Trip 161 - Tuesday - April 19th

 

Just went down to check things out. And to go for a car ride - somewhere.

 

Herman, our adopted Rat. Waiting patiently on top of my printer for more adventurous times. However, he does giggle a bit when printing long documents. I sense he likes the vibration on that massive backside of his. Must be like the twenty five cent "Vibro-Massage" mattresses in those cheap hotels by the highway out on some lonely road.

Did you ever try one? Marcia and I have. Someplace on a desolate hotel stop in Arkansas. Someplace.

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Some of you have wondered how a folding prop works.

I will try to explain.

First off, both blades swivel on pins set in the hub. Then, within the hub, each blade has a gear that meshes with the other blade. When one blade moves, that forces the other to move as well. Some cheaper props do not gear both blades to work in harmony and if one blade does not match the other, some serious vibration results in an out of balance situation.

When underway, and the boat is moving, water resistance against them, forces them to close fully against each other. Then, the boat speed is improved as, the water resistance on the prop is minimal.

When the engine starts and the shaft starts to rotate, centrifugal force spins the suckers around the shaft and they fling out from the folded position.

Then, as the pitch of the blade starts to bite the water, that force against the blade pushes the blade wide open against the hub, as the boat is propelled forward.

In reverse, the blades fling out again, but the resistance is on the opposite side of the blade so it can not open fully as it did going forward. But, in reverse, that is not as important unless one is going to ram the dock.

The blades and hub is made from marine bronze. It tarnishes and does get some algae etc, but by and large, marine growth does not like the taste of this type of bronze. Plus, even is immersed for a hundred years, it will look just as good then, as now.

Howzzatt?

 

Waiting patiently ...

 

Later ...