How often does a cleat snap?

[Goosebumps]

Originally Posted by Rapanui

Itvis extremely difficult to break a cleat if the load is parallel to the deck. However, more and more and especially on cats the cleats are fitted on an incline so the load is inclined vertically to the long axis of the cleat which imposes bending loads on the cleat and reports of failures. Similarly, even if the cleat is fitted horizontally, if there is a lot of rope on the cleat and the load is applied obliquely in the horizontal plane then the cleat can twist and break. Thats what fairleads are designed to obviate

I remember the shocking little stainless steel cleats on a jaguar cat in Cape Town, positioned on the side of the hull ready to be pulled out! Also Maxim cats with same. If you see a cat with such serious fkawed deck tackle forget even looking inside of it if you think of buying it. i have a. catalac and the cleats are oversized,or so i thought untll years of liveaboard on the hook made me realize the cleats cant be strong and large enough.

[deblen]

Originally Posted by hamburking

I have seen this several times at my marina...always the same cause...short dock lines.

Dock lines must be LONG LINES.

A long dock line allows the boat to travel up and down on waves (or wakes) without pulling on the line. Also, a long line is a good "spring", it can absorb and release energy smoothly, without damage.

I recall the most recent time when a power boat had broken both its bow and stern cleats and was somewhat adrift. I helped the owner get the boat back to the dock, where he asked..."now what do I tie my dock line to on the boat?" I suggested he turn the boat around and use the cleats on the other side, to which he replied "Those broke off last time".

A quick walk around my marina and I can find lots of boats with docklines which are almost cleat to bollard, less than 2' of line. This creates huge stresses, totally unecessarily.

Agree 100%. Bow & stern lines should be tied to dock at least 1/2 boat length beyond bow & stern & farther if there is significant tidal rise & fall. Set springs in same manner.
Cheers / Len

[thinwater]

a. We're talking about broken cleats. Backing plates are quite valid but off-topic.

b. 4Winds. The sping line went from the deck cleat to the chock, and then doubled back to the dock cleat, approximately amidships? That puts a terrible strain on a chock. Why didn't you use a midships cleat? FAR less stress.

c. I would agree with Hamburking that short lines were to blame. That is what I was getting at with the question "which bow." On cats, unless you lead the bowline to the outside bow the line is very short, because the sides have less curve than a mono. On the other hand, if you go to the outside, you get a nice long line and good tide adjustment too.

I know that you can get jerking at a dock FAR worse than any jerks at anchor, and that should be an OBVIOUS sign the the forces are far higher. A=F/M, and acceleration is what you feel. Stopping 10 tons of yacht in a few inches is rough.

[TeddyDiver]

Originally Posted by msrcal36

I agree regarding backing plates, a MUST to spread the potentially huge load. Deck cleats (oversized) of bronze or stainless steel are my answer. On our Cal 36 (12,000 lbs) I installed 10 inch ss Herrshoff by Bosun Supplies: Stainless Steel Blue Water Cleat | Bosun Supplies. Our Moody 42 PH ketch (25,000 lbs) was equipped with 12 inch bronze. I look at deck cleats and ask what is the worst it can take then go one size bigger. Dock line should fail before my cleat does. $0.02

Sounds a bit small.. for the Moody I'd choose 14'/35cm. 12'/30cm is spot on for Cal36.

[svlamorocha]

Originally Posted by hamburking

Dock lines must be LONG LINES.

A long dock line allows the boat to travel up and down on waves (or wakes) without pulling on the line. Also, a long line is a good "spring", it can absorb and release energy smoothly, without damage.
(snip)
A quick walk around my marina and I can find lots of boats with docklines which are almost cleat to bollard, less than 2' of line. This creates huge stresses, totally unecessarily.

Spot on.

Moreover, in addition to the "more length means more shock absorption" argument explained above you also have consider that slack in the lines lets the lines align themselves with the force to be transmitted. If the lines are short and have no slack then you may end up in a situation where the lines transmitting the wind/wave force are aligned 75 degrees away from the direction of the force, which means that the force of the line is 4 times bigger than it needs to be.

This explains why a structural or mechanical engineer (who understands this) will typically not like short lines between an amidships cleat and a dock cleat/bollard. That is the usual situation of cleat damage induced by a short line that is also in the wrong angle.

[nelsmay]

About fourwinds post and photo. I had the same thing happen to a chock on my boat two years ago. Fairly strong winds coming into the bay I was docked in (25 kms/hr +). Bow line and spring line running through the same chock and back to the port side cleat, at a similiar sharp angle. I think it may, in part have been caused by the sharp angle around the chock, which I believe increased the load back to the cleat (much as a pulley would create a lever effect). So, after replacing the cleat, I sharted running my docking lines through the chock, across my bow to opposite side cleats. Less of a turn for the spring line back to the midship cleat on the dock. I believe it helps reduce the load on the chock somewhat.

[nelsmay]

ps. I also added snubbers to the bow lines.

[noelex 77]

This is the way cleats should be done on a cruising boat:



The under-deck reinforcment is even more important.

[thinwater]

A common problem with davits is that the stern lines will cross where the dingy hangs. In my case the solution was a carabiner and sling down low on the side of the stern sections, which deflects the line under the dingy. I've seen odd cleat locations intended to resolve this sort of issue, but not all of the solutions were good.



(This is now a wire-gate carabiner; regular biners freeze up, but the wire gate has been there for 7 years)

This solution is also easier on the line than most chocks since it follows the angle. Chafe gear can bunch-up, but Maxijacket is great.

[Beausoleil]

Originally Posted by four winds

To add to my post #3.

It was a 15 foot spring line secured to a piling alongside amidship that snapped my chock.

A parade of tournament sportfishers (50-70 footers) blasted past the docks about 50' off that wrecked havoc on the docks and boats. Probably more than a dozen boats suffered damage. Plus a few pilings snapped or were pulled free.

As far as I know, not a single captain took responsibility for their wake damage.

Assume no one got the names of the boats when it happened? Both US local and federal, and Canadian maritime laws say you're responsible for damage caused by your wake, even when out of no-wake zones.

[Lepke]

Companies that build boats do so with a price range in mind. So do the makers of marine hardware. While you generally get what you pay for, no builder or hardware maker is doing the worst case scenario. They wouldn't be competitive. It is up to the owner/operator to judge if the vessels design and equipment is up to the task and repair or replace as necessary.
I often see yachts getting better equipped after some adventure.

[micah719]

Which loading would be worse: surge at a dock or a tow in rough water?

[GrahamHO]

If the load is more or less in line with the cleat it should never fail, in its designed use. If the load is at right angles to the cleat it can more easily fail. Proper mooring lines or nylon lines are slightly elastic and absorb the shock. Dacron or Spectra etc are very strong. They are not at all elastic, like steel cable, and can create a shock load and should not be used for mooring.

I use proper heavy lines designed for mooring. As I understand they have a nylon core with a polyester sheath on the outside. The nylon provides elasticity and the polyester cover protects the nylon from UV.

Having spring lines as you did was good, especially if you can rig them fore and aft from the centre on each side. Not always possible I know but they greatly absorb the shock loading on the bow and stern lines.


Even when a boat is moored it still tries to rotate around its centre of lateral resistance which is around about the centre of the keel. Having spring line cleats on the gunwale near that location dampens down that yawing, jerking, motion.



The guy with the yacht moored in the marina berth next to mine is a ships master. His stern lines go to the usual stern cleat and then around a sheet winch and then fwd to another big cleat normally used for his headsail sheets. It's a sheltered mooring but we still had 70 knot winds through there July (winter) last year from the most exposed direction. All OK except the name on my boat top sides was rubbed on the marina wheel. It must have heeled 30 or 40 degrees to do that. The floating ring around the pile on the exposed corner must have ridden up the pile to allow that.


There can be great forces at work.

[old pirate]

Only once,,,,,,,,,,,,,,, then you throw it away !

[adlib2]

I've had a couple of 12in Aluminum Cleats snap, but never a stainless steel cleat. More common for Beneteaus, Hunters, Catalina cleats pull out the deck.
Some years ago I installed a 6in Stainless Sampson Post on the foredeck to relieve the aluminum cleats and have replaced some aluminum cleats with stainless. Haven't had a problem for many years in spite of a few hurricanes.