Steelmaker's Skeleton to Save Historic Ship From Crumbling

The ship is incredibly fragile.

Transcript

Alleima is a Swedish steelmaker that makes products out of advanced stainless steel and special alloys. The company, formerly Sandvik Materials Technology, was officially spun out of Sandvik in 2022 and has more than 900 active alloy recipes. The company typically makes seamless steel tubes for the energy, chemical and aerospace industries, precision strip steel for white goods and even ultra-fine wires for medical and micro-electronic devices.

The company recently found itself facing a unique challenge: the crumbling remains of a nearly 400-year-old ship. On August 10, 1628, the Vasa cast off from below Tre Kronor castle in Stockholm and left the harbor. She was a mighty ship with three masts that could carry ten sails, measuring 52 meters from tip to keel and 69 meters long, it weighed 1,200 tons. The Vasa was hit with a mighty gust from the gods that caused her to capsize. Water poured in through open gun ports, the Vasa sank to the floor of the sea, and at least 30 of the 150 or so people aboard perished. 

Most Read on IEN:

About 333 years later, divers found the Vasa. On April 24, 1961, more than 14,000 loose pieces of wood were pulled from the sea and the ship was salvaged, but it has taken a considerable effort to preserve it.

Now on display at the Vasa Museum in Stockholm, the ship is incredibly fragile. Chemical degradation of the wood has caused the old oak hull to lose much of its strength. So, the museum reached out to Alleima to make an inner steel skeleton, a truss built out of tubes to stabilize the hull.

According to the museum, saving the Vasa has been the biggest challenge facing the ship since the salvage. The skeleton will be made out of a high-alloyed SAF 2507 stainless steel material. The inner steel skeleton will reach from the keel to the upper deck and support the loads from the deck and deck beams. However, the inner steel support must be strong and light, and Alleima will use a design that prevents the project from drilling too many holes in the hull. Because the material is so strong, the skeleton will require less of it, and the steel's high corrosion resistance allows it to come into direct contact with the ship without being affected by acid given off by the wood. 

The project should be completed by 2028, which lines up with the ship's 400th anniversary.

This isn't Alleima's first voyage with the Vasa. In 2011, then owned by Sandvik, the company replaced more than 5,000 rusty bolts with a specially developed, high-alloy part. The bolts made the ship more stable and shed some eight tons from the ship's overall weight, about the weight of a yellow school bus. 

Click here to subscribe to our daily newsletter featuring breaking manufacturing industry news.

More in Video