Anchor snubber lines, shock absorbers in reality, offer a number of benefits and several potential problems. Let’s address the rigging first.
The ideal snubber will be made from a stretchy material (we favor three strand nylon), and long enough to provide plenty of give as the loads come on.
Because the snubber line is constantly moving in and out, it is prone to chafe, so a fair lead is essential.
Most of the snubbers we see are on the heavy side, limiting their stretch. For the average 35 to 45 footer we’d use 3/8″/10mm three strand nylon, assuming a non chafing lead.
On Wind Horse we have a 7/16″/11mm primary snubber that is 15 feet/4.5m long, and a secondary which is 3/4″/19mm and 50 feet/15mm long (for heavy weather).
Here is a recap of the advantages of snubbers:
- They reduce shock load on the anchor and deck fittings.
- Windlass is unloaded.
- Noise of the chain grinding on the bottom is reduced or eliminated.
- Increased comfort.
There are, however, several negatives:
- The noise they eliminate is an alarm the chain and possibly the anchor is moving.
- The rubber band effect increases the tendency to sail back and forth at anchor.
- Once rigged you cannot ease or retrieve the anchor without removal.
If we are in a secure anchorage, with a noisy bottom (lots of rocks), we will use a snubber. But in a location like Playa Francesa we prefer to do without.
Posted by Steve Dashew (January 31, 2011)
January 31st, 2011 at 12:39 pm
In adition to the snubber we also tie a second nylon line around the anchor chain between the windlass and the bow roller and cleat it off. This is used in case the snubber breaks the chain will not run off the windlass. Friends lost their boat in Fiji many years ago when the wind switched and a large fetch built exploding the snubber and all the chain ran out. Lost the boat on a reef. Some windlasses do not have a secure locking mechanism on them. Cheap insurance and it only takes another 30 seconds out of your anchoring time. This method may give us a few extra minutes if the snubber parts.
February 11th, 2011 at 7:46 pm
I have a friend who has taken this one step further. His snubber is connected to a bow eye at the waterline.
You can see how it works on his ship’s log at http://joana.ca/page28.php There is a description and a good photo about half way down the page.
I think this is only practical with a metal boat (his is steel) and has to be quite substantial material.
Cheers,
David
February 12th, 2011 at 10:13 am
Hi David:
We specified waterline tangs for snubbers for many years, on both fiberglass and metal boats. But we found we never used them ourselves (or rarely) and our owners didn’t either, so we stopped the practice. Still, if you put them to work, especially in a blow, they make sense.