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.