The Kingsferry Bridge linking the Isle of Sheppey to the rest of Kent was opened in 1960.
To mark her diamond jubilee, we take a fond look back at her life so far.
It was built by British Rail, mainly because ships kept hitting the old, now demolished, bridge and cutting off the Island.
At the time, it was hailed as a wonder of state-of-the-art engineering and its distinctive 'four-poster' design became Sheppey's new symbol. There is only one other bridge like it in the world, it's twin in Holland.
It was meant to breathe new life into an Island which had been rocked by the closure of Sheerness Naval Dockyard.
But as Ridham Dock became busier with bigger ships sailing up The Swale to discharge cargo for Sittingbourne paper mill, it quickly became apparent the bridge lifts were doing more harm than good.
It was infuriating to wait in traffic queues up to seven miles long for anything up to an hour. Many desperate passengers lost their connection with the Olau Line ferry which in those days sailed from Sheerness to Holland.
For children in cars, however, it was a treat to see the red lights flashing and the huge gates gently swing shut.
It meant a chance to run to the front of the queue to watch the bridge go up, wave to the crew of passing boats and then scamper back to their cars as the bridge slowly slid back into place with a road-shaking thud.
It has been featured in films and on the television.
The most famous was the 1975 Christmas edition of the BBC comedy Some Mother's Do 'Ave 'Em when Michael Crawford returned to his home on Sheppey as the hapless Frank Spencer and ended up stranded on the top of the bridge during a driving lesson before finally crashing into the sea at Sheerness.
The Sheppey Pirates would also hijack it once a year as it was the perfect location to hand out their own 'passports' for their World Walking the Plank championships.
The bridge was opened by Princess Marina, the Duchess of Kent, at noon on Wednesday, April 20 and was hailed as a "new gateway" to the Island.
It was the largest lifting bridge built in Britain since the Second World War and boasted twin reinforced concrete towers looming 130ft above The Swale.
The towers are linked by an eight-feet high service tunnel dug under the surface which carries an 18-inch water main, a 12-inch gas main and telephone cables.
Its approach roads are built on concrete piles sunk 80ft down.
The old bridge it replaced was just wide enough for a single track road and could only lift with a clearance of 57ft. The 'new' bridge is 50ft wide with a double carriageway. Its gap is 90ft with a clearance of 95ft above the water allowing access for bigger ships.
Inside the giant towers are huge 100-ton counterweights which help lift the 425-ton carriageway.
When it was opened, the electric motors could raise the bridge in 90 seconds.
It was also fitted with stand-by diesel engines which could raise the road in 15 minutes in an emergency.
It was built by John Howard and Company and cost £1.5 million.
There have been five bridges to the Isle of Sheppey.
The first bridge at Elmley was called Tremsethg and built in the reign of Edward I (1239- 1307) but it was washed away by a freak tidal wave.
After that, the only way of getting on or off Sheppey was by a simple ferry, one at Harty and one, the Kings Ferry, near Iwade.
In the 18th century the ferry man would haul the boat across the water by hand using a cable 140 fathoms long anchored at each side. He was paid £24 a year and allowed to dredge for oysters.
1856: July 7 - The seven-mile-long Sittingbourne and Sheerness Railway is allowed to build a seven-span bridge at a cost of £84,000 to carry road and rail traffic across The Swale and which will permit the free passage of river craft.
1860: Bridge opens.
Tolls were one old penny per person; 2d bicycles; 3d horses; 6d carts; 1s 6d vans; 2s (shillings) wagons. Farmers paid half an old pence for each sheep they drove over the bridge.
1904: November 1 - Bridge rebuilt by South Eastern and Chatham Railway to include a 350-ton American-designed "rolling leaf" hinge to allow bigger ships to pass. Cost: £50,000.
1929: July - Tolls abandoned after Kent County Council pays £50,000 to Southern Railway to surrender its rights.
1957: December - Work begins building the Kingsferry Bridge.
1959: October 1 - A team of 60 workmen use six winches to swing the lift section into position.
1960: February 29 - Bridge opened to traffic. Demolition of old bridge begins at Easter.
1960: April 20: Princess Marina the Duchess of Kent officially opens bridge.
2006: July 3 - The £100 million Sheppey Crossing opens with a four-lane dual carriageway standing 115ft (35m) over The Swale. But it is out of bounds to pedestrians, cyclists or horses which must still use the Kingsferry Bridge. And crashes, breakdowns and high winds regularly close it. Around 10,000 tonnes of steel was used by Carillion under a private finance initiative contract.
The first team of lift operators comprised Bill Starley, 49, of Marian Avenue, Minster; Frank Fisher, 40, of Black Cottages, Lower Road, Minster, and Bob 'Jock' Arnott, 46, of Second Avenue, Rushenden.
The first vehicle over the bridge when it was opened to traffic was a Maidstone and District double-decker bus driven by George White of Maidstone. It was the first time a double-decker had been able to drive onto Sheppey because a low railway bridge blocked the path to the old bridge.
The first car to cross was a green Austin driven by 79-year-old Alfred Clay of Saxon Avenue, Minster. The second was driven by James Boote, president of the Sheppey Chamber of Commerce.
The low-key opening was reported on the BBC television programme Tonight by Alan Whicker.
There were two deaths during the building. A man from Queenborough was suffocated by wet sand after falling into a bore hole and a dumper truck driver from Boughton was killed when his vehicle slipped and crushed him at Iwade.
In 2010 the bridge had a staff of eight - four operators and four engineers.
On a average day it can be raised 20 times.
Look inside the Kingsferry Bridge