T&T: 42 Present and "other" Taiwan boats

[Albin43SDtr]

'Lo All

I would be extremely cautious about removing the "false bilges" found 
on some boats.

The false bilge serves as a structural member on most boats that have 
them. It forms a triangular cross-section with the hull sides to help 
prevent hull flex. I would be very careful about totally removing 
this, without first making sure I was not destroying the ultimate 
integrity of the boat's hull. In benign waters, this loss probably 
would never be noticed, but in rough conditions, if the boat's 
strength is, in part, derived from this structure, resultant flexing 
could cause severe cracking or worse.

If I were to find that removal of all or part of it was necessary, I 
would make sure that the strength was not compromised. If removal of 
water was all that was necessary, a round, removable, inspection 
plate could be installed in the middle, as that should cause the 
minimum loss of overall strength.

If there is any doubt that removal of the false bilge floor is a 
problem, a simple check can be done. Attach a strong (not easily 
stretched) wire across the hull from one side to the other, where the 
removed section is. (If a large section was removed, several wires 
may be needed.) Secure one side so that it cannot move - wrap the 
wire around a strong screw. Clamp the other end of the wire under a 
piece of wood or something so that the wire can move only if pulled. 
Pull the wire taut across the area, leaving the end so that it can 
slip back under the clamp if there is any flexure. Mark the wire(s) 
on the inside of the clamp with a MagicMarker, a piece of tape or 
something such, to provide a reference mark. Go for a boat ride, 
taking some fairly large waves, such as your wake, the bigger the 
better, up to those that you may encounter when in really crappy 
weather. Check to see if the wire moved under the clamp. Hopefully, 
the wire did not move much, if any, but if it did, the structural 
integrity of the hull has been compromised. Further investigation 
would be required to ascertain how much. Remember, if the removed 
bilge floor section was still there, the hull could not have 
appreciably flexed at that point, as it would have pulled the floor 
section loose from the attachment to the hull.

Most boat builders, as almost all builders of anything, only use 
sufficient materials to make their products strong enough to meet 
anticipated/design requirements. They use various methods to meet 
these strength requirements while using the minimum of materials. The 
motivation can be for many objectives, such as weight reduction or 
cost. (I am always astounded at the strength of a box-sparred wooden 
airplane wing, or even a reinforced foam wing, for an example. 
Another example would be the frames of race cars.) Removal of any of 
the truly structural components will seriously compromise the 
ultimate strength.

JMHO - not that anyone asked.....

Take care and be safe.

Wayne
M/V Celestial
Albin43 Sundeck