Bone structure

©NannaDis
Press conference, Kiwanis club in Lier, Mammoth exhibition. c Nanna Dis 2018

A prehistoric mammoth comes home in Belgium.

Story by Julie Saetre
Event photos by Nanna Dis

When a group of workers stumbled upon a pile of bones during a Belgian construction project on a late-February evening in 1860, they at first tossed them away as rubbish. Night was fast approaching, and the bones, resting 10 meters deep in the ground, impeded their progress of digging a diversion canal for the Nete River in the Belgium city of Lier.

Some of the excavation team, though, must have taken a closer look in the fading daylight and realized that these weren’t just any bones. They were the bones of a woolly mammoth, a lumbering, thick-furred herbivore mammal that began a march toward extinction more than 10,000 years ago. The workers began collecting the specimens, eventually excavating remains from three woolly mammoths. One of those skeletons — a male that died when it was about 35 — was nearly complete.

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The original mammoth skeleton at the Royal Belgian Institute of Natural Sciences.

The latter discovery piqued the interest of staff at the Royal Belgian Institute of Natural Sciences, nearly 50 kilometers away in Brussels. At that time, the only mounted mammoth skeleton in Europe was on display in St. Petersburg, Russia. Not about to miss out on a rare opportunity, the Royal Belgian staff decided to create their own exhibit. The bones left Lier never to return, and in 1869 the institute proudly unveiled the only mounted mammoth skeleton in western Europe.

For a while, the mammoth of Lier was a local legend, with the story of the historic discovery taught to school children and recounted by parents. But by the 21st century, Lier was known for its tourist-friendly features like the iconic Zimmer clock tower, which displays 13 clocks marking time on all continents, tides, moon phases and more. Few Lier residents had even heard of the mammoth.

Bart De Bie wanted to change that. During his 2017-18 term as president of the Kiwanis Club of Lier Twee Neten, he suggested an idea: Bring the mammoth back. Well, not literally. The skeleton has been a staple at the Royal Belgian for 150 years. What De Bie had in mind was a re-creation of the structure, to be placed in the City Museum of Lier so that school children and other area residents could learn about this forgotten piece of history.

“It’s a huge animal,” De Bie says. “Children will be amazed when they see it.”

So De Bie and his fellow Kiwanians considered the possibilities for creating an accurate mammoth model, one that would be 5 meters long, 3 1/2 meters high and 2 meters wide. At first, they thought about requisitioning an artist to sculpt the skeleton in bronze, but the cost (around EUR500,000) was much too steep. Next, they considered a wooden sculpture, but the result would not have been as detailed as they wanted.

Then they thought of Materialise, a Brussels-based, worldwide 3D printing powerhouse. Known for its innovations in software, the company prints a wide variety of products for industries ranging from aeronautics to health care to athletic footwear. With capacity to print substantial structures, it often turns out dashboard, bumper and other sizable prototypes for auto manufacturers.

“It’s old and new comes together,” explains De Bie. “The old is the mammoth, and we’re going to re-create it with the new 3D technology printing.”

The Kiwanians approached Materialise’s staff, who agreed to take on the challenge. The company already had tackled some pretty impressive projects, including replications of Egyptian pharaoh King Tutankhamun’s remains, the ice mummy Ötzi, and an elaborate crown used in the movie “Black Panther.” It had not, however, taken on one so large — literally — as re-creating a mammoth skeleton.

“This is a first for us,” says Kristof Sehmke, corporate communications manager for Materialise. “It’s the biggest thing we’ve ever printed, definitely in size. So it’s quite unique, even for us.”

The club approached the mayor of Lier with its proposal and received an enthusiastic response. Lier would donate €25,000 to the project’s €100,000 cost, and the mayor promised to give the mammoth a prominent place in the City Museum — if the Kiwanis club could provide the remaining funds. When others learned of the project and its price tag, more than a few had their doubts. 

“No one believed that we could bring such a huge sum together,” De Bie recalls. “But I said, ‘Whoa. Nothing can not be done.’ I believed in (the project) very much.”

Undaunted, De Bie, some fellow club members and the Lier mayor set out on a day of fundraising. They approached three companies; two immediately agreed to donate, for a total of €50,000. 

“We said, ‘OK. This is going to be a reality,’” De Bie says.

When Materialise got the go-ahead, staff formed a plan of action. Re-creating a mammoth, even with modern technology, is no easy task.


Making a mammoth: The design and production team at Materialise create and assemble the 3D mammoth replica. Photos courtesy Materialise.

 


“It’s not just ‘Here’s the file, push the button and here’s your mammoth,’” explains Sehmke. “It’s a really big team with engineers, specialists, designers and manufacturing people.”

Fortunately, the Royal Belgian Institute of Natural Sciences had already scanned each of the skeleton’s 320 bones, and paleontologist Mietje Germonpré, who specializes in Ice Age mammals, agreed to consult with Materialise. A team of engineers visited the Royal Belgian and, computers at hand, sat with Germonpré in front of the original skeleton to study how all the bones interconnected.

The consultation also gave the team a unique opportunity. The original skeleton is missing a few bones, including the left tusk, and its upper jaw is broken. In addition, knowledge of mammoths has improved since the 1860s. Specialists now know that the tail is longer and the spine’s slope different than the mounted original depicts. Through the 3D printing process, new bones could replace the missing and fractured ones, and individual bone designs could be altered to be more anatomically correct.

“This,” Germonpré notes, “was a very ambitious project.”

Armed with the knowledge gleaned from Germonpré, the engineers turned their attention to mounting the new skeleton. The original used a custom iron support system, which kept the display sturdy but was also in plain view. The Materialise team designed an interior-mount method made of carbon and then integrated entrance and exit holes in each bone’s design for a less visually distracting approach. 

“You hardly can see any of the connectors between bones,” says Sehmke. “You can see the full size of the skeletons and the bones without seeing all the support structures. It’s really impressive.”

©NannaDis

Compared to the planning and design work, the actual 3D printing process was hands-off. The engineers’ digital design files directed the 3D printers’ actions. The printing itself occurred in a large, liquid-resin-filled tank. The surface on which the bones were printed first received a layer of UV-sensitive liquid polymer. A UV laser then moved over the surface in the design designated by each digital file, hardening the liquid into a shape. The remaining resin in the tank stayed fluid in form. 

The surface and the first layer of the object lowered slightly, and the process repeated itself until the 3D bone was complete and could be raised from the tank. Exactly how slightly did that object lower?

“The resin layer is only one-tenth of a millimeter thick,” explains Sehmke. “So vertically, we can do about 10 centimeters per day. We had nine machines running 24/7 to print all of these bones.”

In a serendipitous coincidence, the machines to which Sehmke refers are called Mammoth printers, some of the largest 3D types in the world. The printer bed itself is an impressive 2,100 by 700 by 800 millimeters — what Sehmke calls “about the size of a bus stop.”

It took a full month to print all 320 mammoth bones — the tusks alone required 10 days. And then each printed piece needed to be finished with a combination of paints, textures and lacquers to transform it from semi-transparent plastic to believable bone. Before transferring the bones to the City Museum of Lier, the team did a trial assembly run at Materialise. They then disassembled the skeleton and carefully rebuilt it at its new location.

©NannaDis
Opening at the museum, Kiwanis club in Lier, Mammoth exhibition. c Nanna Dis 2018

On September 27, 2018, the Kiwanians and the City Museum hosted the skeleton’s debut in front of an eager crowd. Anticipation for the unveiling had been building for weeks, thanks in part to Sehmke’s communications team at Materialise.

“My marketing folks, they told me, ‘Hey, we’re going to print a mammoth. Do you think you can do something with that?’” Sehmke says, chuckling. “Yep. I think I can.”

“There was a lot of interest, much more than we expected, by the local and national press and television,” says De Bie. “Two national TV stations brought it in the news at prime time. One, three times. And one local TV station. All the newspapers were there too.”

The mammoth of Lier had come home. And what De Bie had once called “a story that nobody knows anymore” now had a happy — and memorable — ending.


 


This story originally appeared in the January/February 2019 issue of Kiwanis magazine.


 

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