Archive for January 2012

We have seen some great student propeller safety research projects through the years. In an effort to encourage more college students to consider propeller safety projects for Senior Design Projects, Project Classes, Senior Thesis, Capstone Projects, and Thesis, we created a post to attract them, Research Projects for Senior Design Classes, Masters Thesis Projects, & Other Researchers. We followed up that post with a series of posts providing additional information on several of the suggested recreational boat propeller safety projects.

Vlist Propeller Safety Project

Vlist Propeller Safety Project. Eindhoven University of Technology. Netherlands. 2005.

The next step to landing more student researchers is to make the projects more attractive by providing funding, hardware, test equipment, access to facilities and engineers, mentors, internships, software, access to boats, test equipment, fast computers, travel / trips, company tours, branded apparel (caps, shirts), a ride in a fast boat, and related incentives.

Free pizza is always good too.

If your are interested in sponsoring any of the projects listed in any way, please contact us (see contact tab in the menu). If you are in the industry and have another related project you would like to list or sponsor, please contact us as well.

Please step up and help the bright minds of tomorrow take on propeller safety issues today! Read More→

0 Categories : Research Projects

Propeller Guard Design: An Investigation Using CFD. Oliver Lee. University of Sydney (Australia). November 2011.

Mercury CFD mesh

Mercury Marine CFD mesh

We are thrilled to welcome this Computational Fluid Dynamics (CFD) analysis of propeller guards into the library of academic research studies on propeller guards by college students around the world. We also proud to have been a small part of it as it developed. A huge thanks to Oliver Lee for his efforts, to Dr. Steve Armfield his supervisor, to Julian Todd (an Australian propeller safety advocate who assisted with the project), and to the University of Sydney for all their support.

We first heard from Oliver Lee back in late March 2011 as he was getting underway on his Senior Thesis and were able to point him to some information and other studies he found helpful.

Since then he took on a broad swath of propeller guard topics in addition to performing the CFD analysis:

  • Surveyed the types of propeller guards and other propeller safety devices available
  • Investigated the history of propeller guards and the debate surrounding their use
  • Investigated the accident frequency of propeller guards
  • Investigated the relative costs of propeller guard designs
  • Investigated the Australian Safety Propeller and how it fits within this arena
  • Developed a propeller guard rating system based on the protection provided
  • Developed the model and the equations for the CFD analysis

You can download the full pdf document from the link below the thesis. Read More→

0 Categories : Research Projects

Marine drive companies have long employed damping / cushioning technologies to protect marine drives, most typically trim cylinder log strike systems that allow the drive to swing back, up, and over underwater obstacles. Recent years have brought several through hull drives to the market, most prominently Volvo Penta’s IPS, and Brunswick’s / Cummins Mercruiser Diesel (CMD) Zeus Pod Drive.

CMD Zeus Drive

Cummins MerCruiser Diesel (CMD) Zeus Drive

These thru hull drives, typically used on larger boats, are no longer able to be protected by the trim cylinder log strike systems because the drives do not trim. Volvo Penta and Mercury Marine / Brunswick have been issued several patents for break away drives and other techniques to protect the drive and especially to prevent the boat from sinking if the drive strikes a major obstacle, like a large rock.

In November 2011, Brunswick was issued U.S. Patent 8,062,082 for a “Marine Drive With Staged Energy Absorption Capability”. Targeting through hull drives, the patent describes a drive with a long, crushable nose cone. Depending on the amount of energy to be expended when a drive strikes an obstacle (speed of boat and mass of the boat), the nose cone can crush to absorb the energy, or the drive can “breakaway” from the boat. At lower energies (lighter boats and slower speeds) the nose cone crushes to absorb the energy, slow the boat, protect the main part of the drive, and prevent the boat from stopping so fast that people would be ejected. At higher energies (heavier boats and faster speeds), the drive breaks away in a manner that maintains the integrity of the hull and prevents water from entering the boat. The patent includes several charts showing the deceleration capabilities of varies designs. Brunswick introduces the idea of not only crushing the nosecone to absorb the energy, but also of allowing water to fill the nosecone, then forcing it out through one or more orifices during a collision, of filling the cone with an impact absorbing structure, filling the nosecone with an energy absorbing foam, and review previous approaches by others.

The industry is identifying technologies that can protect the boat, and the drive, and do so in a way that does not cause sufficient rapid deceleration to eject people from the boat.

Some of the earlier technologies, and the some of the more recent developments appear to hold significant promise for being able to reduce the impact / blunt trauma felt by humans when struck by a propeller guard. Anything that can reduce the rapid acceleration felt by humans when struck by a marine drive or guard AND the duration of that acceleration is a candidate for reducing injuries and their severity.

We anticipate publishing a post on the science behind blunt trauma injuries in the future which should also be a helpful reference to those pursuing this project. For those not familiar with blunt trauma injuries or who just think of them resulting from being whacked or hit with something, blunt trauma injuries result from sudden accelerations or sudden decelerations. Our organs, tissues, and even bones are damaged when they are accelerated or decelerated too quickly. Blunt trauma injuries can be reduced by reducing the peak accelerations and decelerations of humans struck by propeller guards.

We propose students consider Cushioned Propeller Guard design projects for their Senior Design Projects, Sr. Thesis, and Capstone projects to better protect humans and marine life from being struck by a propeller guard, and provide further information below. Read More→

0 Categories : Research Projects

The U.S. Coast Guard BARD (Boating Accident Report Database) is a vehicle for driving continuous improvement in boating safety, however, it is not being widely used.

We suggest all boat builders closely monitor their boats in all kinds BARD reported accidents, develop and test solutions where needed, and use those solutions to continuously improve the safety of their products. Read More→

Deondra Scott was swimming behind a rented boat at North Carolina’s annual Lake Norman Lake Bash on June 25, 2011. A novice operator backed over her, then went forward over her striking her twice with the Chaparral boat’s propeller. Scott filed suit against the boat operator (Dennis Allen), the boat rental operation (David Orzolek), and the boat builder (Chaparral Boats).

Deondra L. Scott v. Dennis F. Allen, David D. Orzolek, and Chaparral Boats, Inc. was filed on January 3, 2012 in the General Court of Justice Superior Court Division, County of Mecklenburg, North Carolina. Read More→

2 Categories : Legal Shorts

A young boy, David Paul McFarlin, was killed in a May 31, 2010 Storm Lake Iowa boating accident. A Labor Day boat outing on Storm Lake became a tragedy when their 175 horsepower Mercury Marine outboard motor struck a submerged dredge pipe on Storm Lake, the Mercury outboard flipped backwards into the boat, and David Paul McFarlin, a ten years old boy, was killed by its propeller.

CASE UPDATE: This case was settled June 12, 2012. A separate suit was filed May 30, 2012 against the marina (Lakeside Marina in Storm Lake Iowa) that still exists.

The full title of the case is:
Estate of David Paul McFarlin, by its Personal Representative, Jamie Laass, Jamie Laass individually; and Jamie Laass, as parent and next friend of S.L. vs. City of Storm Lake, and Iowa Municipal Corporation, Buena Vista County, and Iowa municipal corporation, Lake Improvement Commission, an Iowa Chapter 28E organization, Brunswick Corporation, a Delaware corporation, dba Mercury Marine and Lund Boat Company, Harry Foote, Randy Redig, Russell Harrington, and David Botine.

Justia titles the case as Laass, et al vs. City of Storm Lake, et al

Jamie Laass is the boy’s mother, Harry Foote was operating the boat, Redig, Harrington, and Botine are the dredging defendants.

Brunswick (Mercury Marine and Lund) is being sued for negligent design and warnings. The case is in U.S. District Court for the Northern District of Iowa Western Division. Read More→

0 Categories : Legal Shorts

Mercury Marine Tiller Outboards

Mercury Marine Tiller Outboards

In McGarrigle v. Mercury Marine Mercury claims McGarrigle’s accident is the first one of its kind involving one of the over 750,000 tiller outboards (portable outboards) they built from 1986 to July 2007. We suspect there were several more. This post documents our quick search for others.

Our Mercury Marine Tells Court the McGarrigil Accident is the First One Involving Mercury Tiller Steered Outboards post defines exactly what Mercury Marine said. Read More→