Saturday, December 29, 2018

I Just Want the Boat to STOP!!

I've research all manner of things sailin-related. Drogues and sea anchors, and MOB prevention tools such as tethers and jacklines have featured prominently. Both respond well to engineering analysis.

I often read of a "last chance" line trailed behind the boat. The line described was most often tragically short. Sail magazine described one only 15 feet long. If you fall in head first, angled away from the boat, and the boat is moving at a 5-7 knots, 75 feet is the minimum required distance based on my testing in summer weather. You better have 150 feet if you want any hope of finding it in adverse conditions. They also think that they can either make the boat stop by tripping the rudder (the boat may just tack away and keep sailing--you did not take the time to trim it for heaving to, or bring the rudder back up) or simply haul themselves back to the boat (impossible over about 3 knots). The other thing they always have in common is that they have not TESTED their theory by jumping in. Man, if you have not tested it, don't even report it as an idea. Someone might believe you.

I imagined myself hanging on the said rope at 7 knots, waiting to get tired and let go. I've been towed as a water skier, so it was not hard to imagine. I also tested the speed At which I could hang on to a 3/18-inch floating line, and the speed at which I imagined I could (dressed in foul weather gear and a PFD) haul myself back to the boat. It becomes clear with in moments that what you will pray for is for the boat to STOP. Nothing else. You would give anything to make the boat stop, like dropping an anchor (see where we are going with this?). And as it turns out, that isn't really so hard, at least not with smaller boats.





Basically, it is a parachute with the floating line as the rip cord. You don't need to pull hard, just enough to pull the gear from the storage bag on the deck. The chute and rope stream out, and about 10 seconds later, the chute fills, creating a whole lot of drag. A nylon climbing rope provides the energy absorption, bring the boat to a slow stop (about 1-2 knots, even with the engine at full throttle). All that remains is to pull yourself to the boat, hand over hand, which is not very difficult with the boat nearly dead in the water.


















 Yup, I tested it repeatedly, sometimes powering, sometimes under sail, upwind and down. It didn't matter. The success rate was 100%. All I asked of the crew was to keep filming.A seemingly crazy idea that simply works.





I'm not at all surprised. For years, in testing, I would drop drogues and sea anchors off the transom at full speed to create maximum impact force, often using non-stretch rodes and larger boats. Although the strain could be high, nothing ever failed.

Staying on the boat is better. Stay low and clip-in when it gets rough.

[Details are in Practical Sailor Magazine. Obviously, the engineering varies with the weight and speed potential of the boat.]

Friday, December 28, 2018

Tiller Reinforcement

Pretty darn simple, but it's the holiday season.

Because the rudder swings down and into a slot in the hull when the rudder is lifted, the pivot was a counter sunk flat head. A flat head makes a nice wedge, and sure enough, most of the tillers developed splits.

Not a lot of room for thick side plates when the rudder is lifted. 

The solution (after cleaning up, repairing with epoxy, and re-varnishing) was to add 1/8-inch thick side plates, counter sink the bolt on one end, and grind it smooth on the other. No play. No splitting.





 

Tuesday, December 11, 2018

Actual Anchor Loads



I spent a LOT of time researching this topic, through the literature and by staring at a load cell for hours and hours. I used all sorts of rodes and snubbers, in all weather, on a number of boats.

ABYC (American Boat and Yacht Council) set standards for rodes and deck hardware 50 years ago, based on testing with boats on all-chain rode in open harbors and shallow water (but no breaking waves) and no snubber. In fact, these values are VERY close to what I got testing in similar conditions. This is very much a worst case situation and is something you should NEVER do, but is a good basis for the design of something that cannot fail. I don't think I've ever heard of a system meeting Table 1 requirements that was in good repair failing, outside the eye of a huricane (an even then it isn't the chain that breaks; they either drag or the roller and cleats fail.


Interestingly, every investigator reported 3-5 times less when they measured the strain on their boat (me too). Of course, they wisely anchored in deeper water (lower waves and more catenary), used rope, or used a snubber.

Looking only at the 60 knot row, which is very likely the most you will ever face without some protection from trees or shoreline, we see that the wind load is only about 20-25% of the ABYC load. Waves and snatching make up the rest. If you use a long chain in deep water (at least 20 feet), a long  snubber (35'-50'), or a rope rode, the load will be only 25-30% of the ABYC value.




For larger boats or those around coral and rocks, all chain is nice. Rig a LONG snubber, even if you have to cleat it at the mid-ships or stern cleats to keep the connection off the bottom.
My PDQ came with rope, but I changed to chain and a long snubber after a few years. I liked the increased security, but the main reason was that the windlass handled all-chain better than chain with a splice. 

In my mind, if your anchor is 35 pounds or more, you will be better served by a windlass and all chain, and if it is 15 pounds or less, manual handling and rope makes more sense. At 25 pounds, the decision is up to you, depending on pocketbook, fitness, and sensitivity to weight in the bow. I'd probably go with chain and a winch on a monohull or heavy cat, and manual with rope on a fast multihull.

 With smaller boats and mud bottoms, the rope is a better answer. It is much lighter, gives good shock absorption, and lasts as long or longer, if it is protected from chafe. You see, chain will fail from corrosion in 5-7 years, even if you don't anchor out, whereas nylon can go even longer if oversized a bit. So go oversize for durability and ease of handling. Finally, nylon can actually be too stretchy if over 100 feet are out, and oversize rope reduces this.
My 24-foot, 1700-pound trimaran only calls for 3/8-inch nylon rode, but I like 1/2-inch for better handling, durability, and reduced stretch. I did the same on my Stiletto 27.

I've even gone to a Dyneema bridle to reduce yawing and to reduce the sometimes-excessive stretch of all-nylon rode. Because the bridle does not distort under shifting loads, yawing is reduced.

[Images excerpted from Rigging Modern Anchors.]

Monday, November 26, 2018

Northill Anchors

It seems quite a few have never heard of these, so I thought I would post a few images. I used one a bit with my Stiletto 27; it was better than Fortress in weed, rocks, and shell, and the new generation anchors had not taken off yet. I used it a little with my PDQ 32, testing in-line rigs, but never collected hard numbers; there did not seem much point, as they are long out of production. But I'm thinking of going back to it for my F-24, since it has a few advantages:
  • Folds flat
  • Very easy to assemble, better than any other break-down anchor (less than 10 seconds)
  • Works on any bottom type
  • Good reset behavior
  • Good holding capacity (450 pounds for 12-pound 6R Utility in mud), comparable to  many new generation anchors. The cross stock adds a LOT of holding power when it meets the bottom. I've tested this anchor to 750 pounds in fine sand and it didn't budge.
It has two disadvantages:
  • The lazy fluke is sticking up. A problem if the tide does a 360, which it can.
  • Unlike new generation anchors, it does not rotate to face a shifting breeze. Instead, it pops out like a pivoting fluke anchor. Fortunately, it is much better at re-setting. Thus, the fault is nearly forgivable. Considering fault one, it's not the anchor to use when tidal reversals are expected.
I still have the one shown below, and I think it is the right size for the F-24. All you do to fold it is unclip a carabiner and slide the stock out.

Northill 6R, 12 pounds.


They suggest a larger anchor, at least a 12R for a storm anchor for the F-24, but I carry a second anchor and I'm pretty good at reducing the load. And really, I'm just day sailing, anyway. If I start cruising, I'll find a nice cove for nights.

Sunday, November 25, 2018

The Tradition of Tandem Anchors

I have never liked tandem anchors, because with a change in direction, the lead anchor always rolls out and becomes pinned on its back, a position from which it often cannot recover. All of the manufacturers, other than Rocna, agree. So how did the idea become popularized?



Some time ago I was reading a 1930s sailing book, pre-CQR and pre-Danforth, and they showed a tandem anchor set up. They liked it for mud, not rocks. And their reasoning made perfect sense for the time, because...

  • The anchors were both traditional fisherman style. There was no back to roll over onto. If it rolls, it is ready to dig again.
  • A fisherman is poor in mud but good in rocks.
  • A fisherman doesn't really bury well, so the negative impact of secondary rode tension is small.
  • V-arrangements are fatal with fisherman's anchors; you will foul for sure. So this is the only logical 2-anchor rig.

So in-line tandems were traditionally used with fisherman's- or yachtsman's-style anchors... but are wrong with today's less symmetrical anchors. 
I wonder if it would work with twin Northills? I'm temped to get another one, just to see. I'll have to watch E-Bay, just because I like to expereiment.


Tuesday, November 20, 2018

Why does the World Sailing Off-Shore Rule Forbid Wider Pulpits?

It can be awfully skinny at the bow. The obvious solution is to set the railings outside, a little wider:

I would like to see a beefy toe rail with this arrangement, required by the Off-Shore Rule. The rule also requires a mid-rail. Net is not required, but it would finish the job.

 The front curve is handy for suporting the bowsprit when foldedI like that the F-24 has a place to attach a safety line at the back corner. It reduces sail snagging and guards a gap.



But the Off-Shore Rule is rather specific:


 Not only does this make for a safer work area, it avoids jib impingement.


I'm confused. It seems like a good idea to me. I understand why this would be important farther aft, since rail meat would be sitting farther aft. but that is a different matter and easily excluded, if that is the intention.

Thursday, November 15, 2018

Hugo Boss Sets a Record, Over 38 Knots

On the other hand, I love my Farrier. I bet my dollar-to-grin ratio is higher. It better be, since I don't have the dollars.


Wednesday, October 31, 2018

Man, We're Getting Old... and It's Getting Worse

(From a 2016 boating trade presentation on the state of the industry)

The conclusion of industry analysts is while new boaters come and go, the core of long-term sailors is stable. Those of us that become addicted occasionally sell a boat, but then by replacement. That's certainly my story, having owned a beach catamaran, Stiletto 27, PDQ 32, and now a Corsair F-24 Mk II.

Unfortunately, new boat owners come, but mostly go. As a result, boating is in gradual decline. Some point to New Age alternatives--the internet and other sports. Some correctly point out chartering is on the rise--boat ownership and all of the maintenance that goes with it is a good fit with the new generation.

Small boats are still a healthy industry. My daughter, for example, would love a sailing dinghy and I'll bet she'll buy one someday. But you can't see her owning a bigger boat. It wouldn't fit her needs, and the maintenance and fiddling would never hold her attention. I can see that. It feels pretty irrational at times to me.

The result is that we sailors are getting older and older. It doesn't just seem that way, it's true. I'm okay with that. By the time the sail population ages enough that my target market has evaporated, I'll have run out of things to write about.

Bow Wind Indicators

Masthead wind indicators are ubiquitous. Unfortunately, they can be hidden by sails, put a crick in your  neck, and take your eyes away from where you are going.

 The highlight vane is enlarged 2x.

On beach cats, a vine under the bridle is common. It's right in your line of sight when the action gets fast and allows you to watch the lee bow, as it tries to turn submarine.

I've always had vanes on the bow. The crew like them both for sailing, and just as much for hoisting sail and anchoring; they arn't all sailors and they don't like looking up while driving forward. They have a point. It can be tricky to locate them so that they are not damaged. In this case, the pulpit and the bow sprit up-haul line (blue) have kept them safe.


Why two vanes? I have been testing vanes for 2 seasons for an up coming article, rotating models from time to time. There is nothing like time-in-service to sift out the top performers.

 You would think the air would be more disturbed by sails. but in fact they reflect only a slight curving of he wind near the sail.

The Bottom Line. I like them all. I find them handy on every point of the sail, but perhaps most useful tacking and jibing. Look for the Write-up in Practical Sailor Magazine.

Monday, October 29, 2018

Trimaran Bridle

Multihulls love bridles, but going out on the skinny amas of a trimaran to rig that bridle is uninviting if there is any chop. Thus, I leave mine rigged but retracted.

 The line is over-size Dyneema; about 15x maximum working load, including allowance for single leg loading. The normal load factor for Dyneema would be about 4x, so this allows me to loose 75% strength to UV and wear before reaching the WLL. That should take over 10 years, based on available desert testing. This also squares with my personal experience with old Dyneema.

 When not in use, they are pulled back to mid-tramp by a Davis Instruments Mini-Shockle (a very heavy duty bungee). The front end is secured to the pulpit with a carabiner.


 To deploy, the Shockles are released and the carbiners are clipped to a prusik sling.

-----

To learn more about anchoring with rope, visit Practical Sailor Magazine. This last image is from and up-coming series on anchoring without chain.

Friday, October 26, 2018

No-Discharge Zones

In 2017 a new No-Discharge Zone (NDZ) was established in the Puget Sound. In stead of allowing discharge of treated wastes 3 miles from shore now there will be none. The local cruisers feel they have been demonized, but in reality it is the cruise ships that were targeted.

The Puget sound is unique in that it is the ONLY large bay where the 3-mile rule applied. All other bays (Chesapeake, San Fransisco, etc.) are considered inland waters, and all discharge of untreated waste is banned, whether 3 miles from shore or not. But the Puget sound is shared with Canada and is thus not the inland waters of the US.

Because the navigable waters are regulated by the federal government, the state has no authority to regulate discharges from boats, OTHER than requesting NDZ status from the EPA, which is quite easy, so the Washington state EPA had only one option; NDZ status.

NDZs began with the Clean Water Act (CWA) in 1972. They are often seen as political statements.


I'm not seeing a correlation with presidential party affiliations. There was a predictable burst when the law passed, no interest nearly a decade, and then a pretty steady rate since. The last Bush administration implemented 4 more NDZs than the Obama administration. If there are politics, they are local in nature and consistent.

Perhaps the rate is now declining, as the map gets filled in.

Interestingly, the Friends of the Earth petitioned the EPA in 2010 to allow several popular high-efficiency treatment systems, arguing they were better for the environment than a ban. How about them apples? It seems they believe that good treatment is better than the cheating that otherwise takes place. Rather like ethanol gas, the full cost of the regulation and the unintended consequences are not always considered. In this case, however, I think it is more a matter of the convoluted nature of regulations; the Washington EPA saw NDZ as the only available option.

Sadly, I don't think the effectiveness of treatment systems, such as the Rairitan Electroscan, is well understood.

Sunday, September 30, 2018

Helmets

After one more like wack on the head, and an invitation from a magazine to write an article, I fond myself pondering where on the safety scale helmets might fall. I'm think we are in the midst of a big change in mind set, akin to bicycle helmets in the 70s and 80s.

US Sailing has this to say [emphasis added]:


2015. A word of caution to all persons who consider using helmets while sailing. There is no data to confirm that helmets will prevent concussions. The brain injury comes from the acceleration/deceleration from the strike, which is apparently not substantially altered by a helmet.
Helmets have been shown to reduce the incidence and severity of facial and skull fractures, contusions and lacerations but not concussions. 

Concussions seem to occur more easily in pre-teen and teens. We also need to be aware that adding a helmet to a young head makes the head a “larger” target and could possibly lead to more head strikes.
Therefore, it is the position of the Sports Medicine Committee of US SAILING that helmets should be considered and encouraged but not mandated for:
♦ aggressive competitive sailing,
♦ crew positions at increased risk for strikes to the head, and
♦ sailors who are learning the sport and thus unfamiliar with the position and movement of rigging and equipment.

In the event that a concussion or head injury occurs, treatment and the evaluation for a return to activity should be done by a trained specialist. 

David Jones, M.D., Chair of the Sports Medicine Committee
Thomas Hubbell, M.D., President of US Sailing


Kayakers have long worn them. In fact, it is the law in many whitewater areas, including my home Potomac river from Great Falls to Chain Bridge. It's easy to get pasted in the head by a rock while inverted.

 The Protec Ace is top rated and economical. I like to for whitewater kayaking as well.

I googled ocean racing accidents. While head injuries represent only a small portion of the total carnage, they represent nearly half of the injuries resulting in evacuations or retirement. I strongly suspect they are a factor in some of the drownings ("So-and-so was knocked overboard by the boom [or spin pole, or banged across the deck] and was recovered drown.). You don't need a skull fracture to be dazed just enough to swallow some water after going in head first.


A little impractical, I think. For a helmet to prevent concussions it needs to be thick enough to provide deceleration distance.All kidding a aside, the risk of entanglement in lines and increased impact when hitting the water at speed disqualify and oversized design.

I googled cruisers. There's a good list of injuries in heavy weather. I've been tapped a good number of times, but a cap is enough for those. I did get swatted to the deck once, but it was just a skimming across the crown and did no damage. But it makes you think.

And then there is the danger of the helmet itself. I wide rim, like a bike helmet could snag on ropes. A brim could add to rotation or catch on the water at high speed. A helmet needs to be compact, such those we are seeing on many performance boat crews. I need to feel the wind. It cannot block my vision. On the other hand, it could keep my head warmer in the winter and it could double as a rain hat. Which brings up the matter of interference with the hood.

As I descend the rabbit hole of article research, I'm becoming convinced they are rational in many settings. Youth through college sailing, beach cats and skiffs, and maybe any small boat racing where mark rounding get crazy. Ocean racing in rough weather. Up the mast off-shore for everyone.

But what about cruising scenarios?  The foredeck when it's bad. Perhaps it is like headlights (if the wipers are on, the head lights must be on); if tethers are needed, so is a helmet? No, that seems like too much as a general rule. On the other hand, seatbelts don't seem very useful until that one instant you need one. When I look at the numbers, including only experiences sailors, It's hard not to see PFD, tethers, and helmets in a similar light. The accident numbers say they are all in the same range. Discomfort and expense are all in a similar range, I think. You wear a hat and I'm pretty used to my bike helmet. But I do miss the wind in my hair and I don't always wear it.

Food for thought.


 

Friday, September 28, 2018

Edit: Why a Jordan Series Drogue is NOT a Very Good Steering or Speed Limiting Drogue

Usually there is a specific event, often personal, that motivates me to research something. In this case, ~ some years ago I jammed a rudder on a submerged tree. I remembered a the loss of Too Good to Be (Alpha 42 Catamaran) due to a bent rudder, and several friends who have been towed in after striking logs. A boat was towed hundreds of miles across the Gulf of Mexico last year, after loosing a rudder in nice weather--with a steering drogue I would have been underway again in 10 minutes, no need to make a call, other than perhaps a Pan-Pan to the US Coast Guard as a condition report. It occurred to me that emergency steering is a least as important to the coastal sailor, because there is so much more debris to hit. So I got interested in emergency steering and drogues in general. 


A JSD is unarguably the correct tool for most serious storm conditions. You can Google "JSD Coast Guard Report" for the details, so I will only summarize. It was an innovative and clever leap forward that sidestepped many of the problems associated with conventional drogues:

  • No single point of failure.
  • Can't tangle.
  • Can't be thrown forward by a wave, because the load is distributed.
  • Can't pull out of a wave face, because the load is distributed. 
  • Very smooth drag.
  • No single heavy piece to handle.


However, it has serious short comings when used at higher speeds as a speed limiting drogue, or more importantly to me, for emergency steering:


  • The cones will shred. Unlike a JSD, which spends most of it's time at 2-3 knots, a steering drogue sees a sustained 5-8 knot speeds, resulting an average load per cone that is 2-10 times higher. Although reversal in direction is less common than for a JSD in a serious storm, they will be working near the surface, breaking out of waves regularly and getting pounded.
  • Longer endurance is required. It will be used for a week of more, not overnight. On a long passage, it might be deploy several times, just for comfort.
  • JSD cones are too close together for proper flow at the higher speeds. Testing of JSDs and plain cone drogues suggest drag is reduced about 30-40% by close spacing. Increase from 2 feet to 3.5-4 feet.
     
And yet it has  potential advantages:

  • No single large element to handle. Pulling a Delta drogue 72 over the transom in rough weather is no picnic. That is an understatement. Single drogues much larger than 2 feet (Seabrake 24, Delta Drogue 72) are simply not manageable by normal or aging sailor in boisterous conditions. Standard JSDs have a reputation for difficult recovery, but this would be 1/3 the length; I'm confident it is easier to man handle than a conventional drogue.
  • Less chance of tangling during deployment or recovery. The worst time with a standard drogue is recovery it; I've had a few get in the rudders.
  • Will not pull out of a wave. This is a considerable advantage, because every conventional drogue becomes unstable above about 5 knots in the presence of steep waves. The wave increases the angle of the rode to the water and the drogue pulls out as the wave passes it. The best you can do is try to put this out of phase with the peak load, which in confused seas, is impossible. This is the primary reason conventional drogues can fail catastrophically as the storm rises; everything seems good, until the speed + load reach a critical level, the wave steepness builds, and the drogue pops out. If it is on a nylon rode, the rode contracts, the drogue snaps forward, and maybe the wind and breaking wave help it along. There is no magic design that can make a single drogue run deep enough to avoid this cycle. I observed this hundreds of times in testing.
  • Drag will be more adjustable. Sometimes you need a lot of drag to make the boat track, and sometimes less would increase both speed and pointing (yes, you can sail upwind with a drogue, just not very high).



Recovering a Delta Drogue 72 (about 24-30 inches across). Even in clam weather it is extremely heavy and must be dumped first--impossible unless you are standing at water's edge, which won't always be practical. Other drogues are awaiting their turn in the dinghy, including a Galerider, Paradrogue, Seabrake, cone, and JSD  from Ace Sail Makers.

In use the drogue is often pulled in very close to the transom, to reduce drag by lifting the drogue. This is how a Seabrake 24 deploys in 10-25 knots for emergency steering; in light winds it is in close, in stronger winds I you add an extension between the chain and the bridle.


I decided to test a modified JSD (call it a Series Steering Drogue) as a speed limiting and emergency steering drogue:

  • Fewer cones. Only about 1/3 the number specified for storm service.
  • Strong construction. Upgrade to 6.5 ounce sail cloth and hem the leaving edge (Ace Sailmakers is building JSDs this way now).
  • Increase cone spacing to 4 feet for better flow at higher speed.
  • Less weight. 10 feet of 5/16-inch chain should be enough, or an 8-pound mushroom anchor. The rogue will be more naturally resistant to surfacing at high load or high speed (same thing).
    The most obvious difference is the that the series steering drogue is much longer, about 75-100 feet. But this is part of its strength--only by distributing the load can the drag remain steady is something as fragile and turbulent as water. 



    The standby rode is to allow us to seamlessly add the rest of the JSD if conditions deteriorate; just attach the rest of the JSD, along with a dedicated bridle attached to the JSD chain plates, and cast the spinnaker bridle free (you will recover it when you recover the JSD).



    Alternatively, A conventional drogue, such as the Seabrake can be used as the new primary drogue. Again, the stand-by rode allows for seamless deployment. The Steering Drogue will still provide stabilization for the new primary drogue (the Seabrake), much like a JSD, but with more adjustable deployment.




    And it was a complete failure. 

    First, the trade mark JDS droop, which allows the tail to run deeper under water does not occur. At higher speeds (5-7 knots) the JSD is pulled right up to the surface by water drag. The droop is not unique to the JSD design, but is only an artifact of Jordan specifying enough cones so that enough drag has been added to reduce the speed to 2 knots or so, which allows the tail to sink. Any drogue design will do this in an equivalent manner, as long as there are at least 2 units and the speed and weight are equal. Although it may retain some resistance to damage if the motion is reversed on the back slope, this is not he case with steering and speed limiting drogues--motion is always forward.  

    Second, smaller drogues (cones in this case) are inherently less stable when running near the surface, and are more easily disturbed by the movement of waves. A large drogue can run at shorter scope because it pushes a lump of water above it, whereas small cones push only froth. The small cones simply splash on the surface, completely unstable, unless the scope is at least 75:1, which is impractical with a 4-foot transom (I had to test them by anchoring near the waterline). Cones also zig-zag and flutter. This is very hard on their construction, fatiguing the cloth.

    Efficient shapes. A cone produces only 55-70% as much drag as a Seabrake or Delta Drogue of the same size. The design is easy to sew but not advanced.



    Finally, drogues are inefficient if they follow too closely behind one another, much like a racing cyclist enjoys the draft by following another closely, and the higher the speed the more significant  the effect. Thus, a steering drogue based on JSD cones must have much greater than normal cone spacing and becomes very long, about 50-60% of storm drogue length length even though it contains only 20% of the number of cones. This is quite cumbersome compared to a single unit, with no apparent advantages. The combined effects of inefficient shape (essential, because so many must be built), close draft, and small size (unstable near surface) are limiting to the function of a truncated JSD.

    It seems it is a matter of horses for courses. The JSD principle has considerable advantages for severe storm management, but only if designed for sufficient drag to slow the boat to less than 2 knots. If truncated to allow for better movement, the design has no advantages and more failings.

    Darn.