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 http://rosslillistonewoodenboat.blogspot.com/2011/05/thinking-about-phil-bolgers-micro.html

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....