An inflatable boat is a lightweight boat constructed with its sides and bow made
of flexible tubes containing pressurised gas. For smaller boats, the floor and
hull is often flexible, while for boats longer than 3 metres, the floor
typically consists of three to five rigid plywood or aluminium sheets fixed
between the tubes, but not joined rigidly together. Often the transom is
rigid, providing a location and structure for mounting an outboard
motor. Some inflatable boats have been designed
to be disassembled and packed into a small volume, so that they can be easily
stored and transported to water when needed. The boat, when inflated, is kept
rigid crossways by a foldable removable thwart. This feature allows such boats
to be used as liferafts for larger boats or aircraft, and for travel or
recreational purposes. Other terms for inflatable boats include
"inflatable dinghy", "rubber dinghy", "inflatable", "inflatable rescue boat"
or "rubber duck". History
= Early attempts= There are ancient carved images of
animal skins filled with air being used as one-man floats to cross rivers. These
floats were inflated by mouth. Sometimes, these images have been
wrongly described as ancient scuba. The discovery of the process to
vulcanize rubber was made by Charles Goodyear in 1838, and was granted a US
Patent in 1844. In late 1843, Thomas Hancock filed for a UK patent, which was
also granted in 1844, after the Goodyear patent had been granted. In 1852, while
traveling in England, Charles Goodyear discovered that Thomas Hancock's company
was producing vulcanized rubber and sued. It was discovered that Thomas
Hancock had been shown a sample of Goodyear's rubber in 1842, but he had
not been told the process that made it and that independently, Hancock said
that he came up with his process. The last of the suits were settled in 1855.
Vulcanization stabilized the rubber allowing it to be both durable and
flexible. Shortly thereafter, several people expanded on experimentation of
rubber coated fabrics. In 1839 the Duke of Wellington tested
the first inflatable pontoons. In 1840, the English scientist Thomas Hancock
designed inflatable craft using his new methods of rubber vulcanization and
described his achievements in "The Origin and Progress of India Rubber
Manufacture in England" published a few years later.
Lieutenant Peter Halkett, an officer in the Royal Navy designed the Halkett boat
in 1845 as the first successful inflatable boat. His first design was
made of rubber-impregnated "Mackintosh cloth." The "boat cloak" served as a
waterproof poncho or cloak until inflated, when it became a one-man boat.
A special pocket held bellows for inflation, and a blade to turn a walking
stick into a paddle. A special umbrella could double as a sail. Halkett later
developed a two-man boat which was carried in a knapsack; when inflated, it
could carry two men operating a paddle on each side, and when deflated it
served as a waterproof blanket to allow the users to camp on wet ground. The
Admiralty was skeptical about potential uses for Halkett's designs; on 8 May
1845, Lord Herbert, First Secretary to the Admiralty, wrote to Halkett that "My
Lords are of an opinion that your invention is extremely clever and
ingenious, and that it might be useful in Exploring and Surveying Expeditions,
but they do not consider that it would be made applicable for general purposes
in the Naval Service". Although the Admiralty saw no use to
which Halkett's designs could be put in general naval service, this larger
design was extremely well received by explorers. John Franklin bought one to
take on the ill-fated 1845 expedition in which the entire expedition party of 129
men and two ships vanished. In his explorations along the Oregon
Trail, and the tributaries and forks of the Platte River during the years 1842
and 1843, John C. Frémont recorded what may have been the first use of an
inflatable rubber boat for travel down rivers and rapids in the Rocky
Mountains. In his account of the expedition he described his boat:
Among the useful things which formed a portion of our equipage, was an
India-rubber boat, 18 feet long, made somewhat in the form of a bark canoe of
the northern lakes. The sides were formed by two airtight cylinders,
eighteen inches in diameter, connected with others forming the bow and stern.
To lessen the danger of accidents to the boat, these were divided into four
different compartments, and the interior was sufficiently large to contain five
or six persons, and a considerable weight of baggage."
In 1848, General George Cullum, U.S. Army Corps of Engineers, introduced a
rubber coated fabric inflatable bridge pontoon, which was used in the
Mexican–American War and later on to a limited extent during the American Civil
War. By 1855 there were numerous types of
inflatable rubber boats in use, some made by Goodyear in the U.S. and other
surprisingly modern looking boats by the Thomas Hancock Company in Britain.
In 1866, four men crossed the Atlantic Ocean from New York to Britain on a
three-tube raft called Nonpareil. From 1900 to 1910, the development of
rubber manufacturing enabled attempts at producing circular rubber inflatable
boats, similar to modern coracles. These were only usable as rafts, and could
only be propelled by paddling. In addition, they tended to crack at seams
and folds due to the imperfect manufacturing process of the rubber.
= The Titanic= With the loss of the RMS Titanic in
1912, and World War I losses of ships to submarine-launched torpedoes, the need
for inflatable boats was plain. One cause of the loss of lives on the
Titanic was the lack of lifeboats. Even if every lifeboat had been completely
filled with passengers and crew, there would have been no way to rescue more
than half of all the people on board. The first SOLAS treaty was designed to
avoid such a disaster happening again. One of its provisions was to ensure that
vessels had enough lifeboats to provide every person aboard the vessel with a
place. Putting this rule into effect was not difficult with cargo ships: they had
small crews and plenty of deck space. Passenger ships had to stack lifeboats
on top of each other to carry enough to accommodate the large number of
passengers and crew. Warships also had large crews and little deck space.
Between the two World Wars, Goodyear found a way to join rubber to other
materials. They made life rafts of square-shaped inflated rubber tubes with
a rigid floor. Such rafts were to be stacked vertically aboard warships,
usually standing on deck and leaning against deck-houses.
= Modern inflatable boat= In the early 20th century inflatable
boats started to be independently produced by the RFD firm in England and
the Zodiac company in France. This was brought about by the development of
rubber-coated fabrics that had initially been used in the airship industry.
Reginald Foster Dagnall, English designer and founder of the airship
manufacturing company RFD, switched in 1919 to the development of inflatable
boats, using the coated fabric from hydrogen airships. The Air Ministry was
impressed with trials of his boat on a lake near Guildford and began to give
his firm contracts for the production of the life-saving equipment.
Meanwhile, in France a very similar pattern was emerging. The airship
company Zodiac began to develop inflatable rubber boats and in 1934 they
invented the inflatable kayak and catamaran which led on to the modern day
Zodiac inflatable boat. Development continued after World War II
with the discovery of new synthetic materials, such as neoprene, and new
glues, which allowed the boats to become sturdier and less prone to damage.
= World War II= Submarine warfare in the Battle of the
Atlantic led to casualties among warships and merchant ships. US warships
began using rubber life rafts. Since the rubber was much higher quality than 35
years before, the inflatable returned, but this time it was boat-shaped.
In the military, inflatable boats were used to transport torpedoes and other
cargo. They also allowed troops to make landings in shallow water, and their
compact size and ability to be stored made overland transport possible.
The Marine Raiders were originally trained to carry out raids and landings
from LCRL inflatable boats carried by high speed transports. In August 1942
the submarines USS Argonaut and USS Nautilus carried elements of the 2nd
Raider Battalion who carried out the Makin Island raid from LCR-L inflatable
boats. Invasions of the Battle of Arawe by the 112th Cavalry Regiment and parts
of the Battle of Tarawa involved amphibious landings in inflatable boats
against heavy enemy resistance. One of the models, the Zodiac brand
inflatable boat, grew to be popular with the military and contributed
significantly to the rise of the civilian inflatable boat industry, both
in Europe and in the United States. After World War II, surplus inflatable
boats were sold to the public. A version of this boat has been adapted by the
Marine Mammal Center for use in rescuing injured marine mammals at sea.
= Post-war inflatables= Inflatable liferafts were also used
successfully to save crews of aircraft that ditched in the sea; bombing, naval
and anti-submarine aircraft flying long distances over water being much more
common from the start of WWII. Until the middle 1950s inflatables were
still rafts in civilian use, hand paddled but the outboard motor came into
use in the early 1950s. Also in the 1950s, the French Navy
officer and biologist Alain Bombard was the first to combine the outboard
engine, a rigid floor and a boat shaped inflatable. The former
airplane-manufacturer Zodiac built that boat and a friend of Bombard, the diver
Jacques-Yves Cousteau began to use it, after Bombard sailed across the Atlantic
Ocean with his inflatable in 1952. Cousteau was convinced by the shallow
draught and good performance of this type of boat and used it as tenders on
his expeditions. The inflatable boat was so successful
that Zodiac lacked the manufacturing capacity to satisfy demand. In the early
1960s, Zodiac licensed production to a dozen companies in other countries. In
the 1960s, the British company Humber was the first to build Zodiac brand
inflatable boats in the UK. Some inflatables have inflated keels
whose V-shape help the hull move through waves reducing the slamming effect
caused by the flat hull landing back on the surface the water after passing over
the top of a wave at speed. Rigid-hulled inflatable boat
The modern rigid-hulled inflatable boat is a development of the inflatable boat
which has a rigid floor and solid hull. The external shape of the hull lets it
cut through waves more easily giving a more comfortable ride when traveling
fast in rough conditions. The structure of the hull is capable of supporting a
more powerful transom mounted outboard engine or even an inboard engine.
Some RHIBs are 14 metres in length and include inboard steering, luxury
features and full cabins. Although most rigid multifunction
dinghies are not actually inflated, they are buoyed partly by air chambers in the
hull as well as by closed-cell foam inside the hull. In addition to their
proactive lifeboat functionality, these boats serve as everyday tenders and as
recreational boats. They are extremely buoyant and/or unsinkable and have great
carrying capacity relative to length. Types
Today's more advanced inflatable boats are manufactured using supported fabric.
They are made of rubberized, synthetic fabrics CSM Hypalon/neoprene, PVC or
Polyurethane, providing light-weight and airtight sponsons. Depending on fabric
choice, the fabric panels are assembled using either hot or cold manufacturing
processes. Different styles of one-way valves are used to add or remove air,
and some brands include inter-communicating valves that reduce
the effect of a puncture. Boats are available in many floor choices, such as
the ribbed air floor, High Pressure Air Floor, fiberglass, and aluminum or wood
panels for rigidity. Inflatable boats that have transoms have
an inflatable keel to create a "deep-v" along the line of the hull improving the
hull's wave cutting and turning performance. Due to the light weight of
these vessels, if powering with an engine, it is best to put weight in the
bow area as the bow will rise while the boat is going up on plane.
A growing use for inflatables is for personal recreational use on lakes,
rivers, and oceans, as well as for white water rafting and kayaking. Fabric
bottom inflatable boats can be deflated, folded, and stored in compact bags,
making them ideal for consumers with limited storage as well as providing for
quick and easy access. Professional-grade inflatable boats and
RHIBs have existed for many decades. Modern versions are complex, and they
can be rapidly inflated using SCBA or scuba tanks as well as CO2 to make them
mission ready. The professional-grade RHIBs are available in many sizes and
styles, some sporting T-tops, cabins, and other features. Since the late
1990s, many varieties of inflatable boats, RHIBs, whitewater rafts, kayaks
and sea kayaks, and canoes, have been developed by Asian, European, and North
American companies. Repairing
Should a section puncture it can be repaired while still underway. More
extensive inflatable boat repairs — due to pinholes, punctures, peeling, leaks
or worn fabric — can be done in dry dock using two-stage synthetic rubber
coatings. Subject to a great deal of wear and tear
from the elements — both water and sun — inflatable boats are often replaced when
they could be restored or even repaired. Products that aggressively adhere to the
damaged Hypalon or PVC shell can fix virtually any surface damage through a
unique chemical bonding between the undercoat and topcoat that permanently
vulcanizes the two rubber coatings together to make the inflatable as good
as new. Uses
Inflatables are commonly between 2 and 7 metres long and are propelled by
outboard motors of 2.3 to 300 horsepower. Due to their speed,
portability, and weight, inflatable boats are used in diverse roles:
Inflatable and rigid-hulled inflatable boats are often used for short scuba
diving excursions. When employed as life saving equipment,
they should comply to the regulations set out by the SOLAS. Some life rafts
also contain additional inflatable section to ensure that the raft will
self righten in heavy seas. Inflatable life rafts have also been
used since the 1930s on military aircraft that operate over water.
These boats are often used by special-operations units of the armed
forces of several nations, for such purposes as landing on beaches. Because
inflatable craft can be stored compactly they can also be transported on midget
submarines such as those operated by the Advanced SEAL Delivery System. They have
also been used by other forces without government sponsorship, such as
guerrillas, pirates, and terrorists. Lifeguards use inflatable boats or jet
skis in order to reduce the time required to reach a swimmer in distress.
Inflatables are also used in conjunction with larger rescue craft such as the Y
class lifeboat used with the Tamar and Severn class lifeboats.
They are used in a number of sporting events and for recreational purposes,
such as Whitewater rafting, Inflatable Rescue Boat Racing, water skiing,
Fishing Although rigid boats are more often
employed, some cruise ships and luxury yachts use inflatable boats as a tender.
See also Inflatable kayaks
List of inflatable manufactured goods References