There's the Rub
Every boat, no matter how big or small, is the sum of its parts, and even on the smallest boat there are plenty of parts. Each fitting, cringle, turnbuckle or block is there for a reason. Any piece of sailing hardware that is not perfect for the job, not well maintained and not perfectly aligned for its task could be creating friction. Because friction makes you work harder and harms your boat’s performance, it pays to take a long, hard look around your boat to see where and how you can make it function as smoothly as possible.
Let’s start with something so basic as to be almost laughable. Before you start spending money on new blocks and lines, take care of the ones you already have by rinsing the boat down with fresh water after each sail. Over time, tiny salt particles slowly build up and impede the smooth operation of your blocks and pulleys. Douse each and every block and fitting with a jet of fresh water to remove all salt residue, and your blocks will start working like they did when they were new. The same applies to lines and halyards. Over time salt crystals build up between the fibers, and the lines get stiff as they fatigue, making them harder to handle. It’s a good idea to run the halyards completely out of the mast (leaving messengers in their place) and soak them in buckets of fresh water. I even go so far as to add fabric softener to the water to really make sure my lines are soft and supple. You will be amazed at how much it reduces friction.
Beyond ridding your boat of salt and crud, if you’re on a mission to reduce the overall amount of friction you encounter in your sailhandling systems you need to take a good look at three areas: blocks, lines and your deck layout.
Modern blocks are light, immensely strong and versatile. They fall into three main categories: plain bearing, ball bearing and roller bearing. Deciding which type is suitable for which application is key in reducing friction. Plain bearing blocks are simple and inexpensive, and typically have bearing surfaces of a low-friction composite like Delrin (also used in ball or roller bearings) running in stainless steel races. Ball bearing blocks have been around for years, but roller bearings are relatively new, at least for sailors. These small cylindrical bearings are used in highly loaded blocks such as those used on mainsheets and genoa sheet cars. In a ball bearing block, the load is transmitted from the outer race of the block to the inner race via the balls. There is only a small contact area between the ball and the race, and the balls may deform under sustained high loads, which is why blocks for bigger boats have stainless steel ball bearings. Roller bearings are cylindrical in shape, and the contact area between the outer and inner race of the block is not a point, but a line. This spreads the load over a larger area, allowing the block to handle much heavier loads.
If you’ve decided you need to replace some or all of your blocks, start with those handling highly loaded lines like halyards, genoa sheets and mainsheet tackle. If you rarely reef then leave the mainsail halyard blocks until last. If you are constantly setting and dousing your spinnaker make sure these blocks are among the first to be changed.
The way a block is secured in place is almost as important as the type of bearing it has. Specifically, it must articulate so that the line enters and leaves the block at the correct angle to avoid touching the inside of the block’s cheek. Often, a block shackled to a toerail won’t be able to move enough to ensure a fair lead as the line exits the sheave.
The latest trend filtering down from racing boats to cruisers is the use of “soft” attachments, like a lashing of low-stretch Dyneema line or Kevlar webbing instead of a metal shackle. This little trick really helps your sheets and halyards run smoothly. If you are a confirmed shackle user, take a close look at the way shackles restrict the articulation of your blocks. Put your lines under tension and get up close to the blocks to check that the line runs freely around the sheave without rubbing on the block’s sides, or cheeks. You’d be surprised at how much friction this can cause.
The size of your blocks also has a direct bearing on friction. Friction increases as load increases, and loads increase proportional to the angle of the line around the sheave. For example, a line that is only deflected a small amount as it passes through a sheave will put little load on the block and therefore generate little friction, but a line return angle of 180 degrees puts nearly twice the load on the block as is on the line, with a commensurate increase in friction. To give you an example, a sheave that turns a line 30 degrees experiences only 52 percent of the load on the line, while a sheave that turns a line 90 degrees experiences 141 percent of the load. The tighter the turn, the higher the load and the greater the friction, so if you’re buying new blocks, make them bigger.
You can greatly reduce the amount of friction on board by replacing your old lines with new high-modulus lines. Rope technology has changed dramatically, and in many cases it’s possible to swap out a halyard or sheet with a smaller-diameter line that can carry an equal or greater load; less surface area means less friction. Take a close look at your running rigging and you’ll likely find numerous places where a halyard or sheet can be changed out for a thinner, lighter, stronger line. This will eliminate a significant amount of friction. Your new smaller diameter lines may slip in your rope clutches, though, especially if they pre-date the 1990s.
The last piece of the puzzle is your boat’s deck layout. You will be amazed at how many areas can be improved with some simple changes. Many sailors like their lines led aft to the cockpit so that sail changes are easier, but the trade-off is the number of twists and turns the line takes on its way aft, with friction increasing at every turn. Again, the sharper the angle, the higher the load and the greater the friction. Make a concerted effort to reduce the number of blocks you use, and avoid having lines make sharp angled turns.
Deck organizers are a good way to run a number of lines aft. An organizer keeps the lines neat and free from chafing against each other, but it must be raised up enough so that the lines do not touch the deck and installed so that lines enter and exit without touching the side of the sheaves or the organizer frame. Get down close and look carefully to make sure your lines are not chafing against the side or top of the organizer or block
All in all, your goal should be to simplify deck hardware or get rid of it altogether to keep your deck clean and uncluttered. Many lines will happily run through fairleads or “bullseyes,” instead of large blocks. Slippery anodized alloy “donuts,” like the low friction rings made by Antal, have a very smooth finish and can be a fine substitute for blocks, especially if the line deflection is not too great or the loads are not too high. On smaller, low-powered boats like daysailers or trailer sailers, these rings can fulfill most of the functions of a bearing block. Switching to simpler gear provides the added advantage of reducing weight.
Finally let’s not forget the old standby: lubricants. Products like McLube’s One Drop added to your ball bearing blocks not only help reduce friction, but also repel salt, sand and other deposits that can clog up bearings.
If you step back from your boat, size up all aspects of it, think through the mechanics of each working line, attempt to simplify systems and be creative and careful in the way you lead your lines, you can greatly reduce the amount of friction and, as a result, greatly improve your boat’s performance.