- Education and Science
Floating Lighthouses: Lightvessels and Lightships
The Need For Lightvessels
Floating lighthouses were used in hazardous waters where traditional lighthouses could not be constructed, whether due to deep waters, shifting sands, mud or seabed ridges and other reasons. These were ships that had a powerful light on a tall mast and which were securely moored in designated positions. They were more commonly referred to as “lightvessels”, though in the US, they were called “lightships”.
Lightvessels had to have two primary characteristics: A light sufficiently strong enough to be seen as needed and moored securely enough to withstand the severest weather. In case one broke its moorings, the crew's immediate and foremost responsibility was to extinguish the light so as not to lure other ships onto shoals.
A Short History
The Romans may have used fire beacons placed on ships, but the first “modern” lightvessel was invented by Robert Hamblin and moored at the mouth of the River Thames in England in 1732. Since that time, all lighthouses and lightvessels in England, Wales, the Channel Islands and Gibraltar have been under the authority of the Corporation of Trinity House in London. By 1819, England had nine lightvessels in service. These were small, wooden ships, often bought from the Dutch and converted to lightvessels, which usually had to be towed into position. The first lights were candle-powered or utilized lamps that burned sperm whale oil.
As time went by, more improvements were added. The lamps were fitted with Fresnel lenses, a very efficient and lightweight lens also used in lighthouses. Iron and steel hulls were introduced, especially designed to reduce rolling and pounding. The introduction of steam and diesel power allowed lightvessels to be self-propelled and power more effective electric lights. Besides maintaining the light, crews also recorded passing ships, observed weather and tidal data over decades and even performed rescues. Warning bells or foghorns were sometimes added. Even later, some had helipads installed so helicopters could resupply them. Lightships around the world generally share a common paint scheme including a red hull with identification markings of its position prominently painted white on its sides.
Lightvessels have been used around the world. Countries that used them include Australia, Belgium, Canada, Chile, Denmark, Germany, Ireland, the Netherlands, Sweden, the United Kingdom and the United States.
Fading Away: No Longer Cost-Effective
As technology and construction techniques improved, many lightvessels were actually replaced by lighthouses. Much later, large automated buoys were created, which were much cheaper to maintain. For example, the British lightships cost around £30,000 annually in 1974, while a buoy cost £3,000 . A large number of lightvessels still exist around the world but are out of service and are moored in harbors as tourist attractions or museums or have been converted to floating restaurants and clubs. Most of the lightvessels in service are British (though there is also at least one German vessel in use). All those in service are automated and have no crews. The eight British lightvessels, which also act as weather stations are:
Channel Light Vessel Automatic – in the English channel
F3 Lightvessel – in the middle of the English Channel, east of Ramsgate
East Goodwin Lightvessel - Goodwin Sands, six miles off the tip of Kent
Greenwich Lightvessel – off the coast of East Sussex, on the Prime Meridian
Sandettie Light Vessel Automatic – in the English Channel, in the Strait of Dover
Sevenstones Lightship – moored off the Sevenstones Reef, 10 miles northeast of the Isles of Scilly
Sunk Lightvessel – in the Thames Estuary
Varne Lightvessel – moored in the Varne Bank, nine miles southwest of Dover