Centuries ago, the Signal Hill noon gun was fired for time-signal purposes. Today the firing of the cannon signals to many working in the City Bowl and surrounding areas that it’s time for their lunch break.
But on at least two occasions recently the gun was not fired at noon and was slightly delayed, and Capetonians want to know why.
Avid hiker Anthony van Rhyn says he often hikes up Lion’s Head and says on Monday 30 May he was quite “embarrassed” when he had to explain to tourists why the noon gun was fired at 12:12.
“The tourists wanted to know whether it was a bomb going off, because it’s quite loud,” he said. “Then I had to explain to them it usually goes off at noon. When one is on Lion’s Head and one looks down, one can see the cannon, and on Monday when it was fired I looked at my watch and thought my time was wrong because it was after 12 o’clock.”
One resident took to social media and posted: “The guns are triggered electronically via the master clock at the South African Astronomical Observatory in Cape Town, which is the oldest timekeeper in the country. Another accolade? But what is happening? Today (Monday 30 May) and last week the gun fired at 12:12.”
Commander Cara Pratten, Acting Fleet Public Relations Officer, says the two 18-pounder smooth bore muzzle loading guns operated or fired by loading a bag of gunpowder into the barrel with a ramrod.
“A percussion tube (which ignites the gunpowder) is loaded into the firing mechanism at the back. Once the firing mechanism is secured, the naval operator retreats about 25 m to a time box and awaits the signal from the South African Astronomical Observatory, which automatically fires the gun.”
She says the late firings occurred on Monday 23 May when it was about three minutes late and on Monday 30 May when it fired 12 minutes later.
“The SA Naval Armament Depot conducted a technical inspection of the gun on (Tuesday) 31 May. No technical faults were found. The Naval Base in Simon’s Town is currently in the process of investigating the cause of the late firings.”
Situated at the Lion’s Battery on the lower slopes of Signal Hill, the noon guns are known as the oldest working guns in the world and have been firing since the 1800s.
Daniel Cunnama, Science Engagement Astronomer at the South African Astronomical Observatory (SAAO), says in the 1800s accurate navigation at sea required an accurate time signal to reset their chronometers.
He says this led to the establishment of the Royal Observatory Cape of Good Hope (now SAAO) in 1820, which became the first permanent scientific establishment in the Southern Hemisphere to provide an accurate time signal to the Royal Navy.
Cunnama says the time signal was given firstly by firing a flare pistol, dropping time balls and finally by firing a cannon.
He says the cannon is the oldest cannon in the world firing a continuous-time signal.
Originally the gun was fired according to a flare set off at about 12:00 from the SAAO.
Cunnama says: “For a while the SA Navy used the City Hall clock as the suitable time. Nowadays it is more accurate. Until recently an electrical signal was sent across telephone lines from the SAAO atomic clock a few milliseconds before noon, but it is now fired by a time service box provided by the SAAO which gets its time from very accurate GPS satellites.”
