The LAB is a space where we explore ideas in construction, engineering and design technology. It's a space where we publish articles and ideas to deliver a better experience for those who build and sail on our boats. And please excuse me if we throw in a few random thoughts here and there. Welcome to the LAB

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DROP THE DRIPS

A rolled edge on the your cockpit roof allows the rainwater and the condensation to roll around the corner and drop onto your cockpit seat cushions or down the back of your neck. . It’s fairly common knowledge that a channel or a lip with a sharp edge will send the drips packing in line with the forces of gravity. But how big to make the channel and where to put it exactly?

 

Daniel Perlman, a biophysicist at Brandeis University apparently spent three years studying the way wine pours from the neck of the bottle to create a solution that would eliminate the drips when pouring a glass of wine. The solution he came up with is a one millimetre wide incision, one millimetre deep just below the lip of the bottle. 

 

Was this rocket science? Is it the optimal solution and did it really take three years and a lot of slow motion video footage to figure it out? Maybe this study was simply an excuse to uncork a few tasty bottles in the research lab. We are yet to see the publication of any detailed technical papers related to this “discovery”. However it’s a good reminder to attend to the issue in your next build project if you have a hard cover over the cockpit.

 

The cockpit roof solution is fairly simple to implement in the build stage. While you have your roof or cabin top upside down on the workshop floor route a groove on the underside about 20mm wide x 20mm deep and fill it with thickened epoxy. Make sure you’re not cutting through any edge reinforcement required to provide stiffness to the cabin top. When the epoxy has cured cut a new groove in your epoxy channel.

 

How wide and how deep? Depends how technical you want to get. Water and wine share different viscosity values and the hydrophilic properties of glass are different to the hydrophilic properties of painted fibreglass or gel coat. (Hydrophilic properties determine how the liquid beads up or spreads out on the surface).

 

In lieu of any technical data on the topic from Mr Perlman let’s make the groove abut 10mm deep and 6mm to 10mm wide. The depth is more important than the width and the outboard edge should  remain sharp to discourage the drips from going around the corner. 

 

Want better data? Do your own testing. Use water and have a glass of wine later.



NEW FLOATS FOR THE PICKLE FORKS

In 1990 we introduced a new float shape for our trimarans we called the V90. It was deployed on the TR series and later as the shape evolved adopted on other trimarans including Trilogy and the Essential Eight.

 

In 2017 we introduce a new float shape design to improve performance and possibly make for a drier ride when pushing hard in a choppy sea. Read the full article here:


Image for Link to article on the new trimaran float design

Articles on Multihull Performance

Image for link to article on foiling catamaran racing in mixed fleet

Float or Fly- Foils in the mix at Airlie and Hammo

For the first time in OMR racing a fully foiling cat mixed with the action at Airlie Beach Race Week and Hamilton Island race Week 2016. So how did the GC32 perform against the other boats competing and what are the implications, if any, for the OMR?

 See the article here

Image for link to article on catamaran hull lines

Optimising Hull Lines for Performance

The lines the 8.5m Livewire sports cat raised a question about the kink in the rocker line. In this article I've addressed the top of rocker profile, hull fineness ratio, and importance of asymmetry in the water planes for pitch damping. See the article here

Image for link to article on the performance of racing catamaran Mad Max

What Makes Max Fast

Mad Max has been dominating the inshore race results in Australia for quite some time now and is the current title holder (2015) of the Australian Multihull Championships having won the series on OMR and taking line honours in every race. 

So what makes Max Fast?

See the article here


Link to article on multihull performance. How fast really?

Multihull Performance - how fast really?

We all know about the bar talk and some of the wild claims that are made about boat performance. We've put together some information about the factors that determine the performance of multihull yachts and some of the ways that performance can be measured and predicted.

And we propose a more credible method for yacht manufacturers to promote the performance potential of their products.

See the article here:

Image for link to article where are the mid size multihulls

Where are the mid sized multis - the case for a class 40 trimaran?

In the 2015 Fastnet Race high performance multihulls dominated the elapsed time results but multihulls were poorly represented in the under 60' LOA size range. Where were the multihulls in the mid size range? We take a look and make some suggestions.



Design and Design Features


Image for link to article on weight and displacement
Image for link to article on multihull building hours

 

Building hours for multihulls

Building hours can vary considerably from one yard to another, but also from one boat to another in the same yard, even when the designs are very similar. 

Building hours are difficult to nail down but we provide some pointers in this article.

Image for link to article on the weight of multihulls


Image for link to article on fixed keels and daggerboards for catamarans
Image for link to article on helming from the inside


Engineering Topics

Header image for articles on engineering of catamaran and trimaran structures

PRODUCTION BEAM DESIGN FOR FOLDING TRIMARANS

Image for link to article on design of beams for folding trimarans Part 1
Image for link to article on design of beams for folding trimarans Part 2
Image for link to article on design of beams for folding trimarans Part 3

Secondary Bonding in Perspective


Image for link to article on secondary bonding in composite materials

When composite components come unstuck the type of epoxy that was used sometimes gets held up as the bad guy. It may not always be the case. In fact in many cases its far more likely that the issue of secondary bonding is at the core of the problem.

Read the article here: