St Clement lighthouses
By Brian Nibbs from St Clement parish magazine 2011
Greve D’Azette and Mont Ubé lighthouses are an inseparable twin, due to their primary use as the western leading marks or western passage for entering St Helier Harbour.
The pair of leading lights are vital for keeping approaching vessels in safe water, and form the main approach to our principal harbour.
The position of Grève D’Azette Lighthouse (sometimes known unofficially as Samarés Lighthouse) is well known to all, being sited prominently on Grande Route de La Côte, but perhaps the position of Mont Ubé Lighthouse (also recorded as St Clément Lighthouse) is not so well known – it lies some 200 yards on the left up Rue de la Hougette from La Grande Route de St Clément.
Each lighthouse has a ‘characteristic’ – which is the detail of the light it exhibits to make it distinguishable by seafarers from other nearby lights. Grève D’Azette has an occulting light, which means it shows a longer period of light than dark during the sequence.
It shows a white light for 4 out of every 5 seconds. The tower is 20 metres high, with the light itself standing at 23 meters above mean high water spring tide and is visible for 14 miles. Mont Ubé tower is 14 metres tall and shows a red light every 5 seconds, again with 1 second darkness. The light is at a height of 46 meters and can be seen for 12 miles.
Both lighthouses are white painted steel lattice towers, constructed in 1896, with their lights being exhibited on 1 October of that year. Initially, due to their varying distances from St Helier, Mont Ubé was oil powered with a 30 candle power burner, and Grève d’Azette, was powered by town gas with a 50 candle power burner.
The two keepers lived in cottages across the road, which no longer exist. The Mont Ubé light was raised 20ft higher in August 1929 to keep the light clear of growing trees.
Several changes in both energy supply and construction have taken place over the intervening years: since February 1971, both lights have been fully automated. Both lighthouses have also been re-painted earlier this year, and are vital reference points for mariners as much in the daytime as during the hours of darkness. For this reason Grève D’Azette has hi-visibility red boards on its sea side.
Day-time operations normally use Grève D’Azette and Dogs Nest beacon in transit as it can be difficult to see Mont Ubé against the background sky and the many submerged rocks along the approaches to St Helier Harbour provide a constant hazard to any vessel should it divert from the intended course.
Apart from their primary use as a western approach transit, both lighthouses are used for striking marks for rocks other than those that are adjacent to the western approach. They are thus both vital to the safe navigation of small and large vessels.