Oh What Fun

Baldwinsville, NY
43 09.34 N 076 19.77 W

I haven't been blogging much for the past couple of days because we've been having so much fun and so many activities.

We had dinner with old dear friends Gerry and Phyllis.   Gerry and I go way back to 1962 as freshmen in the dormitory at Clarkson.  Thank you for the great evening.

Droid at quick draw

The next morning, our granddaughter Katelyn came on board to spend a few days with us.   She is such a pleasure to be around.    She's a beautiful, talented, well behaved and very thoughtful young woman.   She now prefers to be called Katie rather than Katelyn.  Name changes like that give me a particularly hard time.  My niece Lena changed her name to Ilan.  I've been struggling with that change for several years.

Anyhow, Katie, Libby and I have been having great fun.  Friday night, there was a free concert here in Baldwinsville.  They said it would be Led Zeppelin appearing.  Actually it was the Aerosmith Tribute Band –Draw The Line with Special Guests Kane and Mike Ryan Duo.   As you can imagine, there was a big crowd.   We moved Tarwathie as far away from the crowd and the noise as we could.  We could still hear the band just fine.




Last night was time for 4th of July fireworks over the water on the Seneca River.   Again, Libby and Katie stayed on the boat to avoid the crowd.  But I crave the up-close feeling of fireworks shock waves so I moved as close as I could.  I was a bit disappointed right up to the finale.  The finale, lasting perhaps 15 seconds was one of the best I've ever seen.   The final burst was pure art boom-boom-boom-boom-boom  boom-boom (shave and a haircut, two bits).

B'Ville Fireworks

However the real highlight of the weekend was ladies day with Libby and Katie.  Baldwinsville has lots of small shops, some of which are women's boutiques.   Libby gave Katie $30, and told her to spend it wisely.  She sure did.  After three hours, the two ladies came back to the boat.   Katie had a beautiful new hand bag.  More, she had presents for her mother, and sisters as well as herself.  They ate lunch in the famous B'ville Diner where Libby introduced Katie to those old-fashioned machines which let you select songs on the juke box from your table.

Of course, that was the high point from our point of view.  For Katie, it was the moment she discovered that she could get on her Facebook account with my computer, and using a free WiFi from somebody's nearby Linksys modem.   The low point was when I told her that I was out of text messages in my cell phone quota.  :)

Katelyn Marie (; <3

<3

Good Company

Brewerton, NY

44 14.33 N 076 08.50 N

Dean is a former work colleague and a friend.   A few years ago a mutual friend pointed Dean to this blog.  Dean loved it so much that he went all the way back to the beginning and read all the back posts.  That is getting harder every day.  This post is number 1805.   Anyhow, ever since Dean is one of our most loyal readers.    For several years, he has been trying to get together with us when we return to New York.  

Yesterday Dean finally succeeded.  We met his wife Esther and had dinner at their house in Camillus.  The four of us have so much in common that we had a delightful evening.  Thank you Dean and Esther.

Boat Lift Explained

Brewerton, NY
44 14.33 N 076 08.50 N

I've been getting questions about our error with the bridge and the mast.  I find it hard to explain without pictures.  Indeed, it makes me feel like an engineer again.  I should grab some chalk and go up to the board to explain for my students.  We'll do it digitally.

Figure 1

Consider first what I should have done as shown in figure 1.  The gray mast sits on a blue cradle that in turn sits on the blue boat.   The red rope stretches over purple pulley P and windlass W.  The Pulley is attached to the black bridge rail.  The windlass is attached to the blue boat.

Now  pull on the tail of the rope with 500 pounds of force.  Both the mast and the boat will be lifted with 500 pounds of force.  However the mast only weighs 500 while the boat weighs 20000.  The mast will begin to lift.

Figure 2

In Figure 2, we removed the pulley P and draped the rope over the bridge rail.  If the rail is frictionless, everything behaves the same as if the pulley was still there.  When lifting, the rope slides over the rail.

Figure 3

In Figure 3, now suppose that the rope binds on the bridge rail.  If it gets entirely stuck, we would have infinite friction.  It would be as if the two sections of the rope were each attached to separate bridge parts.   As I pull harder on the rope tail, the force lifting the boat increases, but none of that force transfers to the mast.  Instead of lifting the mast we are trying to pull the bridge down on the boat (as my friend Dean said) or lifting the boat up to the bridge.  I show that in Figure 3 as 500 pounds lifting force on the mast with 5000 pounds of force lifting the boat.

Of course if we lifted the boat as in Figure 3, we would also lift the mast with the boat. The force on the mast side of the rope would drop to zero.  But if that happened, it would relieve the friction on the rope and the rope would start sliding over the bridge rail again.  So the total reality was that we had some combination of Figures 2 and 3.   Both halves of the rope had some tension, but there was much more force lifting the boat than the mast.  The distribution of forces would have been irregular as the rope alternately slipped and caught on the bridge rail.

Such big complexities arising from such a simple change.  It makes one appreciate better that "rigger" is a skilled profession.  Riggers do heavy lifting.  It reminds me of the infamous failure of a walkway in 1981 at the Hyatt Regency Hotel in Kansas city.  114 people were killed. That too was caused by a seemingly trivial change in rigging that had enormous consequences.  See the article here.  Luckily for us the consequences were minor.  By the way, we did have the good sense to not stand under the mast.  If the rope snapped I think both Libby and I would not have been hurt.

KISS Principle Disproved

Brewerton, NY
44 14.33 N 076 08.50 N

We had fun last night having dinner with Steve and Barbara from Indian Hill Road, Oran, NY.  They are former neighbors.   Steve offered to help me recenter the mast but it was no good.  We couldn't budge it.  That made us nervous though.  All night, even a tiny wake from a passing boat made us fear that the mast would fall off the cradle and into the water.

Today, with forecast-ed thunderstorms approaching, we were determined to fix it ASAP.   We left the dock early with the following plan:

1. Find a highway bridge crossing the canal in a place with no wind and no current.
2. Loop a rope over the rail of the bridge and lower both ends of the rope to the water.
3. Move the boat under the rope.
4. Put a bowline in one end of the rope and use it to hoist our block and tackle into the air, then make the other end of the rope fast.
5. Use the block and tackle to lift the mast about two inches, push it back into place and lower it centered on the cradle, then retie the numerous safety lines that keep it from shifting.
6. Let go one end of the rope and pull the other end to remove the rope from the bridge.

Well, that's pretty much what we did.   We were successful.   Thank God, we feel secure again.  The more interesting story though is how I screwed it up.

We did the first three steps OK.  I used an old halyard, 100 feet long.  I had to ride my bike 3 miles from a place where I could step ashore to the bridge.  I looped the rope over a square guard rail with rounded edges.  It appeared to be plenty strong.  No problem.

When we got to step 4, I thought of a simpler way.  Skip the block and tackle.  Just put one end of the rope in a bowline around the mast and lead the other end to the anchor windlass.  That windlass is powerful and it could do the job.  No block and tackle would be needed.  That's the KISS principle isn't it?  Keep it simple stupid.  I regret that simplification.

As I cranked the anchor windlass, the rope became taught.  Then it got harder and harder to crank.  In low gear I have a mechanical advantage of 120:1.  To lift a 600 pound weight should need only 5 pounds of force on the windlass crank, right?  Well it didn't  it got harder and harder.  Worse, the mast didn't lift at all, not even a micro inch.   It got to the point that it took all my strength to crank.  I had to work at it 15-29 minutes and I was really bushed.  Finally, with a big creak, the mast lifted and we pulled it back to center. I couldn't believe how difficult it was. What the heck was wrong?

Now for the surprise.  Libby was tailing the rope and I told her to lower the mast as I held it centered with a bear hug.  The mast didn't move but Tarwathie disappeared from under my feet.  It turns out that we had lifted Tarwathie's bow out of the water about 18 inches!!! When Libby slackened the rope the mast satyed still, but Tarwathie lowered back to the water.

No wonder it was so hard.  I wasn't lifting 600 pounds, I lifted a big fraction of 20,000 pounds.

What happened?  I neglected friction of the rope on the rail.   Most of the force and effort went to the up half of the rope from the windlass to the bridge.  The down half of the rope from the bridge to the mast didn't have the same force because of friction at the rail. If I had stuck with the original plan using the block and tackle everything would have gone much simpler.  The KISS principle let me down.

Oh well, no harm done by my mistake, right?  Not quite.  When we retrieved the rope I found one spot that was severely damaged.  That must have been where it caught on the rail.  I'll never be able to use that halyard again. Oh well, only minor damage.

Before: The mast is at the edge of the cradle, ready to fall off.

Preparing to lift.  You see the rope thrice, once tied to the mast, again coming down to the anchor windlass, and a third time leading off to the right where Libby is tailing it.

Preparing to lift.  Now you can see the rig and the bridge.  Ignore the bridge navigation light and the horizontal power lines, in the background.

Job complete.  Everything back in place and safety lines retied.

Challenged

Oneida Lake
43 12.32 N 075 32.36 W

We just got all shook up.  Specifically, I was below working on this computer and Libby was on watch.  Suddenly the boat rocked violently.  The rocking increased in violence with each of the next three or four rolls.   All I could do was to hug the computer and try to prevent it from flying away.  All over the rest of the cabin things were flying through the air.  Never has Tarwathie been rocked so hard; not even out at sea in a gale.

When it subsided after 9-10 rolls, I heard Libby say, "DICK GET UP HERE QUICK!"  I rushed up.  Libby pointed forward.  The mast appeared to have hopped off the cradle.  It looked as if it was ready to fall overboard.

I rushed up, and asked Libby to come help.  We tried lifting the mast.  We needed only 1/4 inch of lift to slide it back into place.  No go. It is much too heavy for the two of us.  We couldn't lift even a millimeter.   We won't be able to put it back into place until we get help from 2-3 strong men.   We'll have to do that tied up to shore someplace.

Examining further. I see that it didn't slide all the way off.  The numerous safety lines I had tied all up and down the mast did the job.  They prevented it from moving too far.  The cradle was still supporting the weight, although the mast was on on edge, not on the side.  (see the picture I just took) I added a few more lines to prevent further motion and we continue on.

Jeez would I love to get my hands on the guy who caused the wake, or to file a police complaint.  Alas, we didn't get his name.   Libby said that he came very close, very fast and that he was so quiet that she didn't hear him approach.  &*)(^*%$^#@$%