As many of you will know CW is the acronym for clockwise and CCW for counterclockwise OR anti clockwise.
Which way does a lighthouse lens rotate?
Now please be careful in your thinking and terminology. The light is fixed in place and the lens rotates around the light which gives the light its characteristic flash. In this post we are talking about the lens, not the light. From outside the lighthouse (seaward) the beam of the light moving makes it appear that the light itself is rotating but it is not.
In ninety-nine percent (99%) of the cases the lighthouse lens rotates in the clockwise direction. Mainly I believe because the drive mechanisms are made from clockwork gearing designs and naturally clocks rotate clockwise!
(photo retlkpr – CW clockwork mechanism at Pachena Point lighthouse)
In the aforementioned movie there is a lighthouse and one strange thing about this lighthouse caught my eye – the beam of the light revolved counterclockwise! This is most unusual and there are only a few lighthouses in the world that revolve CCW, the majority revolving clockwise (CW). Why did the directors make the lens rotate counterclockwise?
I have no idea, so I consulted with my lighthouse friend and guru Chris Mills via Facebook. He said:
. . . those lens systems were always called “French lights” here in the Maritimes (Canada). I believe the BBT (Barbier, Benard et Turenne – original in French; translated to English here) systems rotated counter-clockwise, as opposed to the Chance lights, which rotated clockwise. Not sure why…perhaps the French (or English) just being contrary!
(above photos from http://skipjacksnauticalliving.blogspot.com )
I followed a couple of links on lighthouses from the site above that had BBT lighting but there is no mention of the direction in which the lens rotated.
I found a couple of lighthouses in Australia with CCW revolving lenses as mentioned on this Australian webpage.
Does anyone know the whys and wherefores of CW vs CCW rotation of the lens?
Does anyone have any knowledge of a lighthouse with a CCW rotating lens?
Please contact me. Thanks for any help.
April 10, 2014 – I just received the following comment from Ms. L. Newton:
Hi. I live in one of the Lowestoft Lighthouse Cottages, Suffolk (England) . This lighthouse rotates CCW.
Lowestoft is a town in the English county of Suffolk.The town is on the North Sea coast and is the most easterly point of the United Kingdom.
Lowestoft High Lighthouse, located to the north of the town centre, was built in 1874 and stands 16 metres tall, 37 metres above sea level. The light, which has a range of 23 nautical miles (43 km), was automated in 1975.
The first two lighthouses in Lowestoft were built in 1609, on the foreshore and candlelit, to give warning of the dangerous sandbanks around the coast. By lining up the two lights, vessels could navigate the Stamford Channel, which no longer exists. They were rebuilt in 1628 and again in 1676. It was at this time that one light was moved up onto the cliffs above the Denes – the location of the present lighthouse – to assist vessels further out to sea.
The remaining ‘Low Light’ was discontinued in 1706 following sea encroachment, but re-established in 1730 in a form that could be easily moved in response to further changes to the Stamford Channel and shoreline. It was finally discontinued in August 1923. The ‘High Light’ tower was rebuilt as the present lighthouse in 1874 with the intention of displaying an electric light, but when opened paraffin oil was used instead; it was not until 1936 that it was electrified. The lighthouse, along with two cottages originally used by lighthouse keepers, is a Grade II listed building. – Wikipedia