Inside the world’s smallest working lighthouse: how a 23-foot tower once powered by whale oil still shines up to three miles away

The 7-meter-high Harbor Light Tower was once powered by whale oil and is now the smallest working lighthouse in the world.

The beam still extends up to five kilometers and is now powered by vegetable oil.

Located in North Queensferry, the famous lighthouse replaced an original lighthouse built across the street in 1811.

Garry Irvine, secretary of the Heritage Trust, who moved to the area about 40 years ago, has looked after the historic tower since his retirement.

He said: ‘The little light was built in 1811 in the adjacent lighthouse across the street, but it didn’t do what it was supposed to do.

‘As the Queensferry Passage was the main ferry in Scotland at the time, this meant that the actual ferry passage had to be illuminated.

“They moved the light from the lighthouse to the little light tower, and we renovated that to make it work again.

‘We built it from an example from the National Museum of Edinburgh, so we can honestly say it is the only working light tower in the world.’

Garry went on to explain how the Argand lamp can provide up to three miles of light – using a reflector that magnifies the flame inside by 2,000 times.

‘The lamp is powered by oil. “It was originally whale oil, but we don’t use that anymore, so it’s now vegetable oil,” he said.

‘Lighting the lamp is quite unique and requires some manipulation of the lamp.

‘The lamp is called an Argand lamp and was used for most of Robert Stevenson’s lighthouses at the time he lived.

‘The light keepers at the time climbed those 24 steps twice a day – sometimes more often when they saw that the light was off.

‘The light can last about 18 hours with a tank of oil, which is more than enough for a cold winter day or night.’

The lighthouse provided much-needed light to Scotland’s much-traveled River Forth, but due to its location the original light struggled to illuminate the entire crossing.

Students then worked with civil engineer Robert Stevenson with the aim of finding a suitable solution.

Stevenson and his team painstakingly built the Harbor Light Tower in 1817.

It had a new light room which was in a better position to illuminate the river – and the lighthouse’s Argand lamp was moved to the new tower.

But as railways began to spread across the country, the Queensferry Passage became less and less popular.

The ferry passage became less used after 1890 due to the Forth Bridge, but the lighthouse officially ceased operations in 1964.

That was until 2014, when the North Queensferry Heritage Trust received approval to restore the lamp to full working order.

Today the light tower is fully functional as well as a popular tourist spot and museum.

Garry, who is also an amateur photographer, visits the lightroom two to three days a week and has welcomed visitors from more than 90 countries to the site.

Named after Queen Margaret, who regularly made the journey through Queensferry, the passage attracted around 300 travelers a day – and the light tower now serves as a museum for one of Scotland’s most important crossings.

“It was the shortest crossing from Fife to Edinburgh, and it was quite popular – it was the start of the communications and transport era in Scotland,” said Garry.

“If anyone is interested in the Stevenson Lighthouses, this is a good one to check off your list.

“We can light it upon request, and we have signs that give you a bit of history.

‘You can enjoy what many lightkeepers have done twice a day for hundreds of years; it’s a very enjoyable experience.’