LIGHTHOUSES – WHAT IS THEIR FASCINATION?

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Fisgard-Lighthouse-NIGHT

LIGHTHOUSES 

WHAT IS THEIR FASCINATION?

While the idea behind the lighthouse was a practical one there’s just something elusive about them which fascinate many people, including me.   Perhaps it’s their link with the past; perhaps, that they served an heroic purpose.

Its intention is to simply save lives, to protect all mariners as they approach rocky shores and bring light in the midst of the fog.   It almost seems as though these breath taking structures are guarding a secret from the rest of society, tales of lives that were saved and souls that were once housed within its walls.   The open sea is an eerie thought, but a flashing light in the distance is always a symbol of hope, tranquility and comfort.

I’m not the only person who’s fascinated by lighthouses there’s quite a few of us about you know, but I’m still not sure what it is about these buildings that make us love looking at lighthouses, their pictures or anything lighthouse related.

A lighthouse is a tower, building, or other type of structure designed to emit light from a system of lamps and lenses and used as a navigational aid for maritime pilots at sea or on inland waterways.

Lighthouses mark dangerous coastlines, hazardous shoals, reefs, safe entries to harbors, and can also assist in aerial navigation. Once widely used, the number of operational lighthouses has declined due to the expense of maintenance and replacement by modern electronic navigational systems such as strobes.

Before the development of clearly defined ports, mariners were guided by fires built on hilltops. Since raising the fire would improve the visibility, placing the fire on a platform became a practice that led to the development of the lighthouse. In antiquity, the lighthouse functioned more as an entrance marker to ports than as a warning signal for reefs, unlike many modern lighthouses. The most famous lighthouse structure from antiquity was the Pharos of Alexandria, although it collapsed during an earthquake centuries later.

The intact Tower of Hercules at A Coruna and the ruins of the Roman lighthouse in Corua, Spain give insight into ancient lighthouse construction; other evidence about lighthouses exists in depictions on coins and mosaics, of which many represent the lighthouse at Ostia. . Coins from Alexandria, Ostia, and Laodicea in Syria also exist.

The modern era of lighthouses began at the turn of the 18th century, as lighthouse construction boomed in lockstep with burgeoning levels of transatlantic commerce. Advances in structural engineering and new and efficient lighting equipment allowed for the creation of larger and more powerful lighthouses, including ones exposed to the sea. The function of lighthouses shifted toward the provision of a visible warning against shipping hazards, such as rocks or reefs.

The source of illumination had generally been wood pyres or burning coal. The Argand lamp, invented in 1782 revolutionized lighthouse illumination with its steady smokeless flame. Early models used ground glass which was sometimes tinted around the wick. Later models used a mantle of thorium dioxide suspended over the flame, creating a bright, steady light. The Argand lamp used whale oil, colza, olive oil or other vegetable oil as fuel which was supplied by a gravity feed from a reservoir mounted above the burner. The lamp was first produced in 1784 and became the standard for lighthouses for over a century.

South Foreland Lighthouse was the first tower to successfully use an electric light in 1875. The lighthouse’s carbon arc lamps were powered by a steam-driven magento.   The vaporized oil burner was invented in 1901. The fuel was vaporized at high pressure and burned to heat the mantle, giving an output of over six times the luminosity of traditional oil lights. The use of gas as illuminate became widely available with the invention of the Dalen light. The technology was the predominant form of light source in lighthouses from the 1900s through the 1960s, when electric lighting had become dominant.

With the development of the steady illumination of the Argand lamp, the application of optical lenses to increase and focus the light intensity became a practical possibility. The ability to focus the light led to the first revolving lighthouse beams, where the light would appear to the mariners as a series of intermittent flashes. It also became possible to transmit complex signals using the light flashes.

The advent of electrification, and automatic lamp changers began to make lighthouse keepers obsolete. For many years, lighthouses still had keepers, partly because lighthouse keepers could serve as a rescue service if necessary. Improvements in maritime navigation and safety have led to the phasing out of non-automated lighthouses across the world In Canada, this trend has been stopped and there are still 50 staffed light stations, with 27 on the west coast alone.  Remaining modern lighthouses are more functional and less picturesque; usually they use solar-charged batteries and have a single stationary flashing light sitting on a steel skeleton tower.

In a lighthouse, the source of light is called the “lamp” (whether electric or fueled by oil) and the concentration of the light is by the “lens” or “optic”. Originally lit by open fires and later candles, the Argand hollow wick lamp and parabolic reflector were introduced in the late 18th century. Whale oil was also used with wicks as the source of light. Kerosene became popular in the 1870s and electricity and carbide began replacing kerosene around the turn of the 20th century.

Before modern strobe lights, lenses were used to concentrate the light from a continuous source. Vertical light rays of the lamp are redirected into a horizontal plane, and horizontally the light is focused into one or a few directions at a time, with the light beam swept around. As a result, in addition to seeing the side of the light beam, the light is directly visible from greater distances, and with an identifying light characteristic.

This concentration of light is accomplished with a rotating lens assembly. In early lighthouses, the light source was a kerosene lamp or, earlier, an animal or vegetable oil Argand lamp, and the lenses rotated by a weight driven clockwork assembly wound by lighthouse keepers, sometimes as often as every two hours. These also supplied electricity for the lighthouse keepers.

In recent times, many Fresnel lenses have been replaced by rotating aero-beacons which require less maintenance. In modern automated lighthouses, this system of rotating lenses is often replaced by a high intensity light that emits brief omnidirectional flashes (concentrating the light in time rather than direction). These lights are similar to obstruction lights used to warn aircraft of tall structures. Recent innovations are “Vega Lights”, and initial experiments with LED panels.

In any of these designs an observer, rather than seeing a continuous weak light, sees a brighter light during short time intervals. These instants of bright light are arranged to create a light characteristic or pattern specific to a lighthouse. For effectiveness, the lamp must be high enough to be seen before the danger is reached by a mariner. The minimum height is calculated by trigonometric formula where H is the height above water in feet, and d is the distance to the horizon in nautical miles.

Where a tall cliff exists, a smaller structure may be placed on top such as at Horton Point Light. Sometimes, such a location can be too high, for example along the west coast of the United States, where frequent low clouds can obscure the light. In these cases, lighthouses are placed below clifftop to ensure that they can still be seen at the surface during periods of fog or low clouds. Another victim of fog was the Old Point Loma lighthouse, which was replaced in 1891 with a lower lighthouse, New Point Loma lighthouse.

As technology advanced, prefabricated skeletal iron or steel structures tended to be used for lighthouses constructed in the 20th century. These often have a narrow cylindrical core surrounded by an open lattice work bracing, such as Finns Point Range Light.

In waters too deep for a conventional structure, a lightship might be used instead of a lighthouse, such as the former lightship Columbia. Most of these have now been replaced by fixed light platforms similar to those used for offshore oil exploration

While lighthouse buildings differ depending on the location and purpose, they tend to have common components. A light station comprises the lighthouse tower and all outbuildings, such as the keeper’s living quarters, fuel house, boathouse, and fog-signaling building. The Lighthouse itself consists of a tower structure supporting the lantern room where the light operates.

The lantern room is the glassed-in housing at the top of a lighthouse tower containing the lamp and lens. Its glass storm panes are supported by metal Astragal bars running vertically or diagonally. At the top of the lantern room is a stormproof ventilator designed to remove the smoke of the lamps and the heat that builds in the glass enclosure. A lightening rod and grounding system connected to the metal cupola roof provides a safe conduit for any lightning strikes.

Immediately beneath the lantern room is usually a Watch Room or Service Room where fuel and other supplies were kept and where the keeper prepared the lanterns for the night and often stood watch. The clockworks (for rotating the lenses) were also located there. On a lighthouse tower, an open platform called the gallery is often located outside the watch room or Lantern Room. This was mainly used for cleaning the outside of the windows of the Lantern Room.

In the United States, lighthouses are maintained by the United States Coast Guard (USCG). Those in England and Wales are looked after by Trinity House; in Scotland, by the Northern Lighthouse Board; and in Ireland by the Commissioner of Irish Lights. In Canada, they are managed by the Canadian Coast Guard. In Australia, lighthouses are conducted by the Australian Maritime Safety Authority. The Soviet Union built a number of automated lighthouses powered by radioisotope thermoelectric generators in remote locations. They operated for long periods without external support with great reliability. However numerous installations deteriorated, were stolen, or vandalized. Some cannot be found due to poor record keeping.

As lighthouses became less essential to navigation, many of their historic structures faced demolition or neglect. In the United States, the National Historic Preservation Act of 2000 provides for the transfer of lighthouse structures to local governments and private non-profit groups, while the USCG continues to maintain the lamps and lenses. In Canada, the Nova Scotia Lighthouse Preservation Society won heritage status for Sambro Island Lighthouse, and sponsored the Heritage Lighthouse Protection Act to change Canadian federal laws to protect lighthouses.

Many groups formed to restore and save lighthouses around the world. They include the World Lighthouse Society and the United States Lighthouse Society. A further international group is the Amateur Radio Lighthouse Society, which sends amateur radio operators to publicize the preservation of remote lighthouses throughout the world.

Visiting and photographing lighthouses are popular hobbies as is collecting ceramic replicas. Some lighthouses are popular travel destinations in their own right, and the buildings maintained as tourist attractions. In the U.S., National Lighthouse and Lightship Weekend is celebrated on the first weekend of August, and International Lighthouse and Lightship Weekend on the third weekend. Many lighthouses are open to the public and amateur radio operators communicate between them on these days.

Due to their function as beacons of safety, organizations choose lighthouses as a symbol. The lighthouse is the symbol of Lighthouse International, a U.S. organization for the blind. Lighthouses are often interpreted in dreams as beacons of truth or as male fertility and influence.

Lighthouses were once regarded as an archetypal public good, because ships could benefit from the light without being forced to pay. The Confederate States Constitution explicitly allowed public funds to be spent on navigation, including lighthouses.

Kathy Kiefer

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