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Part 3, Which boat?

December 29, 2009

I wrote this in the previous post:

Fully reclaiming the waters of Milwaukee’s 3 rivers for public use would create a powerful and positive change . When a large number of people are able to enjoy the wonderful, relaxing and restorative benefits of recreation on the rivers they will understand the value of keeping the rivers clean, of creating public access and of maintaining this wonderful asset. The more people that enjoy the rivers the more people there will be that will find reason to advocate for the rivers and the more advocacy for the rivers the more opportunities will be opened for people to enjoy them. This will create  a wonderful, positive feedback loop.

This is idea is at the core of my mission which is is to build boats that would allow and encourage as many people as possible to fully enjoy Milwaukee’s 3 rivers in a non-polluting, ecologically sensitive way.

The question then is what boat would be best suited for this mission? It became time for me to do some serious research.

Over the years I have been collecting many books and articles about small boat design. I pulled out some of the best and started a review.

I started reading, re-reading, taking notes and re-reading again.

One thing I knew was that the boat had to have a certain appeal, a beautiful look. It had to draw attention to itself to get people interested in getting out on the river. People who may have never thought of rowing or boating might be inspired by the beauty of the boat. I had collected a lot of  images that were inspiring me to do this work.

There are a lot of beautiful designs out there to choose from. I had to start thinking about more than just beauty in order to choose the right design.

I know the waters in and around Milwaukee’s rivers and have a pretty good idea of what is needed for a boat to be seaworthy enough to be safe and comfortable here.  A primary concern for novice boaters is how tippy a boat feels. One measure of a boat’s stability is the ratio of the length over all (loa) to the beam (a boat’s width). A narrow skinny boat like a sea kayak is very tippy compared to say a wide life boat. That number isn’t the whole story though. Boats have different degrees of stability depending on how far over they are tipped or heeled. Some boats have  pretty good stability initially only to become less stable the further over they heel. Others are just the opposite with less stability when on an even keel but gain stability as more of the hull is dipped into the water as the boat heels.

I began to gather as much data as I could about various hull shapes. I also collected images of boats at work in order to get an idea of their stability.

Here’s a boat with a lot of initial stability allowing the lobster-man a good working platform to haul his pots.

I began adding my own notes to images I collected.

Another concern is seaworthiness. How able is a boat to handle a variety of conditions. While the waters in the three rivers are usually very smooth, there can be a few waves and some turbulence near the harbor entrance where the rivers meet. Also, it would be nice if the boats I were to build would be seaworthy enough to navigate out into the outer harbor on nice days. Part of what makes a boat seaworthy is how much free-board a boat has, that is how high above the water the sides are.  Too close to the water and waves may slop water into the boat. As with all of the factors I was looking at there is always a balance point. Too much free-board and the boat will be caught by the wind and hard to handle, too little and it may not be seaworthy enough for a modest chop.

A fine entry also adds to seaworthiness. The shape of the boat’s hull as it meets the water when it moves forward or even as a wave approaches from astern is worth considering. A stern with a wide transom, the after end of a boat, adds room and initial stability, however it may cause a boat to be shoved around a bit when hit with a wave from astern.  A wide stern can also make a boat harder to row as the water won’t flow as easily around the boat.

Other concerns I had were:

  • How easy would the boat be to build? I didn’t want the price to be outrageous.
  • How many people would it be able to carry?  I wanted at least enough to make it a means of having a fun outting.
  • How much would it weigh? The lighter the easier it would be to handle ashore.
  • Would the boat have a look that appealed to many people? Some designs were beautiful to my eye but may look a bit “unique” to others.
  • And maybe most importantly, how easy would it be to row?

I began looking at how other builders and designers had solved various issues I was starting to identify. Again, I added notes to images I collected.

I also had to start thinking about how I would get  boats I built out of my shop, my shop on the 5th floor of an old industrial building. I created models of various designs in my 3d modeling program and tried getting them into my virtual elevator.

OK, the elevator option didn’t look like the best way to go. So I started thinking about opening a window and dropping the boat down through it. This looked more promising.

I was collecting as much information as I could about the various designs I had my eye on. In order to make this information useful I collected it into one place. I created a Mind Map using FreeMind software. Here’s a screen capture of part of my map:

This application allows you to create links to various locations on your computer or the web for the nodes you create. You can add pictures and of course text. It was a great way to create a data base that was easy to visually scan and to retrieve information from a wide variety of sources.

Here’s a close up of one section.

By reviewing this information all in one place I was able to start eliminating a few designs but I still had many factors to consider and needed a way of comparing the designs that were left.

This begins the nomograph discussion. You may want to skip ahead to the end of this section if this sort of thing doesn’t appeal to you. I actually think it’s pretty cool.

A good way to compare more than two factors in a decision making process is to create a nomograph listing the factors you want to consider on several axes. I happen to keep a template of a basic nomograph in my modeling program. You don’t need the 3d function, but the ability to move points and shift lines helps make the nomograph very easy to create.

Here’s an overall look at my nomograph-

I start on the left side-

You can click on the image for a larger, more clear view of it.

I started by listing all of the designs I was considering on an axis that scales an estimated amount of time it would take to build that design. This is essentially an estimate of relative time and should not be considered an absolute value. The top of that axis has the fewest hours which is marked “good”. The next step is to draw an axis a little to the right that lists the number of people the boat could carry, or “crew size”. A line is drawn for each boat from it’s position on the “hours to construct” axis to the “crew size axis”. This line is then projected to a 3rd axis which is the first of several intermediate scores.

The important concept in using the nomograph is that the “good” end of each axis reverses as you move from left to right. In this case the “good” score of fewer hours to build is on top followed by the “good” score of a large crew which is at the bottom of the next axis. Following a maximum score leads to the end of the the first intermediate score axis, in this case the best intermediate score is at the bottom of that axis.

Now is when you can start seeing the value of this analytical tool. The next step is start from the the point on the first intermediate score axis for any given boat and then to draw a line from that point to a value on the next axis which in this case lists the stability factor (again, this is relative to the other designs) and then to project that line on to the next intermediate score line. This process can be continued for as many factors as you have to consider.

What you come up with is a way of comparing various options (boat designs in this case) using a large number of variables. You can see how that at any given intermediate score axis you can compare one design against the others for all of the factors to the left.

Here’s a look at just 2 of the boat designs run through the entire nomograph.

The factors or variables that I considered were (from left to right)

  • hours to construct
  • crew size
  • stability
  • weight
  • seaworthiness
  • rowing ease

By the way, the final score axis ended up with the “good” at the bottom.

Here ends the nomograph discussion.

A couple of boat designs scored significantly better than others and I focused on those. At this point I started contacting the boat designers and discussed my plans, my mission and ideas. Eventually I arrived at what I think is the best boat for this project. More on that boat in the next post.

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Part 2, Build It and They Will Come

September 28, 2009

So what changes have taken place along Milwaukee’s rivers?

In the last 10 years there has been an amazing amount of development on the rivers, primarily along the banks of the Milwaukee River.

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Above is view across the Milwaukee River near North Ave. This is just about as far upstream as most boats can travel against the current.

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A little further downstream.

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There is a new Milwaukee Urban Water Trail along this bank as well. Along this section of the trail there are several points of public access to the river including a floating dock where the Milwaukee Rowing Club and Marquette University launch their rowing shells.

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A brewery offers seating and more dock space.

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Read more…

Milwaukee’s Three Rivers

September 24, 2009
google maps
google maps

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This was first posted on my other blog www.fillingham.wordpress.com .

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Milwaukee was built at the confluence of three rivers on the shore of Lake Michigan, the Milwaukee, Menomonee and Kinnickinnic . At present there are 9 miles navigable by small craft before reaching the protected harbor. There is an additional 27 miles or so accessible by canoe or kayak up the Milwaukee River to the dam at Bridge Street in Grafton, Wisconsin.

The three rivers have been used for commerce and recreation for a long time.

Wisconsin Historical Society
Wisconsin Historical Society

Wisconsin Historical Society
Wisconsin Historical Society

Wisconsin Historical Society
Wisconsin Historical Society

Read more…