Alas, the time has come for us to leave the employ of HHI. After three educational weeks, we are off to the University of Ulsan. Our time at HHI has been quite the experience. Our last week has been spent at the Hyundai Maritime Research Institute (HMRI) and Hyundai Industrial Research Institute (HIRI).
HMRI is about the closest thing we have experienced to our normal academic lives. Similar in focus to the Marine Hydrodynamics Laboratory at Michigan, HMRI has a huge towing tank, model shop, model propeller shop, cavitation tunnel and circulating water channel. In English, that means they test their ship designs in small scale. However a small-scale model of their Very Large Crude Carriers is still 25 feet long. I wanted to turn one into a fishing boat, but Greg convinced me it was not cost effective.
**********WARNING: ENGINEERING LANGUAGE FOLLOWS**********
HMRI also has a gravity wave tank. We got to predict the natural frequencies of vertical cylinders in heave, and then verify our predictions with a test. Because the cylinders were on the free surface, they told us to use 0.5*ρ*g*V for the added mass. Greg and I remembered that fully submerged this would be more like 0.1*ρ*g*V, so we were slightly skeptical. However, they actually moored the cylinder with four chains, changing the problem completely. In that case, their 0.5*ρ*g*V worked out to be accurate. For some reason I think they knew that was going to happen…
The other really neat thing at HMRI was the propeller cavitation test. The cavitation tunnel is a dark room, and they have a strobe light set up at the same frequency as the propeller RPM. The propeller was rotating at around 200 RPM, but appeared to be standing still. That way they could see the cavitation on each blade.
**********END WARNING**********
After all the hardcore NA&ME work at HMRI, we were not all that interested in going to learn about steel microstructure and coatings (paint) at HIRI. We were all pleasantly surprised at just how nifty steel microstructure and paint could really be. They had small samples of welded steel joints, which we sanded and polished to a mirror finish, literally. Under 100x magnification no scratches were to be visible. Next, a diluted nitric acid solution was placed on the sample, which ate away at the cell boundaries, highlighting the microstructure. We then viewed the samples under a microscope and were educated about all the microstructures in the base metal, heat affected zone (HAZ) and the weld metal itself. It was pretty much like high school biology, except with steel. After that, we conducted a Vickers hardness test on the sample. Basically you indent the metal with a constant force, and then measure the size of the indent to determine hardness. We also witnessed a Charpy test (Guillotine for an innocent steel sample), and tensile test (drawing and quartering for an innocent steel sample). Our final workday at HHI and HIRI was the crowning glory. Shot blasting.
It was a rainy day, and our guide took us outside and walked us around the back of the building. Awaiting us was what looked like a shipping container, with only a lock on the outside. My mother warned me about situations like this. Two people wearing red jumpsuits arrived, and they handed us a denim and leather set of pants and jacket. If the clothes from Bonanza were blue, these would be them. After donning the equipment, they wrapped our boots in leather and we put on heavy gloves. They opened the doors of the container and we stepped inside. Next, a hood with independent air supply was placed over our head, with a small glass viewport. Greg went first, and it seriously looked like something out of 2001: A Space Odyssey. An HHI man in the same getup was inside to manage the equipment and to help hold the hose. Without the heavy clothes and hood, the steel shot could easily shred all the flesh from an arm or leg, and eat through the bone if given a few seconds. The safety cartoons showed a man with a giant hole in him, and they were not kidding. The door was closed and locked behind us, and we blasted away. This entire experience was great fun. It was a perfect ending for our time at HHI.
Our bags are packed for the move to UoU, and everyone is a little mellow to be turning in their beloved uniform and hardhat.