In 1933 the first gravel runways were built. By 1949 the airport had three runways – the 1,085-metre (3,560 ft) 11/29, the 1,190-metre (3,904 ft) 16/34 and the 1,787-metre (5,863 ft) 04/22. The Sydenham to Botany railway line crossed the latter runway approximately 150 metres (490 ft) from the northern end and was protected by special safeworking facilities. The Cooks River was diverted away from the area in 1947–52 to provide more land for the airport and other small streams were filled. When Mascot was declared an aerodrome in 1920 it was known as Sydney Airport. On 14 August 1936 the airport was renamed Sydney (Kingsford Smith) Airport in honour of pioneering Australian aviator Sir Charles Kingsford Smith. Up to the early 1960s the majority of Sydney-siders referred to the airport as Mascot. The first paved runway was 07/25 and the next one constructed was 16/34 (now 16R/34L), extended into Botany Bay, starting in 1959, to accommodate jet aircraft.  Runway 07/25 is used mainly by lighter aircraft, but is used by all aircraft including Airbus A380s when conditions require. Runway 16R is presently the longest operational runway in Australia, with a paved length of 4,400 m (14,300 ft) and 3,920 m (12,850 ft) between the zebra thresholds.