Bow Roller Extension for Rocna

Hawk Brewer 12.8 

Michael A. Smolek  March, 2017

 

I recently heard a horror story about the damage done by an anchor that was poorly secured and became unseated from the bow roller in heavy weather.  The damage was severe as the loose anchor frolicked about the bow with each diving wave.  This got me thinking about my newly purchased 55 lbs. Rocna and the wide surfaces that these new generation anchors present to oncoming seas. I clearly needed more than tension from the windlass on the chain, and more than a small lashing to make sure that the Rocna stayed home in the bow roller.  Besides needing to keep the anchor snugged against the roller, I also needed to eliminate the prodigious side-to-side wobble of the anchor.  Since I didn’t want to make major, permanent changes to the existing roller or fabricate a new design to fit just one type and size of anchor, I wanted any modifications to be removable and changeable.

After considering several different and complex changes, I arrived at what I believe to be a pretty simple solution.  It doesn’t look too awful either.  I purchased some ¼”x 4” SS stock (www.OnlineMetals.com) and I cut and bolted on an extension to allow a ½” retaining pin to fit through the trip line hole in the anchor shank.  I attached the extensions using the two existing ½” holes in the sides of the roller, which I assume are present on many of the Brewers (?).    I was able to create the extension with basic power tools.  I sanded and buffed the original mill finish, because I couldn’t readily find, and probably would not have paid for, a small piece of 4” two-sided mirror-finish SS stock.

To attach the side extensions, I used standard SS hex head ½” bolts with the heads inward. While carriage bolts would provide a smoother path for the chain, I didn’t want to make permanent changes and the carriage bolts would have required tediously squaring the existing holes. The outside nuts are acorn nuts. To keep the anchor retaining pin from going swimming, I attached the pin with a small cable through a small hole in a bent fender washer under an outside nut.  Being attached outside the roller, it is more likely that the pin will stay away from the action of letting out chain

With the pin in place, there is much less rocking of the anchor from side to side, but there is still some because the hole on the anchor shank is 5/8” and the pin is only ½”.   The scrap pile of my local machine shop provided a short piece of black nylon rod which I drilled and cut to create spacers between the anchor shank and roller walls. The black nylon rod is a larger diameter than really needed, but it is what they had in their scrap pile.  Some PVC pipe, dowel or wood blocks would have worked as spacers also. To keep the spacers under control when inserting and when not in use, I screwed them to a piece of U-shaped stainless.  I attached this spacer assembly with a cable as well.    The system seems to work well and it will be easy to modify or change. 

 SS bar stock cut and drilled

SS bar stock cut and drilled for installation as an extension to the roller sides to hold the anchor in place.

 

Extension bolted in place

Extension bolted in place with the pin installed through anchor shank.  The U-shaped nylon spacer  assembly is lying uninstalled on the roller frame.

 

Anchor with the U shaped spacer

Anchor with the U-shaped spacer assembly in place.