Flying
July 18, 2011
The coming week or two promises to be exceptionally hot. Newspaper headlines are trumpeting an unusual heat wave across the nation. Pittsburgh has not been spared. However the winds this day were forecast to be strong and steady: 9 mph from the West South West. The river currents were low enough to be no bother at all. Here they are for the Allegheny, Mon, Yough and Ohio, with the last merely 7,110 cubic feet per second.
By now I was pretty confident that I knew what the wind conditions would be on the rivers. On the ride over I found what I expected: good steady winds of 6 mph from roughly the West on both the Allegheny and at the Ohio at the Point.
It was nearly 1 pm when I put into the Ohio downstream of the West End Bridge. There I'd expected a gently breeze blowing downstream. Instead I found fairly calm air, with the only motion a slight one upstream, opposite to the direction expected. It seemed to prudent to take what nature delivered, so I let that slight breeze slowly carry me upstream. It was hot--in the high 80Fs--and I was suffering. These temperatures are not onerous if there is wind. Without it, this poor sailor cooks. Only one thing saved me from misery: it was quite cloudy, so there was no direct sun.
Here's a photo as the boat approaches the West End Bridge. The water is glassy and the sail is as full as the light wind can make it on a slow run:
I then turned the camera back towards me:
Here's a close up of my sweating brow:
None of this made sense to me then; and I cannot make sense of it now. The actual wind conditions recorded were:
Around 1pm there was a 13 mph wind blowing from the SSW. I'd expected this to break through the valley at the West End Bridge and be seen on the river as a breeze blowing downstream.
It took about 25 minutes until I reached the Point. Then everything changed. From then on, the wind conditions on the rivers were pretty much exactly as I'd come to expect. With South Westerly winds, both the Ohio and Mon will be shielded and the winds will be erratic there. However, they will blow steadily up the Allegheny.
When I arrived at the Point around 1:15 pm, the wind just suddenly picked up and blew me steadily up the Allegheny. The story can be seen in the gps plots.
The change is most visible in the second plot, color coded for speed. I've run slowly from my start in the top left corned. (The track is the straighter one, representing a run with the wind behind the sailboat.) The speeds are slow: red, yellow, orange, green, which means 0-3 mph. Then, at the Point, the line turns blue, and I am sailing at a happy 5-6 mph.
I took these winds up to the Convention Center. It was encouraging to see the flags on the Center. When the winds are variable, this row of flags tend to flap in all direction. Here they were all pointing upstream.
There I docked for a sailor's lunch: a melted protein bar, soy nuts and lots of water.
The rest of the afternoon was just delightful sailing. I measured a steady wind of at least 6mph on the water, blowing up the Allegheny. I tacked into that wind. It was steady enough for me to start to hike out--lean out over the edge of the gunwale to balance a heavily laden sail.
From time to time, the windward hull of the boat would lift out of the water. This is "flying a hull" and is the way caramarans are supposed to achieve their best speeds, for now the water resists only one of the two hulls. I'm not sure it made much difference to this catamaran. When one hull flies, the other tends to bury itself in the water. That surely offsets any gain from the flying hull.
All in all, it was perfect sailing. I could keep steady speeds throughout, moving everywhere from 3-6 mph, as I navigated under bridges and past the magnificent downtown skyline.
I tacked all the way to the Southern shore of the Ohio at the Point. The winds were strong there, now. I could see a large barge, coming up the Mon. I didn't know where it would go. Perhaps it might turn up the Allegheny? I was not confident that the steady winds would persist this close to the Western shore. So I sailed well out of the way over to the Northern shore under Heinz Field. There I furled my sail, drifted and watched as the huge monster lumbered in and docked on the Southern shore. It seemed to be carrying parts of a recently demolished, steel girder bridge.
The winds on the Allegheny were clearly the best, so I sailed back up the Allegheny, almost to the Sixth Street Bridge; and then repeated the experience. How wonderful!
Since I now knew that the winds were steady, it seems prudent to keep exploring. So I decided to sail a little up the Mon to see what the winds there were like. The gps tracks suggest stable winds. But they were not so stable. They blew roughly downstream. I sailed on a run just past the Fort Pitt Bridge and then tacked back. It was tough going, with occasional gusts and short calms.
I paused under the Fort Pitt Bridge for some water (it was still hot) and to put on more sunscreen:
I freed myself from the Mon by sailing very close to the Point. I help up my camera and clicked as I sailed past the Point:
Just past the Point, I looked upstream and could see a river boat approaching:
I'd now been out for over two hours and was getting tired. The weather forecast had called for thunderstorms after 4pm. So it was time to head home. With South Westerly winds, I expected the winds to be funneled into the Ohio at the valley aligned with the West End Bridge.
That is just what I found, as the gps tracks show. Approaching that valley, I tacked into the wind, following it as it turned. Then, with the valley on my port, I sailed on a fast beam reach past the valley. Finally, the wind from the valley is behind me as I run quickly home to the Newport Marina.
It seemed to me that I was feeling stronger gusts in the last hour or so. The recorded winds affirmed that. They had dropped around 2-3pm but were freshening by 4pm to 12 mph, WSW.
The predicted storm came at 4:30pm, with dark clouds and lightning. Yet, it all seemed to be North of the Point and no rain came until much later.
John D. Norton
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