Lighthouse facts

Some interesting light house facts

It has been estimated that there are about 3000 to 3500 ship wrecks along the South African coast and this is a conservative total. We have some of the most treacherous coastal waters in the world and the countless wrecks I have walked past bare testimony to this. We have no way to estimate how many ships went down before the 1500’s as there are no records. The archaeological evidence has also been destroyed in our rough seas as these were all wooden ships and have not survived the ravages of time.

As I travel down the coast, I get to see most of the country’s lighthouses. Some are architecturally stunning, others just a simple steel pyramid. Yet they have been vital to shipping. Lighthouses still invoke a beacon of hope, promise of safe harbour, warning of danger and an end to an arduous journey. This has lead me to ponder about light houses so I decided to put together some interesting facts.

Pharology’ is the study of lighthouses

The first accepted, known lighthouse dates back to 300-280 BC in Egypt. This lighthouse was known as the ‘Pharos of Alexandria’ and it stood 350 feet high (106m), an amazing feat for its time. By the 1300’s AD it had been destroyed by successive invasions and earth quakes. Finally in 1480 AD The Sultan of Egypt, Quaitbay, built a fort on its foundations. It was considered one of the seven wonders of the ancient world.

The oldest lighthouse still standing today is ‘La Coruna’ in Spain, also known as ‘Tower of Hercules’. It was built by the Romans in 20 BC and is still operational today.

The tallest lighthouse in the world is ‘Jedda light’ in Saudi Arabia and stands an incredible 436ft (132m).

Hilbre island lighthouse’ in England, Mersey, is reputed to be the shortest lighthouse in the world standing at 3 m

The statue of liberty was used as a lighthouse for 12 years, the light being housed in her torch.

South Africa

There are 45 lighthouses in South Africa

The first lighthouse built in South Africa was the ‘Greenpoint lighthouse’, built in 1894.

The shortest lighthouse is ‘Cape seal lighthouse’ in Plettenburg bay.

The tallest lighthouse is ‘Slangkop lighthouse’ in Kommetjie standing at 33m, it is also the only cylindrical cast iron lighthouse in South Africa.

The last manned lighthouse to be built in South Africa is the ‘Cape columbine lighthouse’ built in 1936

St Blaize lighthouse’ is still manned

Dassen island lighthouse’ is still manned due to its dangerous location. Due to the high number of shipwrecks near this island, tortoise, rabbits and dassies were introduced as a food source for the survivors. It takes its name from the Dutch word for dassies.

There are five lighthouses you can stay at in South Africa. Even if its only the keepers cottage and not the actual lighthouse.

Cape Columbine’ -Paternoster

Cape St Blaize’ -Mosselbay

Great fish point’ – Great fish river

Danger point’ – Near Gansbaai

North Sand Bluff’ – Port Edward

The workings

Lighthouses are painted in different patterns and colours. Their lights also reflect and revolve at different intervals and rates. No two lighthouses in the same geographical location are the same. This is in order for ships to be able to identify their location both day and night without confusion.

Over the millennia, different lighting systems have been used, from open fires; oil lamps, paraffin lamps to candles and electricity. They amplify the brightness of the lamp by shining them through lenses, first curved lenses were used to magnify the light and then with the invention of the Fresnel lens which allowed much higher magnification for far less weight and bulk. In order for it to appear to flash, it meant that the lenses needed to rotate.

A clockwork mechanism invented in Sweden in 1780 finally allowed the system to rotate. The system is rather like that of a grandfather clock in that weights suspended on a chain drove gears that were regulated by an escapement. The challenge was the weight of the lens mechanisms meant that very large weights needed, in the order of 250 pounds (113kg). The light house keeper would have to hoist these in order to keep the lights turning. He would have to do this every 2-6 hours depending on the height of the tower and size of the lenses.

Many systems were tried from wheels to carriages and bearings but these all had friction problems. Eventually in 1890, an almost frictionless bearing using a mercury bath allowed lenses in the order of one ton to be set in motion with the push of a finger. The mercury surface needed to be kept clean and mercury vapour poisoning was an issue. This allowed bigger lenses to rotate faster with much smaller clock mechanisms. For the first time the flash incidence could be brought to as low as tenths of a second. These systems eventually fell into disuse with the advent of electricity.

The majestic hay days of spectacular buildings, manned lighthouses and lonely isolation have fallen way to spindly iron lattice frame works with electric lights. Slowly, the lighthouses I knew in my generation and all those before me are becoming obsolete.

Like the wooden sailing ships of old, the lighthouses that served to warn of peril, are also fading into the past. A footnote in history.

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