CLASS No 1
SHIPBUILDING AND OFFSHORE INDUSTRY
1.1 SHIPBUILDING INDUSTRY
 Long history from the earliest beginnings of mankind
 Very traditional and conservative
 Slow introduction of change
 Basic approach is similar over the years
 Change from wood to iron to steel
 Change from oars to sail to steam with paddlewheel to propeller to diesel
 Factors impacting shipbuilding (compared to automobile and aircraft
industry)
- Portability of the product - able to pick it up anywhere in the world
- Use in world trade - product travels all over the world
- Flags of convenience
- Foreign labor costs/conditions
- World trade growth
- National goals (policies)
- Relatively low labor skills required for both shipbuilding and ship
operation
- Labor intensive with easily transferred shipbuilding skills and
contribution to balance of payments makes it an attractive industry for
developing countries
 Relatively low investment cost.
 Shipbuilding Industry made up of many segments (see Fig 1)
 Company Types:
 Depends on where you are in supply chain. A pump manufacturer is a
part supplier to a shipbuilder, but to the casting company the Pump
Manufacturer is an "OEM". So from the point of view of a
shipbuilder or boatbuilder
 Original Equipment Manufacturer OEM
o
Shipbuilder - Ships
o
Boatbuilder - Boats
 Supplier
o
Engine Manufacturer
o
Propeller Manufacturer
o
Crane Manufacturer
o
Pump Manufacturer
o
Etc.
1.2 OFFSHORE INDUSTRY
 Offshore oil industry was a natural migration from land.
 Originally in shallow water, bays, swamps and close offshore coast lines.
 Started in U.S. West Coast, California, in 1897 and by 1900 there were
many wharfs or wooden piers stretching out into the Pacific Ocean with
drilling rigs on the ends. But it was the Gulf of Mexico where the industry
and technology developed.
 Moved to lake in Venezuela.
 Construction of offshore bottom supported rigs was by land rig builders
rather than shipyards.



Drill ships have been built by shipbuilders as have a number of semisubmersible rigs. However, all of the bottom mounted rigs have been
constructed by companies from the oil construction industry.
Some U.S. shipyards (Litton and Avondale) built jack up drilling rigs but
they did not do so profitably.
There are many types of platforms, but they can be classed into:
Bottom Mounted
- Fixed structure -
Steel
Concrete
Jack-up
Floating -
Self propelled/
Dynamically positioned
Moored -









Traditional cables &
anchors
Tension leg
Offshore technology development benefited from North Sea Oil field
discovery.
Offshore activities consist of Exploration, Drilling and Production.
Different platforms are used for different activities.
Drilling/Production Platforms can be of steel or concrete construction
Concrete construction is usually performed in large man dug basins
(holes) near the shoreline and the platforms are launched by flooding the
basin, removing the earth between the basin and the sea and then towing
the platform out to sea. If another platform is to be built the land is filled
in again, the basin drained and construction starts. The top levels of
concrete platforms are often of steel.
Steel platforms are built in fabricators yards. It may simply be a level land
site.
The platform bases are usually built up from large cylindrical tubes and
large diameter pipe. The platform bases are transported to the offshore site
by barge. The launch from the barge looks simple but it is quite
complicated. Especially as the platform must right itself and sink to the
bottom at a precise location.
The upper decks of the platforms are usually built separate from the bases,
sometimes by completely separate companies. They are again, barged to
the offshore site and lifted onto the installed platform base by very large
(6,000 ton) floating cranes.
Builders of the steel bases and upper decks are not usually equipped as
well a the typical shipyard. They make do with less.
Self propelled drilling rigs are usually built by shipyards
HANDOUTS:
 Paper THE SHIPBUILDING BUSINESS IN THE U.S.
 Introduction, Oil and gas, Exploration and Drilling Rigs from
OFFSHORE PRIMER
 Paper on the construction of Offshore Platforms
 View Video1 Video 2
 Lecture notes: ShipBuilding & Offshore Industry (text only)
CLASS No 2
SHIP TYPES AND COMPONENTS
2.1 KEY CONCEPTS:
 Ship Types Classified by industry segment and use (see Fig 1)
 Ship Systems conveniently grouped into:

Structure

Propulsion Machinery

Electric Plant

Command & Communication

Auxiliaries

Outfit
 Naval Architect's job to integrate the systems - Systems Engineering in
shipbuilding
 Structural component names carry over from wooden ships(see Fig 2)
 Many outfit component names also carried over from early ships
COURSE NOTES:
 PDF file shiptypes.pdf
CLASS No 3
CLASS No 4
TECHNICAL COMMUNICATION
MARKETS, DEMAND AND SUPPLY
4.1 MARKETS, DEMAND AND SUPPLY
 Market Share of different types of ships:
- Large
- Medium
- Niche
 Changing value over time of different ship types per CGT
 World Shipbuilding capacity is 50% greater than demand
 Result is fierce competition and prices below construction cost
 This requires subsidies in some form or other from governments
 Korea has increased its shipbuilding capacity by 50% over 1994-96,
whereas most other countries are constraining their ambitions
COURSE NOTES:
 NSRP Short Course Section on SB Markets, Demand and Supply
 PDF file dem_sup.pdf
CLASS No 5
PRODUCTIVITY AND COMPETITIVENESS
5.1 PRODUCTIVITY
 U.S. Productivity half that of the best in the world shipbuilding
 Definition of Productivity is uncertain
 Man Hours per Ton of Steel is not a good metric
 Best internationally accepted factor is Compensated Gross Tonnage
(CGT)
 CGT not understood in U.S. shipbuilding so not widely used
 Productivity is a multi-factored product not linear
 Influenced by:
- worker effort
- worker skill
- management competence
- facilities
- effectiveness of work organization
- level of technology used
5.2 COMPETITIVENESS
 U.S. is not competitive with the world class shipyards
 Both productivity is low and material cost is high
 U.S. is far above the Competitive Cost Curve
 Not recognized by world shipowners as place to get commercial ships
 U.S. delivery times are twice the competition
 Competition is a multi-factored
 Influenced by:
- productivity
- labor rate
- material cost
- worker skills
- worker availability
- national shipbuilding policy
- financing schemes
 Some are within control of shipbuilder, most influenced by country's
government
COURSE NOTES:
 NSRP Short Course Section on Productivity
 NSRP Short Course Section on Competition
 PDF file: productivity.pdf
CLASS No 6
TECHNICAL COMMUNICATION
CLASS No 7
CONTRACTS, SPECIFICATIONS AND
MARINE COST ESTIMATING
7.1 CONTRACTS
 Contract is a legal document, an agreement between two parties to do
something
 There are many types of contracts.
 The major two types are Cost Plus Fixed Fee and Fixed Price
 Most others are variations of these two usually including performance
incentives for the shipbuilder
 Commercial ship contracts are usually fixed price
 Even though there are many standard contracts they are usually
customized during final negotiations
 Ship Contracts reference Contract Specifications and Contract Drawings
 When there are differences between contract, specification and drawings,
the order of precedence is Contract - Specification - Drawings
7.2 SPECIFICATIONS
 The Specification describes the technical and commercial requirements of
the ship and along with the Contract Drawings are used as the control
documents for the further development of design, construction, testing and
delivery of the ship
 the two best known specifications in this country are the Navy's GEN
SPECS and the old MarAd Standard Specifications
7.3 MARINE COST ESTIMATING
 Marine cost estimating is not an exact science
 It has grown through application of methods and historical data
 Is an area where significant improvement would help all shipyards
 In the U.S. it is really pricing of estimated quantities of raw material and
equipment
 World class shipyards use more parametric estimating than U.S. shipyards
 A shipyard can be requested to give ROM, Preliminary or Detailed
Estimates
 In most shipyards, Engineering is very involved in the estimating process,
usually responsible for material take-off and definition of system design
and associated equipment.
 In addition, Engineering must estimate how much man hours and material
it will require to design the ship
 Because of the time and cost of preparing estimates, shipbuilders usually
are selective on what the will bid on. Most shipyards management have a
"Bid- No Bid" meeting for each invitation to bid
 Bid decision is based on:
- ongoing work
- product fit to facilities and capabilities
- extent of competition
COURSE NOTES:
 Paper on Bid Preparation in Shipbuilding
 Marine Cost Estimating for Engineers
 PDF file: cost_est.pdf
SHIPBUILDING INDUSTRY
It is not possible to say who invented the boat or ship. Archeologists have
determined that there were boats over 12,000 years ago. As such they have been
the means of providing a platform from which to ford a river or to fish for
countless generations. Boats were developed where there was a need for them and
were almost invariably built for basic utilitarian requirements.
All the early communities of man were located on the banks of rivers or on the
coastline. There is evidence in early cave drawings, paintings and even models
showing early use of water for transport and fishing. People quickly learned that
water transportation was easy and cheap (a fact that many in the U.S. seem to
have forgotten). Two initial approaches were developed, namely:
1) The dugout tree trunk in which the builder had little control of the maximum
size.
2) Craft built from buoyant material, such as trees, reads and bamboo, which
were lashed together, and where size was decided by the builders experience
on what would hold together in the seas.
The development of the ship has been gradual (evolutionary) rather than
revolutionary. The initial step-discovery that some materials floated on water-was
probably discovered by chance. Although the dugout tree with outriggers for
stability, was a significant development, logs and rushes bound together, was the
first step into larger boats. The next development was light framework covered by
animal skins. As primitive wood working tools developed, so did the construction
of the ship. Planking replaced skins and boats grew into ships.
It is known that many nations have been influential in the evolution of the ship
and shipbuilding. Table I gives a brief chronology of the countries involved and
the sequence of shipbuilding development. The needs that fostered the
development were the transportation of people and cargo, fishing, exploration and
war.
Early shipbuilding development paralleled the development of civilization and the
growth of trade between countries separated by the sea. It is uncertain whether the
Babylonians learned shipbuilding from the Chinese, or the other way around, but
it is known that the Babylonians influenced the Phoenicians, the pioneer
shipwrights of the Mediterranean. Although its origins are not so clear, the
northern center for shipbuilding developed in the Baltic region about the same
time as the Phoenician development. Through exploration, warfare and then trade
the two centers became one. The Venetian’s carried on the development of the
shipbuilding process and, through their influence, Portugal and then Spain,
developed their shipbuilding industries.
French shipbuilding began to flourish in the early 17th century. France developed
the theory of naval architecture and was so far advanced of other maritime
nations, at the time, that even English shipbuilding was completely under French
influence. This was mainly accomplished by copying capture French ships. The
publishing of books on naval architecture and shipbuilding commenced around
1740 by the French. The first drawings to be used in shipbuilding were introduced
about the same time. Prior to that ships were built without any drawings relying
on the skill of the master shipwright and sometimes ship models.
Their shallow rivers and bays restricted the development of large shipbuilding in
Holland. France and Britain (England and Scotland merged their parliaments in
1707) had access to deeper water and therefore their size of ships constantly
increased.
Shipbuilding on the North American continent could be claimed to have started
when the Indians built large canoes. However, U.S. shipbuilding really
commenced during colonial days. Many fine ships were built for the Royal Navy.
After independence, the U.S. achievements in sailing ships were significant.
Unfortunately, the twilight of the sailing ship was brought on by the industrial
revolution in Europe and the resulting development of the steamship.
TABLE I - BRIEF CHRONOLOGY OF SHIPBUILDING TECHNOLOGY
DEVELOPMENT
The civilizations and countries which have been linked to the development of
shipbuilding technology are:
Crete
10000 to 4000 BC
Egypt
5000 to 2100 BC
Egypt
2100 to 600 BC
Phoenicia 1500 to 331 BC
Carthage 800 to 241 BC
Greece 700 to 146 BC
Rome
270 BC to 420 AD
Mediterranean seagoing for trade
Nile river warships
Mediterranean seagoing warships
Mediterranean seagoing for trade
Mediterranean, Europe and Africa for trade
Mediterranean trade and warships
Mediterranean, Europe and Africa warships
Mediterranean and Europe trade with warships
Venice 420 to 1500 AD
for protection
Genoa
640 to 1500 AD
Same as Venice
Vikings 900 BC to 1066 AD Ships for exploration and war
England 811 to 1850 AD
Wooden ships for war and trade
Hanse
1241 to 1660 AD
Ships for trade
Spain
1500 to 1600 AD
Ships for exploration
France 1500 to 1900 AD
Ships for war
USA
1776 to 1875 AD
Sailing ships and first clipper ships
Britain 1838 to 1950 AD
Iron and steel hulled steamships
Britain 1920
First all welded ship
USA
1916 to 1919 AD
World War I emergency fleet
USA
1940 to 1945 AD
World War II emergency fleet
Germany 1945 to 1955 AD
Diesel motor ships
Denmark 1945 to 1960 AD
Diesel motor ships
Japan
1958 to Present
Development of large shipbuilding
National program to become world’s biggest
Korea
1973 to Present
shipbuilding country.
The largest wooden ships were less than 200 feet in length. This was considered
the structural limit for them. (The recently built wooden hull MCM’s are 225 feet
in length and are the largest wooden ships built in the U.S.)
Iron was first used as reinforcement for details, such as beam knees, in wooden
ships and eventually for the complete framing structure with the shell and decks
still wood planking. The first complete iron ship, the VULCAN, was built in 1819
on the Clyde in Scotland. However, iron did not replace wood in ocean going
ships due to the magnetic compass deviation of iron hulls. Fortunately, in 1838,
Sir George Airy developed the method to correct for the deviation and the door
was opened for ocean going iron ships.
The first iron ships were Brunel’s GREAT BRITAIN and the East India
Company’s warship, NEMISIS. The Royal Navy built a considerable number of
iron hulled warships but experience with them was unsatisfactory due to the
damage caused by shrapnel as well as the difficulty of repairing resulting jagged
shell holes. Meanwhile, the use of iron for merchant ships increased rapidly.
Although the clipper ship IRONSIDE, built in 1838 and the LORD OF THE
ISLES, built in 1853, were completely of iron, most ships were being built as
composite ships with iron framing and wood planking.
Thick iron plates had been used armor on the French and British floating batteries
in the war with Russia with some success. Experiments after the war with wood
backed armor iron plating indicated that it would stop all existing shells. The
British then design and built the WARRIOR in 1862, which was iron hulled with
wood backed armor iron plating.
The building of the 680 foot GREAT EASTERN in 1858, by Scott Russell was
the climax of iron shipbuilding.
Mild steel started to replace iron in 1877 and the steel manufacturing process was
so well established that Lloyds Register of Shipping rules included testing of steel
at that time. Steel quickly replaced iron by 1880 because of its greater strength
and easier working. It has remained the best material for shipbuilding. It’s only
challengers are aluminum and fiberglass and these are only acceptable for special
applications.
When steel was first used it followed the iron ship joining method of riveting. The
way the ship was constructed was not really different to that for a wooden and
then iron ship. The keel would be laid first. Then the stem bar and the stern frame
would be erected. Next the frames and deck beams would be install and held in
place by ribbands and shores. The shell and deck planking/plating would be
attached to the framing and everything nailed/riveted together.
It was welding which allowed the way ships were built to change. However, this
did not happen overnight. Welding was first used for ships in the 1914-18 World
War, but the first all welded ship was not built until 1920. Even this achievement
was slow to be followed and it took the second World War to really promote full
use of welding in shipbuilding. Up to this time ships were still built by erecting
individual small parts. Welding allowed the pre-fabrication of structure into
assemblies, which were then erected on the building berth, and by the end of the
war the approach of structural assemblies was fully developed.
Pre-outfitting, the installation of outfit items such as structural fittings and pipe,
was introduced in the mid 1950’s.
The achievement of the emergency fleet construction in both world wars, by the
U.S. must be recognized, especially as much of the new techniques using welding
were developed by them during the second world war.
The growth of shipping, in the period between 1960 and 1975, for both bulk dry
cargo and oil fostered the development of new shipbuilding methods and large
ships. First Scandinavia and then Japan emerged as the world shipbuilding
technology leaders. Germany held the spotlight for a brief period but was never
the world leader. Korea has grown into an equal, in deadweight tonnage built, and
formidable competitor to Japan. However, it has done so using shipbuilding
technology developed by other countries. It is not yet considered a shipbuilding
technology leader.
From the earliest shipbuilding, it was necessary to float the boat, craft or ship
once it was built. Early launching consisted of placing logs under the boat to
"roll" it into the water (Vikings). There is the gruesome story (no reference
available) that the Egyptians used the bodies of slaves to form the launching
lubricant and that is why ships used to be christened with red wine and not
champagne. The Egyptians are also reported to have launched Cleopatra’s barge
sideways. Most launchings of large ships were end launching, although there are
many areas of the world, including the U.S., where side launching is still the
preferred approach. It is known that the Venetians constructed ships in dry-docks
and all the British three decker wooden warships were built in dry-docks. The
Japanese built their largest World War II battleships in dry-docks. However, the
first use of dry-docks for constructing large commercial ships was started by
Burmeister & Wain in Copenhagen in 1959. This was followed by Gotaverken
who built a new "green field" or perhaps one should say "solid rock" shipyard at
Arendal, which had two building docks but the ships were extruded out of the
building hall into the dock on rollers and tracks. All of the new shipyards
developed after this time had building dry-docks, except for Litton’s new
shipyard in Pascagoula who used a level land building approach and a floating
dry-dock with removable wing walls on one side for launching the ships. Existing
shipyards such as Maryland Shipbuilding & Dry-dock, NORSHIPCO and
Avondale and all developed a floating dry-dock launching approach.
Along with the development of shipbuilding technology has been the parallel
development of the workers involved. First their were only shipwrights, riggers
and sailmakers. Then loftsmen, iron workers, platers, riveters and boilermakers
were needed. Riveters were replaced by welders. Outfitting trades developed to
cover joiner work, sheet metal and painting while machinery trades included
machinists, and pipe fitters. In some countries the specialization of trades was
carried to extremes and the outcome was competition damaging demarcation
strikes.
Although the U.S. leads the world in warship, including submarine, technology,
apart from the emergency shipbuilding programs, the U.S. has not been in a
consistent commercial shipbuilding technology lead position since the demise of
the sailing ship. There are many reasons for this, some of which will be discussed
in the next part on "Factors Impacting Shipbuilding."
Factors Impacting Shipbuilding
If we ignore fishing and military needs for the moment, the sole reason for a
nation to have ships is to conduct trade with other nations separated by the sea.
While this sea transportation could be provided by the ships of other nations, it is
the tendency of nations that rely on trade to transport a good share of their
imports and exports in ships belonging to their nationals.
Unfortunately for the U.S., nations with lower labor costs such as Norway,
developed large merchant fleets to carry cargoes for other countries. Britain, on
the other hand, developed a large merchant marine to service her own interests in
expanding her trade and political ties with her commonwealth partners. Once the
commonwealth disbanded, Britain’s merchant fleet contracted significantly. As
other developing countries entered international shipping it became difficult for
countries like Britain, Norway and the U.S. to sustain merchant fleets of any
significance.
As the U.S. was not a colonizing nation and as adequate foreign shipping has
always been available to carry her cargoes, even with operating subsidies, it has
never been able to sustain a large merchant fleet in peacetime. With the
elimination of operating subsidies the fleet has dwindled to almost nothing. Only
the ships in the Jones Act fleet and a few on special charter to the Military Sealift
Command are still operating.
Obviously, the high cost of building the ships in the U.S. and the high cost of
operating with U.S. crews, both because of labor rates as well as large crew size,
were other factors. This was recognized by the U.S. government in 1936 and an
act was passed that provided both construction and operating subsidies to make
up the difference between U.S. cost and the international competition.
This helped the U.S. to maintain a reasonable merchant fleet which, in turn,
allowed a number of innovative ship designs to be developed in the U.S., such as:
o Nuclear powered ship SAVANNAH
o LNG Carriers
o Container Ships
o Barge Carrying Ships
It should be noted that construction subsidies have become the norm in most
shipbuilding countries as international competition has forced the price of new
ships below their cost in many countries. It should also be noted that many
countries, and especially Japan and Korea build 100% of the ships owned by their
respective shipowners, irrespective of the country of registry.
This is not the case for U.S. shipowners, of which there are still many. The large
U.S. owned oil companies are an example. The international nature of shipping
allows them to build, crew and flag their ships wherever the choose. This led to
the growth of "Flags of Convenience." For years Panama and Liberia were the
original countries of choice, but other countries such as Hong Kong, Bermuda and
Malta have provided this service.
Ships involved in international trade do not have a natural domestic market,
unlike most other industrial products. They can be constructed, crewed,
maintained and repaired anywhere in the world that such service is offered.
Current Shipbuilding Situation
The U.S. shipbuilding industry is, again, at another critical cross road in its long
history. It’s traditional market, ships for the U.S. government is drying up very
quickly, partly due to the peace dividend and partly due to the Navy’s previous
accelerated build up resulting in a dearth in the need for new military ships for the
next 5 to 10 years. Apart from the world war years, the U.S. has never been a
major player in the international commercial shipbuilding market. However, it is
the only opportunity to sustain the industry over the next few years and if they are
unable to capture a significant share of the international commercial shipbuilding
market, the current 70,000+ employees will decline to below 30,000.
Not only is the U.S. shipbuilding industry the largest builder of complex naval
ships in the world, it is also the largest employer of shipbuilders, if China is
ignored due to their unique situation. The U.S. shipbuilding industry employs
about 50% more than the next country, which is Japan.
The U.S. shipbuilding industry is an important part of the U.S. defense industrial
base. While the demand for naval ships is almost non-existent for the next few
years, the government has given the U.S. shipbuilding industry an opportunity to
enter the international commercial shipbuilding market by two key programs,
namely; by extending the Title XI Financing Guarantee to foreign shipowners and
by ordering a series of Fast Deployment ships for the Military Sealift Command
from a number of U.S. shipyards. Through the first program they anticipate
getting foreign shipowners to consider building their ships in the U.S. and through
the second program they are giving the shipyards involved on-going programs
with which to improve their productivity and thus competitive position.
The U.S. does not have a formal national shipbuilding policy. One could argue
that its informal policy is to help some shipyards win commercial ship orders
from the international market to sustain the shipbuilding industrial base so that if
and when new naval ships are needed there will be U.S. shipbuilders to build
them. This in fact is the stated position of some of the large U.S. shipbuilders.
They anticipate the future need for naval ships, early in the next century, and their
goal is to use the increased international demand and improving new ship prices
as an interim program to sustain their operations at an acceptable level throughout
the waiting period.
On the other hand, the non-military, so called "second tier", shipyards see the
opportunity differently. They see it as a way to improve their ability to sustain
their operations and maybe even grow in what, until now, has been a very
fluctuating demand, with long periods of drought, for their services.
This makes the opportunities and the ways to respond to them different for both
groups.
It is interesting that those shipyards that have obtained international commercial
ship orders belong to the large shipbuilder group. There are a number of the
smaller, non-military, shipbuilders in final negotiations with foreign shipowners,
but as of this time no firm orders have been won by them.
Other U.S. industries have had to change their customer base from a domestic to
international focus in order to stay in business. However, none have been in the
same position as the U.S. shipbuilding industry having zero share. Nor has their
productivity and delivery time been so out of kilter with the world class
competitors. Some people compare the U.S. shipbuilding challenge as being
similar to a new start up company or industry, but this is not correct. A new
company would not be encumbered with existing practices, organization and
cultures of which the U.S. shipbuilding have many traditional and detrimental
examples which result in uncompetitive cost and delivery time.
OWNERS
CHARTERS
SHIP BUILDERS
WORK BOAT BUILDERS
PLEASURE BOAT
BUILDERS
RIG BUILDERS
OCEAN STUCTURES
MANUFACTURERS
MACHINERY
MANUFACTURERS:
ENGINES
PROPELLERS
CONTROLS
GENERATORS
PUMPS
STEERING GEARS, ETC.
EQUIPMENT
MANUFACTURERS:
LIFEBOATS
RAMPS
FURNITURE
WINDOWS
DOORS
LIGHTING, ETC.
SHIP REPAIRERS
SHIP SCRAPPERS
CLASS REGISTERS:
ABS, LLOYDS, DET
NORSKE VERITAS
REGULATORS:
USCG, BRITISH DOT
RAW MATERIAL
SUPPLIERS:
STRUCTURAL STEEL
STRUCTURAL
ALUMINUM
PIPING
ELECTRIC CABLE
INSULATION
PAINT
COMPOSITES
BOAT DEALERS
SHIP BROKERS
MARINE INSURERS
FIGURE 1 – Marine Organizations
OFFSHORE INDUSTRY
The exploration and extraction of oil expanded from land to lakes and then to the
shoreline in the U.S. in the late 1950’s and then around the world. Shallow water,
bottom mounted structures were first used, but as drilling in deeper water
developed many different approaches were used. Drill ships, both new designs
and conversions of existing ships were built as well as jack-up, semi-submersible
rigs. Later bottom mounted steel and concrete platforms were developed for use
in both the Gulf of Mexico and the North Sea. The drill ships and semisubmersible rigs both use mooring systems and there has been continuing
development of these over the years.
As the drilling moved further offshore supplies were barged out to the rigs. This
was not adequate and it was necessary to develop service craft such as high speed
crew boats and offshore supply vessels. The early builders of the offshore supply
boats were the Southern barge builders, who simply added a bow to the barge,
made it self propelled and provided accommodation for the crew, and the
structural design of the Gulf built supply vessels still reflect this origin today.
The development of the offshore industry around the world supported the growth
of a large construction industry, requiring special craft such as large barges for
launching large bottom mounted structures, large crane barges and ships to lift
platform structures onto the supports at sea. The diverse locations around the
world also included some with harsh environments from very rough sea
conditions to extreme cold and ice.
While some shipyards around the world entered the offshore rig building business
most successful builders were companies that were offshore related who built new
facilities or took over old, closed down, shipyards and built the equipment as it
was required. While drill ships and semi-submersible rigs could be transported
over long distances, it was better to build the bottom mounted rigs as close to the
operating site as possible. This fostered the development of many green field
operations. These all were based on minimum investment in facilities, by using
mobile cranes and large earth moving equipment to dig large holes on the shore in
which the rig was built and to dig a channel to let the water in and float the rig out
when it was ready. They also used a lot of subcontractors rather than be a self
contained operation.
The offshore industry reached its peak in the early 1970’s and has been struggling
since then until mid 1997 when it has began to boom again. Many of the original
companies are gone and new ones are born in countries as the offshore activity
moves to them.