Day 223, Standing rigging, measurements and Dyneema rigging planning, Boat became documented

Mast

My son to the top of the mast

This weekend me and son spent to measure all tings on the mast. Goal was to get all what we may need to make setup for switching to synthetic ropes.

Plan is keep forestay in SS all other shrouds and stay replace with Caligo DUX Dyneema.

Here is the standing rigging measurements table for Irwin 34 78' here.

A lot of information in the table including all mast dimensions starting of mast height, and up to diameter of each clevis pin.

Link

Some basic measurements here:

I am looking to make custom parts to terminate stay on the boat. At least mast side connections and spreader ends will be custom.

Most fun part to design - Spreader ends terminal.

Boat has non-continuous shrouds connected on the ends of spreader.

Originally it was kind of chainplates

It is good for steel ropes, but not so nice synthetic. I decided to make special shaped speader cup providing as most reliable connection between two parts of cap shroud, avoid small bend radius, ropes friction between each other, making bending force to the end of spreader, make forces me joining in the center and boat holding the cap on the spreader is going thought this point.

Ended up with two interlocking splice ends twisted against each other like shown below

Then I designed cap with integrated tumbles to to follow the form.

Same part, different angle of view

Shrouds to mast connections.

Original connections

Straight forward for steel, but cam be made easier for synthetic.

I designed tilted thimbles made in my rigging angles and having curved surface in contact with the mast.

Cap shrouds to mast connector

Secondary has bigger angle

Secondary shrouds to mast connector

Using these terminators will avoid several parts and simplify (make more reliable) solution, as well minimize amount of stainless steel contacting the mast.

Most hard to design - spreader root connection.

Original connection

Here I spent a lot of time to invent way HOW TO DO IT.

I ended with idea to do splicing "in place" literally push each lower shroud through both slots and over the spreader root and splice them below the spreader.

To prevent chafing and provide some bend radius (it appeared 1:4.4 instead of recommended) but I convinced myself it will be ok to lost 10-20% of strength here.

Design.

Idea to make insert to guide ropes and better distribute load from ropes to spreader root. Currently clots in the root are 10.5mm I will need to file them to 12 mm width (1.5mm on one side), to be able to insert connector.