Monday, May 30, 2011

Thinking About Phil Bolger's MICRO - Part 2

A little while ago I wrote a preamble in response to a request from Dennis Marshall for comments about Phil Bolger's wonderful Micro design - see

Dennis' request went as follows: -
Dear Ross,
I hate to commandeer your blog with all my questions and comments. I do enjoy it immensely. I was wondering if you would be so kind as to comment on Bolger's Micro at some future date. I would be very interested in hearing about your experiences with her and your assessment of her abilities. That was the first boat plan I ever bought. And ten years later, she still intrigues me.

My feeling is that Micro was designed while Phil Bolger was at his peak. Some of my very favourite Phil Bolger designs (but not all) come from that period, and include Black Skimmer, Micro, Long Micro, Martha Jane, Sparkler, Scooner (a.k.a Light Schooner), Otter II, Manatee, Surf, Folding Schooner, Harbinger, Dovekie, Defender, Light Dory Type V, Light Dory Type VI, Victoria, Thomaston Galley, Fieldmouse, Lynx, Monhegan, Yarrow, Nahant, Hope, June Bug, Burgundy, Pico, Apogee and Birdwatcher - the list goes on and on, and I really don't know where to draw my personal line. Suffice to say that of all the designers I'm aware off, Phil Bolger has had the greatest influence on my thinking.

You may think it is a case of hero-worship, but I don't believe that is the case. It is just that Phil had such an open mind from a technical point-of-view that I am constantly discovering more thought gems. It is noteable that he said on a number of occasions that Ray Hunt was the designer who had the most influence on his own thinking, and that it was because of Ray Hunt's open mind....

To Micro... well, where do I start? From the bow, I guess.

    Integral boarding ladder which makes the boat go faster!
  • The first thing you notice is that Micro has a transom (or flat) bow with a couple of prominant holes. I believe that the reason for this is that Phil was attempting to match up the curve of the topside panels (in plan view) with the curve of the bottom panel (in profile view). If the bow was drawn out long enough to come to a point, the side panels would have been longer than two butted plywood sheets, and the heel of the stem would have been way up in the air adding weight and windage, but without any hydrodynamic improvement. So, he just cut the bow off at the length of two plywood sheets. The boat is faster and better handling as a result. Being a sharpie, she sails on her chine and doesn't need a sharp bow. The resulting flat bow transom has been turned into a superb boarding ladder - that is what the holes are for - and where do you push-off when leaving a ramp or a semi-submerged trailer? From the bow, of course! How many people have you seen struggling to get onto a boat through the pulpit? With Micro, it is simple, elegant, and (usually) graceful.
  • The self-draining, open bow well. This compartment is a superb amenity, and can be seen on many Phil Bolger sharpie designs. When standing in the well, one is well supported at hip height, so that working on the mast, halyards, or ground tackle is made into a two-handed affair - no need for the "one hand for the boat, and one hand for youself" routine
  • Well supported in the self-draining forward compartment
  • The Cat-Yawl rig allows the masts to be positioned at either end of the boat, meaning that the entire length of the boat is free for accomodations. A minor drawback is that the weight of the main mast is in the eyes of the boat, and therefore drugs her in a chop. But Micro quite full in the forward sections, and can stand the weight. I make my masts hollow, so weight is reduced. The mast step and partner arrangement is simple, reliable, and allows for easy stepping and lowering of the mast - all without the weight and complication of a tabernacle.
  • Micro's simple, rugged, and easy-to-use mast stepping arrangement
  • The cabin and cockpit are overlapped. The lower legs of a person on one of the bunks in the cabin are under the butt of a person sitting in the forward part of the cockpit. Therefore, crew-weight is concentrated in the middle of the boat, while still having a combined length of cockpit and cabin which is shorter than the sum of the two. Think about how quarter berths work, but the Micro solution to accomodation problems is even more elegant.
  • Micro's cockpit doesn't have a conventional foot-well. The cockpit is in fact a deck on which one sits, with a hatch in the middle through which you can hang your legs if weather permits. The hatch is on the centreline, so that even if she is on her beam's end, the capsised water-line is below the hatch opening. The hatch also gives access to the enormous cargo hold below the aft end of the cockpit. If there were a foot-well, this superb hold would not be possible. The hold can also be accessed from within the cabin.
  • Right aft, there is another open, self-draining well into which the mizzen mast, outboard mount, outboard fuel tanks, ground tackle etc all fit. In the event of the cockpit flat being pooped, all of the green water can instantly run into the aft well, and the majority will pour out of the large outboard opening in the transom in an instant. The remainder will flow out of the drain holes and the opening around the rudder post.
  • Drain holes visible just aft of the tie-down strap, and around the rudder post
  • The rudder is mounted on the aft end of the keel, and because the rudder post runs up into the self-draining stern well, there is no need to worry about sealing where the rudder post goes through the hull - ever!
Convenient motor mounting which also acts as a super-fast way of ridding the cockpit of water
  • The keel structure is hollow other than for the middle section in which the 412lb lead ballast casting is located. The remaining hollow sections are free-flooding to make use of the neutral buoyancy of the water filling, and to obviate the problems of swelling and contraction of large timber deadwood components. In addition, solid timber deadwood sections tend to float (which the water filling doesn't) resulting in a reduction in stability when heeled. So Micro's water and lead-filled keel is cheaper, easier to make, lighter, and provides more stability.

Just visible near the bow is one of the vent holes in the keel structure. The solid lead casting runs from approximately the first trailer roller to the third trailer roller.
  • There is a vent in the forward bulkhead, another one in the aft bulkhead, and a clever arrangement for venting under the companionway hatch. All of these are arranged to allow air in and out while keeping water outside the hull - even when partially capsised. Even with the boat totally closed up, she is well ventilated.

There are many, many other subtle details in the design of Micro, but I've written too much for one sitting. A careful study of hundreds of Phil Bolger designs will reveal many similar examples of the designer's genius. The great pity is that so many people see the simplicity of his more notorious designs without understanding the genius which produced them. As a result, the majority of the amateur-built PCB boats we see have been altered to a greater or lesser degree - usually without the builder or owner being aware of the design elements being violated along the way. What happens is that the crudities remain, but the genius is lost forever....

Friday, May 27, 2011

Self-Steering - Phonix III Video

It is generally thought that single-masted boats can't be made to self-steer. But there are plenty of examples of people who have made it happen - the best known being Joshua Slocum.

Here is a video showing Phoenix III doing the job, sailing to windward in mild conditions. I guess that many of you may have already seen this video, but I post it for those who have missed the action.

In the clip, owner/builder Paul Hernes is lying in the bilge of the boat, but he is not touching the tiller, nor in any other way cheating. The tiller has been lightly lashed and the boat is sailing herself. The rig is the balance lug, which sets on the standard mast which is used also for the sprit-sloop rig. Have a look at the tell-tales to see how well the rig has been trimmed.

With all of my designs, I try to use a single mast location and a common mast with the various rig options. This requires careful design and manipulation of sail size, shape, and location - but the net result is that it is possible to have different rigs without having to make a new mast, and more importantly, it is not necessary to change the mast step and the mast partner.

Paul frequently goes to the boat ramp with both the sprit-sloop rig and the balance lug rig. He makes the decision about which rig to set after he gets to the launch site. Sometimes he starts the day with one rig, and finishes the day with the other.

I promise that I will get an entry written dealing with Micro part 2 as soon as possible. Trust me, I have been really busy!

Sunday, May 22, 2011

Thinking About Phil Bolger's MICRO - Part 1

A few weeks ago, Dennis Marshall wrote to me asking for comments about Phil Bolger's superb Micro. Here is Dennis' message: -

Dear Ross,

I hate to commandeer your blog with all my questions and comments. I do enjoy it immensely. I was wondering if you would be so kind as to comment on Bolger's Micro at some future date. I would be very interested in hearing about your experiences with her and your assessment of her abilities. That was the first boat plan I ever bought. And ten years later, she still intrigues me.

Well, I am keen to respond to this request, although I have to admit to being intimidated by the idea of making comment about the work of someone as well-regarded as PCB. I hope to write something this week. 

I've been very busy over the last week, and have also been away, so the writing has been delayed. However, I thought it may be appropriate to start off with a very short piece I wrote about ten years ago dealing with an imaginary cruise aboard a Micro.

The style is a direct copy of the type of essay which Phil used to write about cabin arrangement in issue #86 of Woodenboat Magazine. Although the trip is from my imagination, the information is based on experiences I have had over a decade or so.

Mike Rowe stood in the companionway of his small cat-yawl holding a mug of black coffee, which was now half-cold due to his habitual day-dreaming. He was at last starting to relax after the mental and actual turmoil of the preceding days. It seemed to him that the only place he could really unwind was on the water, and the current conditions were his favourite. A light north-easter was moving his keel-sharpie steadily past Earlando Resort and he was anticipating with satisfaction the first mental milestone of his outing – Gloucester Island.

Mike, who was approaching middle age with at least some grace, had calculated a speed over the ground of 4.63 knots since departure four hours earlier. Calculating was habitual for him. At this rate they should reach the rendezvous with his friend Ian by one pm the next afternoon, allowing for the present favourable ebb tide.

Although Mike’s coffee was now cold and unfinished, it had provided him with satisfaction beyond measure, just by having been prepared in the tiny cabin while the boat steered herself. How many times he had dreamt of such activity he could not have told anyone; but although long in the gestation, the situation had been as sweet as he had anticipated.

The other activity he had particularly enjoyed was lighting the kerosene navigation lights. These had come from a supplier in Canada many years before (he also habitually bought gear before it was needed, as though it would bring a cherished project to fruition ahead of time!) and promised to be a worthwhile investment as long as the contents of the reservoirs could be prevented from permeating the vessel. To this end, the skipper had stored the filled lights in a plastic nappy bucket. This he had chosen because of its robust construction and close-fitting lid. It normally resided in the aft free-flooding well, where kero spills could be washed away with seawater. They were more reliable than the corroded wiring of his mate’s GRP sloop – electricity had its place, but that place was not on a small boat.

Just after eight pm, Mike went below to rest. Had anyone else been present he would have justified his action on the grounds of tiredness – but as he was alone he could indulge himself for the real reason, which was that he loved to feel the little yawl steer herself. The feeling was heightened enormously when he went below. The wind was forecast to veer, so any unnoticed course change should be towards open water. A medium sized, spherical compass was mounted through the main bulkhead, so he could monitor headings from the bunks as well as from the cockpit. Danger of collision was his only concern, but during construction he had stuffed crumpled aluminium foil inside the hollow wooden masts to act as radar reflectors.

The hypnotic sound of water against the 6mm plywood planking lulled him into a short, relaxing sleep, but the novelty of this trip soon saw him back in his favourite position in the companionway. What had always puzzled him was why so few people followed the cheap and simple route to boating pleasure? Mike’s boat had cost him only a few thousand dollars, and six months part-time labour – yet she was built of the best materials and had an effectively unlimited life expectancy. His friend’s glass boat had been much more expensive (even second-hand) but gave little extra other than internal room. On the other hand, it was in need of major work to treat osmosis, and was a real handful on a trailer. To each his own – but Mike Rowe felt happy in the knowledge that his boat was simple to maintain, and that her total cost including trailer was less than the expense that Ian had incurred upgrading his vehicle to tow the second-hand GRP boat. The little wooden boat had no standing rigging, no sail battens, no stainless fittings, no winches – yet she was a true open water vessel. Self-righting, positive buoyancy, two full-sized bunks, dedicated storage hold – all very shipshape in her brush painted finish.

Mike Rowe’s advice to those who came to see his boat? : -
·        Start building, even if it is smaller than the project of which you dream;
·        Use high quality timber, adhesives, paint and tools;
·        Keep up the momentum of the project – letting the job remain idle for even a few days makes it much more difficult to continue;
·        Never leave anything in the construction which you don’t feel good about – no bad timber, no bad glue mixes, no bad joints etc;
·        Seal all surfaces and joints;
·        Follow the application instructions for the painting system religiously;
·        Resist the urge to varnish;
·        Keep it simple.

Here is a link to a youtube video taken from on-board a Micro. It was a very light day - 8 knots of wind max - but the little boat went very well indeed on the smooth waters of Wivenhoe Dam here in Queensland, Australia.

Sunday, May 15, 2011

Up-Date - Rig #6 from "100 Small Boat Rigs" ("103 Sailing Rigs")


Back in early April I wrote an entry about the above rig. You can find the article here

At the time I wrote the piece I didn't have any sailing pictures showing the modified rig in action. Now I can show you a couple. They are low-resolution, but they give a good idea of how much the rig has been improved.

The mast used to bend back alarmingly when sheet and vang were tensioned - now everything stays where it should be and the boat's behaviour has been improved dramatically.
Setting out for a day of pleasant sailing with a vastly improved rig

Saturday, May 14, 2011

Sailing a Wooden Classic

I was brought up in an environment where building one's own boat was part of competeing at the local Yacht Club. I'm talking about the early sixties and seventies, and I'm grateful to have been around for the experience. Why don't people build their own boats for competition any more?

These days it seems that dinghy racing revolves around the purchase of an off-the-shelf production boat, whether it be new or second-hand. Well, in the past there were a lot of good boats designed for ordinary people to build and race, and one of the most prominant designers was Jack Holt. Tens or even hundreds of thousands of his designs were constructed by amateurs - Mirror Dinghy, Heron, Enterprise, GP 14, 125 to name just a few.

Arguably, one of Jack Holt's best designs was the Lazy E or as it is currently known, the National E. It is said that the Lazy E was designed as a successor to both the Enterprise and the GP 14, and that she had all of the virtues of the preceding designs with none of the vices.

A few months ago my middle son, David, bought an old and fairly rough Lazy E. He was hesitant at the time, being in a position where he had to be careful with his money, but decided to go ahead anyway. The old boat has proven to be a great success, and here is a short video to show what fun one can have with somebody else's cast off equipment. This shows Dave and my oldest boy, Geoffrey, enjoying a simple day-sail off Manly, Queensland, Australia. Dave on the tiller, and Geoff on the trapeze. Despite what some people say, I believe in the new generation!

Enjoy the video - you can do it as well!

Wednesday, May 11, 2011

Hollow Masts Built Using a Traditional Approach

A while back I put up two posts describing (briefly) the process of building a hollow mast using the "Bird's Mouth" method. The "Bird's Mouth" system is just a variation on a traditional method where a number of staves are edge-bevelled and glued together in something like an elongated barrel.

Another traditional approach is to make a spar in two halves just as you may build a solid spar, but to hollow out the internal parts of the halves before assembly. I do not like this method, because the skill required to ensure that the wall thickness is even on both sides is substantial. In addition, and more importantly, the mast is likely to bend in varying conditions of temperature and moisture content - somewhat like a bi-metallic strip.

Some time back, I was asked to make a mast this way for a customer, and here are some pictures in case you are interested in the alternative method.

One of the test pieces I used for calculation, along with my rough drawings
In the photo above you can see a dummy section of the stock from which I intended making the mast. I had drawn two cross-sections of the mast so that I could calculate how deep to run a circular saw blade at various distances from the centreline to approximate a cylindrical cut-out. I think I was limiting the wall thickness to 20% (the mast was for a Penobscott 14) and I divided the cutting process longitudinally into two main sections of the mast so as to build in an approximation of internal taper.

Two halves with saw kerfs finished
Above you can see the two halves of the mast with the saw kerfs finished. This was a job which demanded patience and attention to detail, as any slip would ruin the valuable mast halves. In addition to keeping the wall-thickness even, I had to take into account the places in the mast where solid sections were required.

Adjusting the cut for breadth and depth to account for taper

Look carefully in the photo above, and you will see how the width and depth of the cuts has been changed to account for taper.

Solid portion at the tip where halyard sheaves will be placed
I terminated the cuts against a circular line so that the hollowed out end would finish in a hemispherical shape
Using a chisel to remove the kerfed sections. Demanding work, as a slip or a bit of chop-out due grain reversal would be a disaster.
Close-up of chiselling work - lots of adrenalin!
Finishing the interior with a convex plane.
Mast halves being glued together
In the photo above you can see the finished hollow halves being glued together on a strongback to ensure straightness. The yellow colour of the epoxy squeeze-out is because I was using WEST System Brand 207 Special Coating Hardener. I did this because the mast would end up being varnished, and I didn't want the thin glue line to turn opaque and yellow over the years of exposure to UV. A small point where there is only a glue line, but very important where large exposed surface areas of epoxy are clear coated.

All spars were marked for eight-siding using this homemade device which automatically adjusts to the taper of the spar
Initial cuts were made using a drawknife, but a plane will do it with less risk, even though it is slower.

Finishing off drawknife cuts with a plane
After planing to an octagonal section, I mark with pencil to more easily guage the cut when planing to a sixteen-sided shape
Planed to a sixteen-sided shape. See how the pencil marks help with visualisation. The process then continues to a thirty-two side shape, and then the spar is sanded to a final round
Halyard sheaves and shoud and stay chocks at mast head - dry-fitted at this stage

The design called for three cleats and a boom shelf. I do not like screwing fittings to a spar as it can cause stress concentration at the screw holes, but these wooden fittings were glued as well, so they added structurally to the mast.

Close-up of the cleats I made prior to gluing. These types of fittings can be quickly and easily made from timber found around the workshop, so you don't need to buy plastic ones - wood looks better, is cheaper, and works better.

Gaff jaws and boom jaws before being glued to the spars.
I show these photos as a matter of interest, but my recommendation for hollow spars is to use the "Bird's Mouth" system. It results in a spar which will stay straight, the work is less nerve-racking, and the resulting component is stronger.

Thursday, May 5, 2011

Water Rat

Edward has written in regard to the discussion about flat-bottomed hulls: -

Hello, There was a flat bottom sharpie built in England in 1898. Very unusual at the time. She was 14ft and had a sprit main and jib. Mr. Lillistone could you look at this picture of her from Dixon Kemp, and comment on what you think? I'd quite like to build an historical replica to see how she went (fast by all accounts at the time as she was banned from racing). Regards Edward

Thanks for the comment and the drawing, Edward. I am flattered that you are interested in what I have to say, but I am mildly worried that people may think that I know more than I actually do!

Anyway, here is my opinion, and I'd welcome input from others who may have a deeper understanding of the subject.

I view this boat in two separate parts - the forward sections and the aft sections. She is quite wide for her length, which immediately introduces problems with eddying around the chine. The line of the chine is very flat up for'ard, which also increases the problem of wild eddys forming around the chine, causing drag and wild steering.

However, the chine line in the aft sections shows a nice lift when viewed in the body plan, and I think it comes close to the optimum when hoping to prevent eddying. If you look closely in the body plan (i.e. the end elevation) you can see that the line of the chine more-or-less bisects the angle between the bottom and the topside panels.

So, I think that this boat would perform well as long as she was sailed flat with the fore-foot lifted clear of the water - which she would naturally do considering her large sail area and tucked-up transom. Her shape looks similar to plenty of racing dinghies from the last forty or fifty years. If built lightly, I think she would go rapidly, but I also think she would be a handful in a decent breeze.

The potential for the chine at the bow to produce turbulence would not be a problem when running fast and level in flat water, but if she stuck her bow into the back of a wave (especially running down-wind) I think she could sheer off wildly and suddenly.

That is my opinion, but just remember that there is no guarantee that I have any idea about what I'm saying!

Beachcruising by Magic Carpet

Many years ago I wrote this little piece tfor publication in the print magazine Australian Amateur Boatbuilding and I think it was subsequently re-published in Duckworks but I'm not sure.

Re-reading it now makes me feel a bit self-concious, but I still agree with the sentiments expressed, and I can't think of much in life which can return as much per dollar as a wholesome sailing or rowing boat. Here it is again if you are interested....

Beachcruising by Magic Carpet

Mild adventure; self reliance……

Looking over the gunwale at the shallows moving past – so foreign and threatening, and yet so wholesome and familiar.

Approaching the shore of an island that only lifts above the sea for half of the tide – the thrill of walking on its surface during its brief exposure – what will swim above it at high tide?

Shells rustling the wavelets – so mild and safe now that their energy has been expended on the bar – twenty-five meters between ferocious power and rippling familiarity – maybe this ripple was born on the western seaboard of America?

My small vessel is the magic carpet which gives me access all of this, and more. She is a capable seakeeper, yet she spends most of her active life in benign surroundings – kids, sun, shallow waters, fishing lines, esky.

I see the towering white, chrome and glass gas-guzzlers, but do they see me? The grim and determined looks on the faces of their owners – does their Nautical Appliance give more than it takes? Does their vessel communicate with subtle and ever-changing pressure on the tiller? Does their lifestyle allow receipt of the messages from helm, hull and air? Perhaps, but they don’t seem to have the relaxed posture of the man sitting in his tinnie, at anchor just outside the channel. The man’s face is lined, but breaks easily into a smile, and my heart tells me that I’m seeing the real man – not his self-proclaimed image. As I rock and pitch in the steep wake of the polished fiberglass monster, a cormorant takes flight from the beacon, and I follow its swoop to the mangrove………..

I stand beside my boat – we are between the Big Island and the mainland – three miles one way and two miles the other; yet she gently swims in knee-deep water over a sandy bottom, undisturbed by the vehicular ferries and cabin cruisers – protected by the very shallows which give so much pleasure…….

Night – the wind tugs at the boom tent and dodger, protecting me from the squadrons of mozzies and sandflies which inhabit the nearby shoreline. After my simple meal I read a favourite book by the light of a battery lantern – the sounds of partying from the boats down the bay compete with the lapping of small waves against the plywood planking inches from my ear – no competition……….. Much later I awake and listen – the human noise has gone, but the wind and waves remain.

Why do so few people know of this secret existence? Most of them probably think of it as adversity – one man’s meat is another man’s poison.

My boat is a teacher – she has taught me the folly of setting out without adequate preparation; she patiently tolerated my lack of attention to maintenance during those early days when I knew that I was bulletproof, and hormones ruled my mind. Now she rewards me when I scrape, sand, and then apply that magical first coat of primer; when I drive home the silicon bronze screw; when the resin oozes from the scarphed-in dutchman as I tighten down on the bar clamp.

She teaches the kids as well, but they don’t realise it yet. She gives and gives, and takes very little.

Is there any other possession in life which gives so much for so little? Perhaps to the painter, his brush, pallet and canvas; to the musician, his favourite instrument; to the woodworker, his tools. But this boat can carry me over countless miles of water, yet she came from my own hands and mind – a piece of functional art.

You can build her too……………………………..