" Description
The Pierre de Herpin lighthouse indicates the entrance to Mont-Saint-Michel bay. It is built on the rock of Pierre de Herpin northeast of the Pointe du Grouin, in the town of Cancale. The tower is cylindrical in ashlar. The "oak barrel" base offers better seating and great resistance to waves.
History
Construction of the Herpin, approved on October 25, 1864, did not begin until 1876. It was exactly the same model as the first lighthouse in the Grand Jardin. But unlike the Grand Jardin lighthouse, it was not destroyed during the Second World War.
The lighthouse was lit in 1882 after six years of work and difficult docking conditions which required the construction of a breakwater with a small railway to transport the stones.
In 1909, a fog horn was installed; it was replaced by an audible signal in 1932. In 1940, during the occupation, the lighthouse was closed. Only a fortnightly maintenance visit is provided.
In 1954, the lighthouse commission obtained the suppression of the sound signal in order to reduce energy consumption. It was not until 1964, after numerous interventions, that the fog horn was returned to service.
In 1970, the fire, originally with oil and then with petroleum vapor, was electrified. The power of the lamp is 150 watts for the main light and 40 watts for the emergency. The Herpin light has 2 occultations (L = 3s Obs = 1s L = 1s Obs = 1s total = 6s) and has a range of 17 miles.
Currently the Pierre de Herpin lighthouse works with an LED lamp. The energy of the lighthouse is entirely produced by six solar panels. A generator is kept and produces energy if necessary.
The Pierre de Herpin lighthouse is remotely controlled from the Saint-Malo Lighthouses and Beacons antenna. "