Exploring the Development of Anchor Handling Tug Supply Vessels

This report provides an overview of the development of Anchor Handling Tug Supply (AHTS) vessels, tracing their origins and evolution within the offshore oil and gas industry. It highlights the increasing demand for multi-purpose vessels capable of performing various tasks, including anchor handling, supply transport, and emergency response. The report discusses the adaptation of AHTS vessels to operate in harsh conditions, such as cold weather regions, emphasizing the importance of winterization measures and crew training. Furthermore, it examines the design considerations for AHTS vessels, including the integration of high horsepower engines, advanced thruster systems, and strengthened deck spaces to support heavy equipment and sub-sea mooring operations. The report also touches on the market dynamics affecting AHTS vessels, including oversupply issues and the need for flexibility in design to meet future demands and regulatory changes.

Anchor Handling Tug Supply vessels
Development of Anchor Handling Tug Supply vessels
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Anchor Handling Tug Supply vessels
Contents
Abstract............................................................................................................................................2
Introduction......................................................................................................................................3
Origins of anchor vessels.................................................................................................................3
Development of the Anchor Handling Tug Supply vessel..............................................................4
Evolution of offshore vessels...........................................................................................................5
Conclusion.....................................................................................................................................12
Bibliography..................................................................................................................................13
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Anchor Handling Tug Supply vessels
Abstract
The vessels in the offshore industry developed due to the growth which took place in oil and gas
industry. The use of multi-purpose vessels to assist in numerous industrial needs would be
realized during the period of specialization in the late 20th century. In the years to come, the
offshore industries will enlarge as well as the popularity of multi-purpose ships will increase and
become the established norm. The vessels will also make use of ductile materials in the
construction of vessels which are exposed to low air temperature cold weather places. An
important role is also played by AHTS design.
Optimization of AHTS simply relies on proper design thus making it suitable for providing
services relating to oilfields in a competitive environment. Easy modification of AHTS makes it
possible for the vessel to attain future demand and this simply communicates that flexibility is
needed in the design as well as the planning stage. There also the need of altering the modes of
operation, geographic theatres and regulations of Anchor Handling Tug Supply Vessels
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Anchor Handling Tug Supply vessels
Introduction
The offshore industry consist of so many vessels for example the Anchor Handling Tug Supply
vessels and Platform Supply vessels. These particular ships are changing, as a result, various
demands accruing in the industry as well as the fuel cost and economic pressure. To ensure the
traditional trends that were normally used are reversed, there is a need to combine the task into a
ship which is multipurpose. The preparation of Anchoring Handling Tug supply vessel to operate
in cold regions is sometimes becoming a problem. The operations and winterization have to
attain certain requirements and crew needs, and in the case of the Arctic environment, the
winterization of vessels is difficult. Some of the requirements of winterization for AHTS vessels
to carry out their operations in cold weather include;
 Training of crews.
 Considering the crews.
 Personnel should have safety systems.
 Construction of hull.
 Coatings and materials.
 Vessel machinery and systems.
 Specific vessels needed for four vessels types.
Origins of anchor vessels
Anchor Handling Tug Supply vessels are needed to carry out supply duties replenishing other
vessels and drilling rigs in operational supplies field. Anchor Handling Tug supply vessels are
super strengthened and they are manufactured to sustain even in a difficult working condition of
the sea by ensuring the crew safety, efficiency and comfort. Their efficient features make it
possible for them to be used in sub-sea mooring operations in the Oil and Gas offshore fields
(Brown, 2009, p. 433). There are certain features entailed in Anchor Handling Tug Supply
Vessels for example; AHTs vessels have superior bollard pull plus a higher engine rating making
them necessary in anchor handling, the combination of multiple thrusters together with the twin
screws CPP system used in fitting the AHTS vessels and the stowing of equipment wires heavy
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Anchor Handling Tug Supply vessels
in weight and chains can be done due to a large amount of strengthened deck space of the
accommodation areas (Buffa, 2016, p. 221).
The numerous duties showed simple articulate that AHTS vessels are in a position of performing
traditional duties which were being undertaken by other vessels such as the Multi-purpose
Supply Vessels, Emergency Rescue and Recovery Vessels or Diving Support Vessel and lastly
the Platform Supply Vessels. In the years to come, an oversupply of vessels will greatly affect
the vessel owners and AHTS market is characterized by a large demand and supply imbalance as
well as high standardization in the specification of vessels leading to ease in switching to
alternatives. Compared to the past decades, the prices of vessels have stabilized at very low
levels (Ambrose, 2009, p. 34)
Around Lake Catto in the year 1910 was when the water drilling operations began while in 1947,
the ship development started on a serious notice immediately Kerr acquired the Land ship tank
(Skidmore, 2011, p. 332). Before the appearance of mobile drilling unit in 1950, the
commissioning of Ebb Tide in 1955 took place to back up Mobile Offshore Drilling Unit owned
by Mr. Charlie. (Taggart, 2011, p. 128).
In 1956, the arrival of the three-legged jack-up was a major change which took place in the
offshore industry and within that year; Scorpion was the first to enter the market. The supply
chain vessels at the seal level were greatly minimized as a result of legs minimization. This made
it very important to tie up the stern as well as dropping the anchor and this is known as
Mediterranean moor. To ensure the AHTS has the ability to carry supplies to the platform,
anchor handling operations and towing drilling units then there is need of ensuring it is designed
with high horsepower. Nowadays, the use of higher horsepower vessels is increasing in deep
water exploration thus making it handles heavier gear needed to operate at such depths.
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Anchor Handling Tug Supply vessels
Development of the Anchor Handling Tug Supply vessel
The AHTS is increasing in usage since the offer a multi-utility facility thus they are demanded in
a higher coverage area. An increase in AHTS usage is relevant and makes a lot of sense because
of the increase in oil drilling from the oceanic areas which is a regular operation. The concept of
AHTS is not something new though the knowledge is not common among various people who
commonly engage in shipping and oil drilling activities. The creation of AHTS by the marine
world is very helpful since apart from aiding development in technology with smooth progress,
they assist in the prevention of mishaps at the sea (Ambrose, 2015, p. 123)
Offshore Anchor Handling is an activity that can be termed as thrilling as well as tedious and
terrifying and it more rewarding professionally point of view (Vergottis, 2008, p. 67). Testing of
vessel handling proficiency of expert can be done by the anchor handling. Anchor Handling Tug
Supply vessels are powerful ships that assist in deploying, recovering and shifting a subsea
mooring pattern. The types of vessels mentioned above normally perform effectively with
offshore installations. When carrying out anchor handling operations, heavy machines, as well as
related tools, are repeatedly pushed to their extreme in a very hostile surrounding. Vessels are
seriously damaged when they are working in a tough operating condition (Vergottis, 2008, p.
89).
By 1960, there were a number of operations carried out by the tidewater but there singly
depending on carrying of cargo, daily supplies as well as drilling the tools being carried. A
difficult operation involving deploying anchors and moving tags was carried out by tugs
During the 1960s, adding towards the deck forward end and A-frame aft permitted mooring of
supply vessels. The recovery, as well as the deployment of the anchors, was achieved by A-
frame differentiated the two kinds of water (sociology, 2008, p. 34). In around 1960s, North Sea
started recording high amount of oil therefore making the two Americans, Mr. Louise and Cap to
start using the American supply vessels as well as the tugs to service the operations. Some of
those who own ships also decided to perform the operation followed by the tug owners from
Dutch and Germany. (Mcgrail, 2013, p. 532).
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Anchor Handling Tug Supply vessels
Evolution of offshore vessels
Anchor Handling Tug Supply vessels are majorly created to handle anchors for oil rigs, tow them
to locations and use them in securing the rig in place. Operations related to supply transport and
Emergency Response and Rescue Vessels are also performed by the AHTS vessels (Keit, 2014,
p. 143). The designing of these vessels was mainly carried out to attain the harsh conditions of
the North Sea and can carry out the tasks related to supply duties between the sites drilling is
taking place and land bases. Fitting of AHTS vessels with winches for towing and anchor
handling makes it different with the Platform Supply Vessels. They allow decking of anchors
since they have open stern. The AHTS also can perform certain activities apart from towing and
anchor handling, for example, the remotely operated underwater vehicle (ROV) services, rescue
and safety services, as well as supply duties between the offshore installation and mainland
(Kaiser, 2012, p. 56).
In 1965, the first supply vessel to enter the service was Smit-Lloyd 1 consisting of funnels
located just after the pilot house. Ocean Inchcape (OIL) came in early 1970s and they were
focusing in anchor handling with almost 2980 KW plus a deck area 372 m2. However, the deck
carrying capacity for the dry back bulk, for example, betonies, cement and barite, and drill water,
fuel and potable water were retained. The versatile ship carried out a complete process and it
entailed numerous activities, for example, hiring and assigning anchor handlers. Hiring as well as
assigning anchor handlers were possible in this particular versatile ship and a complete process
was fulfilled by this particular ship. Anchoring was taking place after the towing of the rig,
followed by anchoring, and then supplying the drilling equipment from the shore (Hensen, 2016,
p. 56).
The building of fixed platform in North Sea was done in 1970s and later it was fixed with the
field jackets. Hamilton brothers went ahead in 1975 and came up with oil by converting a semi-
permeable Trans-world 58. Introduction of supply ship took place and their construction as well
as their operations was very easy. (Dincer, 2011, p. 312).
Offshore Supply Association plus the Star Offshore decided to erect small ships having the
ability to carry two lengths of pipe and this decision came after realizing the need for pipe
carriers in the middle decade. A large ship was built in Norway which was in a position of
carrying there lengths of pipes. The offshore installation process and working cargo were altered
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Anchor Handling Tug Supply vessels
after the arrival of this particular ship in North Sea. This is because there were no mooring ropes
provided to platform which were still under construction. (Deen, 2009, p. 43).
Anchor dropping from the rig was the mainly accepted task for a working cargo and in order to
reach the deck of the ship then the crane of mobile units is preferred. For the task to be handled
two vessels with hydraulic deck were produced by the OIL and they can be moved immediately
after clearing the stern area. A two large dedicated supply ships were introduced by Zapata
which was an American company and the vessels were equipped in a similar manner. If the
weather was too rough to tie up, and if the requirement for the cargo was urgent, the Master
might be asked if he could "snatch" it (sociology, 2008, p. 345). This involved positioning the
stern of the ship under the crane without tying up and holding it there for as long as it took for
the crew to hook on the lift. In case ropes were not installed in platforms, then snatching of
whole cargoes, and eventually for bulk cargoes to be discharged with long hoses (Ambrose,
2015, p. 211). Hence, with the advent of underwater side thrusters, instead of the ship lying
stern-to the rig, it could be aligned alongside; making the whole deck available to the crane. The
ship alignment made the pipe carriers to start carrying cargo and they were capable of handling
cargo in large needed in certain locations. However, the industry had not abandoned the
possibility that cargoes would also be carried on anchor-handlers, and several operators
continued with the traditional technique of hiring a rig and anchor-handlers which would form
support throughout the operation (Charles, 2012, p. 138).
In the late 1970s, there were numerous support vessels carrying out their duties on the seabed by
operating through the delivery of divers to the site or with manipulators. These vessels include
submarine support vessels and mini-submarine vessels. The submarine was deployed in the sea
to operate in the seabed. (Buffa, 2016, p. 12). Compared to the harbor tugs, Anchor Handling
Tug supply vessels are super strengthened and they are manufactured to sustain even in a
difficult working condition of the sea by ensuring the crew safety, efficiency and comfort. Their
efficient features make it possible for them to be used in sub-sea mooring operations in the Oil
and Gas offshore fields (Brown, 2009, p. 433). There are certain features entailed in Anchor
Handling Tug Supply Vessels as mentioned below;
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Anchor Handling Tug Supply vessels
 AHTs vessels have superior bollard pull plus a higher engine rating making them
necessary in anchor handling.
 The combination of multiple thrusters together with the twin screws CPP system is used
in fitting the AHTS vessels.
 The stowing of equipment wires heavy in weight and chains can be done due to a large
amount of strengthened deck space of the accommodation areas.
 These particular vessels have chain lockers in large capacity thus enabling the sufficient
amount of anchor chain to be stowed on board.
 To enhance both deep-water anchors handling plus towing is achieved due to extreme
powerful multi-drum catering twin winches owned by Anchor Handling Tug Supply
Vessels (Blank, 2011, p. 123).
 Various duties can be performed by the AHTS vessels since they are multipurpose and
these duties include carrying fuel, water, and deck cargo in large quantity.
There are certain applications that are performed by the Anchor Handling Vessels and they
include;
 They are used as multipurpose work boats in oil and gas offshore field.
 They take the role of rescuing and salvaging in case there are no readily available tugs.
 Anchor Handling Tugs assist in installing the SBM mooring and buoys.
 They are used for towing and anchor handling of newer offshore structures for example
Tension leg (Bertram, 2010, p. 124).
The design of AHTs plays an important role in AHTS operations as well as maintenance.
Optimization of AHTS simply relies on proper design thus making it suitable for providing
services relating to oilfields in a competitive environment. Easy modification of AHTS makes it
possible for the vessel to attain future demand and this simply communicates that flexibility is
needed in the design as well as the planning stage. There also the need of altering the modes of
operation, geographic theatres and regulations of Anchor Handling Tug Supply Vessels (Huitt,
2016, p. 321). To ensure the AHTS has the ability to carry supplies to the platform, anchor
handling operations and towing drilling units then there is need of ensuring it is designed with
high horsepower. Nowadays, the use of higher horsepower vessels is increasing in deep water
exploration thus making it handles heavier gear needed to operate at such depths.
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Anchor Handling Tug Supply vessels
The construction of OSVs fleet is optimized by the fabrication of AHTS and the demand for
AHTS is increasing now and again since it has certain advantages even the OSVs are lacking.
The AHTS quantity and quality can meet the demand from the oilfield market and requirements
from advanced offshore activities currently (Becky, 2015, p. 65).The performance and quality
issues relating to AHTS can only be solved by ensuring fabrication is carried out which will
enhance its lifetime performance as well as quality. The fabrication of AHTS is a hugely
complex project with features such as heavy workload, long period of design and fabrication,
wide operations and technology intensive. The building of Anchor Handling Tug Supply vessels
needs to attain certain requirements such as the formability, strength and weld ability
characteristics as well as toughness.
The AHTS is increasing in usage since the offer a multi-utility facility thus they are demanded in
a higher coverage area. An increase in AHTS usage is relevant and makes a lot of sense because
of the increase in oil drilling from the oceanic areas which is a regular operation. The concept of
AHTS is not something new though the knowledge is not common among various people who
commonly engage in shipping and oil drilling activities. The creation of AHTS by the marine
world is very helpful since apart from aiding development in technology with smooth progress,
they assist in the prevention of mishaps at the sea (Ambrose, 2015, p. 123).
Anchor Handling Tug Supply vessels are an important feature of the offshore oil and gas
industry carrying out various operations such as mooring, positioning and towing of drilling rigs
a\s well as other marine equipment. They are equipped with specialized winches and powerful
engines and their duties hey required to carry out may include;
 Deploying as well as retrieving of anchors.
 Towing/tugging rigs, vessels are pushes to location or assistance during docking.
The equipment used in Anchor Handling Tug Supply vessels need to meet these requirements of
Classification Societies and the parties involved. Anchor Handling Winch should be design for
holding braking capacity and adequate dynamics to control a normal combination of loads. The
towing winches are designed to permit the quick release of drums and lines in the emergency
situations or operational situations. Both the anchor handling line, as well as the towline, may be
either fiber rope or steel wire.
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Anchor Handling Tug Supply vessels
Conclusion
A well- designed ship is due to collaboration, state art of equipment, innovation and experience.
The maintenance of the design will enable the manufactures to achieve certain factors such as
reliability, environmentally, safety and economy. The performance of the AHTS vessels is
greatly influenced by certain factors, for example, the form. The form of the vessel influence the
vessel operability and AHTS is designed with forecastle in the open deck, in the bow and in the
stern like OSVs. Vessels having certain features such as environmental friendly hull lines
optimized for improved eco-drive in all weather conditions. These type of vessels put into
consideration certain things such as low consumption of fuel, good sea keeping abilities and
adhere to Clean design requirements.
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Anchor Handling Tug Supply vessels
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