The granddaughter of the most senior officer to survive the sinking of the Titanic has revealed a century-old secret that could rewrite history.

UK author Louise Patten says the ship had lots of time to shift course when its crew members spotted an iceberg, but plowed straight into it because of a simple steering error.

Patten, the granddaughter of the Titanic’s Second Officer Charles Lightoller, told the The Daily Telegraph she has known about the secret since the 1960s.

She comes clean about it all in her new novel, Good as Gold.

“It just makes it seem all the more tragic,” Patten told the Telegraph. “They could have easily avoided the iceberg if it wasn’t for the blunder.”

More than 1500 people died when the ship sank on April 15, 1912.

Patten said the crash happened because a crew member steered right when he should have steered left.

The Titanic was built at a time when the world was converting from sail to steam ships, which used two different steering systems, Patten said.

Some of the Titanic’s crew were used to using the old Tiller Orders, where you steer right to go left and left to go right.

Others were more familiar with the modern Rudder Orders, where you steer the way you want to go.

In a moment of panic, the steersman used the wrong orders and turned toward the iceberg. The ship had four minutes to change course but by that time it was too late.

The Titanic hit the iceberg at 11:40 p.m. on April 14 and sank about two-and-a-half hours later.

Patten said her grandfather hid the truth about the crash because he was afraid it would bankrupt the Titanic’s owners and leave his colleagues jobless.

Loading... Loading... Loading... Loading... Loading... Loading...

She told the Telegraph she kept it hidden for so long because she and her family worried it would destroy her grandfather’s good name.

“This sounds mad, I know, but once I started thinking about it, I felt as if I owed it to the world to share the secret. If I died tomorrow then it would die with me.”