Flagstaff

FLAGSTAFF

The site of Sydney Observatory, now known as Observatory Hill, was previously known as Windmill Hill, Citadel Hill, Fort Phillip and Flagstaff Hill, describing its functions over time. All of these functions relied on its position at the highest point overlooking Sydney Harbour.

The current flagstaff on top of Observatory Hill, generously provided by the Bruce and Joy Reid Foundation, was installed in June 2008 to commemorate the history of the site as a signal communication point and as part of the celebrations of Sydney Observatory’s 150th anniversary.

Signal flagstaffs were first erected here on Fort Phillip’s walls about 1810, followed shortly after by a semaphore mast. During the 1850s these were replaced by two tall signal masts, which remained in use until the 1930s – more than a century of shipping signals sent and received from here.

A signal station was set up on the hill in 1825 to receive messages from the station at South Head about ships arriving in the harbour. Until the 1920s two flagpoles were used to pass messages to other signal stations and the port authorities. Signal flags on the hill announced the arrival of ships into Sydney Harbour. The flags also informed port authorities of the names, origin and cargo of new arrivals. Weather and other information was communicated by signal flags to ships in the harbour, and to other signal stations at Bedlam Point near Gladesville and then to Mays Hill above Parramatta.

The cottage next to the flagstaff was designed by colonial architect Mortimer Lewis and built in 1848 as a residence and store for the signal master and his family. The cottage was extended in 1859 to add storage and office space.

Sydney Observatory flagstaff
Make your own flag decoder
You can decode the flags by looking at the the legend on the bottom decoder wheel (see pdf below). And you can make your own flag decoder by printing out both of the pdfs below, cutting out both circles and the window in the top circle, and attaching them to each other by a paper fastener through the centre. Use the heaviest paper your printer can handle, or glue the paper to card before cutting out.

Flag decoder – bottom plate (pdf document)

Flag decoder – top plate (pdf document)

The flags currently flown are:
- The Australian National Flag
- The NSW State Flag
- Australian Aboriginal Flag
- Torres Strait Islander Flag
- Constellations visible in the night sessions
- Planets visible in the night and pre dawn sky
- Phases of the Moon
- The maximum expected temperature for Sydney (three flags)
- Astronomical events including equinoxes, solstices, meteor showers and eclipses
- Various shipping signals (Not actual Sydney Harbour information)