Regarding the discussion on Alado furlers in the February 1, 2004issue, Aladocanada, the Canadian agent, has a separate website. The contact is www.aladocanada.ca.
With regard to the comments about the manual, the criticism is just and constructive. The manual does need more diagrams showing installation as it progresses, although we have had few complaints. The factory is aware of the issue and we expect the next rewrite will address this matter. One minor correction: The Canadian website on the specification page does include a numbered parts diagram.
-Don at Aladocanada
A one-sail roller-furling rig is a lazy man's step away from sailing. Based on my experience, a large overlapping roller-furling headsail is not conducive to sailing your boat smartly. Such a rig is expensive, has a narrow range of efficiency, discourages needed sail changes, and is more likely to encourage motoring. A full-foretriangle, hanked-on working jib with light- and heavy-air alternatives (a somewhat classic cruise inventory) is time- and sea-tested, easy to sail with, safe, efficient, and economical. A three- headsail system is so easy it will even work for an over-65 sailor like me.
The primary sail is a Dacron hanked-on full-foretriangle, self-tacking (or not) jib. This sail always remains hanked-on to the headstay, and when not in use gets stuffed in a bag, still hanked-on. This is your 6- to 20-knot sail, always there and ready to go. If you are worried about getting it down in a blow, rig a downhaul line to the cockpit and learn how to drop it across the foredeck while hove-to.
The second sail is one that will not be used often, but when needed will put the boats with furlers to shame. This sail should be a heavy-duty oversized storm jib with a pendant at its tack long enough to set the sail above the hanked-on primary jib, which in heavy wind is either tied to the lifelines or in its bag tied to the pulpit. This sail is usually small enough that even an old man can crawl up to the bow and hank it on.
The third sail for light air and downwind use is a 2-oz. nylon ripstop material, full hoist, 140-150% overlap jib, with fewer hanks than would ordinarily be used on a sail of this size. This sail, because it is nylon and light, is easy to stuff into a bag or down a hatch.
In summary, if you are going to sail, why not put in the small amount of effort to do it well?
Great job summing up the furlers. One detail that should be clarified regarding the Furlex jib furling: You mentioned that we "only" use righting moment when specifying which Furlex fits the boat. Primarily we look at headstay diameter, length, and pin size, just like everyone else. What we can do is calculate the righting moment at 30 degrees if needed, to make an educated decision.
Take, for example, the Pearson 10M—a 33-foot boat that has a 3/8" forestay. Most 33-foot boats have a 1/4" forestay, or maybe a 5/16" forestay. Using the beam, ballast, draft, and displacement of the boat, we can calculate the righting moment, which tells us the rig loads to expect at 30 degrees heel. In this case, the Pearson 10M can comfortably move into a 5/16" wire.
Keep up the good work!
Selden Mast, Inc.
Fixed vs. Variable
The description by Steve Resser (Mailport, February 1, 2004) confuses propeller pitch with pitch angle and further compounds the confusion over variable pitch.
Pitch is the linear distance through which a propeller would theoretically move forward through the water in one complete revolution if the water were solid, not allowing for slip. In boat propellers it is measured in inches. Because the tip of the propeller blade moves farther in one revolution than the blade at the hub, efficiency is improved by building a twist into the blade so that the angle between the blade and the plane of the propeller's rotation is shallower at the tip than at the hub.
In the case of the solid propellers that most of us use, the pitch of the propeller is constant from hub to tip, but the pitch angle (the angle of the pressure face of the blade with the plane of rotation) decreases from the blade root to the tip.
There are many other variables in propeller design, including blade shape, the shape of the foil cross-section used in the blade. One of those variables in solid propellers relates to pitch. There are, for example, progressive-pitch propellers, with the pitch increasing along the radial line from leading edge to trailing edge; regressive pitch, with the pitch decreasing along the radial line from leading edge to trailing edge, and even variable pitch in the sense that Captain Resser uses the word.
But it is not only ignorant boaters who use the term differently. A quick Google search confirms that variable- pitch propellers are most commonly defined as "propellers for which the angle of the blades is adjustable."
In aviation, there seems to be widespread agreement that propellers are classified as to whether the blade pitch is fixed or variable. Variable propellers are classified as to whether the pitch is adjustable (that is, by a mechanic) or controllable by mechanical means during flight.
By Captain Resser's use of the term, flat-bladed feathering propellers such as those by Max-Prop and Martec, are variable-pitch propellers because the pitch angle remains constant along the length of the blade, making the actual pitch different at each point. By the more commonly used criteria, Max-Prop and Martec propellers are variable-pitch propellers because their pitch can be changed by adjustment.
For most of us, propeller design and selection is a bit of a mystery. The mystery is compounded by terminological confusion. But it is not unprecedented in nautical terminology to use a single word to mean quite different things.
I suggest that we adopt the aviation terminology described above, which probably corresponds to the way most of us use the terms. Solid propellers with no provision for changing the pitch are "fixed-pitch" propellers. Whatever the pitch structure of these propellers (progressive, regressive, or variable), the structure remains fixed. Propellers whose pitch can be altered or adjusted can properly be called "variable-pitch" propellers. They include two subcategories: adjustable (can be changed, but not necessarily easily) and controllable (can be changed by using mechanical means, either manual or automatic while the boat or ship is making way).
Captain, U.S. Navy (Ret.)
We received other letters about this from Ken Dunipace, Charles G. Fischer, and John Vigor. Captain Cox does a good job of providing a set of definitions (from the aviation world) that we should all get used to.
I just got my February 1 issue of Practical Sailor, and I must strongly disagree with your reply to Tony Smith regarding hand signals between the anchorer and the helmsperson (PS Advisor).
My advice is to forget the hand signals entirely, because they just don't work very well. Besides, the anchorer needs both hands to do his job. Moreover, the helmsperson needs to be cognizant of other things going on about the boat and not just staring at the anchorer's hand signals. What to do? Spend only a few dollars for a set of walkie talkies, the kind you wear on your head. They are voice-activated and powered by a small battery pack worn on the belt. Find them at places like Radio Shack or even a toy store. Now you can talk in a normal tone of voice, give direction, discuss options, and really look cool making that ancorage or approaching the mooring. I've also found this helpful at night or in a fog by having crew on deck or standing in the bow hatch where they can see better and hear better away from the engine noise.
You will only think this is silly or unnecessary until you try it.
We were anchored in a quiet but beautiful cove one tranquil early evening, at peace with everything, when a really well-varnished picture- beautiful yacht glided in, with an immaculately dressed couple on board, the man at the bow, ready to drop an anchor, the woman at the helm waiting for his signals. No voice would disturb their tranquility as they efficiently set about anchoring for the night.
He signaled and finally dropped the anchor. He signaled and the boat glided aft, but the anchor didn't catch. Another set of signals and again no set. A repeat and again no set. Once again, no set, but he was now wet, mud-splattered, and arm-weary.
This time he raised his voice and shouted directions as they glided towards the rocky shore. Fifty feet from the rocks he wheeled around, a curse on his lips, unuttered as he realized that she had left and gone below.
He dashed madly for the helm, stopped the boat, and motored out of the cove.
I found your tests of bilge pumps (February 15) very informative, but I think you failed to draw a significant conclusion that can be taken from an evaluation of the data. Not only is the capacity of the pump significant, but how long the pump can continue to deliver its capacity from the available battery power can also be very important, particularly if the pump is protecting an unattended boat or the engine is not running.
I took your data and calculated the gallons per volt-ampere-hour at both 12.2 volts and 13.6 volts, and then sorted them [in Excel] from lowest to highest at 12.2 volts. In most cases the same results would have occurred if it was sorted at 13.6 volts. The difference in energy consumption between pumps is impressively large. In general, the Attwood pumps were the best performers.
There were a few things I still wanted to know after reading the bilge pumpcomparison in the February 15, 2004 issue. Dimensions of the pumps would have been useful, especially for those with limited space. I chose a pump for my last boat based partly on this criterion. I also wanted one that would fit through a 4" access port in the cabin sole for easy access. The Attwoodwas considerably shorter than the comparable Rule. I picked the largest(V900) that fit through the port. Easy access for cleaning. I used a clear access port. The pump is pretty easy to find that way. The clear cover also serves as a spare for the vent port on the foredeck. I like redundancy.
I think it's interesting to look at the gallons-per-amp-hour for the various pumps. How much water you can move for a given amount of powerconsumption might be as important as maximum rate, maybe more for some. I made an Excel table with this information, based on the data in your table. When sorted by my GPAH value, the Attwoods are consistently at the high end of the GPAH scale.
You made good points about the wire on the pumps and using 14+ feet in your test is a good real-world comparison. I think it would be useful to mention that keeping the wire leads as short as possible will help the performance of these pumps by decreasing voltage drop.
DIY Refrigeration Fan
I had to chuckle when I read the review on the Tubefan (Chandlery, January 15), particularly the $135 price, since we built something similar a few months back for around $10.
Granted, a high-quality unit manufactured and sold by a small business is generally more expensive than a DIY project, but fabricating an equivalent unit from a few parts is so trivial that even the most thumb-laden boatowner should be able to do it.
What used to be a 10-degree difference between the top and bottom of our refrigerator and freezer box is now uniform. The important test is that the lettuce doesn't freeze in the fridge and the steaks don't defrost in the freezer.
Details: The fan is from Jameco, a great source for "geeky" electronic parts: www.jameco.com. The fan is the most expensive part. It's Jameco part number 207052CP. Specifications: 12V, 0.06A (Only 1.44 Amp-Hours/Day!), 5.5 CFM (enough to stir things up, which is all you need), with ball bearings (important for longevity and continuous operation). Price: $6.95.Its dimensions are 1.6" square by .25" inch thick.
The 65-cent fan guard is Jameco part 123502CP. The pipe is 1.5" PVC (available at any hardware store) with your choice of 45- or 90-degree elbow. Plus some miscellaneous parts—wire, connectors, fuse, fuse holder, some screws, tie-wraps and/or double stick tape. Total cost: a few bucks.
1. Measure your box, and cut the PVC a bit shorter—allowing for any slope in the side of the box. Cut the bottom of the pipe at an angle (e.g. 45 degrees) or use another elbow so that you can rest the bottom of the pipe on the bottom of your box without blocking airflow.
2. Attach your pipe to elbow. Put a short stub of PVC in the other end of the elbow so you can use four little (#4) screws to attach the fan and fan guard to the PVC (see picture). Note: We didn't glue anything—the snug fit was sufficient.
3. Wire up the fan to your boat's 12V electrical system—be sure to follow proper wiring procedures. We ran the wires through the same opening in the side of the box that our refrigerant tubes pass through, and sealed things up with modeling clay. We connected two fans (one for the fridge, one for the freezer) through a fuse holder and 0.25-amp fuse to a circuit that's always on when we’'e running the fridge.
4. Attach the assembly to the inside of the box. We found it convenient to use tie-wraps, but double stick tape would also work fine.
Santa Rosa, CA
Thompson's Water Seal
Here is a cheap and simple way to make papers and charts waterproof, and you can still read and write on them as before.
Simply brush on Thompson's Water Seal, available at most hardware or discount stores. The pages will be wet, but not falling apart. Hang or lay the pages somewhere a few hours to dry. When dry, they look, feel, and fold like they did before you treated them. Water, even drenching, won't cause them to fall apart or make the ink run.
I have used such treated charts and other papers while sailing and during wilderness canoe trips in Canada, where everything gets wet every day. They are still usable 20 years later.
By the way, the same treatment works for your favorite hat, canvas, or what have you.
Punta Gorda, FL
I recently read your November 1, 2003 article on "Sailmakers' Advice and Prices," and would like to clarify a comment about Rolly Tasker Sails sent in by one of your readers. Kevane Sails is a distributor of Rolly Tasker Sails in New England and New York.
We are not a mail-order-only distributor, as stated in the comments. We offer a little different approach to our customers. We measure their boat to assure a custom fit, and we are always available to our customers for any questions or problems that may arise, and these would be handled locally.
-Patrick Kevane, Kevane Sails
Too Many Bullets
I enjoyed your article on the C&C 29 (March). While the quotes attributed to me are generally accurate, one conclusion you draw is ludicrous. In parentheses, you state that I won every race I entered in my 29. No sailor in the history of the world has ever won every race he has entered, least of all me. I can't imagine where you came up with that, but I have already heard from several old competitors who have solid grounds to dispute that statement.
While we were certainly very competitive on Illusion in the Lake Ontario 29 fleet, and won our share of hardware, we lost our share too. We still race and cruise our 29 on Lake Rathbun in southeastern Iowa.
Des Moines, Iowa