When it comes to selecting an anchor rode for your cruising yacht, you will be faced with a multitude of choices. To begin, we will separate two main groups of options: Dock candy (which has no practical use) and real ground tackle.
Dock candy is anything stainless steel. This can be in the form of a polished stainless steel anchor, or even worse, polished stainless steel chain! Stainless steel polishes to a beautiful mirror finish that makes the bow of your boat glisten in the sun, therefore, it should be thought of as Dock Candy and nothing more.
Stainless steel suffers from two main problems, work hardening and crevice corrosion. The cyclical loading of the anchor rode will lead to work hardening which will make the metal brittle and break. Crevice corrosion will cause your precious anchor or chain to simply fail catastrophically and with little warning.
If weakness and brittleness were not enough of a reason to ward away from stainless steel ground tackle, there is one other reason: Cost!
For example, 5/16 BBB galvanized chain costs $6.19 per foot. The same chain in stainless steel costs $29.99. This makes the price of a 300 foot rode skyrocket from $1,857 to $8,997. That is a $7,140 price jump for some shiny chain! Anchors are the same scenario, with a 65 pound Mantus Anchor made of galvanized steel costing $619.99, while the stainless steel version costs $1,479.99! An $860 price jump.
The same ground tackle setup would cost $2,476.99 in galvanized steel or $10,476.99!
Needless to say, the only reason you would buy a more expensive but less reliable ground tackle is because it is shiny and looks pretty while you walk past it on the pier.
So, now that we have ruled out stainless steel options, we can look at the real options for ground tackle, which are the three main grades of galvanized steel chain.
The bottom, but old standard is BBB, also referred to as Grade 3 or Grade 30. This chain is the weakest and heaviest of the chains, but when it was first introduced, it was rather revolutionary. It is made of regular low carbon steel and can be safely re-galvanized over its lifetime. The chain derives its strength from simply making each link rediculously thick and hefty.
The next tier is the first HT chain, referred to as Grade 4, Grade 40, or Grade 43. This chain is heat treated, giving it more strength for the same size, allowing you to use a smaller chain and still have the required strength.
The top tier is the next level of HT chain, referred to as Grade 7 or Grade 70. This chain is heat treated through a strenuous process which makes it very strong for its weight and then allows you to use an even smaller link for the same strength requirement. Being how the heat treatment process is so crucial to its strength, re-galvanizing the chain can reduce its strength as the heat of the process can damage the links ever so slightly.
While all this information is fun to have, it isn't very useful without a way to draw it into the real world. Luckily, the world of chain anchor rodes has a very real application, the bow of your yacht!
For our examples, we will be looking at rodes of the standard cruising length of 300 feet.
If we need a rode that can withstand 4,000 pounds, the our options would be as follows:
300 feet of 1/2 BBB
Weight: 840 pounds
Strength: 4,500 pounds
Cost: $2,460 ($1,731*)
Safety Factor: 4x
300 feet of 3/8 G4
Weight: 450 pounds
Strength: 5,400 pounds
Cost: $1,917 ($1,536*)
Safety Factor: 3x
300 feet of 5/16 G7
Strength: 4,700 pounds
Cost: $1,947 ($1,170*)
Safety Factor: 3x
*When you buy items from marine chandlers in large quantities, they will usually give you a discount. This should be your target number to aim for in your negotiation. If you can get it down lower, great, but at least try to get it to this level.
As you can see, BBB chain is considered to be an inexpensive chain, but the links need to be very large to support the load, and you end up purchasing a very large and heavy chain that costs a lot of money. As you move up to Grade 4, you can see that you are able to go down a link size. The same occurs as you move up to Grade 7. While the chain is more expensive per foot in the same link size as you move up in grade, the increased strength lets you go down a link size and save on the smaller chain. It should be noted though that the higher grade chains use a smaller safety factor than BBB does, but these chains are still very strong by comparison.
Not only do you save on money, but you also save on weight!
The switch from 1/2 BBB to 5/16 G7 saves 540 pounds of weight in anchor rode and also saves around $530 in the process as well!
When choosing an anchor rode, don't be put off by the higher cost per foot of the higher grade chains because you might actually find that you are able to save money and weight by going with the fancier galvanized chain!