Sudan University of Science and technology College of Engineering School of Mechanical Engineering Production Department Design of Tugboat

A Project Submitted in Partial fulfillment of the Requirements of the Degree B.Sc. (Honor) in mechanical Engineering

Prepared by: Ahmed Adel Awad Bilal Ahmed Jamal Mukhtar Ahmed Mamdoh Mohylden Edrees

Supervisor: Ustaz. Alsiddig Abdelazim

October 2017 ﻗﺎل ﺘﻌﺎﻟﻰ:

ﻫﻭ ﺍﻟﱠﺫﻱ ﻴﺴﻴﺭﻜﹸﻡ ﻓﻲ ﺍﻟﹾﺒﺭ ﻭﺍﻟﹾﺒﺤﺭﹺ ﺤﺘﱠﻰ ﺇِﺫﹶﺍ ﻜﹸﻨﹾﺘﹸﻡ ﻓﻲ ﺍﻟﹾﻔﹸﻠﹾﻙ ﻭﺠﺭﻴﻥ ﺒﹺﻬﹺﻡ ﺒﹺﺭﹺﻴﺢﹴ ﻁﹶﻴﺒﺔ ﻭﻓﹶﺭﹺﺤﻭﺍ ﺒﹺﻬﺎ ﺠﺎﺀﺘﹾﻬﺎ ﺭﹺﻴﺢ ﻋﺎﺼﻑﹲ ﻭﺠﺎﺀﻫﻡ ﺍﻟﹾﻤﻭﺝ ﻤﻥ ﻜﹸلﱢ ﻤﻜﹶﺎﻥﹴ ﻭﻅﹶﻨﱡﻭﺍ ﺃَﻨﱠﻬﻡ ﺃُﺤﻴﻁﹶ ﺒﹺﻬﹺﻡ ﺩﻋﻭﺍ ﺍﻟﻠﱠﻪ ﻤﺨﹾﻠﺼﻴﻥ ﻟﹶﻪ ﺍﻟﺩﻴﻥ ﻟﹶﺌِﻥ ﺃَﻨﹾﺠﻴﺘﹶﻨﹶﺎ ﻤﻥ ﻫﺫﻩ ﻟﹶﻨﹶﻜﹸﻭﻨﹶﻥ ﻤﻥ ﺍﻟﺸﱠﺎﻜﺭﹺﻴﻥ

ﺼﺩﻕ ﺍﷲ ﺍﻟﻌﻅﻴﻡ

ﺴﻭﺭﺓ ﻴﻭﻨﺱ ﺍﻻﻴﻪ 22

Acknowledgment

Firstly, we would like to thank Allah, who blessed us with wiling to accomplish this project we are so grateful to him for his help.

When we express our sincere grated to our supervisor T.alseedig abduelazim for the continuous support, for motivation, and immense knowledge.

His guidance helped us in all the time of research and writing of this thesis. Beside our supervisions, we would like to thank the department of mechanical engineering for their insightful comments and encouragement, but also for the hard question which helped us to widen our research from from various perspectives. We thank engineer Ahmed Abdlamajed Shareef Aldeen for his help. Dedication

We dedicate this humble effort to our sweet and loving families whose untiring support and assistance have made possible fruition to our efforts whose affection, love, encouragement and prays of day and night make us able to get such success and honor.

To our friends and classmates for their cooperation while conducting the project. To respected teachers in school of mechanical engineering.

ABSTRACT

In this research, have reduced the number of tugboats driven to a cargo ship (50 thousand tons), by (towing and ship) process and used power of engines to moved, and defeat the resistance force.

Sudan has numbers of ports and many of them are used in commercial import/export trades, thus the available tugboats fleet has weight limitations. Which leads to disability in accepting large heavy ships to be moored locally, the main objective of this project is to Design a tugboat that has the ability of maximum towing 50 thousand tons in deep water .the result of this project reduced the number of tugboats driven to a cargo ship (50 thousand tons), by (towing and ship) process and used power of engines to move the ship, and defeat the resistance force.

ﺍﻟﻤﺴﺘﺨﻠﺹ

ﺍﻟﻬﺩﻑ ﺍﻟﺭﺌﻴﺴﻲ ﻤﻥ ﻫﺫﺍ ﺍﻟﺒﺤﺙ ﻫﻭ ﺘﺼﻤﻴﻡ ﻗﺎﻁﺭﺍﺕ ﺒﺤﺭﻴﺔ ﻟﻘﻁﺭ ﺴﻔﻴﻨﻪ ﻜﺘﻠﺘﻬﺎ 50 ﺍﻟﻑ ﻁﻥ

ﺒﻭﺍﺴﻁﻪ ﻋﻤﻠﻴﺘﻲ ﺍﻟﺩﻓﻊ ﻭﺍﻟﺸﺩ ﻭﺍﻟﺘﻐﻠﺏ ﻋﻠﻰ ﻤﻘﺎﻭﻤﺔ ﺍﻟﻤﺎﺀ ﻭﺍﻟﻬﻭﺍﺀ ﻭﺍﻋﻁﻰ ﺍﻜﺒﺭ ﺴﻤﺎﺤﻴﻪ

ﻟﻠﺴﺤﺏ. NUMBER TITLES PAGES

I اﻵﯾﺔ II اﻹھﺪاء Acknowledgment III Abstract IV V اﻟﻤﺴﺘﺨﻠﺺ Table of Content VI List of Table VII List of Figures VIII CHAPTER ONE INTRODUCTION 1.1 Introduction 2 1.2 Problem of Research 2 1.3 Project Importance 3 1.4 Project Aims and Objectives 3 1.5 Project Scope 3 CHAPTER TWO LITRETURE REVIEW 2.1 Tugboat Background 5 2.1.1 Types of Tugboats 5 2.1.1.1 Deep-sea tugs 6 2.1.1.2 Harbour Tugboat 7 2.1.1.3 River Tugboat 9 2.2 Specification of the Tugboat in Sudan 9 2.3 Interaction with Ship 11 2.4 Historical Data & Previous Studies 13 2.4.1 Conventional Tugs 13 2.4.2 Voith Schnider (Tractor Tugs) 13 CHAPTER THREE METHODOLOGY 3.1 Preface 24 3.2 Engine Specifications 25 3.3 Design of Energy and Force Propulsion 27 3.3.1 Kinetic Energy 27 3.3.2 Torque of Engine 27 3.3.3 Impulsive Force 28 3.4 Design of Rope 28 3.5 Resistance of Water 31 3.5.1 Frictional Resistance 31 3.5.2 Residual Resistance 32 3.5.3 Air Resistance 32 3.5.4 Effect of Resistance Force 32 CHAPTER FOUR RESULTS AND DISSCUTION 4.1 Calculated the Value of Energy and Forces 34 Effects 4.1.1 Kinetic Energy 34 4.1.2 Torque of Engine 34 4.1.3 Impulsive Force 34 4.1.4 Tension Force of Tugboat Rope 34 4.1.5 The Resistance of Water and Air 36 4.1.5.1 Effect of Resistance Force 36 4.2 Tugboat Model by Solidwork Software 37 4.3 Simulation Results 41 4.3.1 The Roller and the Rope 41 4.3.2 Study Results 44 CHAPTER FIVE CONCLUSIONS AND RECOMMENDATIONS 5.1 Conclusions 47 5.2 Recommendations 47 References

FIGURE NO. FIGURE PAGE 2.1 Types of Tugboats 5 2.2 Deep Sea Tug 6 2.3 Harbour Tug 8 2.4 River Tug 9 2.5 Tugboat’s Contents 11 2.6 Pressure Zones 12 2.7 Methods of Connecting 15 the Rope 2.8 Luna tugboat 18 2.9 NOKOMIS Tugboat 19 2.10 The PEGASUS Tugboat 20 2.11 SOCONY Tugboat 21 3.2 Caterpillar C-280-12 26 Engine 3.3 HMPE Rope 28 4.2 Tugboat Front View 35 4.3 Tugboat Top View 36 4.4 Tugboat Back View 37 4.5 Tugboat Right View 38

TABLE\CHART NO. TITLE PAGE 2.1 Local in-use tugboats 10 propulsion 3.1 The Design 24 METHODOLOGY 4.1 rope (HMPE) 33 4.2 Towing Parts 39 4.3 Towing Parts 40 Specifications 4.4 Loads and Fixtures 41 4.5 Force Direction 41 4.6 Stress Simulation 42 4.7 Strain Simulation 43

CHAPTER ONE

INTRODUCTION

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1.1 Introduction

Tugboat, small, powerful watercraft designed to perform a variety of functions, especially to tow or push barges and large ships. In 1736 Jonathan Hulls of Gloucestershire, Eng. patented a boat to be powered by a Newcomen steam engine to move large vessels in and out of harbours. The first tugboat actually built was the Charlotte Dundas, powered by a Watt engine and paddle wheel and used on the Forth and Clyde Canal in Scotland. Screw propulsion for tugboats was introduced in the United States about 1850, the diesel engine about 50 years later. Tugs are still indispensable in berthing large ships. Oceangoing tugs are used for salvage missions. Also, moving a ship without the chance of colliding with underwater stones and leftover debris in some ports can be complicated process also, there may not be large spaces for ships to move easily and move around. All these difficulties can be avoided by tugboat transportation.

Many tugboats have firefighting monitors, allowing them to assist in firefighting, especially in harbors without the usage of tugs, the anchoring process may become unsafe and can cause serious damages. Added to that, a well-designed tug with a powerful engine has a positive impact in an economical way.

1.2 Problem of Project

In Sudan we have numbers of ports and so many of them are used in commercial import/export trades, thus the available tugboats fleet have weight limitationsand the maximum horse power can obtained from a local tug is 4000 Hp. Which leads to disability in accepting large heavy ships to be moored locally. Moreover, that has a negative commercial impact on the import/export process therefore; increasing tugboats capacity and start to consider designing them domestically will help to leap forward in river transportation field.

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1.3 Project importance

The research contributes to the industries sector by constructing tugboats natively. Which can reduce the cost taking in consideration ordering them from foreign companies. It also enhances the river transportation process and increase the maximum capacity of a ship to be towed using a tugboat. Which has an important role in how many tugs are used to tow/push a ship into the port’s mooring area.

1.4 Project Objectives

Designing a tugboat that has the ability of maximum towing range of (45~50) thousand tons in deep water using an engine that produces up to (10.800) HP obtained at (900) r.p.m.

1.5 Project Scope

Design a (Deep-Sea) configuration tugboat and focus on its towing roller and pushing surface. And run them under simulation conditions to insure the desired capacity.

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CHAPTER TWO

LITERATURE REVIEW

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2.1 Tugboat Background

A tugboat is a boat or ship that manoeuvres vessels by pushing or towing them. Tugs move vessels that either should not move by themselves such as ships in a crowded harbor or a narrow canal, or those that could not move by themselves, such as barges, disabled ships, log rafts, or oil platforms. Tugboats are powerful for their size and strongly built, and some are ocean going. Some tugboats serve as icebreakers or salvage boats. Early tugboats had steam engines, but today most have diesel engines. Many tugboats are equipped with firefighting monitors in order to assist the ship’s crew or the salvage company in controlling a fire on board a passenger liner or ferryboat especially in harbors. A ship on fire is not only a potential dangerous area for inexperienced crew and passengers, but as a result of the fire there could be threat to the marine environment.

2.1.1 Types of Tugboats

Fig 2.1: Types of Tugboats

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2.1.1.1 Deep-sea tugs

Seagoing tugs (deep-sea tugs or ocean tugboats) fall into four basic categories:

1. The standard seagoing tug with model bow that tows its "payload" on a hawser. 2. The "notch tug" which can be secured in a notch at the stern of a specially designed barge, effectively making the combination a ship. This configuration is dangerous to use with a barge which is "in ballast" (no cargo) or in a head- or following sea. Therefore, "notch tugs" are usually built with a towing winch. With this configuration, the barge being pushed might approach the size of a small ship, with interaction of the water flow allowing a higher speed with a minimal increase in power required or fuel consumption.

Fig 2.2: Deep Sea Tug

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The "integral unit", or "integrated tug and barge" (ITB), comprises specially designed vessels that lock together in such a rigid and strong method as to be certified as such by authorities (classification societies) such as the American Bureau of Shipping, Lloyd's Register of Shipping, Indian Register of Shipping, Det Norske Veritas or several others. These units stay combined under virtually any sea conditions and the tugs usually have poor sea-keeping designs for navigation without their barges attached. Vessels in this category are legally considered to be ships rather than tugboats and barges must be staffed accordingly. These vessels must show navigation lights compliant with those required of ships rather than those required of tugboats and vessels undertow.

-"Articulated tug and barge" (ATB) units also utilize mechanical means to connect to their barges. The tug slips into a notch in the stern and is attached by a hinged connection. ATBs generally utilize Interco and Bludworth connecting systems. ATBs are generally staffed as a large tugboat, with between seven and nine crewmembers. The typical American ATB operating on the east coast customarily displays navigational lights of a towing vessel pushing ahead, as described in the 1972 ColRegs.

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2.1.1.2 Harbour Tugboats

Fig 2.3: Harbour Tug

Compared to seagoing tugboats, harbor tugboats are generally smaller and their width-to-length ratio is often higher, due to the need for a lower draught. In smaller harbors these are often also termed lunch bucket boats, because they are only manned when needed and only at a minimum (captain and deckhand), thus the crew will bring their own lunch with them. The number of tugboats in a harbor varies with the harbor infrastructure and the types of tugboats. Things to take into consideration includes ships with/without bow thrusters and forces like wind, current and waves and types of ship (e.g. in some countries there is a requirement for certain numbers and sizes of tugboats for port operations with gas tankers).

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2.1.1.3 River tugboats

Fig 2.4: River Tug

River tugs are also referred to as towboats or push boats. Their hull designs would make open ocean operation dangerous. River tugs usually do not have any significant hawser or winch. Their hulls feature a flat front or bow to line up with the rectangular stern of the barge, often with large pushing knees.

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2.2Specification of the Tugboats in Sudan

The table below describe the details of the local tugboats that operate in the eastern costs:

Table 2.1: Local in-use tugboats propulsion

No Tug’s Name Built Engine Horse Knot L.O.A. Beam Draft Bollard Type Power (M) (M) (M) Pull (HP) (RPM) (ton) 1. KURMUK 2011 MAN 4612 13.7 28.67 10.43 4.6 55

8L21/31 (1000) 2. HYDOB 2011 MAN 4612 13.7 28.67 10.43 4.6 55

8L21/31 (1000) 3. TOMALAH 2009 MAN 2612 12.1 29.24 8.84 4.40 35.1

L23/30A (900) 4. WARATAB 2009 MAN 2612 12.1 29.4 8.84 4.40 35.1

L23/30A (900) 5. ELHAMADAB 2006 MAN 2612 11.9 30 8.84 4.40 34.4

L23/30A (900) 6. ALBARAKA 2004 MAN 2612 11.9 26.09 7.94 4.04 30

L23/30A (900) 7. GEBIET 1995 MAN 1526 9.5 22.5 7.25 3.75 22.5

L20/27A (900)

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8. ARWAWEET 1994 MAN 1526 9.5 22.5 7.25 3.75 22.5

L20/27A (900) 9. SAWAKIN 1986 MAN 1632 10 22.15 6.60 3.42 24

L20/27A (900) 10. HEGLIG 2001 MAN 1632 10 24.25 7.20 3.00 24

L20/27A (900)

Fig 2.5: Tugboat’s contents

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2.3 Interaction with ship

Since the ships are getting bigger, tugboats remain at their normal size which is kind of small comparing to many ships. Statistic show that most of the accidents that happen to the tugboats are caused by engaging with other ships.

When a ship is moving it creates two pressure zones around its self

1. High pressure zone in the front. 2. Low pressure or drag zone in the back.

Fig 2.6: Pressure Zones

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In the upper part (a) of fig(2.6) num.1 or the area marked by the sign \ is the clear space of a tug to move at. Num.2 or the area marked by the sign + is the high pressure drag area which is caused by the ship movement, a tug must keep a distance from this area which is variable based on how big the ship is.

In the lower part (b) of the same fig num.1 is the correct path to approach the ship is pushing process. Num.2 is the boundaries of the low pressure zone which is caused by the thrust.

2.4 Historical Data & Previous Studies

As we discussed in the previous point () the modern types of tugboats, there were only two major types of tugs in the past. The rest of types were categorized based on their facilities, capacities, dimensions and functions and that was when tugs played an important role in all kinds of ports.

Those types are:

2.4.1 CONVENTIONAL TUGS

There properties were:

1. Conventional thrusting rudder 2. The hook is placed in the middle of the tugboat and connected to a tackle in the back of the tugboat.

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2.4.2 VOITH SCHNIDER (TRACTOR TUGS)

There properties were:

1. Diesel Engine 2. Winch on board

The tackle or the GOB ROPE is a way to link the ship that is being towed to the tugboat in order to change the center of gravity and to increase the availability of the tugboat to perform hard turns if needed while the towing process is in progress.

In the case of liner or forward towing process, it is recommended to connect the wire directly to the hook in the middle for safety purposes and to keep a distance between the two ships.

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Fig 2.7: Methods of Connecting the Rope

A tugboat's power is typically stated by its engine's horsepower and its overall bollard pull. The largest commercial harbor tugboats in the 2000s-2010s, used for towing container ships or similar, had around 60- 65 tons of bollard pull, which is described as 15 tons above "normal" tugboats.

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Tugboats are highly maneuverable, and various propulsion systems have been developed to increase maneuverability and increase safety. The earliest tugs were fitted with paddle wheels, but these were soon replaced by propeller-driven tugs. Kort nozzles have been added to increase thrust per kW/hp. This was followed by the nozzle-rudder, which omitted the need for a conventional rudder. The cycloidal propeller was developed prior to World War II and was occasionally used in tugs because of its maneuverability. After World War II, it was also linked to safety due to the development of the Voith Water Tractor, a tugboat configuration which could not be pulled over by its tow. In the late 1950s, the Z-drive or (azimuth thruster) was developed. Although sometimes referred to as the Aquamaster or Schottel system, many brands exist: Steerprop , Wärtsilä, Berg Propulsion, etc. These propulsion systems are used on tugboats designed for tasks such as ship docking and marine construction. Conventional propeller/rudder configurations are more efficient for port-to-port towing.

The Kort nozzle is a sturdy cylindrical structure around a special propeller having minimum clearance between the propeller blades and the inner wall of the Kort nozzle. The thrust-to-power ratio is enhanced because the water approaches the propeller in a linear configuration and exits the nozzle the same way. The Kort nozzle is named after its inventor, but many brands exist.

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A recent Dutch innovation is the Carousel Tug, winner of the Maritime Innovation Award at the Dutch Maritime Innovation Awards Gala in 2006. The Carousel Tug adds a pair of interlocking rings to the body of the tug, the inner ring attached to the boat, with the outer ring attached to the towed ship by winch or towing hook. Since the towing point rotates freely, the tug is very difficult to capsize.

The Voith Schneider propeller (VSP), also known as a cycloidal drive is a specialized marine propulsion system. It is highly maneuverable, being able to change the direction of its thrust almost instantaneously. It is widely used on tugs and ferries.

From a circular plate, rotating around a vertical axis, a circular array of vertical blades (in the shape of hydrofoils) protrude out of the bottom of the ship.

Each blade can rotate itself around a vertical axis. The internal gear changes the angle of attack of the blades in sync with the rotation of the plate, so that each blade can provide thrust in any direction, very similar to the collective pitch control and cyclic in a helicopter.

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The first well developed Tugboat with its modern concept is an American tugboat named Luna, its project was launched under the code NOKOMIS (YT-142, later YTB-142 & YTM-142) in the middle of the nineties, from(1940-1975) to be exact.

Before that date a severalattemptswere made to come up with a machine to perform the tug’s function, the ships were made of iron and that was in 1902 under the name of (TUG JUPITER)

Fig 2.8: Luna tugboat

The Luna shown in (Fig 2.7) Preservation Society (LPS) is a non-profit organization dedicated to the restoration and preservation of the tugboat Luna.

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It is a well-known National Historic Landmark moored in Boston,MA. The Luna was the first commercial diesel-electric ship-docking tug of its kind and played an important role in the development of Boston Harbor. It is the last surviving full-sized wooden tug on both the Gulf and Atlantic coasts and its currently undergoing refurbishing process to be putted in the museum.

"The tugboat's NOKOMIS shown in (Fig 2.8) is a 218-ton harbor tug, was built at the Charleston Navy Yard. NOKOMIS tugboat was a project between a Japanese company and the American marine’s industries in March 1943.

Fig 2.9: NOKOMIS Tugboat

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It was assigned to the Fourteenth Naval District for service at Pearl Harbor. Reclassified YTB-142 in May 1944 and YTM-142 in February 1962, Nokomis operated in the Pearl Harbor area into the early 1970s. It was stricken from the Naval Vessel Register in May 1973 and sold in April 1975.

The Tug PEGASUS shown in (Fig 2.9) Preservation Project was an effort under charter from the Regents of the State University of the State of New York. And the project study took place in 1960 at the university.

Fig 2.10: The PEGASUS Tugboat

The Pegasus’s mission was looking forward to bring to the public access to the waterfront of the great Hudson River and the Port of New York

20 and using the tugboat as a platform to interpret to the American’s maritime history."

This excerpt shown in (Fig 2.10) is taken from the Tugboat Jupiter's fact sheets "The charcoal iron tug JUPITER, built in the Philadelphia shipyard of Neafie and Levy in 1982, is the oldest continually operating harbor tug on the Delaware River. JUPITER as it is listed in The International Register of Historic ships, was built in 1982 for the Standard Oil Company of New York (SOCONY) and christened SOCONY 14."

Fig 2.11: SOCONY Tugboat

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CHAPTER THREE

METHODOLOGY

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3.1 Preface

The towing process depends on three factors , these factors are : thrust power, water resistance ( concidered as a coffecient of 0.3) based on previous studies and the different types of water existed and maximum shear stress on the towing wire wich is shown in equ (3.3),(3.4). For the first factor Thrus power it is the major factor to start the towing operation therefore, the larger the ship is the larger power that generated by the engine is reqiared. The power generated is firstly used to ovtercome the static energy of the large ship to be towed which is always larger the the dynamic energy, secondly it is used to control the direction of ship during th operation. It is a fact that several tugboats are needed to complete one tow prosses , a lead tugboat to performe the tow process ( it can also be two tugs if the ship was very large and the capacity of one tug is not suffiecnt) and two other tugboats to guide or to control the diresction of the ship by pushing it on the two sided ( left & right ) while the tow is being proced .

In process of tug and push the ship in this research used two types of tugboats was used, one of them drives (push) in the same direction as the motion, and the other tugboat is tug the ship in the same direction as the motion , the velocity of both tugboats same.

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Chart 3.1: The Design METHODOLOGY

Design

Fuel capacity content Type: Initial Dimension: Of: • Deep-sea tugs Length: 44m Fuel oil overflow: • Harbor Breadth: 14.03 2,118 gallons (8.02 m3) Tugboats Depth:7.62 Dirty oil: 1,153 gallons (4.36 m3) • River tugboats Design Dra: 6.4 m Oily water: 1,225 gallons Material Construction: (4.64 m3) mild Steel (ASTM A36 Hydraulic oil: 570 gallons (2.16 Steel) m3) Net weight: 2000 tone Freshwater: 19,060 gallons Power: (72.15 m3) Engine provides Gray water: 6,474 gallons up to 10880 (24.51 m3) BHP Sewage holding: 5,582 (diesel) gallons (21.13 m3)

Foam storage: 1,436 gallons (5.44 m3) Lube oil: 2,900 gallons (10.98 m3)

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3.2 Engine Specifications

Power Range: 4640-5440 BHP (3460-4056 BKW)

Speed Range: 900 RPM

Emissions: IMO II

Aspiration: TTA

Bore: 11 in (0.279 meter)

Stroke: 11.8 in (0.299)

Displacement: 13546.0 in3 (344 meter)

Rotation (from flywheel end): Counter clock wise or clockwise

Configuration: Vee 12, 4-Stroke-Cycle Diesel

Length: 182.0 in (4.620 meter)

Width: 80.0 in (2 meter)

Height: 134 in (3.4 meter)

Dry Weight: 57276.0 lb (29 tons)

The engine is shown in (Fig 3.2)

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Figure 3.2: Caterpillar C-280-12 Engine

3.3 Design of Energy and Force Propulsion

Process of selecting Engine power depends on tonnage requires.

3.3.1Kinetic Energy

K.E = ∗ M ∗ V (3.1)

Where:

K.E= Kinetic Energy

M= Total Mass of Tugboat (Tanks of Fuel + Engines + Other Equipment) = 2000 tons

V= Velocity of Tugboat.

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3.3.2Torque of Engine

P= T*ω (3.2) Where: T = Torque of engine ω = Angular Speed 3.3.3Impulsive Force

Impulsive force is a force that pushing ship to move its direction.

F = M(U − U) (3.3)

Where:

F = Impulsive Force

M = Mass of Tugboat

U= Velocity of Impulsive

U= Primary Velocity

3.4 Design of Rope

Process of selecting tugboat rope should have high characteristics, in order to increasing their abrasion and temperature resistance.

Material: HMPE (High Modulus Polyethylene)

Abrasion resistance: perfect, suitable for heavy duty operations.

- Can afford load >100 thousand tons - Diameter of rope: 72 mm

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The Equation

P = V * F (3.4)

Where:

P = Power of the Engines

F = Tension Force on Rope

V = Velocity of Tugboat

Figure 3.3: HMPE Rope

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3.5 Resistance of Water

To move a ship, it is first necessary to overcome resistance, i.e. the force working against its propulsion. The calculation of this resistance plays a significant role in the selection of the correct propeller and in the subsequent choice of main engine.

General a ship’s resistance is particularly influenced by its speed, displacement, and hull form. The total resistance consists of many source- resistances.

This can be divided into three main groups:

1. Frictional resistance 2. Residual resistance 3. Air resistance

The influence of frictional and residual resistances depends on how much of the hull is below the waterline, while the influence of air resistance depends on how much of the ship is above the waterline. In view of this, air resistance will have a certain effect on container ships which carry a large number of containers on the deck.

3.5.1 Frictional Resistance

The frictional resistance RF of the hull depends on the size of the hull’s wetted area AS, and on the specific frictional resistance coefficient. the friction increases with fouling of the hull, i.e. by the growth of algae, sea grass and barnacles.

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3.5.2 Residual Resistance Residual resistancecomprises wave resistance and eddy resistance. Wave resistance refers to the energy loss caused by waves created by the vessel during its propulsion through the water, while eddy resistance refers to the loss caused by flow separation which creates eddies, particularly at the aft end of the ship.

3.5.3 Air resistance In calm weather, air resistance is, in principle, proportional to the square of the ship’s speed, and proportional to the cross-sectional area of the ship above the waterline. Air resistance normally represents about 2% of the total resistance.

3.5.4 Effect of resistance force F=M*A (3.5)

Where: M = mass of tugboat

A = acceleration

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CAPTER FOUR RESULTS AND DISSCUTIONS

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4.1 Calculated the Values of Energy and Forces Effects 4.1.1 Kinetic Energy From the equation of Kinetic Energy founded:

K.E= ∗ ∗ (4.1) M= 2000 Tons= 2000000 kg v= 7 knots = 3.7 m/s

K.E = ∗ 2000000 ∗ (3.7) = 13690 * 10kw 4.1.2 Torque of Engine From the equation of torquefounded: P= T*W (4.2) W= (2*N*)/60 =(2*3.14*900)/60 = 92.2 rad/sec Power of tugboat engine = 8113kw T= (8113*10)/92.2 = 87.99 kn.m 4.1.3 Impulsive force From the equation ofImpulsive forcefounded: In the push tugboat impulsive force was used (the amount of motion), the primary velocity () value is 0, because before process of impact, and Velocity of Impulsive () is the velocity on impulsive in the impact moment and value of velocity equal 3.7 m/s,also the mass of the tugboat effect on the same direction of movement (tug process), all of those react on the ship by the amount of motion (*m).

F= M( − ) (4.3)

− = 7 knots=3.7m/s, =3.7 m/s),=0 M = 2000000 kg F = 2000000*3.7 = 7.6*10N.S

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4.1.4 Tension Force of Tugboat Rope In the tug process the tension force effect in the structure and the rope that connected to the roller. The speed of tug process don’t exceed (7knots =3.7 m/s) P = V * F (4.4) P= 8113kw V = 3.7 m/s F = (8113*10)/3.7 = 2192.70 KN Table (4.1): specification of the loads effect on the rope (HMPE)

Diameter Circ. maximum Breaking (mm) (inch) load (KN) 36 4.50 912 38 4.75 1010

40 5.00 1140 44 5.50 1380

48 6.00 1610 52 6.50 1920 56 7.00 2190

60 7.50 2520 64 8.00 2880 68 8.50 3260

72 9.00 3630 76 9.50 4020 80 10.00 4510

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The value of Tension force effect on rope and roller connect =2192.70 KN 2192.70 KN56 mm The diameter rope selected is 72 mm 3630 KN (maximum effect tension force), There is permission to add more tension force. 4.1.5 The Resistance of Water and Air Resistance (RT)= Frictional resistance + Residual resistance+ Air resistance =

0.3 Approximate

4.1.5.1 Effect of resistance force Total resistance effect on motion. F=M*A (4.5) A = 0 (there is no acceleration because the velocity value is constant) The amount of motion in pushing tugboat= 2000*10*3.7*0.1= 7.4*10N.kg (direction of motion). In tug process slope angle equals10. Tug force = csc 10*2192.70*10= 2159.38 KN (direction of motion). The Force of the Ship Weight (fraction force) = 50000000*0.1−2195.70*sin 10 *2159.38*10 = 5*10 KN (opposite of the direction of motion). Total force in the direction of motion = 2159.38*10+7.4*10 = 9.59*10KN. The value of the total force is greater than the value of fraction force, and then the ship can be moved.

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4.2 Tugboat Model by Solid work Software The models shown in figures (4.2),(4.3),(4.4) and (4.5) describe the tugboat’s projections that were used to connect the towing parts with. In order to run the towing process simulations and discover the the results.

Figure 4.2: Tugboat, front view

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Figure 4.3: Tugboat, Top view

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Figure 4.4: Tugboat, Back view

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Figure 4.5: Tugboat, Right view

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4.3 Simulation Result 4.3.1 The roller and rope the tension force effect to roller is 2192.70 KN

Model Information Table (4.2): Towing Parts

Model name: Part1 -sim1 Current Configuration: Default Solid Bodies Document Name and Document Path/Date Treated As Volumetric Properties Reference Modified Boss-Extrude77 Mass:331476 kg Volume:42.2263 m^3 C:\Users\iceland\Desktop\Par Solid Body Density:7850 kg/m^3 t1 -sim1.SLDPRT Weight:3.24847e+006 N Oct 21 19:57:12 2017

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Table (4.3): Towing Parts Specifications

Model Reference Properties Components

Name: ASTM A36 Steel SolidBody 1(Boss- Extrude77)(Part1 - Model type: Linear Elastic sim1) Isotropic Default failure Max von Mises criterion: Stress Yield strength: 2.5e+008 N/m^2 Tensile strength: 4e+008 N/m^2 Elastic modulus: 2e+011 N/m^2 Poisson's ratio: 0.26 Mass density: 7850 kg/m^3 Shear modulus: 7.93e+010 N/m^2

Curve Data:N/A

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Table (4.4): Loads and Fixtures

Fixture name Fixture Image Fixture Details

Entities: 4 edge(s)

Type: Fixed Geometry

Fixed-1

Resultant Forces

Components X Y Z Resultant

Reaction force(N) -2.19404e+006 -4.91553 -1.20929 2.19404e+006

Reaction Moment(N.m) 0 0 0 0

Table (4.5): Force Direction

Load name Load Image Load Details

Entities: 1 edge(s) Reference: Face< 1 > Type: Apply force Values: ---, ---, 2.19405e+006 N Force-1

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4.3.2 Study Results

Table (4.6): Stress Simulation

Name Type Min Max Stress1 VON: von Mises Stress 17236.2 N/m^2 2.41407e+007 N/m^2 Node: 18838 Node: 1236

Part1 -sim1-Static 1-Stress-Stress1

Name Type Min Max Displacement1 URES: Resultant Displacement 0 mm 0.201316 mm Node: 2606 Node: 1237 In figure 4.6 the magnitude of stress we found the stress is 2.028N/m^2< maximum stress 2.43 N/m^2 - The stress simulation Table (4.6) shows that when the force is to be applied which is (2192.70K N) the maximum stress is concentrated in the middle thus, the entire mechanism survived the test and it can handle the discussed towed weight.

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Table (4.7): Strain Simulation

Name Type Min Max Strain1 ESTRN: Equivalent Strain 6.61404e-008 5.89553e-005 Element: 1969 Element: 13325

Strain-Strain1-ﺣﺸﻘﻒPart1 -sim1-Static 1 In figure 4.7 strain of material structure, we found the strain is 4.93

- The strain simulation Table (4.7) which accurse due to stress shows that when the force is to be applied (2192.70 KN), the strain also happened to be placed in the middle of the part thus, the entire mechanism strained within the controlled limit.

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CHAPTER FIVE

CONCLUSION AND DISCCUTION

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5.1 Conclusion

In this project a tugboat was design with high specifications made of mild steel select engines with high capacity can be pushing and to towing huge ship (40~50) thousand tons using an engine that produces up to (10.000) HP obtained at (900) r.p.m, identifying influential forces, determined maximum stresses and strain of the structure and determined maximum tension force effect on rope and increase permeation of towing process.

Finally, this project open a wide door for boat deigns in Sudan. 5.2 Recommendations

1. Use the hybrid engines with (LNG) liquefied natural gas to reduce fuel cost and maintenance the engines. 2. This design can be modified into a river tugboat with some differences and can be used as an investment. 3. The towing parts can be supported even more to assure that no failure can take place, only if needed.

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REFERENCES

1. Jane's Ocean Technology 1979-80 / Jane's Yearbooks, 1979 - ISBN 0-531- 03902-1. On Tugboats: Stories of Work and Life Aboard / Virginia Thorndike - Down East Books, 2004. Under Tow. 2. A Canadian History of Tugs and Towing. ھﯿﺌﺔ اﻟﻤﻮاﻧﺊ اﻟﺒﺤﺮﯾﺔ اﻟﺴﻮداﻧﯿﺔ – اﻟﺨﺮﻃﻮم- ﺷﺎرع اﻟﺒﻠﺪﯾﺔ .3 4. Donal Baird - Vanwell Publishing, 277 p., 2003 - ISBN 1-55125-076-4 Pacific Tugboats: / Gordon Newell - Superior Publishing Company 1957, Seattle Washington. Primer of Towing / George H. Reid - Cornell Maritime Press, 1992.

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