Today a little story about how the St. Lawrence river with it’s current dictates the cruise schedule and how it can affect the docking time in Montreal and Quebec. Sailing to Quebec from Montreal and also towards Montreal is regulated by the time that the ship can pass under the bridge at Quebec. The Veendam is 46.3 meters high above the water and the bridge has a clearance of 50 meters above chart datum. Chart datum means, the imaginary level that is used as zero. Heights start above this line, depths start under this line. The tide on the St. Lawrence river coming from the sea, reaches past this bridge and reduces the clearance under the bridge. Also the water level sustained by the water brought down can add to this. If heavy rainfall occurs upstream, then it severly affects the window of opportunity for pasing under the bridge. Thus the pilots calculate the times when due to the ebbing, the water level drops sufficiently that the ship can pass under the bridge. Some ships, such as our Vista Class, or the Queen Mary 2, are too big in principle and can not pass under the bridge at all. The Veendam can, but only at half tide or low tide. This can play havoc with the cruise schedule, if low tide is late in the morning, or way before sailing time. This could mean that instead of a normal arrival of 8 am. the ship would only be able to dock at noon time in Quebec. Same with going up river to Montreal. We have to be on time there, due to the flights from the disembarking guests and that could mean cutting the call at Quebec short. This time I could pass any time after 03h06 in the morning, so I set the bridge time for 05.00 hrs. and that meant docked by 06.30 in Quebec with an official 08.00 arrival time. The 05.00 am was choosing as that is the regular time that the sailors start working each day, so all arrival work would fall in their regular hours.
The approach to the dock is also depending on the tide. If the current is flooding, that is going towards Montreal, than the ships dock portside alongside. Is the tide ebbing, that is going towards open sea, then the ships dock sb alongside. This is done so that the bow of the ship always heads into the current, which makes it easier to control the vessel. Unfortenately on departure the ship might have to make a 360o turn if the heading of the ship is opposite to the intended direction of sailing. I would have preferred to dock portside alongside, during this call, so on departure the Veendam would already be pointing to open sea.
But this was not to be. The ebbing current was still too strong according to the pilots. In the middle of the river there was over 5 knots and at the dock more then 2 knots. Thus we made a big turn, starting close to the south shore and heading across the river to the North shore. While doing that the ship gets the ebbing current full on the beam and drifts considerably down stream. We started the turn, half a mile above our docking location and by the time that we had the bow into the current, we had drifted over a mile downstream. This manuevre is done by the pilot. The moment the ship is lined up, approx. 300 feet off the dock, the captain takes over and brings the ship alongside.
The trick with such a current running, is use the current to push the ship slowly towards the dock. By using the bowthruster you can keep the current just on the port bow or just on the sb bow and in thus control the speed of the push to the dock. The ships propellors are used to keep the ship in position abeam the dock where the final location will be. Ships that have no thrusters use tugboats to get the same effect. Docking at the passenger terminal in Quebec is a bit special, as due to the shoreside gangway, we have to dock on the inch. The gangway location is fixed and so the ship has to be parked in the exact position so that this gangway fits into the hull opening. The saying, docking on the inch, is quite true here. We had once again a glorious day, with constant sunshine and no wind.
Tomorrow we go further down river to visit Saguenay again.
Note: dear readers, for some unknown reason some of your comments disappear directly into the spam box of the web manager and I can not get them out of it. If you do not see you comment appearing at the bottom of the blog entry the next day: please re-enter. I do not censure any comments but do filter out emails about viagra etc………………
September 24, 2007 at 7:57 pm
Captain – It’s simply AMAZING how close everything is! You really are docking your ship inch-to-inch. I’m SO impressed. Thank you for this very detailed explanation.
And approximately 12ft. clearance under the bridge – it must be quite a sight to be driving across that bridge when a beautiful ship like Veendam is sailing underneath, so close.
susan