Preparing ourselves for the worst but almost with great certain that it would not be that bad, we sailed into the Golfo de Tehuantepec. Guests were advised during my Voice from the Bridge announcement, signs were posted and tanks prepared. The Statendam has 9 direct ballast tanks, 8 fresh water tanks, 7 regular fuel tanks, two large heeling tanks (that normally keep the ship upright) and a whole host of other smaller tanks for various purposes. The trick is now to have as many of those tanks available and empty on the side of the ship that you expect the wind to come from. We normally do not count on the fuel tanks, as fuel has to be heated first before it can be pumped over and sometimes we cannot pump it anyway if it is fuel from different suppliers. Fuel from the west coast is different than from the east coast and although all under the label of HFO, the chief engineers do not like to mix it. However ballast and fresh water tanks do not have that restriction. Freshwater tanks when full can of course not be emptied out but what we can do is USE water from tanks on the windy side of the ship and add the water made on board to the tanks on the lee side of the ship. With nearly 2000 people on board whom all consume water, plus the kitchen and the laundry, it makes quite an impact.
The main help comes however from the ballast tanks. These are meant to compensate for weight, e.g. stability loss, when fuel is consumed. Here on board they are mostly empty as with the bunker cycle that we have, we do not get to the critical stability zone very often. If they are not empty then the First Officer in charge of stability ensures that the weight in the various tanks are arranged in such a way that the tanks on the windy side of the ship are mostly empty. Then before we approach the wind field we fill some of these tanks up. That would cause a list to the windy side but that we compensate by pumping the water in the heeling tanks (this is a closed circuit system) to the opposite side. Now when the wind starts blowing, we can keep the ship upright by adjusting the heeling tank levels. If the officer of the watch thinks that this will not be enough, another ballast tank is being filled while the bridge continues to regulate the list with the heeling tanks.
We can do that with winds up to 50 to 55 knots full on the beam (that is severe storm)by the time we come to that limit, I will start to do things anyway as it is not a great idea to have those sort of winds blowing full beam on the ship. Even items that have been properly secured could come loose again and if the wind would continue to intensify then the ship would start to list while we would not be able to control it anymore. A listing passenger ship is not a great idea as the guests on board are not used to heeling floors and that could cause dangerous situations. (Except a few die hard yachtsmen, who might even enjoy it………….) If such winds are expected in an area, I will not go there or if I happen to be there, I will turn the nose into the wind and ride the storm until it abates.
However nothing of the above was needed. The bridge observed 35 knots for a short while, what we roughly expected, and then quite quickly the wind died down to almost zero again. That gave reason for a very warm day in Huatalco by the time we were docked. The sun was brightly shining and the temperature rose to the mid 90’s. I hope that all who were going ashore wore sufficient sun tan lotion, as the direct glare from the sun and the reflection from the water can cause sun burn quite quickly.
This was our evening call, put in the schedule to compensate for our cancelled call at Acapulco. The security forecasts for that area are still not good and thus I am not expecting that we will be returning to that port in the near future.
Tomorrow and the day after we are at sea, sailing along that long Mexican coast until we reach Cabo San Lucas on the 23rd. I have just been told that there will be two mega liners in, the Carnival Splendor and the Sapphire Princess and that means a busy, busy port day. Where have the days gone that there was only one cruise ship in whatever port you called at. At least the weather will be good, so that is one thing to be happy about.
November 22, 2011 at 1:13 am
Thanks for the detailed explanation of how you prepare the ship for Golfo de Tehuantepec – very interesting! I did not realise the lateral control that you have until I recently docked in Vigo, Spain and the Captain created a list to keep the gangways from becoming too steep.