A huge plan of the historic Titanic ship that was used during a 1912 inquiry into the ship’s sinking, has been sold for £195,000 (US $243,000).

According to a CNN article, the item was sold at a recent auction staged by Henry Aldridge and Son Ltd. The plan is said to still bear the red and green chalk marks used to indicate where ice was believed to have penetrated five water-tight bulkheads. The 33-foot (10-meter) long plan is also believed to be “one of the most important and well documented pieces of Titanic memorabilia in existence today.”

“This plan of the ship was prepared by the Naval Architects Department of the White Star Line, the company which owned the Titanic, and was used during the inquiry investigating the disaster. It hung from the ceiling so that participants could refer to it using a pointer, and the cable holes in the linen are still visible,” the CNN article read.

Andrew Aldridge, managing director of the auction house, told CNN that the price for the plan was a reflection of the “rarity of the material … but also the enduring appeal of the Titanic story.”

The inquiry’s transcripts are filled with references to the plan as it considered the testimony of nearly 100 witnesses and other evidence which concluded that the Titanic sank after colliding with an iceberg. CNN reports that many maritime safety reforms were implemented as a result of the findings of the investigations.

The Titanic was the largest ocean liner in service at the time and was thought to be nearly impregnable. But it struck an iceberg in the Atlantic on April 14, 1912, killing more than 1,500 people.

Other pieces were sold at the same auction, including an accommodation plan of the Titanic for £60,000 ($75,000), a collection relating to the rescue ship Carpathia.