PS Advisor May 15, 2000 Issue

PS Advisor

Cleat Strength
I am upgrading the anchoring system on my Morgan 382. So far, Iíve installed a 5/16" chain rode with a 45# CQR. By paying close attention to load limits and ultimate strengths, Iíve been able to purchase component parts with similar ratings, including shackles, swivel and some nylon at the end of the chain should I ever need to cut the rode free in a hurry.

Iíve upgraded the bow rollers, beefed up the windlass installation and have finally reached the end of the project, literally, the cleats. The original cleats are two-bolt horn cleats mounted on top of the bulwarks. Two 5/16" bolts donít seem ďbeefyĒ enough, so Iím looking for four-bolt bronze cleats to mount securely on the deck, to better distribute the heavy loads.

The problem is that I canít find any strength data on cleats. It would be unfortunate if, after having carefully matched all the components for strength, I ended up with cleats not strong enough. One of the best methods for determining what equipment is strong enough is to look at commercial boats. They donít mess around! However, in this case, their massive bitts and welded-on cleats donít help me much. Can you?

Jim McEntyre
Kona, Hawaii

As with anchors, there are at any given moment sailors in every time zone whittling patterns for new cleat designs. But when tug comes to yank, the cleat sailors depend on is the good old horned version.

It can be a fat finger of teak, ironwood or lignum vitae mounted in two cast bronze rings with mounting feet; these are favored in Europe and they are handsome.

It can be open-based (with lots of room to tie fenders and a pull-rope), a slimmed down mid-section, tapered ends and very thick legs accommodating in each foot a pair of flathead machine screws. Sometimes called a Herreshoff cleat (West Marine calls them ďyacht cleatsĒ), they come in stainless or bronze.

A cleat also can be a two-bolt closed or open base casting of chrome-plated zinc or Zamak. Thereís also a teardrop-shaped thing that looks like a hood ornament on a car. Thereís even one of these plated cleats that looks like the Herreshoff cleat, and it costs more than stainless ones.

As for strength, a stainless Herreshoff cleat (especially powerful are Wichardís forged versions, in either stainless or bronze) contains a lot of metal, especially in the legs. The tensile strength of the cross-sectional metal could be calculated, but it would exceed that of the fasteners. So, it becomes the strength of the fasteners that is the issue.

And thatís why the four-bolt versions shine.

A good quality #10 stainless machine screw has a breaking strength in excess of 6,000 lbs. A #12 goes about 7,750 lbs.

So, an 8" Herreshoff cleat, stainless or bronze, with four feet containing four #12s, with a good backing plate and generous washers, yields a breaking strength of about 30,000 pounds!

As a practical matter, the size of cleat to buy is determined mostly by the amount of line you intend to belay on it. A 4" cleat with four #8 fasteners may well be strong enough, but a 10" cleat will take a lot more turnsóand there are times when it will be expected to handle two, three or even more lines.

Because you mentioned cleats plural in your question and want bronze, weíd suggest a couple of Wichard 6" #1362BRs, each with four #10 bronze or stainless fasteners treated with an anti-seize compound. In the West Marine catalog, they go for $13.99 each. Bronze fasteners and washers? If you canít find them on the islands, you can get them from Jamestown Distributors, 28 Narragansett, Jamestown, RI 02835, 800/423-0030, fax 800/423-0542.

Comments (1)

So - I recently heard that as a general rule, cleat size should be 16 times the diameter of the line held. Example, 5/8" line needs a 10" cleat...sound right?

Posted by: Unknown | October 29, 2014 11:01 AM    Report this comment

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