2016.07.13 - Samson Post Support
Having three fairly hefty beams for the foredeck is probably a bit over the top. Two sightly smaller ones would probably have done the job were it not for the samson post. On Naiad this is a piece of oak 3" square and long enough to extend from the bottom of the hull on the inside, up through the foredeck and extending about 6" above the deck. It is used to attach mooring ropes and to serve as the attachment point for the anchor chain when anchored. It has to be able to take a fair deal of strain. If the boat is pitching up and down in stormy weather whilst anchored or attached to a mooring buoy the rope or chain will snatch constantly on the samson post and if it is not well supported you can lose the boat when the foredeck breaks open.
So, the forward two beams are just far enough apart to slide the samson post between them and two short connecting beams will be added so that the samson post is supported on all four sides. The beams are strongly tied to the beam shelf and hull and there will be additional strengthening due to the foredeck as well. Hopefully that will be more than sufficient.
Once the beams are in place I will make the samson post since once the foredeck is in place it will be virtually impossible for me to cut the mortice in the keel. To make the samson post I now need to buy a new power plane. I've not needed one until now but the prospect of trying to plane the oak beam down from 3" a the point just under the deck beams to 2" at the foot by hand is a "pleasure" I will respectfully decline.
Here you can see two of the three foredeck beams now in place.
The third beam has been laid on the hull in the position that it will be fitted, more or less.
This is where the samson post will go. The oak is too long at the moment and will taper down to about 2" square at the bottom and there will be a tenon cut on the bottom which will fit in to a mortice cut into the keel. The mortice will be no more than an inch deep but that will be a sufficient restraint given the leverage. To stop the samson post from lifting out I will drill 10mm hole through the two beams and the samson post for a long bolt.