Misplaced Pages

#632367

47-438: The most important element of lightship design is a tall mast upon which to mount the light. Initially, these lights consisted of oil lamps that were run up the mast and could be lowered for servicing, while later vessels carried fixed lamps which were serviced in place. As they became available, Fresnel lenses were used, and many vessels housed them in smaller versions of lighthouse lanterns. Some lightships had two masts, with

94-412: A century later, the simple box form of mast was arrived at. Although sailing ships were superseded by engine-powered ships in the 19th century, recreational sailing ships and yachts continue to be designed and constructed. In the 1930s aluminum masts were introduced on large J-class yachts . An aluminum mast has considerable advantages over a wooden one: it is lighter and slimmer than a wooden one of

141-615: A crude estimation of the lightship's location relative to the approaching vessel. Tests conducted by Trinity House found that sound from a bell submerged some 18 feet (5.5 m) could be heard at a distance of 15 miles (24 km), with a practical range in operational conditions of one to three miles (1.6 to 4.8 km). Holding the vessel in position was an important aspect of lightvessel engineering. Early lightships used fluke anchors , which are still in use on many contemporary vessels, though these anchors are prone to dragging, making their performance unsatisfactory in rough seas. Since

188-546: A few notable companies are Hall Spars, Offshore Spars, and Southern Spars. After the end of the age of sail , warships retained masts, initially as observation posts and to observe fall of shot , also holding fire control equipment such as rangefinders , and later as a mounting point for radar and telecommunication antennas, which need to be mounted high up to increase range. Simple pole, lattice , and tripod masts have been used—also, on some past Japanese warships, complex pagoda masts . Light float A light float

235-522: A fundamental transformation in Mediterranean navigation: the lateen which had long evolved on smaller Greco-Roman craft replaced the square rig , the chief sail type of the ancients, that practically disappeared from the record until the 14th century (while it remained dominant in northern Europe). The dromon , the lateen-rigged and oared bireme of the Byzantine navy , almost certainly had two masts,

282-571: A larger foremast and one midships. Their length has been estimated at 12 m and 8 m respectively, somewhat smaller than the Sicilian war galleys of the time. Multiple-masted sailing ships were reintroduced into the Mediterranean Sea by the Late Middle Ages . Large vessels were coming more and more into use and the need for additional masts to control these ships adequately grew with

329-536: A prestige object commissioned by king Hiero II of Syracuse and devised by the polymath Archimedes around 240 BC, and other Syracusan merchant ships of the time. The imperial grain freighters travelling the routes between Alexandria and Rome also included three-masted vessels. A mosaic in Ostia (c. 200 AD) depicts a freighter with a three-masted rig entering Rome's harbour. Special craft could carry many more masts: Theophrastus ( Hist. Plant. 5.8.2) records how

376-463: A sizable foresail rigged on a slightly inclined foremast is depicted in an Etruscan tomb painting from 475 to 450 BC. An artemon ( Greek for foresail) almost the same size as the galley 's mainsail can be found on a Corinthian krater as early as the late 6th century BC; apart from that Greek longships are uniformly shown without it until the 4th century BC. In the East, ancient Indian Kingdoms like

423-436: A steel mast of an equivalent strength can be smaller in diameter than an aluminum mast, allowing less turbulence and a better airflow onto the sail. From the mid-1990s racing yachts introduced the use of carbon fibre and other composite materials to construct masts with even better strength-to-weight ratios. Carbon fibre masts could also be constructed with more precisely engineered aerodynamic profiles. Modern masts form

470-496: Is a slightly larger type of vessel that derives its power from diesel electric generators. Where a main light with a visible range in excess of 20 nautical miles (37 km) is required, a '20 class' vessel is used, as the main light from a Trinity House solar lightvessel has a maximum range of 19 nautical miles (35 km). Hull numbers: 19, 22, 23 and 25 (the 20 class); 2, 5, 6, 7, 9, 10, 17 (solar lightvessels); and LF2 and LF3 (solar lightfloats). The first United States lightship

517-403: Is a type of lighted navigational aid forming an intermediate class between lightvessels and large lighted buoys ; they are generally smaller than lightvessels and carry less powerful lights. In times when most lightvessels were crewed, the term was sometimes also used to describe a full-size lightvessel converted to unmanned operation. Light floats usually have a boat-shaped platform: this

SECTION 10

#1732852011633

564-502: Is short for Feuerschiff , which means lightvessel in German. Two of them are normally located at: Both positions have the same characteristics: All three ships are operated by the Waterways and Shipping Office Wilhelmshaven and can be seen in the harbour of Wilhelmshaven during maintenance. In Russia , lightships have been documented since the mid 19th century. The lightvessel service

611-431: Is the mainmast. This contrasts with a ketch or a yawl , where the after mast, and its principal sail, is clearly the smaller of the two, so the terminology is (from forward) mainmast and mizzen. (In a yawl, the term "jigger" is occasionally used for the aftermast.) Some two-masted luggers have a fore-mast and a mizzen-mast – there is no main-mast. This is because these traditional types used to have three masts, but it

658-664: The Civil War lightships were identified by name, usually that of the station where they served. As they were moved from station to station, however, the keeping of records became hopelessly tangled. Therefore, in 1867 all existing lightships were given numbers by which they would be permanently identified, and the station at which they were presently serving was painted on their sides, to be changed as needed. Lightships held in reserve to serve in place of those in dock for maintenance were labeled "RELIEF". Surviving lightships are commonly taken to be named according to these labels, but for instance

705-464: The Great Lakes ). The first United States lightships were small wooden vessels with no propelling power. The first United States iron-hulled lightship was stationed at Merrill's Shell Bank, Louisiana, in 1847. Wood was still the preferred building material at the time because of lower cost and ability to withstand shock loading. Wooden lightships often survived more than 50 years in northern waters where

752-601: The Kalinga from as early as 2nd century are believed to have commanded naval sail ships. One of the earliest documented evidence of Indian sail building comes from the mural of the three-masted ship in Ajanta caves that date back to 400–500 CE. The foremast became fairly common on Roman galleys , where, inclined at an angle of 45°, it was more akin to a bowsprit , and the foresail set on it, reduced in size, seems to be used rather as an aid to steering than for propulsion. While most of

799-533: The Romans imported Corsican timber by way of a huge raft propelled by as many as fifty masts and sails. Throughout antiquity , both foresail and mizzen remained secondary in terms of canvas size, although large enough to require full running rigging . In late antiquity , the foremast lost most of its tilt, standing nearly upright on some ships. By the onset of the Early Middle Ages , rigging had undergone

846-472: The pintle -and- gudgeon rudder , all advanced ship design technology necessary for the great transoceanic voyages was in place by the beginning of the 15th century. The first hollow mast was fitted on the American sloop Maria in 1845, 28 m (92 ft) long and built of staves bound with iron hoops like a barrel. Other hollow masts were made from two tapered timbers hollowed and glued together. Nearly

893-481: The rule of thumb being 6 feet (1.8 m) of chain for every foot of water. As well as the light, which operated both at night and in fog from one hour before sunset to one hour after sunrise, early lightvessels were equipped with day markers at the tops of masts, which were the first objects seen from an approaching ship. These markers were primarily red and occasionally white, and their designs varied. Filled circles or globes, as well as pairs of inverted cones were

940-773: The "Lightship Chesapeake " actually served at two other stations as well as being used for examinations, and last served at the Delaware Light Station. In another case, the LV-114 was labeled "NEW BEDFORD", though there has never been such a station. In an attempt to sort out the early lightships, they were assigned one or two letter designations sometime around 1930; these identifications do not appear in early records, and they are to some degree uncertain. There are three different and overlapping series of hull numbers. The Lighthouse Service assigned numbers beginning with "LV-" and starting from 1; however, not all numbers were used. When

987-621: The Baltic in the 1980s, it was briefly renamed Ventspilssky while serving near Ventspils port in the Latvian Socialist Soviet Republic . The last Russian lightvessel in service was Astrakhansky-priyomniy , of the same class as Irbensky. Until 1997 she was marking the deepwater channel leading to Astrakhan harbour while it was doing service in the Caspian Sea . Because lightvessels must remain anchored in specific positions for

SECTION 20

#1732852011633

1034-645: The Coast Guard took over the lighthouse service, all existing lightships were renumbered with "WAL-" prefixes, beginning with "WAL-501". In 1965 they were renumbered again, this time with "WLV-"; however in this case the numbers given were not sequential. Given that only six vessels were constructed after the Coast Guard takeover, the "LV-" series numbers are most commonly used. It is estimated that there are 15 United States lightships left today. Among them: There are currently three identical unmanned German lightvessels in service, named FS1, FS3 and FS4. The initialism FS

1081-512: The Lake Huron Cut. From 1854 until 1860, the lightvessel that operated at Minots Ledge , Massachusetts , had a light yellow hull, to increase contrast between the blue-green seas and the hills behind it. David Avery and Robert Hamblin in 1731 placed the earliest British lightship at The Nore near the mouth of the River Thames . This was a private venture that operated profitably and without

1128-596: The United States ended on March 29, 1985, when the United States Coast Guard decommissioned its last such ship, the Nantucket I . Many lightships were replaced with Texas Towers or large navigational buoys  – both of which are cheaper to operate than lightvessels. In fact, lighthouses often replaced lightships. The naming and numbering of American lightships is often confusing. Up to and through

1175-471: The West, the concept of a ship carrying more than one mast, to give it more speed under sail and to improve its sailing qualities, evolved in northern Mediterranean waters: The earliest foremast has been identified on an Etruscan pyxis from Caere , Italy , dating to the mid-7th century BC: a warship with a furled mainsail is engaging an enemy vessel, deploying a foresail . A two-masted merchant vessel with

1222-423: The ancient evidence is iconographic, the existence of foremasts can also be deduced archaeologically from slots in foremast-feets located too close to the prow for a mainsail. Artemon , along with mainsail and topsail , developed into the standard rig of seagoing vessels in imperial times , complemented by a mizzen on the largest freighters. The earliest recorded three-masters were the giant Syracusia ,

1269-603: The approach to Kronstadt . Other Baltic lightships were located further to the West, with Werkommatala by Primorsk (Koivisto) harbour, Lyserortsky at the entrance of the Gulf of Finland , and Nekmangrund over the treacherous shoals off Hiiumaa Island's NW shore, known as Hiiu Madal in Estonian . Another well-known lightship was Irbensky of the Soviet Union era. It was the next-to-last Russian lightship. Having been located in

1316-411: The danger of rotting was reduced. Lightvessel 16 guarded Sandy Hook and Ambrose stations for more than 80 years; she had both an inner hull and an outer hull with the space between filled with salt to harden the wood and reduce decay. Several lightships built with composite wood and steel hulls in 1897 proved less durable than either wood or steel. The first modern steel lightship in United States service

1363-444: The deck, into which a mast is fixed, with a pivot near the top so that the mast can be lowered"; "large bracket attached firmly to the deck, to which the foot of the mast is fixed; it has two sides or cheeks and a bolt forming the pivot around which the mast is raised and lowered"; "substantial fitting for mounting the mast on deck, so that it can be lowered easily for trailering or for sailing under bridges", "hinged device allowing for

1410-446: The early 19th century, lightships have used mushroom anchors , named for their shape, which typically weigh 3 to 4 tons. The first lightvessel equipped with one was a converted fishing boat, renamed Pharos , meaning lighthouse, which entered service on September 15th, 1807, near Inchcape , Scotland with an anchor weighing 1.5 tons. The introduction of cast iron anchor chains in the 1820s improved their effectiveness dramatically, with

1457-495: The easy folding of a mast 90 degrees from perpendicular, as for transporting the boat on a trailer, or passing under a bridge" The oldest evidence for the use of masts comes from the Ubaid period site of H3 in Kuwait, dating to the second half of the sixth millennium BC. Here, a clay disc made from a sherd that appears to depict a reed bundle boat with two masts has been recovered. In

Lightship - Misplaced Pages Continue

1504-476: The increase in tonnage. Unlike in antiquity, the mizzen-mast was adopted on medieval two-masters earlier than the foremast, a process which can be traced back by pictorial evidence from Venice and Barcelona to the mid-14th century. To balance out the sail plan the next obvious step was to add a mast fore of the main-mast, which first appears in a Catalan ink drawing from 1409. With the three-masted ship established, propelled by square rig and lateen, and guided by

1551-471: The leading edge of a sail's airfoil and tend to have a teardrop-shaped cross-section. On smaller racing yachts and catamarans, the mast rotates to the optimum angle for the sail's airfoil. If the mast has a long, thin cross-section and makes up a significant area of the airfoil, it is called a wing-mast; boats using these have a smaller sail area to compensate for the larger mast area. There are many manufacturers of modern masts for sailing yachts of all sizes,

1598-541: The majority of their time at sea, they are more at risk of damage or destruction. Many lightships have been lost in hurricanes. Mast (sailing) The mast of a sailing vessel is a tall spar , or arrangement of spars, erected more or less vertically on the centre-line of a ship or boat. Its purposes include carrying sails , spars, and derricks , giving necessary height to a navigation light , look-out position , signal yard , control position , radio aerial or signal lamp . Large ships have several masts, with

1645-457: The most common designs among them. For visibility purposes, most later lightships had bright red hulls that displayed the name of the station in white, upper-case letters; relief light vessels displayed the word RELIEF instead. Some vessels had hulls coloured for specific purposes. For example, the Huron Lightship was painted black since she was assigned the black buoy side of the entrance to

1692-405: The naming is less standardised) are: When a vessel has two masts, as a general rule, the main mast is the one setting the largest sail. Therefore, in a brig , the forward mast is the foremast and the after mast is the mainmast. In a schooner with two masts, even if the masts are of the same height, the after one usually carries a larger sail (because a longer boom can be used), so the after mast

1739-555: The need for government enforcement of payment for lighting services. Further vessels were placed off Norfolk in 1736, at Owers Bank in Sussex in 1788, and at the Goodwin Sands in 1793. Over time, Trinity House , the public authority charged with establishing and maintaining lighthouses in England and Wales, crowded out the private light vessels. Trinity House is now responsible for all

1786-410: The remaining lightvessels England and Wales, of which there are currently eight unmanned lightvessels and two smaller light floats . In the 1930s, "crewless lightships" were proposed as a way to operate a light vessel for six to twelve months without a crew. The first lightvessel conversion to solar power was made in 1995, and all vessels except the '20 class' have now been converted. The '20 class'

1833-675: The required height, the masts were built from up to four sections (also called masts). From lowest to highest, these were called: lower, top, topgallant, and royal masts. Giving the lower sections sufficient thickness necessitated building them up from separate pieces of wood. Such a section was known as a made mast , as opposed to sections formed from single pieces of timber, which were known as pole masts . Those who specialised in making masts were known as mastmakers . For square-sail carrying ships , masts in their standard names in bow to stern (front to back) order, are: Some names given to masts in ships carrying other types of rig (where

1880-405: The same strength, is impervious to rot, and can be produced as a single extruded length. During the 1960s wood was eclipsed by aluminum. Aluminum alloys, generally 6000 series, are commonly utilised. Recently some sailing yachts (particularly home-built yachts) have begun to use steel masts. Whilst somewhat heavier than aluminum, steel has its own set of advantages. It is significantly cheaper, and

1927-579: The second housing a reserve beacon, in case of the main light's failure. Initially, lightship hulls were constructed of wood, shaped like the small merchant ships of the time, but this proved unsatisfactory for a permanently anchored ship, so the shape of the hull evolved to reduce rolling and pounding. As iron and steel hulls were popularized, they became used in lightvessels, and the advent of steam and diesel power led to self-propelled and electrically lit designs. Earlier vessels had no propulsion systems and had to be towed to and from their positions. Much of

Lightship - Misplaced Pages Continue

1974-444: The ship was taken up by storage for lamp oil and other supplies, as well as crew accommodations. The crew's primary duty was to maintain the light; other tasks included keeping records of passing ships, observing the weather, and occasionally performing rescues. In the early 20th century, some lightships were fitted with warning bells mounted on their structure or lowered into the water, to warn of danger in poor visibility and to permit

2021-432: The size and configuration depending on the style of ship. Nearly all sailing masts are guyed . Until the mid-19th century, all vessels' masts were made of wood formed from a single or several pieces of timber which typically consisted of the trunk of a conifer tree. From the 16th century, vessels were often built of a size requiring masts taller and thicker than from single tree trunks. On these larger vessels, to achieve

2068-506: Was established at Chesapeake Bay in 1820, and the total number around the coast peaked in 1909 with 56 locations marked. Of those ships, 168 were constructed by the United States Lighthouse Service and six by the United States Coast Guard , which absorbed it in 1939. From 1820 until 1983, there were 179 lightships built for the U.S. government, and they were assigned to 116 separate light stations on four coasts (including

2115-402: Was found convenient to dispense with the main-mast and carry larger sails on the remaining masts. This gave more working room, particularly on fishing vessels. On square-rigged vessels, each mast carries several horizontal yards from which the individual sails are rigged . Folding mast ships use a tabernacle anchor point. Definitions include: "the partly open socket or double post on

2162-466: Was lightvessel 44 built in 1882. One of the last United States wooden hulled lightships built, lightvessel 74, went into service at Portland, Maine, in 1902. The first United States lightships with steam engine propulsion were built in 1891 for service on the Great Lakes where seasonal ice required prompt evacuation of light stations to avoid destruction of the lightships. The official use of lightships in

2209-873: Was subordinated to the Russian Hydrographic Office and most of the lightships under it were in the Baltic Sea . In the early 1900s there were about ten lightships in the Russian sector of the Baltics. Among these the following may be mentioned: Yelaginsky , located on the Yelagin Channel  – later moved to the Petrovsky Channel and renamed, Nevsky in the middle of the main channel to St. Petersburg , and Londonsky on Londonsky Shoal off Kotlin Island on

#632367