Williwaws and other extreme conditions challenge Alaska pilots

Piloting in western Alaska has its unique aspects, but in the end the profession of piloting, wherever it is done, carries with it the same responsibility: It is a pilot’s job to guide ships into and out of port safely.

Oftentimes the pilot is required to do this under demanding and difficult conditions. In western Alaska, these conditions can include working in winds that sometimes blow in excess of 100 knots.

The Williwaws, powerful winter winds that come avalanching down the steep slopes of the surrounding mountains, are the worst. Forget about the normal physics of ship handling; they don’t work. Nothing goes right. Imagine being at work and the ship you are on no longer behaves in any conventional manner. Suddenly you are heeling over 10° as a wall of wind and snow crashes against the ship’s sides. Visibility drops to zero, and your vessel starts to move sideways like a giant crab. Everyone is scared.
In such a situation, confidence born from a life at sea is in strong demand on the bridge.

The semi-permanent winter and Aleutian low-pressure systems that form over eastern Siberia are some of the more challenging aspects of piloting ships in western Alaska. Beginning in October and continuing through March, these huge weather systems lick their lips and come pouncing down on the Aleutians, bringing with them one monster storm after another. The challenge during these months for a ship pilot, or anyone else who works on the waters of western Alaska, is not just making a living but staying alive.
A typical winter storm warning issued by the National Weather Service for the area would read something like this:

“Storm warning through tonight. Today, north wind 35 knots, increasing to 50 knots in the afternoon, increasing to 65 knots in the evening, with higher gusts through bays and passes. Seas 25 feet. Snow showers. Freezing spray.”

With such a forecast, the U.S. Coast Guard issues a severe weather advisory to all parties who have a stake in keeping commerce moving safely. In response to this document preparations are made to batten down the hatches and prepare for the worst.
Vessels moored along docks are secured with extra lines. In the designated anchorages, second anchors are often deployed. If the vessel is particularly vulnerable to the upcoming weather or the ship’s ground tackle is deemed to be insufficient, then these ships put to sea and heave to until the weather system passes. For those vessels that remain in port, cargo is shored up in case the vessel must proceed to sea during the storm. When a forecast calls for sustained winds in excess of 45 knots, all offshore cargo operations taking place at anchor are terminated and the vessels are separated for the duration of the storm.
Once everyone is tucked away, you would think the western Alaskan pilot could now recline cozily at the pilot station as the world comes crashing down. But we have learned not to be lulled into complacency. Oftentimes the wind blows with such force that stacks of shipping containers topple over. Waterspouts fill the harbor. Whole houses shake from the violent blasts of cold arctic air. Windows flex and bow, as if ready to explode. When it really gets to hooting, it is not unusual for a car or two to roll over or to see someone’s roof go blowing by.
A forecast of this intensity and direction is most problematic for the containerships berthed in Dutch Harbor. During one of these blows, a northwest wind coupled with the Williwaws that often accompany this wind direction will bodily shove these boxy beasts off the terminal face until their mooring lines begin to part. To avoid this, the trick is to know when to intervene. A case in point was the visit of Sealand Voyager to Dutch Harbor during a particularly nasty winter night several years ago.
Voyager is classified as a D-9J containership. At 845 feet long and 32,629 gross tons, by modern-day standards it isn’t considered a large ship. However, a vessel of this size can become a handful during hurricane-force winds.
By nighttime the winds had begun to blow in earnest. With sustained winds in excess of 50 knots out of the northwest with gusts approaching 100 knots, the wind alarm on the container crane had been sounding constantly, bringing cargo operations to a standstill.
In Dutch Harbor proper the containership terminal, or City Dock as it is known locally, is situated at the base of a steep mountain called Mt. Ballyhoo. As the winds built up on the windward side of this mountain, the Williwaws began tumbling down Ballyhoo’s southern face, causing Voyager to surge away from its berth.
Concerned for his vessel’s safety Voyager‘s captain radioed the pilots’ office to discuss the weather. With conditions in the port rapidly deteriorating, I recommended that the harbor’s only two tractor tugs be immediately dispatched to offset the effects of the colliding winds. When both tugs were alongside, they were instructed to commence pushing. After our conversation ended, I suited up in my winter gear and drove down to the ship to lend whatever assistance I could to ensure that Voyager would make it safely through the storm. On the bridge, the ship’s master and I watched as each wave of wind slammed into the side of his ship.

Measuring the impact of the storm, the master and I discussed whether we should leave port for the safety of the open sea. One of the factors was the prevailing conditions over the bar. Voyager‘s departure draft was 38 feet. The bar outside Dutch Harbor has a controlling depth of 42 feet. With 1 foot over mean lower than low water at the time of our discussion, we would have 5 feet of under-keel clearance. Or would we?
Of the three conditions of squat, heel and swell, squat was the only known quantity that could be figured accurately by formula. Realizing that any wrong combination of the other two conditions could easily eat up our “sleeve oil,” it was decided that the vessel would need to cross the bar making only the minimum amount of speed in order to maintain steerage. This precaution was taken to minimize any increase in draft that the ship might pick up as a result of excessive heeling or heavy swell conditions over the bar.
After we agreed that we could clear the bar with an acceptable margin of safety, I went on to explain that staying would involve several more hours of surging alongside the dock. Furthermore, with any increase in wind, the tugs would probably be unable to hold the ship alongside, at which point the mooring lines would begin to part. Recognizing the risks of trying to maneuver clear of the harbor with a ball of tangled and broken lines dangling off the stern, the master quickly agreed that we should depart the berth immediately.
Timing is everything in these conditions. Williwaws don’t blow steadily; instead they come in huge gusts. In spite of their wild and unruly nature, these gusts can be timed in much the same manner as a set of swells. Once the period of calm (relatively speaking) has been calculated between the blasts of wind, a known window of opportunity is  created.
Our window that night was about 10 minutes in duration: 10 minutes to let go 14 mooring lines and heave them all home isn’t much time. Careful coordination with the dock and deck crews was required to let go both ends of the ship simultaneously. This component of the evolution lent new definition to the meaning of “bridge team management,” as the entire undocking team had to work closely together in difficult conditions to accomplish this.
Once the ship was free from its moorings, with the wind on its beam, the ship breasted off easily from the dock. Shifting my attention back to the wind, I looked up the side of the mountain and could see that we had used up our 10 minutes as the next barrage of wind-driven snow was now rapidly advancing down the mountain toward us. Stopping the forward tug, I let the full force of the Williwaw hit the ship broadside. With the after tug now pushing full again to hold the stern up into the wind, the ship twisted around like a big wind vane as the bow fell off downwind.
 Once the wind was blowing directly on the stern, I began the process of regaining control of the ship using its own power. With the distance between the ship and the lee shore quickly closing, my next command was no longer just advisory in nature. The ship’s survival depended on this order being executed exactly as it was given. Skipping the range of softer bells, I called for half ahead to offset the effects of set and drift. When the captain questioned my order, I asked, “Captain, do you want to avoid an extremis situation?”
“Yes, of course,” he replied.

“Then please, half ahead.” Spoken in a calm, but loud enough voice to be heard over the shrieking winds, this command produced the desired results.

With engine speed now greater than ship speed, the vessel easily maneuvered around a long sand spit that hems in the harbor.
Once in the main shipping fairway, the last obstacle to be negotiated was the bar. Watching the fathometer, the captain and I shared a sense of relief. As the ship glided over the bar, we both noted that the ship had 2 full feet to spare under its keel. •


Capt. Peter Garay has spent the past 15 years of his career working as a state-licensed pilot on the waters of western Alaska.

By Professional Mariner Staff