data to the control unit. • The control unit continuously monitors the output signal of OCM and if alarm arises, it will not allow the oily water to go overboard by means of operating 3-way solenoid valve. Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

cont’ 2. Coalescing Oil Separators use oil attracting media packs which are fixed inside the treatment chamber. The surface area on the media attracts suspended oil droplets in the wastewater and forces them to collide and form larger oil droplets 3. Capacitance probe - as a level sensor , send a input signal to control switch Coalescing filter Malaysian Institute of Marine Engineering Technology (MIMET) capacitance probe Marine Auxiliaries / WAS / Jan 2021

Operation of the OWS Marine Auxiliaries / WAS / Jan 2021 • The operation of oil water in the seperator takes place in two stages. In the first stage, the seperation is by gravity, whereas in the second stage, the seperation is by coalescing filters. • First, the bilge pump delivers clean sea water to the first stages of the seperator through the inlet valve. The vent is kept open till all the air is removed from the seperator and water issues out. • Oily water is delivered to the seperator. As it enters through the inlet valve, oil separates by gravity and collects at the top of the seperator. • The remaining oil sticks to the baffle plate as the water passes to the second stage. Oil droplets from the plates tend to travel upwards to the oil collection space. • Oil from the top of the chamber is automatically drained to the oil tank where the level reaches the bottom of the censor as shown. • The oil drain valve from the top of the first stage seperator is a diaphragm controlled piston valve, control air is supplied to the diaphragm through a solenoid operated pilot valve Malaysian Institute of Marine Engineering Technology (MIMET)

cont’ • The capacitance probe senses oil quantity in the collection space and energises the solenoid through the control switch. • Water passes downwards from the first to the second stage coalescer through a central pipe. • The filter in the right chamber removes solids and some oil. Coalescing filters in the left chamber take out the remainder of the oil in the form of small droplets, which coalesce to form larger drops. • These rise to the oil collection space. Oil content of the final discharge is below 15ppm. • In case the discharge of the water after the second stage is more than 15ppm, the monitor senses this and gives an audible and visual alarm in the engine room • At the same time, the monitor sends a signal to the three way valve on the overboard discharge line, which closes the overboard and opens to the bilge tank Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

cont’ • The sensor reverts to normal operation once the oil content drops below 15 ppm. The test cocks can be used to ascertain the levels of oil and water manually. • However it is essential that a relief valve be provided on the shell or incoming mixture line to prevent over pressure and accidental discharge to a confined space or prevent overboard under all working condition. • Such a relief valve should be preferably led back to the suction side of the supply pump or an overflow tank. • The usual working pressure for the seperator is in the region of two bar, i.e the pressure at which the spring loaded water discharge valve is set. • The relief valve is set at about 2.5 bar approximately. Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

How does the oil content monitor works? The principle used is that of ultra-violet fluorescence. This is the emission of light by a molecule that has absorbed light. During the short interval between absorption and emission, energy is lost and light of a longer wavelength is emitted. Oil fluoresces more readily than water and this provides the means for its detection. A sample is drawn off from the overboard discharge and passes through a sample cell . An ultra-violet light is directed at the sample and the fluorescence is monitored by a photoelectric cell. The measured value is compared with the maximum desired value in the controller/recorder. Where an excessive level of contamination is detected an alarm is sounded and diverting valves are operated. The discharging liquid is then passed to a slop tank. oil in water monitoring system Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

What is the best pump to use with an oil water seperator Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021

The information which must be entered in the Oil Record Book when Marine Auxiliaries / WAS / Jan 2021 pumping out bilges • When making entries in the Oil Record Book Part I, the date, operational Code and item number shall be inserted in the appropriate Columns and the required particulars shall be recorded chronologically in the blank spaces. • Each completed operation shall be signed for and dated by the officer or officers in charge. The master of the Ship shall sign each completed page. • The Oil Record Book Part I contains many references to oil quantity. The limited accuracy of tank Measurement devices, temperature variations and clingage will affect the accuracy of these readings. The entries in the Oil Record Book Part I should be considered accordingly. • In the event of accidental or other exceptional discharge of oil statement shall be made in the Oil Record Book Part I of the circumstances of, and the reasons for, the discharge. • Any failure of the oil filtering equipment shall be noted in the Oil Record Book Part I. Malaysian Institute of Marine Engineering Technology (MIMET)

END OF SLIDES Malaysian Institute of Marine Engineering Technology (MIMET) Marine Auxiliaries / WAS / Jan 2021