Sep 26, 2013 I used a Windline URM-3 Large Anchor Roller Mount. It did not come pre drilled mounting holes. I drilled the bow roller base and had a piece of 1/4' aluminum plate clamped underneath so the 4 holes would line up with the plate. I used 1/2' stainless bolts and bolted through the deck and used the aluminum plate underneath for support. Very nice installation on a sailboat. The windlass is hidden below the anchor locker hatch. The black and silver ring holds a bowsprit for an asymmetric spinnaker.

This section is intended for those designing a new vessel or bow roller assembly, or those willing to heavily modify an existing set-up should it be considered inadequate. It provides ideas and concepts with a mind toward creating the 'ideal' anchor roller set-up, particularly for a Rocna. Concepts and illustrations below are only recommendations. Please note that we do not provide design, drawing, or CAD services. We can however assist you or your nominated designer with any queries, including the provision of patterns and plans for the anchor size(s) required.

Comments on prefabricated roller units are also provided. Contents • • • • • • • • • The ideal roller for a Rocna The ideal set-up for a Rocna involves orienting the anchor in order it will self-launch, and come home without fuss, and then be stowed securely on the bow. A number of elements are involved. The roller(s) A single roller would ideally match the radius of the inside curve of the anchor's shank. A smaller roller is also fine, as the shape of the Rocna's shank is designed to prevent vertical motion so long as it is pulled aft securely. So long as the anchor is restrained fore-and-aft, it will not be able to move at all in any dimension. However, the larger roller will better deal with lateral rocking, and also present better behavior of both the anchor and chain during deployment and retrieval (the will also be more greatly stressed when pulling chain over a small roller).

If matching to a particular Rocna, we suggest that the roller is as large as possible up to a maximum diameter equaling double the radius of the inside curve of the anchor's shank, as outlined in the below table. Jurnal Stoikiometry. Maximum ideal roller diameter Size Rocna Original Rocna Fisherman 4 (9 lb) 40 mm 40 mm 6 (13 lb) 50 mm 50 mm 10 (22 lb) 75 mm - 15 (33 lb) 90 mm - 20 (44 lb) 100 mm - 25 (55 lb) 100 mm - 33 (73 lb) 100 mm - 40 (88 lb) 110 mm - 55 (121 lb) 130 mm - 70 (154 lb) 150 mm - 110 (243 lb) 150 mm - Dual rollers can be employed in some cases, and a secondary roller aft of the primary can assist with self-launching and retrieval behavior; and guidance of the chain down to a main roller hung below the deck-line.

If matching to a particular Rocna, we suggest as above that the forward roller is as large as possible, and that the secondary roller - which may be smaller - is positioned back roughly one third of the distance to the end of the shank. They would be vertically positioned so that the aft upper line of the shank is horizontal when the anchor is home. Roller design Roller sizing is discussed above. The profile of the roller should ideally be grooved such that it accommodates the chain, with a central groove for vertically aligned links, and a wider space for the alternate horizontal links. This will provide ideal behavior from the chain during deployment and retrieval, and help avoid twisting and similar problems.