Cruise Ship and the Environment

Last week I spoke of how our experience on a cruise ship could be a metaphor of the life of the church. This week, I’m doing a little reflection about the environmental side of the experience. Some of these reflections will be facts and figures, I’ll let you draw your own conclusions.

The last day of our trip, we received a handout/pamphlet called the “Cruise Log.” This one sheet (Legal Size) trifold contains the days of our cruise, places stopped, noon position (if applicable) and weather. Here are examples from the first three days:

Saturday, June 29, 2013 – Vancouver, B.C. Canada

16:00 Held Mandatory lifeboat drill

16:39 Zuiderdam sails for Juneau, Alaska

17:00 Zuiderdam passed under Lions Gate Bridge

Sunday, June 30, 2013 – At Sea

12:00nn Ship’s position: 52degrees 51’8 N 129degrees 11.6’W

                Weather: Overcast, Calm Seas, 14 degrees C/57 degrees F

17:47 Disembarked Canadian Pilot

Monday, July 1, 2013 – Juneau, Alaska

05:19 Embarked Alaskan pilot at Kake Pilot station

12:00nn Weather: Cloudy 13 degrees C/55 degrees F

12:22 Zuiderdam docks in Juneau, Alaska

22:43 Zuiderdam sails for Skagway, Alaska

All in all, this log is fairly general, but it does provide some information about the ship and voyage, too. For instance, the Zuiderdam sailed 1974 NM (1 Nautical Mile = 1.15 statute miles = 1.85 kilometers). The ship also consumed (via diesel generators) 90 tons/day which equates to 57,000 gallons/day. The power comes from 5 diesel generators (3 x 16,000 hp  2 x 12,000 hp); 1 gas turbine (1 x 18,000 hp) for a total of 84,000 hp. The propulsion comes from 2 x ABB Azipods (2 x 17.5 mw) for a total of 46,000 hp.

Did you catch that last one? The Zuiderdam is propelled by electric drive – and the pods can turn close to 360 degrees (if not a full 360 degrees). This means that they can work as thrusters, which further means the Zuiderdam doesn’t need the help of a tug boat.

The log tri-fold also mentions water production and consumption: Potable Water Production, 1,700 tons/day (450,000 gallons) and Potable Water Consumption 750 tons/day (200,000 gallons).

This log sheet mentions that there were 1916 guests and 823 crew. We were told that this week’s trip actually carried more guests, so my post last week used that number. For the calculations I’m about to do, I’m using this number.

What does all this mean? Before going about some calculations, I want to point out some interesting things I read about and/or heard while we were aboard. The first is regarding the food (especially the fish). We heard that Holland America works hard to continue to provide sustainably caught (and if applicable, wild caught) food. There have been issues with large ships colliding with whales, often causing severe injury to the whale, if not death. So I was happy to see that Holland America had designed a whale warning system that NOAA is now encouraging other ships to use. I also noticed that when whales were in the area, we were cruising at a much lower speed. I know that electric drives produce much less noise than a diesel engine driven propeller. What I don’t know is how much noise the diesel generators would be producing. To what extent is the non-noise of the electric drives over-ridden by the noise the generators are making to produce the electricity to run the engine?

People aboard the Zuiderdam: 1916 + 832 = 2739.

Water Consumption per person: 200,000 gallons / 2739 people = 73 gallons/person each day. How does this compare to what you are consuming on land? More? Less?

Miles per Gallon: (A Side Note: most marine engines are computed in terms to of hours per gallon) 1974 Nautical miles x 1.15 Statute miles = 2270.1 Statute miles. 57,000 gallons x 7 = 399,000 gallons. 2270.1 statute miles / 399,000 gallons = 0.0057 statute miles/gallon. This doesn’t sound very good as a comparison for a car on the road. But how many people does your car carry? If we divided this number by the people we would get miles/gallon per person: 0.0057 mpg / 2739 people = 0.000002081 mpg/person. How does this compare to a car? A van getting 22 mpg / 5 people = 4.4 mpg/person.*

All the above gives some food for thought, and I haven’t even considered what 2 cruise ships (they seem to travel in pairs – the other one traveling with us was one of the Princesses lines’ ships) does to the local economies of the small towns. Do they become a blessing or a burden? Probably depends upon who you talk to.

Blessed Be

Joel

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*I need to point out something regarding the calculations at this point. While we were in Juneau, we actually were able to turn off the generators and connect to shore power. Juneau has enough power to also supply the 5 cruise ships that were also docked at that time. We departed Vancouver on Saturday at 16:39 and arrived back a week later the next Saturday at approximately 07:00. While I know they were bunkering fuel, I don’t know if they turned off the generators while doing so. I’ve made this calculation simpler by keeping us at 7 days of fuel. The actual numbers maybe higher or lower.