Friday, August 07, 2009

This screw isn't loose!


As of today, I have a new propeller on the Vereeniging, although now I am more used to the Dutch word Schroef or just screw. When the ship was on the slipway on May we had the old screw adjusted in the hopes of improving its almost nonexistent reversing capabilities.

It didn't help at all as was evidenced by our getting grounded on the slipway when we were supposed to be leaving it (I don't think I mentioned that incident before, did I? Ah well, it was a bit embarrassing). So, after doing some calculations, I decided to bite the bullet and order a new propeller. We've had it a while but this week has been the first opportunity to put it on, as due to a mix up, no one was occupying the helling.

This morning, Koos, with Craig's willing help, fitted it, so voila! Below and above are photos of both the old and the new. The one with Momo is the old propeller. I'll update this later when I know how it has performed. Keep your fingers crossed, though. It was quite an investment!


This is the old one after it had been remounted following adjustment.



And this is the new one! It seems these bigger blades will make all the difference...I do hope so.

Update

Well our trip back to the mooring was not really a good test, but I have to say I was a bit disappointed. I really really hope that when we get a chance to test it again, it will prove to be more effective. If not, well, that will be quite a heap of euros sunk into harbour...

11 comments:

  1. Good luck with it, hope everything goes well!

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  2. Yes indeed, good luck with it all. guess there is nothing like a good screw to prop you up. eke did I just write that?

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  3. Aw, I am sorry the trip didn't go so well. I sure hope the next test proves better.
    lol I have to laugh at Lesleys comment!

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  4. Oh Lesley, very good!! You've given me a good chuckle!

    Thanks Grace, and yes, as you can see, I had to laugh at Lesley's comment too ;-)

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  5. Hey maaa, sorry it was a dissapointment. Maybe the motor needs some adjustments too, cars often need tuning so that they perform optimally, so perhaps this is the case here too?

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  6. Oy, Val. I hope further tests work things out for you.

    xx
    AM

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  7. Wow... Reminds me I have to do maintenance on the screw on my dinghy as well. Screved it up (hi!) last Saturday while reversing into a gravel bank close to my summer house. :(
    One blade got slightly bent out of line and is now causing a lot of cavitation.
    Larger blade area will increase the efficiency when driving slow or when reversing but will cause a larger drag when running at marching speed and may prevent you from reaching optimal rpm:s
    That can be compensated by reducing the pitch to an amount where you again can reach optimum rpm at the engine.
    I can imagine it was a heavy investment, my propeller cost multiple Euros two years ago and your screw seems to be twice the diameter of mine and would be 4 times more expensive. Talking 4-digit sums here...

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  8. Hans, thanks so much for all that technical information. I had no idea! In any event, I asked about it and apparently it has been made taking the pitch into account and the size is apparently correct for my ship and my engine so in theory, it should operate well. We'll just have to wait till the next test round. And by the way, you are right about the cost!

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  9. Fingers duly crossed, breath held...

    That is one big propeller!
    It makes our boat's prop look like a mere toy.
    Eugene rents a commercial space to a marine and boat repair outfit, and you wouldn't believe the shape some of some of the propellers that get brought in there. They look like they have been chewed up by metal-eating iron men.
    I really don't think a lot of people know they have/had a propeller on their boats!

    Good luck and I hope you get to give Vereeniging's upgrade a true test soon!

    xx

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  10. So, in The Netherlands, in order to, let's say, put a piece of art on the wall, you have to propeller it into place?

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  11. LOL Dale, you might just say that, yes ;-)

    I wish we could bring the Hennie H over there to Eugene's space.....

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