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View Full Version : Anchor roller/ bowsprite



Kaladar
08-21-2006, 08:07 AM
I would like to add an anchor roller to the front of my Sam Devlin Dipper and was wondering if anyone had a nice design for the wood support piece. I was thinking of perhaps oak with epoxy? Thanks
http://www.devlinboat.com/dipper.gif

donald branscom
08-21-2006, 05:58 PM
Keep it as short as possible.
Glue will not hold it. It will have to be through bolted.
Just make a weldment and bolt it to the breast plate.
You could just skip the oak.
When the bow is bouncing up and down the force applied is multiplied times 1000 for every foot it sticks out. Think about that.
The best deal is to have a short piece of 3 strand nylon attached to
the bow near the waterline on the stem. (can't remember the name at the moment) The other end of the short line should have a chain hook attached to it. If you have all chain. That way the forces will be pulling from down low.
I was a welder for many years and have seen many bow sprits bent.
The West Marine type stuff is not good. There should be something beefy to keep the line on the roller when the bow goes down. Like a bail. The Marine store type stuff is too small. Use some thick plate (3/16) bent into a U shape Get a roller made for line. If its ALL chain the roller should be made for rope and chain. IT is important that where the line exits the roller that the side plates curve outwards and back so the line will not get chaffed. Because or unless you keep a mizzen type sail up at the rear of the boat the boat will drift around the anchor line and when looking down at the anchor line from the deck you will see that the line goes out of the roller and back towards the back of the boat. Thats why its good to hank on a small 10 square foot triangular sail onto the backstay to keep the boat pulling on the anchor from the proper direction instead of drifting all around the anchor. You can use some sail scraps or a old surfboard sail.
The very best design bow roller is a thick pipe (2 inches diameter) bent into or welded into a "U" shape as close to the width of the sheave/roller as possible,so that the line cannot get caught between the roller and the side support.
That way the line will not chaffe. You will sleep very well.
Remember nylon line is best with about 10 feet of chain on the end.
The coast guard has lost boats that had two all chain rodes and anchors. When they used nylon with chain it survived because it could stretch and absorb some of the shock.
I will try to make a drawing and post it soon. Qiuck SKETCH below
http://i8.tinypic.com/2589fs1.jpg

Kaladar
08-22-2006, 03:03 AM
Thanks Donald, much appreciated.