Mundra Port to acquire biggest cutter suction dredger

Dec 25, 2011, 12:41PM EST

Mundra Port and Special Economic Zone Limited on a robust expansion of its dredging fleet

 Mundra Port and Special Economic Zone Limited (MPSEZ), India’s largest private port and special economic zone will acquire the biggest cutter suction dredger ever to be owned by any Indian company.  Under construction at the IHC Merwede shipyard in Sliedrecht, The Netherlands, the dredger was named Shanti Sagar XVI during its recent launch.

MPSEZ, which is part of the Adani Group, already has 13 dredgers in its fleet and has placed orders for three new building which includes Shanti Sagar. Two more dredgers are being built in India for MPSEZ. First being a water injection dredger and another self propelled hopper grab dredger. Both are scheduled to be delivered by the middle of next year.    

Giving details about the Shanti Sagar XVI being built at the IHC Merwede shipyard, Col. Vinod George, Head of Dredging Operations of MPSEZ informed that the dredger is a 13,000kW stationary cutter suction dredger and will be deployed for capital dredging at ports under MPSEZ.

“The dredger is under construction at the IHC Merwede shipyard,” Col. George said. “The contract for the design, construction and delivery of the vessel was signed in November 2010, and the keel was laid on 11 May 2011. The vessel will be delivered in the second quarter of 2012.”

The new cutter suction dredger is an IHC Beaver® 9029C, which is capable of dredging a wide range of materials. The vessel is equipped with three Cutter Special® dredge pumps, which are specially designed with a large sphere passage for cutter suction dredge operations. The anchor boom and spud-tilting installations allow the dredger to operate in remote areas with limited support equipment. The large fuel oil carrying capacity also allows for a high level of autonomy.”

“Dredging is critical to the development of Mundra Port and the work is managed by Mundra Port Special Economic Zone’s dredging fleet,” stated Bala K. Subramaniam, Director of Adani Shipping (India) Pvt. Ltd., and the Senior Advisor to Adani Shipping Singapore Ltd., the Adani Group and also the Mundra Port and Special Economic Zone Ltd., (MPSEZ) “In all we have 11 dredgers built at IHC Merwede shipyard and two from China. The SHANTI SAGAR XVI will be the largest vessel supplied by IHC Merwede to date.”

“At the moment our dredging activity has been concentrated exclusively for deepening and maintaining the draft at our own ports at Mundra and Hazira,” stated Col. George. “We have done some dredging for TATA’s but that has been incidental. We also have our other facilities at Dahej port, Goa, Vishakhapatnam and elsewhere. We have not undertaken any outside dredging contracts so far but in course of time we may consider taking up even international projects.”

Adani Group is a business behemoth based in India having a global footprint with interests in Infrastructure, Power, Global Trading, Logistics, Energy, Port & SEZ, Mining, Oil & Gas, Agri Business, FMCG products, Real Estate Development, Bunkering, et al. Founded in 1988, Adani Enterprises Ltd. (formerly known as Adani Exports Ltd.) is today the flagship company of the Adani conglomerate.

 

Fresh Water from Sea Water on Ships

When preparing for a voyage ships take on fresh water which is supplemented throughout the voyage by water making plants. Fresh water is used in motorships as an engine component cooling medium, but steamships use only the distilled water produced by the water-making plant for boiler feed make-up.

When I was a lad at sea many years ago, I sailed on motor and steamships as an Engineering Officer. In those days we had evaporators which used steam from the boilers or the main diesel cooling water as a heating medium to evaporate the seawater. As I gained experience and promotion, one of my duties as 4th Engineer was looking after the vaps, as we called them (among other things).
Nowadays, there are several very efficient types of evaporators still using the same heat sources, and of course we now use osmosis as well.
In the following sections we will examine the current evaporators in use, fresh water and condensate storage tanks, and condensate feed water testing. In this article we shall examine two categories of water evaporators, tube and flash, and have a look at how osmosis equipment operates to produce fresh water from seawater.
We begin with an examination of the types of evaporators used aboard ships.

Types of Fresh Water Evaporators

There are numerous types of evaporators and osmosis equipment used to produce fresh water from seawater on our ships today. Here we shall examine the following types:

• Multi-stage Flash Evaporator
• Tube or Coil Evaporator

Multi-stage Flash Evaporators
This type of evaporator uses a multi-stage process which has two components, the seawater heater and the flash drum, with these being two separate units.
The seawater can be heated using steam or the main engine cooling water, depending on the main propulsion unit.
The heated seawater is pumped into the flash drum, which has numerous sections all at a lower pressure than that of the water heater. Some of the hot seawater flashes of to steam in the first section, before going on through remaining sections, flashing as it moves through them. The steam rises up the flash drum through a demister, and upon contacting the condenser tubesis condensed and pumped via a salinometer to the fresh water or boiler water feed tanks. Should the salt content in the distillate rise to an unacceptable level, the salinometer alarm will be activated and the distillate diverted to bilges.
A sketch of a typical multi-stage evaporator is shown below:

                                                       Multi-Stage Seawater Evaporator

Coil or Tube Seawater Evaporator
This is a modern version of the type used when I was at sea in the 1960s. They used heating coils in those days as opposed to the pipe nest heaters of today. The coils used to become scaled in salt, with the attendant loss in output of distillate.
I was in charge of the vaps and I remember the old Chief coming down to the engine room on my watch and balling me out for the downturn in distillate. We were having problems with the boiler feed water purity (another article will cover the testing and treatment of boiler feed water), so I was blowing down the boiler regularly, which with the associated make-up requirement meant we needed more water pronto.
Anyway I took him up to the vaps and showed him the scaling on the heating coils, reminding him that I was pumping Foss chemicals into the beast to try and break this away.
He pushed me aside and shut off the seawater supply opening up the steam supply which rapidly dried the salt layer on the coils. He then opened the seawater inlet and hey presto – the salt scale cracked and fell of the coils. I used this system several times until I was up for Seconds ticket and examiner wasn’t too pleased to hear of this method, and called the old Chief several unprintable names!
Today we don’t have to resort to these measures as there is an innovative device which uses a material that emits oscillations counteracting the natural seawater oscillations, thereby altering its properties and preventing calcium carbonate scale. (See references section.)
A tube and coil evaporator consists of a steel vessel which has a nest of heating pipes near the bottom of the vessel being fed by steam or hot water from the main engine.
There is a tube condenser cooled by seawater installed near the top of the vessel. A vacuum is drawn in the vessel by air ejectors operated by steam or pressurised seawater.
Seawater is fed into the evaporator just covering the heating pipes. Heat is supplied to the pipes and, this combined with the vacuum conditions begins to boil the seawater producing steam. The steam rises up through a demister into the tube condenser where it is evaporated to distilled water. This is collected and pumped via the salinometer to the storage tanks.
A typical tube condenser is shown below.

Tube Evaporator Used Aboard Ships

Osmosis Equipment

Reverse Osmosis Process
Osmosis is a natural process which occurs due to osmotic pressure between two substances divided by a semi-permeable membrane. When the membrane divides two substances of different concentrations of solids, the solvent from the less concentrated solution will flow into the higher concentrated solution, with the membrane blocking the solids.
In an engine room, reverse osmosis takes place in a pressure vessel which contains a tank holding a quantity of seawater and freshwater separated by a semi-permeable membrane. In natural osmosis the freshwater would flow into the seawater, however when pressure is applied to the seawater side the process is reversed. This causes the seawater to flow into the freshwater side, the solids being stopped by the membrane.
A sketch of osmosis in action on ships blackwater is shown below. This can be applied to freshwater osmosis water-makers.

Reverse Osmosis Applied to Seawater Distillation

Role Of Compressed Air In Engine Starting

Do you know how diesel engines are started in ships? Equivalent in size to a four-story building, the main propulsion engine is started with the help of compressed air at a pressure of 30 bar. Learn more about how a ship gets its compressed air supply from.

Why compressed air?

We discussed diesel engine starting problems in our previous article and saw how various methods are used to overcome this problem. We also saw how a marine engine is different due to its size and location, and that compressed air is the solution to starting the diesel engine.
As you know that a ship is a mobile power plant or a moving mini-city. It has all facilities, sometimes better than what we find ashore. These moving giants have a pre-designed and erected compressed air system, which facilitates many activities onboard a ship. There are mostly 4 to 8 and sometimes 10 air compressors found onboard. These Air compressors take suction from the engine room atmosphere which is already under a slight positive pressure. These air compressors compress the air in stages and fill up the huge air bottles, which acts as accumulator. The air compressors compress usually upto 30 bar and keep the air bottles filled up all the time. The number of air bottles and its volume(capacity) depends on the power (size) of the main propulsion engine. These Air compressors are of varying capacity and used as per the requirement onboard.

Role of compressed air on a ship

The role of compressed air onboard is of a very vast nature. Every Ship will be having a "DEAD-START" or "The FIRST START" arrangement. This is nothing but when the ship is totally "Dead" i.e, with out any power and no machineries running and no compressed air in the air bottle to start the generator engine(auxiliary diesel engine), then a provision is given for every ship to get the air bottle filled up to bring back the ship to safe, normal, working condition. This is provided either by a "Emergency Air Compressor" driven by a small diesel engine or electric motor getting its power supply from "Emergency Generator". The various uses of compressed air onboard ship are listed below: 1. To start main propulsion engine
2. To start Auxiliary diesel engine(power generation)
3. To blow ship's whistle
4. For Engine Room general service and cleaning.
5. For the operation of pneumatic tools
6. For deck services, to carry out chipping.
7. For Automation & Instrumentation of various machineries,
8. For fresh & sea water hydrophores,
9. Fire alarms & operation of Quick closing Valves,
10. For Soot Blowing Exhaust Gas Economizer etc and many more...!!

Compressed Air System Layout

The compressed air system onboard typically has a set of 4 to 6 compressors, out of which 3 will be main are compressors, 2 service air compressors & one topping up air compressor. The Emergency air compressor is not to be counted as a normally used machinery.

Main air compressors: These are used only when a ship enters or leaves a port, mostly during maneuvering only. They are of higher capacity of all. During maneuvering, these compressors when put in use, fills up the air bottle faster than other compressors, thus enabling the ship to berth herself in the port. Topping-Up air compressors: These are comparatively of lesser capacity than the main air compressors. They are just used when the ship is sailing in the mid-seas where the consumption of air is very less (only for engine & deck services).
Service Air compressors: These are general service air compressors, which are used either for engine or deck service. They are of lesser capacity and their are designed for their pure strict oil free air quality. These compressors are used for pressing up the control air bottle and thus the control air of high purity is used for various automation purposes in the engine room and the pump room for oil tankers.
There may be set of main air bottles, service air bottle and a control air bottle for their respective purposes. The system also incorporates many pressure reducing valves and driers(de-humidifiers) to get rid of the moisture present in the compressed air.

Starting of an Auxiliary Diesel Engine

The auxiliary diesel engine is mostly started with the help of compressed air,depending upon the size of the engine. Other means of starting includes Electric start(battery) and air motor(engaged in the flywheel). The most common method is the use of compressed air. The lay out for starting the auxiliary engine is given below.

Before starting the auxiliary engine, the following safety checks must be carried out:
1. Turning gear disengaged(if available).
2. Lubricating oil sump level normal
3. Turbocharger oil level( both turbine & blower)side normal
4. Lubricating oil priming pump running.
5. Fuel oil/diesel oil booster pump running.
6. lube oil, cooling fresh water, fuel oil pressure normal.
7. Rocker arm tank level normal.
8. All valves in compressed air line open to the engine.
Referring to the above starting diagram of an auxiliary engine, the" main air" from the main air bottle arrives at the air starting valve. There is a tapping from the main air starting line, "pilot air" going to the starting air distributor. When the engine rotates, the camshaft also rotates which in turn rotates "the starting air distributor cam". This cam is designed as per the firing order of the engine such that, the distributor rotates and lets the pilot air to the particular unit. The pilot air reaches on top of the air starting valve, opening it, in turn making the long awaited main air to let inside the combustion chamber. The main air which is at 30 bar, pushes the piston down making the crankshaft to rotate. This leads to continuous rotation of the crankshaft making the engine to achieve the minimum r.p.m at which firing of the injected fuel takes place. When the engine picks up on fuel, the air is cut off and drained. Thus the auxiliary diesel engine is started with the help of compressed air.
In the next article, we will take up the study of the various valves mentioned in the starting air systems namely master air starting valve, cylinder valves and so forth.

Starting & Reversing Problems in Marine Engines

There are a number of reasons for starting and reversing problems in marine engines. This malfunction is one of the most frightening and dangerous situations to encounter when maneuvering a ships main diesel engine, but it can be avoided through regular maintenance of the air start components.

A ship’s main marine diesel engine is started on compressed air that is controlled by various components of the air start system. It is a well-tried and tested reliable system, but it can go wrong if not properly maintained.
The following sections examine a typical air start system, with the first section providing an overview of the system.

Overview of System

The air start system looks rather complicated, but it is quite simple when you examine it without the safeguards. These are put in place to prevent such occurrences as starting the engine without having a signal from the engine room telegraph, trying to start the engine with the turning gear engaged, or trying to start ahead when the telegraph asks for astern. There are also safety systems incorporated such as a bursting disk and numerous non-return valves in the event of a leaking air start valve.
The next section lists some of the problems that can be encountered when maneuvering.

Problems in Air Start Systems

We shall look at two common problems encountered when maneuvering the main engine: not starting and starting in the wrong direction (reversing instead of starting ahead).

• Not Starting

As we have seen, there are various interlocks in place to prevent the engine being started until certain criteria are met. If the engine won’t turn over on air, the bridge should be informed then the following checks should be carried out.

1. Check air start supply valves from air receivers are open and that the pressure is 30 bar.
2. Check that the turning gear is disengaged
3. Check that the turning gear and telegraph solenoid valves have actuated. This will supply air to the automatic valve, air distributer, the air manifold, and air start valve.

These are the initial checks that can be quickly carried out. If these are all satisfactory, then the problem lies in the controls ahead/astern solenoids. The air distributer or the air start valve itself may be stuck in the closed position. The ship will need to anchor or be towed alongside for these checks to be carried out.
Engine starts in wrong direction
If the engine starts in the astern instead of ahead direction, the following checks should be carried out.

1. Ensure the air start control moves to reverse mode at the control station. This is a visual check and can be observed when the telegraph rings from ahead to stop then astern. If this does not happen, the solenoid valve may be stuck.
2. The oil and air supply to and from the reversing valve should be checked. A blockage of either will stop the reversing servo motor operating and allowing change over from the astern to ahead position.

This again will take further investigation, so the ship should anchor or remain tied up to the quay.
As this ahead/astern changeover is controlled by lube oil and compressed air and is interlocked with the fuel pumps. These are the usual culprits and the starting point of a thorough investigation. I have experienced this situation only once and fortunately we were leaving port and still tied to quay by stern spring. Once the bridge was informed, a rope from the fo’c’sle was thrown ashore and made fast. This gave us the chance to check for the fault, which turned out to be the oil supply from the crosshead oil supply pipe being blocked.
As I have said before, the maintenance of the air start system components is paramount to the operation of the system.

Main Components of the System

Air supply system

• Two air compressors
• Two air start vessels
• Numerous non-return valves
• Numerous drain valves

Control system

• Turning gear out sol v/v
• Telegraph signal sol v/v
• Automatic valve
• Ahead and astern change-over
• Air distributer
• Air start valve

Anti-explosion components

• Air supply to manifold from air vessels non-return valve- this prevents hot gasses from returning to air receivers.
• Air manifold pressure relief valve – this operates if pressure rises due to heat from gasses.
• Air supply to air start valve bursting disk – this disk ruptures under increased pressure caused an air start valve leaking back.

Mandatory Safety Precautions

Before we get into the operation of the system in the next section, this is an opportune moment to make a closer examination of the precaution against explosion, which is a very real threat even in today’s modern engines that incorporate the latest in engine management systems.

• Compressors

The compressor air inlet filters should be positioned in an oil-free zone, i.e. no oil fumes should be present.
The compressed air supply lines to the air receivers must be protected by non-return valves.

• The air receivers

There are two air receivers, linked by a common discharge pipe to the system. The air from the compressors will contain oil and water (there is no way around this). This mixture ends up in the air vessels as a mist, eventually settling to the bottom of the vessel. It is imperative, and I cannot overstress this, that the mixture be drained from the vessels after every charge, and regularly when maneuvering. The oil also coats the internal of the supply pipes; this too can be reduced by draining the air vessels.
These actions, as well as checking by hand for heat in the air supply pipe between the air start valve and the air manifold, form part of the watch keeper’s duties. Any excess heat here, and the fuel and air to that particular cylinder should be isolated, and the bridge made aware of the situation.
Before we leave the precautions there are many examples of air start system explosions. One of worst ones occurred on the MV Capetown Castle, killing seven engineers. Lloyd’s register recorded 11 such explosions between 1987 and 1998; all down to oil gathering in the receivers and piping and ignited by exhaust gasses. One a year speaks for itself: drain the air vessels regularily and maintain the system.
A sketch showing an air start system where the air start valve is leaking is shown below. Note the pipe that should be checked by hand for overheating;

                                  Air Start System Depicting a Leaking Air Start Valve

The Operating Principles of Marine Engine Air Start Systems

I have sailed on quite a few marine diesel engines, including B&W, Sulzer, and Stork/Werkspoor. All had variations of the system I am about to describe, but the principles are much the same.
I drew a sketch from memory (45 years ago) but updated it from a very good website referenced at the end of the section. The sketch also appears at the end of the section and can be referred to during the reading of the notes.
We begin then with the bridge ringing down standby on the engine room telegraph. (We used to change over fuel from Heavy Fuel Oil to Modified Diesel Oil for maneuvering.)
1. If in port, ensure turning gear is not engaged.
2. Open both air receivers’ isolation valves and start up a compressor to fill receivers to maximum; drain oily water of reservoirs and also from dead leg on supply pipe work.
3. This allows the compressed air to flow as far as the turning gear solenoid valve. Provided the turning gear is disengaged, this will allow the supply of air at 30 bar to the automatic valve passing though the non-return valve and into the manifold. From here the air is piped to the air chamber in the air start valve. (This is the pipe that will get hot if you have a leaking air start valve.) The valve is held in the shut position by the spring tension.
4. When an ahead or astern movement is rung and answered on the engine room telegraph, the telegraph start signal sol v/v is activated allowing air to the ahead and astern solenoid valves mechanism.
5. The air is now directed to the starting air distributer that is fitted on the end of the camshaft. This enables it to select the appropriate cylinder(s) to supply air to. This will be the relevant cylinder that is just passed TDC and on the downward stroke.
6. The air from the starting air distributer is at 30 bar, and this is injected into the air start valve top piston. This overcomes the spring tension and forces the piston downwards thus opening the valve and introducing the air at 30 bar to the cylinder(s) having been supplied earlier to the air chamber.
7. Depending on the engine make and model, air can be supplied to several cylinders to assist starting. A "slow start" supply can be used if there has been a lapse of half an hour between movements when maneuvering.

                   Typical Air Start System for a Marine Engine Operating on Local Control

Maintenance of System Components

• Compressors

Regular inspection of filters, suction and discharge valves, as well as piston and ring checks should be performed at the manufacturer’s recommended periods. Intercooler tube nests should be cleaned ensuring optimum air flow.

• Air supply Manifold Relief Valve

This should be regularly inspected to ensure that the spring is operating correctly, with the complete overhaul being to manufacturer’s instructions.

• Air Start Valves

This is the most important component and if not maintained, will begin to stick due to a weak/badly adjusted spring or worn piston rings allowing hot combustion gasses into the compressed air piping.
The valve should be replaced regularly with an overhauled and tested spare, the spare then being stripped and spring, pistons, and rings inspected. The valve is ground into the seat using fine lapping paste before rebuild and bench pressure testing.

Managing Severe Injury and Medical Ailments aboard Ship

Working on a ship can involve a substantial amount of risk to a seafarer's life. Numerous hazardous agents on a ship can be risky and even life threatening. So what should be done in case of an injured or ill sailor onboard a ship that is far away from the shore... and the nearest hospital?

Getting injured or becoming chronically ill aboard a ship risks the life of the person it happens to. Facing either of these circumstances involves not only the suffering attached to the mishap, but also the burden of unreliable diagnosis and ineffective medical monitoring. A patient on a ship is fully dependent on the skills of the medical officer and the meager first aid tools available.
Earlier, in situations involving serious injuries or sickness, there was nothing more that could be done other than giving sedatives or treating the person with whatever resources were there on hand. However, times have changed now, and so have been the procedures for providing emergency medical aid on ship.

History of Emergency Medical Care for Merchant Marine

In the last few decades, many steps have been taken to reduce the risk to life onboard a ship. Qualified medical officers have been deployed to reduce the level of risk as much as possible. It is to note that none of these officers are doctors, but only certified first aid and emergency medical care providers. Thus, in case of extreme emergency, all that a medical officer will provide is basic emergency care and some type of medication or sedative to ease the patient’s pain until the ship reaches the next port.

Starting in the 1920s, ship’s radios were used to communicate with a physician located onshore to obtain the right kind of medical aid. However, because of the variability of radio propagation, this system often couldn’t be used beyond a certain range. If the ship was within 200 nautical miles, high speed "life boats” and helicopters were a viable option for saving the distressed sailor. However, in bad weather and beyond 200 nautical miles, even this option could not be used. Also, if a person’s life is in serious danger, there was always an option of diverting the ship, but then the decision would be a serious blow to the company from a financial perspective.
With the advent of satellite communication, ways of providing medical aid to patients onboard a ship also changed. A new term, telemedicine, came into being and started providing remote medical aid to seafarers using high technology such as emails and live video footage. Telemedicine has now become the new face of providing medical aid at sea.

1950s Cardiac Monitoring and Recording Device (EKG)

Wikipedia Commons by user Daderot placed in public domain by photographer

Telemedicine

Telemedicine is a technology that uses modern methods such as email, face-to-face video, and audio communication to treat a diseased or injured person on a ship. In the early days, telemedicine had serious problems such as inferior video quality, limited file transfer, and network restrictions. Moreover, only recorded video and audio files could be transferred and those, too, of only short lengths. Now because of the many new satellites launched, the potential of telemedicine has increased from a file transfer medium to a fully capable live video exchanging device.

How does Telemedicine Work?

Telemedicine is a whole new way of communicating from the ship to the shore and vice-verse in times of medical emergencies. The working of telemedicine can be divided into three main stages:

1. The medical personnel onboard the ship
2. The medical advisor panel on shore
3. The monitoring device and satellite

Telemedicine makes the whole remote diagnostic process very realistic. The injured or diseased person on the ship is monitored using a special device that involves taking real time measurements of diagnostic conditions (signs and symptoms) like the patient’s pulse rate, blood pressure, and cardiac trace or electrocardiogram. The medical panel on shore analyzes the situation and parameters and provides the right aid to the patient. Telemedicine also facilitates providing timely advice for injuries involving open wounds through the taking and transmission of high resolution pictures of the injury.
Shipping companies have begun investing heavily in telemedicine facilities because of the several benefits it provides. They realize that in a mishap involving a human element, there is nothing more important than saving the life of the seafarer. Also, the right investment in telemedicine can also save a large amount of money later, which a ship diversion or other methods never will.

References

• Author's experience