Variable-pitch propeller
A variable-pitch propeller or controllable-pitch propeller is a type of propeller with blades that can be rotated around their long axis to change the blade pitch. Reversible propellers—those where the pitch can be set to negative values—can create reverse thrust for braking or going backwards without the need to change the direction of shaft revolution. Propellers whose blade pitch could be adjusted while the aircraft was on the ground were used by a number of early aviation pioneers, including A. V. Roe and Louis Breguet. In 1919 L. E. Baynes AFRAeS patented the first automatic variable-pitch airscrew; the French aircraft firm Levasseur displayed a variable-pitch propeller at the 1921 Paris Airshow, which, it claimed, had been tested by the French government in a ten-hour run and could change pitch at any engine RPM. Dr Henry Selby Hele-Shaw and T. E. Beacham patented a hydraulically operated variable-pitch propeller in 1924 and presented a paper on the subject before the Royal Aeronautical Society in 1928, though it was received with scepticism as to its utility.
The propeller had been developed with Gloster Aircraft Company — as the Gloster Hele-Shaw Beacham Variable Pitch Propellor — and was demonstrated on a Gloster Grebe, where it was used to maintain a near-constant RPM. The first practical controllable-pitch propeller for aircraft was introduced in 1932. French firm Ratier pioneered variable-pitch propellers of various designs from 1928 onwards, relying on a special ball bearing helicoidal ramp at the root of the blades for easy operation. Several designs were tried, including a small bladder of pressurized air in the propeller hub providing the necessary force to resist a spring that would drive the blades from fine pitch to coarse pitch. At a suitable airspeed a disk on the front of the spinner would press sufficiently on the bladder's air-release valve to relieve the pressure and allow the spring to drive the propeller to coarse pitch; these "pneumatic" propellers were fitted on the DH88 Comet aircraft, winner of the famed long distance 1934 Mac Robertson race and in the Caudron C.460 winner of the 1936 National Air Races, flown by Michel Detroyat.
Use of these pneumatic propellers required presetting the propeller to fine pitch prior to take-off. This was done by pressurizing the bladder with a bicycle pump, hence the whimsical nickname Gonfleurs d'hélices given to the aircraft ground mechanics in France up to this day; such propellers are used in propeller-driven aircraft to adapt the propeller to different thrust levels and air speeds so that the propeller blades don't stall, hence degrading the propulsion system's efficiency. For cruising, the engine can operate in its most economical range of rotational speeds. With the exception of going into reverse for braking after touch-down, the pitch is controlled automatically without the pilot's intervention. A propeller with a controller that adjusts the blade pitch so that the rotational speed always stays the same is called a constant-speed propeller. A propeller with controllable pitch can have a nearly constant efficiency over a range of airspeeds. A common type of controllable-pitch propeller is hydraulically actuated.
This design led to the award of the Collier Trophy of 1933. de Havilland subsequently bought up the rights to produce Hamilton propellers in the UK, while the British company Rotol was formed to produce its own designs. The French company of Pierre Levasseur and Smith Engineering Co. in the United States developed controllable-pitch propellers. Smith propellers were used by Wiley Post on some of his flights. Another common type was developed by Wallace R. Turnbull and refined by the Curtiss-Wright Corporation; this electrically-operated mechanism was first tested in on June 6, 1927 at Camp Borden, Ontario and patented in 1929. It was favoured by some pilots in World War II, because when the engine was no longer running the propeller could be feathered. On hydraulically-operated propellers the feathering had to happen before the loss of hydraulic pressure in the engine; as experimental aircraft and microlights have become more sophisticated, it has become more common for such light aeroplanes to fit variable-pitch propellers, both ground-adjustable propellers and in-flight-variable propellers.
Hydraulic operation is too expensive and bulky, instead light aircraft use propellers that are activated mechanically or electrically. The Silence Twister prototype kitplane was fitted with the V-Prop, an automatic self-energising and electronically self-adjusting VP propeller. A variable-pitch propeller can be efficient for the full range of rotational speeds and load conditions, since its pitch will be varied to absorb the maximum power that the engine is capable of producing; when loaded, a vessel needs more propulsion power than when empty. By varying the propeller blades to the optimal pitch, higher efficiency can be obtained, thus saving fuel. A vessel with a VPP can accelerate faster from a standstill, can decelerate much more making stopping quicker and safer. A VPP can improve vessel maneuverability by directing a stronger flow of water onto the rudder. However, a fixed-pitch propeller is both cheaper and more robust than a VPP. An FPP is more efficient than a VPP for a single specific rotational speed and load condition.
Accordingly, vessels that operate at a standard speed will have an FPP optimized for that speed. At the other extreme, a canal narrowboat will have a FPP for two reasons: speed is
Port of Hamburg
The Port of Hamburg is a sea port on the river Elbe in Hamburg, Germany, 110 kilometres from its mouth on the North Sea. It's Germany's largest port and is named the country's "Gateway to the World". In terms of TEU throughput, Hamburg is the third-busiest port in 15th-largest worldwide. In 2014, 9.73 million TEUs were handled in Hamburg. The port covers an area of 73.99 km ². The location is advantaged by a branching Elbe, creating an ideal place for a port complex with warehousing and transshipment facilities; the extensive free port was established. It enabled duty-free storing of imported goods and importing of materials which were processed, re-packaged, used in manufacturing and re-exported without incurring customs duties; the free port was abandoned in 2013. The port is as old as the history of Hamburg itself. Founded on 7 May 1189 by Frederick I for its strategic location, it has been Central Europe's main port for centuries and enabled Hamburg to develop early into a leading city of trade with a rich and proud bourgeoisie.
During the age of the Hanseatic League from the 13th to 16th century, Hamburg was considered second only to the port and city of Lübeck in terms of its position as a central trading node for sea-borne trade. With discovery of the Americas and the emerging transatlantic trade, Hamburg exceeded all other German ports. During the second half of the 19th century, Hamburg became Central Europe's main hub for transatlantic passenger and freight travel, from 1871 onward it was Germany's principal port of trade. In her time the Hamburg America Line was the largest shipping company in the world. Since 1888, the HADAG runs a scheduled ferry service across various parts of the Elbe; the Free Port, established on 15 October 1888, enabled traders to ship and store goods without going through customs and further enhanced Hamburg's position in sea trade with neighbouring countries. The Moldauhafen has a similar arrangement, though related to the Czech Republic exclusively; the Speicherstadt, one of Hamburg's architectural icons today, is a large wharf area of 350,000 m² floor area on the northern shore of the river, built in the 1880s as part of the free port and to cope with the growing quantity of goods stored in the port.
Hamburg shipyards lost fleets twice after World War I and World War II, during the partition of Germany between 1945 and 1990, the Port of Hamburg lost much of its hinterland and many of its trading connections. However, since German reunification, the fall of the Iron Curtain and European enlargement, Hamburg has made substantial ground as one of Europe's prime logistics centres and as one of the world's largest and busiest sea ports. Deepening of the river Elbe for large vessels is controversial for ecological reasons. In part due to cooperation with Lower Saxony and Bremen to build a new container port in the deep waters of Jadebusen in Wilhelmshaven, Hamburg withdrew from this plan after a change of government in 2001. Hamburg is a major cruise destination and one of Europe's largest ports of call for cruise passengers traveling the Atlantic, or the Norwegian and Baltic Seas; the port is a major location for shipbuilder and shipyards, designing and reconditioning yachts and cruise liners.
Hamburg has three passenger terminals for cruise ships: Hamburg Cruise Center HafenCity, the Hamburg Cruise Center Altona and the Hamburg Cruise Center Steinwerder, all three capable of processing the world's largest cruise ships. The Port of Hamburg is one of Hamburg's largest attractions, both as a living and logistic center but as a backdrop for modern culture and the port's history. Among these are various museum ships, musical theaters, bars and hotels - and a floating boat church; the annual celebration of the port's birthday during the first weekend of May is one of Hamburg's biggest public events. National and international visitors come to experience the festivities. Tugboats perform "ballets", old galleons and new cruise ships are open for tours, fireworks explode at night. Tour guides on boat tours in the port are called he lüchts after an used call of dock workers when they overheard the stories told to tourists. BallinStadt Elbe 17 Port of Hamburg Website Hamburg Chamber of Commerce Port of Hamburg: Facts and outlook HafenCity Website The Elbe Philharmonic Hall Currently under construction in the HafenCity Arts in the HafenCity Ship Movements, Photos & Videos from Hamburg
Z-drive
A Z-drive is a type of marine propulsion unit. It is an azimuth thruster; the pod can rotate 360 degrees allowing for rapid changes in thrust direction and thus vessel direction. This eliminates the need for a conventional rudder; the Z-drive is so named because of the appearance of the mechanical driveshaft or transmission configuration used to connect the mechanically supplied driving energy to the Z-Drive azimuth thruster device. This form of power transmission is called a Z-drive because the rotary motion has to make two right angle turns, thus resembling the letter "Z"; this name is used to differentiate the arrangement of drive to that of the L-drive. It does not refer to an electric motor in a rotating pod; the device is different from the Voith-Schneider marine propulsion system, which can quickly change the direction of thrust, as the Z-drive uses a shrouded conventional screw that pivots or rotates the propeller, unlike the variable-geometry blades of the Voith-Schneider. The Z-drive transmission was invented in 1950 by Joseph Becker, the founder of Schottel, used in the first azimuth thrusters built by Schottel GmbH in Germany in the 1960s under the Schottel brand name and referred to as Rudderpropeller since.
Joseph Becker was awarded the Elmer A. Sperry Award for this invention as a major contribution to the improvement of transportation worldwide. Counter-rotated Integrally installed/hull installation Deck mounted outboard Retractable Floating dredge Tank ship Coastal trading vessel Platform supply vessel Passenger ship Patrol Boat Ferry Fishing trawler Cargo ship Self-sailing pontoons Barge Yacht Tugboats Saildrive, a Z-drive with fixed azimuth, for sailboats Propulsor Voith Schneider Propeller L-drive Kort nozzle Sterndrive Propulsion Pleuger L- and Z-drive Rudderpropeller
United States
The United States of America known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U. S. is the third most populous country. The capital is Washington, D. C. and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico; the State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean; the U. S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The diverse geography and wildlife of the United States make it one of the world's 17 megadiverse countries.
Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago. European colonization began in the 16th century; the United States emerged from the thirteen British colonies established along the East Coast. Numerous disputes between Great Britain and the colonies following the French and Indian War led to the American Revolution, which began in 1775, the subsequent Declaration of Independence in 1776; the war ended in 1783 with the United States becoming the first country to gain independence from a European power. The current constitution was adopted in 1788, with the first ten amendments, collectively named the Bill of Rights, being ratified in 1791 to guarantee many fundamental civil liberties; the United States embarked on a vigorous expansion across North America throughout the 19th century, acquiring new territories, displacing Native American tribes, admitting new states until it spanned the continent by 1848. During the second half of the 19th century, the Civil War led to the abolition of slavery.
By the end of the century, the United States had extended into the Pacific Ocean, its economy, driven in large part by the Industrial Revolution, began to soar. The Spanish–American War and World War I confirmed the country's status as a global military power; the United States emerged from World War II as a global superpower, the first country to develop nuclear weapons, the only country to use them in warfare, a permanent member of the United Nations Security Council. Sweeping civil rights legislation, notably the Civil Rights Act of 1964, the Voting Rights Act of 1965 and the Fair Housing Act of 1968, outlawed discrimination based on race or color. During the Cold War, the United States and the Soviet Union competed in the Space Race, culminating with the 1969 U. S. Moon landing; the end of the Cold War and the collapse of the Soviet Union in 1991 left the United States as the world's sole superpower. The United States is the world's oldest surviving federation, it is a representative democracy.
The United States is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, other international organizations. The United States is a developed country, with the world's largest economy by nominal GDP and second-largest economy by PPP, accounting for a quarter of global GDP; the U. S. economy is post-industrial, characterized by the dominance of services and knowledge-based activities, although the manufacturing sector remains the second-largest in the world. The United States is the world's largest importer and the second largest exporter of goods, by value. Although its population is only 4.3% of the world total, the U. S. holds 31% of the total wealth in the world, the largest share of global wealth concentrated in a single country. Despite wide income and wealth disparities, the United States continues to rank high in measures of socioeconomic performance, including average wage, human development, per capita GDP, worker productivity.
The United States is the foremost military power in the world, making up a third of global military spending, is a leading political and scientific force internationally. In 1507, the German cartographer Martin Waldseemüller produced a world map on which he named the lands of the Western Hemisphere America in honor of the Italian explorer and cartographer Amerigo Vespucci; the first documentary evidence of the phrase "United States of America" is from a letter dated January 2, 1776, written by Stephen Moylan, Esq. to George Washington's aide-de-camp and Muster-Master General of the Continental Army, Lt. Col. Joseph Reed. Moylan expressed his wish to go "with full and ample powers from the United States of America to Spain" to seek assistance in the revolutionary war effort; the first known publication of the phrase "United States of America" was in an anonymous essay in The Virginia Gazette newspaper in Williamsburg, Virginia, on April 6, 1776. The second draft of the Articles of Confederation, prepared by John Dickinson and completed by June 17, 1776, at the latest, declared "The name of this Confederation shall be the'United States of America'".
The final version of the Articles sent to the states for ratification in late 1777 contains the sentence "The Stile of this Confederacy shall be'The United States of America'". In June 1776, Thomas Jefferson wrote the phrase "UNITED STATES OF AMERICA" in all capitalized letters in the headline of his "original Rough draught" of the Declaration of Independence; this draft of the document did not surface unti
Panama Canal Authority
The Panama Canal Authority is the agency of the government of Panama responsible for the operation and management of the Panama Canal. The ACP took over the administration of the canal from the Panama Canal Commission, the joint US–Panama agency that managed the canal, on December 31, 1999, when the canal was handed over from the United States to Panama as per the Torrijos–Carter Treaties; the Panama Canal Authority is established under Title XIV of the National Constitution, has exclusive responsibility for the operation, management, preservation and modernization of the canal. It is responsible for the operation of the canal in a safe, continuous and profitable manner; the Organic Law of the Panama Canal Authority, passed on June 11, 1997, provides the legal framework for the canal's organization and operation. Because of its unique nature, the ACP has financial autonomy, as well as ownership of the canal's assets; the Board of Directors is responsible for establishing policies for the operation and modernization of the Canal, as well as supervising its management pursuant to the National Constitution, the Panama Canal Authority Organic Law, the Regulations thereto appertaining.
The board of directors is made up as follows: One Director designated by the President of the Republic, who shall chair the Board of Directors and shall have the rank of Minister of State for Canal Affairs. One Director designated by the Legislative Branch, who may be appointed or removed thereby. Nine Directors appointed by the President of the Republic with the consent of the Cabinet Council and ratification by an absolute majority of the members of the Legislative Assembly; the Directors shall serve in their posts for a term of 9 years, may only be removed for the reasons set forth in Article 20 of the Panama Canal Authority Organic Law. The Panama Canal is defined by law to be an inalienable patrimony of the Republic of Panama. Therefore, it may not be sold, mortgaged, or otherwise encumbered or transferred; the Panama Canal Authority Board of Directors is responsible for establishing policies for the operation and modernization of the Canal, as well as supervising its management. At present, the Panama Canal Authority Board of Directors is made up of the following members: Official website
Förde Reederei Seetouristik
Förde Reederei Seetouristik or Fast Reliable Seaways is a German transportation company specialising in passenger ferry and freight transportation. A regional passenger ferry operator founded in 1866, it has expanded in recent years to an international business group and became one of Europe's leading ferry operators. FRS provides conventional ferries, as well as high speed ferries. With 64 vessels and 1500 employees worldwide, FRS is transporting 7.9 million passengers and 2.1 million vehicles per year. The company group with its headquarters in Northern Germany, comprises 24 subsidiaries located in Europe, North Africa, Middle East and North America. Focussing on national and international ferry and catamaran operations, FRS is specializing in Offshore Logistics, Port Management and Maritime Consulting. If FRS Iberia and FRS Maroc are counted as separate entities, FRS includes 14 subsidiaries. Clipper Navigation, of Seattle, United States, acquired in 2016 FRS Iberia/Maroc, operating in the Strait of Gibraltar Helgoline, serving Heligoland and the lower Elbe FRS Muscat, operating in Oman Nordic Coast Line, serving various Finnish islands Rømø-Sylt-Line, connecting the German island of Sylt and the Danish island of Rømø Weiße Flotte, with service in the Baltic Sea, as well as electric ferries for passengers in Berlin and Wolfsburg Reederei Hiddensee, a subsidiary of Weiße Flotte, serving the island of Hiddensee FRS Caribbean, operating the routw between Miami and Bimini Albanian Ferry Terminal Operator, managing ports on the Adriatic Sea FRS Offshore, an operator of offshore service vessels along the north coast of Germany FRS Windcat Offshore Logistics, a joint venture with Windcat Workboats FRS Ship Management, providing crewing and software HSC Ceuta Jet, operated by FRS Iberia S.
L. HSC Algeciras Jet, operated by FRS Iberia S. L. HSC Tarifa Jet, operated by FRS Iberia S. L. HSC Hormuz, operated by FRS Management MS Jawharat Masirah, operated by FRS Management MS Shannah, operated by FRS Management HSC Al Hallaniyat, operated by FRS Management HSC Sawqrah, operated by FRS Management HSC Masirah 4, operated by FRS Management Taxiboot Pirat, operated by Reederei Hiddensee GmbH Taxiboot Störtebeker, operated by Reederei Hiddensee GmbH HSC Victoria Clipper, operated by Clipper Navigation, Inc. HSC Victoria Clipper IV, operated by Clipper Navigation, Inc. HSC San Gwann, operated by FRS-Fast Reliable Seaways, LLC HSC Victoria Clipper V, operated by Clipper Navigation, Inc. prior HSC Halunder Jet, operated by FRS Helgoline GmbH & Co. KG HSC Newbuild, operated by FRS Helgoline GmbH & Co. KG MS Tanger Express, operated by FRS Iberia S. L. MS Kattegat, operated by FRS Iberia S. L. MS Al Andalus Express,operated by FRS Iberia S. L. MS Miramar Express, operated by FRS Iberia S. L. MS Gellen, operated by Reederei Hiddensee GmbH MS Schaprode, operated by Reederei Hiddensee GmbH MS Insel Hiddensee, operated by Reederei Hiddensee GmbH MS Altefähr,operated by Weiße Flotte GmbH MS Hansestadt Stralsund, operated by Reederei Hiddensee GmbH MS Bültenkieker, operated by Weiße Flote GmbH MS Hanseblick,operated by Weiße Flotte GmbH Wappen von Breege, operated by Weiße Flotte GmbH MS Kleine Freiheit, operated by FRS HanseFerry, prior Seebad Juliusruh, operated by Weiße Flotte GmbH MS Sundevit, operated by Reederei Hiddensee GmbH MS Alfagen, operated by FRS Management MS Knipan, operated by FRS Management MS Viggen, operated by FRS Management MS Ejdern, operated by FRS Management MS Gudingen, operated by FRS Management MS Skiftet, operated by FRS Management MS SyltExpress MF Vitte MF Stahlbrode MF Glewitz MF Warnow MF Breitling MF Wittow MF Stralsund Nordic Duck SF Fährbär 1, operated by Weiße Flotte GmbH, used in Berlin SF Fährbär 2, operated by Weiße Flotte GmbH, used in Berlin SF Fährbär 3, operated by Weiße Flotte GmbH, used in Berlin SF Fährbär 4, operated by Weiße Flotte GmbH, used in Berlin SF Sünje, operated by Weiße Flotte GmbH, used in Wolfsburg SF Aluna, operated by Norddeutsche Binnenreederei GmbH CTV Windcat 28, operated by FRS Windcat Offshore Logistics, used for Offshore-Windparks in the German Baltic Sea CTV Windcat 34, operated by FWOL, used in the German Baltic Sea CTV Windcat 35, operated by FWOL, used in the German Baltic Sea CTV Windcat 40, operated by FWOL, used in the German Baltic Sea MY Störtebeker, operated by Reederei Hiddensee GmbH MY Pirat, operated by Reederei Hiddensee GmbH Swanti, operated by Weiße Flotte GmbH Nordic Jet, betrieben durch die Nordic Jetline Paule III, operated by Weiße Flotte GmbH MS Atlantis HSC Tanger Jet Dolphin Jet HSC Thundercat 1 MS Kloar Kimming HSC Hanse Jet HSC Baltic Jet HSC Flying Viking HSC Cat No. 1 MS Wappen von Hamburg MS Helgoland MS Wilhemlshaven MF Vikingland MF Westerland MS Baltic Star MS Dania MS Ostsee MS Ostsee MS No
Colombia
Colombia the Republic of Colombia, is a sovereign state situated in the northwest of South America, with territories in Central America. Colombia shares a border to the northwest with Panama, to the east with Venezuela and Brazil and to the south with Ecuador and Peru, it shares its maritime limits with Costa Rica, Honduras, Jamaica and the Dominican Republic. Colombia is a unitary, constitutional republic comprising thirty-two departments, with the capital in Bogota. Colombia has been inhabited by various indigenous peoples since 12,000 BCE, including the Muisca and the Tairona, along with the Inca Empire that expanded to the southwest of the country; the Spanish arrived in 1499 and by the mid-16th century conquered and colonized much of the region, establishing the New Kingdom of Granada, with Santafé de Bogotá as its capital. Independence from Spain was achieved in 1819, but by 1830 the "Gran Colombia" Federation was dissolved, with what is now Colombia and Panama emerging as the Republic of New Granada.
The new nation experimented with federalism as the Granadine Confederation, the United States of Colombia, before the Republic of Colombia was declared in 1886. Panama seceded in 1903. Beginning in the 1960s, the country suffered from an asymmetric low-intensity armed conflict and rampant political violence, both of which escalated in the 1990s. Since 2005, there has been significant improvement in security and rule of law. Colombia is one of the most ethnically and linguistically diverse countries in the world, with its rich cultural heritage reflecting influences by indigenous peoples, European settlement, forced African migration, immigration from Europe and the Middle East. Urban centres are located in the highlands of the Andes mountains and the Caribbean coast. Colombia is among the world's 17 megadiverse countries, the most densely biodiverse per square kilometer. Colombia is a middle power and regional actor in Latin America, it is part of the CIVETS group of six leading emerging markets and a member of the UN, the WTO, the OAS, the Pacific Alliance, other international organizations.
Colombia's diversified economy is the fourth largest in Latin America, with macroeconomic stability and favorable long-term growth prospects. The name "Colombia" is derived from the last name of Christopher Columbus, it was conceived by the Venezuelan revolutionary Francisco de Miranda as a reference to all the New World, but to those portions under Spanish rule. The name was adopted by the Republic of Colombia of 1819, formed from the territories of the old Viceroyalty of New Granada; when Venezuela and Cundinamarca came to exist as independent states, the former Department of Cundinamarca adopted the name "Republic of New Granada". New Granada changed its name in 1858 to the Granadine Confederation. In 1863 the name was again changed, this time to United States of Colombia, before adopting its present name – the Republic of Colombia – in 1886. To refer to this country, the Colombian government uses the terms Colombia and República de Colombia. Owing to its location, the present territory of Colombia was a corridor of early human migration from Mesoamerica and the Caribbean to the Andes and Amazon basin.
The oldest archaeological finds are from the Pubenza and El Totumo sites in the Magdalena Valley 100 kilometres southwest of Bogotá. These sites date from the Paleoindian period. At Puerto Hormiga and other sites, traces from the Archaic Period have been found. Vestiges indicate that there was early occupation in the regions of El Abra and Tequendama in Cundinamarca; the oldest pottery discovered in the Americas, found at San Jacinto, dates to 5000–4000 BCE. Indigenous people inhabited the territory, now Colombia by 12,500 BCE. Nomadic hunter-gatherer tribes at the El Abra, Tibitó and Tequendama sites near present-day Bogotá traded with one another and with other cultures from the Magdalena River Valley. Between 5000 and 1000 BCE, hunter-gatherer tribes transitioned to agrarian societies. Beginning in the 1st millennium BCE, groups of Amerindians including the Muisca, Zenú, Tairona developed the political system of cacicazgos with a pyramidal structure of power headed by caciques; the Muisca inhabited the area of what is now the Departments of Boyacá and Cundinamarca high plateau where they formed the Muisca Confederation.
They farmed maize, potato and cotton, traded gold, blankets, ceramic handicrafts and rock salt with neighboring nations. The Tairona inhabited northern Colombia in the isolated mountain range of Sierra Nevada de Santa Marta; the Quimbaya inhabited regions of the Cauca River Valley between the Western and Central Ranges of the Colombian Andes. Most of the Amerindians practiced agriculture and the social structure of each indigenous community was different; some groups of indigenous people such as the Caribs lived in a state of permanent war, but others had less bellicose attitudes. The Incas expanded their empire onto the southwest part of the country. Alonso de Ojeda reached the Guajira Peninsula in 1499. Spanish explorers, led by Rodrigo de Bastidas, made the first exploration
Australia Bhagwan Marine
Germany HOCHTIEF Solutions AG
United States Bordelon Marine
Brazil Starnav
Colombia SPR Cartagena
Singapore Smit Lamnalco
Panama Panama Canal Authority
Denmark Faergen
United Kingdom Osiris Projects
Netherlands Kotug International BV
Italy Micoperi Srl / Saipem S.p.A.