NOAA Teacher At Sea
Aboard NOAA Ship Thomas Jefferson
June 20- July 1, 2022
Mission: Hydrographic Survey
Geographic Area of Cruise: Lake Erie
Date: Tuesday, June 28, 2022
Latitude: 41° 36′ 5 N
Longitude: 81° 30.7′ W
Altitude: 138 m
Weather Data from Bridge
Wind Speed: 1.6 kts
Surface Water Temperature: 22.2 °C
Air Temperature (Dry Bulb Temperature): 18.2 °C
Wet Bulb Temperature: 12.7 °C
Relative Humidity: 55 %
Barometric Pressure: 10.24 in
Today, I am going to share some science and technology information from the engineering department. The engine room is located on the two decks below the main deck. The engineers have many tasks and responsibilities on the ship. I am going to share some of the main ones.
The first responsibility is to make sure the ship engine is working properly. Engineers work around the clock to make sure that in the case of an emergency, they can act quickly. As you may imagine, the ship has a huge engine with many cylinders. I was very lucky to see the engine before and after it was working. When we anchored our ship near the Rocky River, we stopped the engine. The ship’s electric power is powered by three diesel generators. This powers various systems in the ship such as AC, heating, computers, refrigerators etc.
When we were ready to get underway from anchorage for our next journey on Lake Erie, I thought it was a good idea to observe the engineering department and see how they start and operate the engine. Anyway, I went down there about 20 minutes before our departure. Engineers were busy as bees around the machines touching, clicking, opening/closing valves. There was a constant movement. They all know what to do, including me. My job is to watch how the ship engine operates. I was roaming around to see what would be the best place for me to videotape the moment when they start the engine. Luckily, I found one, and “loudly” waited there. Oh, I forgot to mention. Before you enter this place, you have to have hearing protection. I put my ear plugs in and on top I put on ear muffs. I was told the noise was going to be so loud. Once they checked all the parts, it was time to start the engine. All the pistons started to move, and it reminded me of the sound of my mom’s old sewing machine, where there was constant ticking, clicking sounds. It was fascinating to witness that moment.
Hear this! Every important part in the ship has a back up. Some of them even have third, or fourth back up. For example, when I went to the bridge to learn about how they control the ship up there, the first thing they told me was that everything has a back up. If one screen shows a map, here is the same map on a different screen. So the engine also has a back up, an auxiliary engine, in the case of an emergency it would quickly kick in. However, the auxiliary engine does not have the same power as the main engine. Its role is to keep the ship out of danger, until the main engine issue is resolved, or the ship can pull into port. There was also a steering room down in the engine room in case the deck loses its steering control, they can manually steer the ship down below. Isn’t that cool! For that purpose, there is always an engineer on watch who monitors the steering gear around the clock. Remember, the ship works 24 hours.
Besides engines, the ship has a water treatment system down in the engine room. To be honest, this was the moment where my excitement made its zenith point. You would understand this when you read what I am about to say on this. The water treatment system consists of many tubes which contain membranes to filter the water, desalinate it, and make it ready to drink. The system uses the concept of reverse osmosis (RO) to make drinkable water out of any water systems, even the ocean. However, I must note that even though the technology allows you to make the water, engineers make decisions whether to make the water based on several factors. First, it is preferred to be at least 12 nautical miles offshore in open water. This is because the water is less likely to have pollutants that could clog the filters, which would quickly lead to other issues for engineers to deal with. Deep water is also preferable for similar reasons; sediment, mud, and sand that can be churned up in shallow waters is another way for the filters to be clogged. In the case of Lake Erie, engineers decided to NOT make water because we are working relatively close to shore, and would not be an efficient use of resources. This is because the ship fills all its potable water tanks (~50,000 gallons!) in port using municipal water from the City, which is enough to supply the ship for several weeks. The ship uses ~1,500 gallons of freshwater a day! But remember, that is for a 30 person crew – eating/drinking, showering, cleaning, etc. Long story short, we have sufficient water in the tanks for the duration of our mission. Therefore, there is no need to make more water.
Okay, let’s go back to the concept of desalination by using reverse osmosis. It sounds complicated, right? It is quite simple in principle. To be honest, even myself, who trained in biology both during my bachelors and graduate school, thought that so many people in the world can’t use ocean/sea water to solve the water crisis because the technology is very “expensive” and that is not an option. On the contrary, it is a very simple science concept and it is relatively cheap when you think of the product and the benefits it has. However, why is it still not accessible to everyone in the world? I guess the question will stick in my mind from now on.
Let’s get back to the science concept of osmosis and reverse osmosis. In osmosis, you have a semi-permeable membrane where water moves freely without energy input to the system until the two sides of the membrane have equal number of water molecules. The osmotic pressure to the membrane is equal in both sides due to having the same amount of water molecules on both sides of the membrane. Cells in our body are semi-permeable and water can go in and out of the cell based on the concentration of solutes in both sides of the membrane. You can see the concept of osmosis in every biological system. We have even applied the concept of osmosis since ancient times to preserve foods by dehydration with salt or sugar such as jams, pickles, pastrami and so on. The microorganisms that make food go bad can’t survive without the presence of water. That’s why honey is the only natural product that never goes bad due to its high concentration of substances.
In reverse osmosis, the movement involves water molecules passing through a higher substance concentration (sea water) to a lower substance concentration. As you can see it is the opposite of osmosis. Water should move the other way around. How do we achieve that? When we apply a pressure high enough to the point where it is higher than the osmotic pressure to the saline water, it causes fresh water to flow through the membrane while holding back the salt. The higher the applied pressure above the osmotic pressure, the higher the rate of fresh water transports across the membrane. Here you have freshwater on the other side of the membrane. Pure and simple. Based on the membrane you use in the system, it also traps all the other pollutants as well. Mind blowing! This is how the ship makes its own freshwater.
So far, we talked about engines and the RO system of the ship. We also have generators down there. They are the ones that generate electricity by using fuel. The ship generally runs on one generator at a time, but may require two during some operations. However, the ship has three generators on board in case others fail.
I guess I’ll leave it here and let you learn more about the science and technology of ship engines and RO systems on your own!
As educators, we often fail to connect our discipline to other disciplines. We usually don’t understand how one concept has many other applications. If being a Teacher at Sea on Thomas Jefferson taught me one thing, it’s that science concepts intervene with other disciplines. If students don’t see these connections, or how the concepts they learned apply to different circumstances, then I believe they fail to see the bigger picture. As a result, “true” learning will never be achieved.
I was a scientist by training before I became an educator, and of course I know what osmosis is in biological systems. However, I must confess that I did not see the applications of osmosis this far, not even during my graduate studies. There has not been a single educator who showed me the concept of osmosis in this perspective. I don’t blame them. They probably haven’t had a chance to learn that way too. All I remember is the “U” shaped diagram with a semi-permeable membrane in the middle, and each side having different concentrated solutions, which shows how the water moves freely. And then they explained how once it reached equilibrium, both sides of the membrane had equal concentration. From there, they talked about different solution types, energy requirements of moving molecules from one side to another, etc. I guess you all remember this from your biology or related courses.
From this teaching, did you ever think about how this science concept is used in different applications? Like in this case, reverse osmosis to make freshwater from seawater. If you did, lucky you! You are one of those lucky ones- I didn’t have that opportunity. At least, I did not think about it at the moment. All I worried about was learning the concept and moving on. I guess my teachers at that time had the same “vision” as me. Teach the concept, test it with multiple choice questions and then move on thinking that students learned. When those students come across the same concept in different settings, they mostly fail. The justification of the educator would be like, “I don’t know why they failed. I taught them the materials and had great scores. They must have had a bad day during the testing.” Yeah! Yeah! Yeah! I know those.
Sorry for my long thoughts about our educational system. We really should, at least, teach science concepts to our classroom through its real world application. Only then, would they appreciate the power of the science concept they are learning, which could open a lot more creative ideas on their own, leading to innovation. These were thoughts that sparked my mind thanks to reverse osmosis (RO) system technology on the ship.
Another important thing that came to mind while I was down in the engine room was the importance of teamwork, and how important it is to always have a back up. We all know the importance of teamwork, and how the members of each team are equally important. But when it comes to teaching teamwork to the kids who have not experienced real teamwork, do they really understand its importance? If we want our students to work as a team in our classrooms, we need to design our lessons in a way that if one of the team members fails to complete a task assigned to them, the whole task fails along with it. Once they know this, I think the true understanding of teamwork will prevail to the students.
These were the thoughts that I have been contemplating while witnessing all the cool things I saw in the engine room. Who knows how students would be impacted if they saw these things?
Did you know?
- Waves in Lake Erie are mainly caused by winds because of its shallow nature. If those waves move away from their generation zone, they become more regular and then are referred to as swells.