The sound signals at Cap-des-Rosiers

Fog has always been one of the biggest dangers of navigation. During the day, navigators could not see the coast and the landmarks which they needed to pursue their trip; during the night, they could not easily distinguish the lighthouse lights. The sound signals had different durations according to their locations, warning a navigator trapped in fog that he was close to the coast and that it was time to save his ship by correcting course. The signal told him the location in front of which he sailed.

The maritime community asked not only for the building of a lighthouse at Cap-des-Rosiers, but also the installation of a fog signal. 

The fog canon

The first sound signal at Cap-des-Rosiers was a fog cannon, a nine pound calibre piece. It is likely that it became operational at the same time as the lighthouse at the beginning of the 1858 navigation season. A report from the Quebec Marine agent, dated 1877, indicates that the powder magazine had existed since 1857.

Between 1858 and 1881, according to various reports from this period, the Cap-des-Rosiers fog cannon fired blanks every hour during fog or snow storms using 1500 pounds of powder per navigation season. It doubled its powder consumption after October 3rd, 1881, when the firing frequency changed officially from once an hour to once every half-hour.

With an hourly shooting, the ships had time to attain the coast; more frequent firings helped to avoid this and allowed the ships to maintain a reasonable speed during periods of mist or storm, thus avoiding undue delays. The popularity of the St-Lawrence River and Gulf increased because of this improvement.

However, powder cost a considerable sum to increase the audible sound range and subsequent security.

The handling of fog cannons was dangerous, and sometimes deadly accidents occurred as in August 1881 at Rochers-aux-Oiseaux lighthouse or in 1891 at Heath Point lighthouse on Anticosti.

Between 1858 and 1873, the powder was provided by the British imperial government. To save costs, especially on transportation, the Marine and Fisheries department decided to acquire Canadian manufactured powder after this date. The Chinic et Beaudet firm was chosen to provide powder manufactured in Windsor, Quebec. It was of excellent quality and was cost-efficient; at the end of the 1870s, a 100 pound barrel cost $20 or $0.20 a pound. Exceptionally one year, the powder was bought from Hamilton Powder, another Canadian company.

The cannon powder had to be stored in a secure and dry place far from dwellings while avoiding humidity that could have rendered it unusable. Similarly, the cannon was sheltered in a shed to protect it, and those who handled it, from the weather. A powder magazine was erected on the Cap-des-Rosiers lighthouse station site in 1857. In 1876-77 a new roof, made of zinc, and a new floor in the cellar were installed. It is possible that the present powder magazine is a second one which would have been built in 1881 or 1882. According to deputy-minister William Smith's report from January 1st, 1883 " a new shed and magazine (for powder?) have been constructed at this station (Cap-des-Rosiers) ".

The alarm whistle

It is also possible, however, that it was a shed for the lighthouse burner's fuel, because in 1882, the Marine and Fisheries Department authorities decided to replace the fog cannon with an alarm whistle. It therefore seems peculiar that a new powder magazine would have been erected. The steam-powered alarm whistle at Cap-Gaspé, put in service on May 22nd, 1874, would have cost $2000 at this time. On January 27th, 1883, a notice informed navigators that at the next navigation season's opening this whistle would be moved to Cap-des-Rosiers. On July 30th of the same year, another official announcement indicated to the maritime community that the whistle had been installed and would be officially operational on August 15th. The fog cannon's use stopped. The whistle installation cost, including the building of the sheds to shelter it, the machinery producing steam and the fuel (coal) supply and transportation rose to a sum of $5517.41. The whistle, functioning on the same principle as locomotive whistles, sounded 10 seconds every minute.

The fog horn

This device didn't remain the main sound signal for long. In 1884-1885, a fog horn replaced the steam-powered whistle kept as a backup in case of a horn failure. The snare of the fog horn, differently from the one of the whistle, is hit by a shot of compressed air produced by steam. The sound features remain unaltered.

On November 1st, 1899, the inverse situation occurred. The air actuated fog horn was relegated to a backup function while the steam-powered whistle became the main sound signal.

The diaphone

In 1906, a considerable improvement was brought to the sound signal system at Cap-des-Rosiers. The whistle was replaced by a diaphone, a device using compressed air, also produced by steam, but with better output. The diaphone, invented in 1902 by Professor J.P. Nothey of the university of Toronto, was marketed a short time after its invention by the Canadian firm Fog Signal Co. of Toronto.

The unique sound of this contraption descended toward the bass at the end of every sound. A hollow piston, bored with circular slots along equidistant planes to the axis, moved at high speed in a cylinder with matching bored slots, alternately covered and uncovered by the movement. The air compressed by the steam produced by boiling water in boilers was contained in big reservoirs and actuated the piston.

In 1905 and 1906, a new wooden building was erected as an extension to the old building sheltering the former whistle. Numerous other improvements were conducted to make the operation of the new device easier. On August 1st, 1906, the new device became officially operational for navigation needs and the use of the steam-powered whistle came to an end. The sound produced by the diaphone lasted 7 seconds every minute (sound 7 sec, silence 53 sec).

The diaphone was in operation at Cap-des-Rosiers until 1972. In the beginning of the 1916 navigation season the steam-powered mechanism, using actuated air was changed for a motor run with oil. This change, made under the direction of foreman Lavergne of the Quebec agency, cost $4406.90.

The sound signal underwent two modifications. The first, at the beginning of the 1912 navigation season; the sound was composed then of three (3) calls of two seconds and a half each, separated by intervals of the same duration, every minute (sound 2.5 sec; silence 2.5 sec; sound 2.5 sec; silence 2.5 sec; sound 2.5 sec; silence 47.5 sec). The second, when the steam-powered system was replaced by internal combustion at the beginning of 1916; the duration of the sounds passed from two seconds and a half to two seconds; the intervals between the sounds were raised to three seconds; their number stayed the same during each minute (sound 2 sec; silence 3 sec; sound 2 sec; silence 3 sec; sound 2 sec; silence 48 sec). 

The electronic fog detector with horns

In 1972, at the time of the lighthouse's automation, the diaphone was supplanted by an entirely automatic electronic device (mist detecting and loud). Taking less space, this more reliable electronic device didn't require a continuous human presence. The sound signal of the two horns was the same as that of the diaphone. This fog detector and its horns ceased operation in 1993.