Sunday, January 19, 2025

Tillerating

 Anchor Locker

In a previous episode the anchor locker was featured in a paint primer state.  It has since been finished as you are soon to see.


This is view into the anchor locker with the anchor roller assembly to the left.  An over center latch, in the upper right, hooks onto the anchor chain to secure the anchor while stowed.  The cleat in the lower right serves as a backup securing point for the anchor rode (line) while anchored.  The anchor rode is attached to an anchor bridle extending from each bow as the primary attachment points.  Such an arrangement is necessary on catamarans to keep the boat from slewing back and fort relative to the wind.


   The anchor locker lid is hinged at two points so that it folds in half towards the aft end.  Two latches are installed adjacent to the center hinge ends to prevent the locker from being blown or washed open.


Above is the installed anchor locker with a nonskid lid surface.  I'm torn between really liking it and thinking it might be over the top.

 Swim Ladder/Cat Walk


Side rails are install on either side of the swim ladder.  These rails will serve as attachment points for the aft trampolines.  Hardware is installed on the rail, after crossbeam and ladder to raise or lower the ladder from the cockpit. 

Tillers


Now that the hurricane season has passed, the sun shade is re-erected.  The rudders are lashed onto the hulls to support the cantilevered tiller arms.  The tiller arms are reinforced with lashings fore and aft of the rudder heads.  The tiller bar joins the tiller arm ends at a comfortable arm rest height in the cockpit.


As with the crossbeams, the rudders are lashed to the hulls.  The rudder lashing are in a figure 8 pattern to form an effective hinge.


As the boat goes through a turn, the outside rudder travels through a larger radius circle than the inside rudder.  This requires a difference in deflection for the inside and outside rudders.  The geometry of curved tiller arms achieve this deflection differential.  This is similar to the steering on an automobile. 

The tiller arms are constructed of two lengths of 3/4" thick mahogany joined together at the cockpit end.  The 3/4" thick material is too stiff to readily bend so thinner laminations are used.  Blocks are screwed to the work table to clamp the arms into the desired shape as the epoxy sets.


The tiller bar pivots on pins installed in the tiller arm ends.  The pins must be inclined at the same angle as the rudder hinge angle in order to function without binding or breaking.  This was accomplished by drilling through a mahogany block at a square angle. The blocks were then cut at the required hinge angle before the blocks were epoxied to the arms.  The holes then served as a drilling guide to continue the holes into the tiller arms.  The heads were cut off two bolts and rounded over to serve as pivot pins when epoxied into the drilled holes.

The tiller arms are the only exterior components I have not sheathed in fiberglass.  It might have taken better than a week to complete such a process and I might have ended up with tiller arms that would no longer fit on the rudders.  The mahogany, two coats of epoxy and five coats of paint should offer good enough protection from the elements for a number of years.