You are looking here at the top of the raw water take stand pipe. The clear plastic lid provides a view of what is going on inside. If you suck up a large plastic bag or clump of weed, remove the plug and a mop handle can be used to clear the debris. This lid is above the load waterline so in smooth water no leakage should occur with the plug removed.
Posted by Steve Dashew (January 29, 2010)
January 29th, 2010 at 8:43 am
Hi Steve,
I have a question regarding the standpipe. On Dutch ships standpipes seem to be the timeproven, standard practice. However my question is: How will they work on boats travelling at higher speeds? Is there a risk of a Venturieffect, creating a negative pressure in the pipe or is the pipe meeting the bottomplate at an angle less than 90 deg. (leaning aft so to speak?)
Reg.
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Steve Dashew Reply:
January 29th, 2010 at 9:52 am
Hi Nils:
Our experience is that with designs like the FPB, where the standpipe is well below the waterline and speeds are moderate, the standpipe works well. Even the with FPB 83 surfing at 20+ knots we have not had negative pressure issues.
However, on some of our sailing designs, I am thinking here about Beouwlf, at high speeds under sail or motorsailing, the salt water manifold can be sucked dry by the negative pressure on the hull – with the engine running! This is a function of the light displacement and high Froude numbers.
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