Journal Entry 10.26.01

From: Gabriel Warren

October 26 2001.
1956 hrs.
Aboard the CCGS Louis S.St-Laurent
74 Deg. 24.7 Min. N, 085 Deg. 22.5 Min. W
Course 085 Degrees true, Speed 7.4 knots
Sky: clear. Wind NW, 10 knots. -18.7C (-1.7F)

We left Resolute Bay this morning at exactly 0800, heading east to our rendez-vous with the MV 'Arctic' , the bulk carrier which we are to escort into the 'Polaris' mine on 'LCI'-- Little Cornwallis Island. By 0900 the ship was banging and bouncing a bit, and by 1000 the going was heavy indeed at the southern end of the Wellington Channel where ice discharges ihnto Lancaster Sound.The machinery was working hard to keep us moving. Although I watched from the bridge, I could see in my 'mind's eye' what was going on below, since we had recently had a tour of the engine rooms and machinery spaces.

Most commercial ships-- tankers, container ships, bulk carriers, etc.-- have one HUGE engine and one HUGE screw (propeller). This minimizes construction and maintenance costs. This ship has a different job to do, and requires flexibility, versatility, and the ability to function despite equipment failures, which will happen from time to time. So, this ship has three shafts instead of one. Each shaft is about two feet through, and is turned by an enormous electric motor-- electric motors are very reliable since they have very few moving parts. These motors are the size of a room, a cube about 4 meters (12') on a side.The electricity to run them is provided by five engine / generator sets, which total about 27,000 horsepower. As the ice gets tougher, more electricity is needed, so more engines are started. This system is called 'diesel-electric'-- some railway locomotives use it too.

Another reason why it is a good idea to power the shafts with electric motors is that they will not be damaged if really strong ice stops the screw. On the other hand, if the shaft is powered by an engine, through a reduction gear and transmission-- alll mechanical parts-- and the shaft is stopped suddenly, something is likely to break.

The electricity is managed through a huge bank of computer controlled switching gear-- the heart of the engineers world. A large room is filled with lights and dials and meters and so on. It is very, very complicated.

Other engines provide 'ship service' electricity for lights, and everything else that needs it. Heat is provided by two big boilers that use the same fuel as the engines. Each one is about ten feet across and twenty tall. There is also another 'genset'-- engine-generator combination-- high up in the ship, for emergencies. If the main engine rooms are flooded, this will provide enough electricity to keep some pumps running, and power the radiotelephones. I hope I don't get to see it used for real.

Usually, you want a ship to have lots of cargo space, be stable in rough seas, and be as inexpensive as possible; icebreakers have different requirements, so their hulls have different shapes. To do their job, icebreakers are shaped like half a football. They ride up over ice and force it down, snapping it. The resulting ice cakes are turned on their sides as the hull slides past. In open water, though, icebreakers roll from side to side a great deal, since they are not somewhat square-shaped like cargo boats. They are nicknamed 'polar rollers'.

The hulls are also built very, very strongly. This one has 18" of solid steel at the stem, the part that will bump the ice first. It is nice to know that when you hit a hard piece of old, tough ice, and the whole ship rolls to one side, shears off course, or even stops.

Icebreaking technique is fairly simple in principle, but you still have to know a lot to run any ship, and more to run one of these. Basically, the ship is simply powerful enough to push her way along, forcing the ice out of the way. As the ice slides along the hull, some of it will get into the screws, which grind it up like a giant cuisinart. This is called 'milling'. It makes a lot of noise, and the whole ship shakes. If you are making a channel for another ship to follow, the smaller pieces make it easier for them. In really heavy ice, you might have to back up and charge a tough spot a few times to blast through. You have to be very careful in reverse not to damage the rudder, so it must be put amidships first.

In variable ice, the kind we see here, you look for weaker spots, thinner and younger ice. In ice of even thickness, like I have seen in the Antarctic, you either have enough horsepower or you don't-- pretty straightforward. Some icebreakers use 'trim tanks' to change the way the ship floats in the water to help free her if she gets pinched, by rocking her from side to side or fore and aft. This one doesn't. Many times, the skill in running an icebreaker isn't tactical-- whether to steer around this or that cake, how to power the screws and so on-- but strategic: descisions based on where was the heavy ice in previous years, what have the winds been doing and what is the forecast, what do you know about ice conditions from satellite, plane patrol, and your own helos, and information of that type. The best way to deal with proplem ice is not to get into it in the first place.

Like on any boat or ship, it is crucial that things be checked over and over, and then used with care. Things that break are never good at sea, but especially so here and at this time of year. We can't call the Coast Guard if we get into trouble: we ARE the Coast Guard.

GW