What is a snubber anyway?
Using a rope snubber on an all-chain anchor rode
A what? You thought your ground tackle was complete, right? You can get away without using a snubber if you have line on your boat roller (which will act as a snubber). Otherwise, you will be sleeping with a ‘Bang’ , ‘Bang’ , ‘Bang’ every time your boat swings from one side to another. If you sleep in your V-berth, I’m sure you know what I’m talking about :). Beside the noise, it will also protect your windlass and reduce the load on the anchor chain.
A snubber is a device that act as a shock absorber and will prevent that banging noise from your chain on the bow roller. If you don’t believe me, on the Rocna website (which is also a more in-depth article about snubbers), it’s described as follow:
Snubbers reduce or eliminate noisy ‘chain rumble’ and noise which travels as vibrations up the chain. This sound can otherwise be quite severe in the forepeak or forward berths of a boat. On the other hand, while some boaters find this irritating, this noise can also provide feedback regarding what the chain and anchor is doing on the seabed.
Because of its elasticity/stretch and high breaking strength, 3-strand nylon is a good option for a snubber. A snubber can be as inexpensive as a piece of nylon or you can spend more money for a more sophisticated set-up.
According to the Practical Sailor, double-braid or brait nylon is even better for snubber (something I just learned today!) as it is less prone to chafe.
Snubber diameter and length
There are a lot of articles out there that will explain how you should calculate the maximum absorption energy your snubber should be able to sustain to determine your snubber size. But, as a rule of thumb, your snubber diameter should be:
Snubber diameter = Displacement (in lbs) ^0.4 x 0.00832
So, for a sailboat with a displacement of 13,000 lbs, the snubber diameter calculated is 0.37 in or 3/8″.
For a double-legged snubber, the line diameter should be 70%. So, it would be: 3/8″ x 70% = 1/4″.
And a snubber length would be:
Snubber length = 1.3 x boat length
You can use the calculator below to get a snubber length and diameter quickly.
So, for a 35 ft sailboat, the snubber length calculated is 46 ft.
I use this great article as a reference for the above calculations.
Tie up a piece of nylon to your chain using a rolling hitch knot (animatedknots.com is your friend!) and let out the necessary length usually 10ft in shallow waters and fair weather and secure on a cleat on your boat (ideally lined up with your bow roller if one leg or going through bow chock if double-legged). Rocna points out that a rolling-hitch is much better than a hook because it doesn’t wear the chain and will spread the load over multiple links of chain rather than putting strain on a single link.
DIY snubber: Spliced nylon line with hook
This website describes how to make your own snubber using nylon lines and a hook (see picture below). They also sell it on their website.
This snubber consists of:
- a two 3-strand nylon lines:
- one long line: 2 to 3 times the height of bow
- one short line: 1 time the height of bow
- a thimble:
- use either galvanized steel or stainless but build your entire setup with the same material to avoid corrosion!
- it should be the same size as your 3-strand nylon line
- a shackle (optional) – same material as the thimble (one size up than your thimble)
- a grab hook (same size as your anchor chain an same material as thimble and/or shackle)
Make an eye splice to the end of both the long and short lines (animatedknots.com is still your friend!) to secure to your port and starboard cleats. Then splice these two lines together a distance about equal the height of bow (or freeboard). So you you will have one long snubber with 2 eye loops. Hang on, you’re almost done: splice a thimble to the end of the long snubber with a grab hook (similar to this snubber) OR use a shackle to attach a grab hook and connect it to your thimble.
I’ve actually never made a snubber like this so I’m trying to be as accurate as possible but can’t guarantee of the performance of such a set up. It is used widely around in anchorages.
Or, rather than improving your splicing skills (and trusting them!), you could treat yourself with a fancy snubber. Mantus sells nice ones similar to the spliced nylon line with hook with additional chafe protection
Now that you have you anchor, chain and snubber, you can go out, anchor out and sleep well at anchor! Stay tuned for our next article about ‘Anchoring tips’.