The fog alarm—from cannon fire to the electronic sound signal

Whenever weather conditions reduced visibility at sea, the lighthouse keeper had to replace the usual visual signal (i.e., the beacon) by a sound signal. The Pointe-au-Père lighthouse played an important role in testing different types of sound signals, which were subsequently implemented in other Canadian lighthouses.

The first sound signal used at Pointe-au-Père was produced by a cannon, which the keeper had to load with gunpowder and fire every half hour.

The cannon signal was replaced by explosive bomb signals (1894 to 1903), and then by a Scotch siren fog signal (1903). A diaphone, a kind of giant compressed air whistle operated by a fog alarm, was implemented in 1904. Finally, in 1972, this system was replaced by an electronic sound signal, which was used until the Pointe-au-Père navigational aid centre closed in 1997.

The main alterations made to the Pointe-au-Père fog alarm shed today continue to bear witness to this history of experimentation. A semicircular rail behind the building allowed the horn to be oriented depending on wind direction.