Below is a list of the special projects the Propeller Guard Information Center is working on, in addition to maintaining our existing web site, recording propeller accidents on our Media Coverage of Propeller Accidents Blog, and other elements of our mission.

Many of the projects are already well underway, but we will not complete all them in 2011, some will be carried over into 2012 and others will be replaced by new projects, but this is our current agenda as of early 2011.

2011 Propeller Guard Information Center Projects

• Converting our website to WordPress to allow easier navigation and quicker indexing by the search engines.
• Finishing a tool that allows boaters to evaluate the risk of propeller injury to them and others on or near their boat based on their specific situation. It helps boaters select the best methods to reduce their risk. The tool is built around a check list that evaluates their risk for specific types of propeller accidents (like running over people being towed by others, running over swimmers, running over someone that fell in
  from your boat, etc.) based on their exposure due to operator error, behavior of those on their boat, specifics of their boat, their on water activities, activities of others on the water, water conditions, potential for underwater obstacles and other variables. 

  The check list also evaluates their need for boater safety education and behavioral modification, as well as their exposure to risk from other boaters.The checklist is accompanied by a written discussion and a group of radar charts showing the relative degree of avoidance/protection offered by various devices to specific types of propeller accidents. In addition to helping boaters select the appropriate device(s) to reduce their greatest exposure to propeller injuries based on their exact situation, it also prescribes boater safety education, and behavior modification where appropriate.

• Closely monitoring USCG’s ongoing development of a propeller guard test protocol and being a voice of reason when things may have been overlooked.
• Closely following continued developments of the Australian Safety Propeller.
• Continuing to call for reissue of the “Don’t Wreck Your Summer” Public Service Announcement (PSA). The boating industry effectively banned USCG from airing a high impact video PSA featuring a propeller accident.
• Establishing a PGIC presence on Facebook.
• Calling more attention to the possible application of two old Brunswick trim cylinder system patents (U.S. Patent 3,999,502 and U.S. Patent 4,050,359) to cage type propeller guards. The patents describe a method that allows a marine drive to freely swing up and over obstacles when striking them at slow speeds. This is in addition to the pressure relief valves and memory piston system normally used to rise up and over obstacles struck at high speed such as submerged logs. These designs were initiated by Brunswick to help prevent people from being thrown from a boat when striking an obstacle at slow speed (not enough momentum to open the system for high speed strikes so the boat abruptly stopped, or if their was enough momentum there would still be an abrupt jerk as they kicked in).The approach described by the patents may have application to propeller safety in two manners. (1) Reducing blunt trauma to people and marine mammals (like manatees) that might be struck by a guard at slower speeds. (2) Protect guards themselves from damage due to striking rocks, other obstacles, or striking bottom at slow speeds. The drive would just swing up with minimal impact to the guard.The forces on the guard during a slow speed forward impact would be limited to the propeller thrust and the forward momentum of the lower unit of the drive. Those forces would even be somewhat counterbalanced by the momentum of the portion of the drive above where it hinges.Proper sizing of the components might significantly reduce blunt trauma loads to people and impact loads to drives on up into midrange speeds.

  The two Brunswick trim system patents can be viewed by entering their patent numbers 3,999,502 and 4,050,359 one at time into the search box at Google Patents. The interesting part is what they call “trail out” at low speed impact.

  The process is detailed further in our response to withdrawal of the houseboat proposed regulations.

  More recently, Teleflex has been awarded a patent that appears even more promising, and actually a cost reduction.

• Especially monitoring propeller accidents outside the U.S. to those visiting that country from another country. We have become aware several international vacationers are being struck by propellers at tourist destinations that focus on water activities (Cancun Mexico, Cozumel Mexico, other Yucatan Peninsula sites, Fiji Islands, Hawaii, the Caribbean, and other well known snorkeling / diving/ beach areas). We are focusing on people from one country being injured in another country while on vacation at a major tourist destination.
• Continuing to promote the concept of Flip-Up guards for houseboats and pontoon boats. It is a convention cage except the end cover (cap) to the rear flips up when underway due to a tab near the bottom of the flip up portion. The tab creates enough weight to pull the cap down when at rest, and enough resistance to flow when going forward to cause the cap to rise and ride parallel to the surface when underway. The design reduces drag when underway, while still providing full protection to the rear when stopped or in reverse.
• Drawing a huge “Fault Tree” that uses logic “ANDs”, “ORs”, etc. to show how and where various propeller injury avoidance devices try to break the accident chain and which accident chains they can and cannot break, as well as how multiple propeller injury intervention devices and approaches interact with one another.
• Following up on some propeller flow and wake studies that appear to open up a concept nobody seems to have looked into before. It involves the inflow path to propellers when they are not advancing (when the prop is turning but the boat is not moving, like when the boat is just starting to take off) and concerns the slope of the open surface of the water on the suction side of the propeller.
• Launching a new web based portal that we think will be vital in encouraging college students to do design and research projects in the area of propeller safety.
• Posting a list of propeller guard tests and propeller test reports from marine drive manufacturers, propeller injury avoidance device manufacturers, boat builders, boat rental operations, the U.S. Coast Guard and others.
• Promoting the use of computer simulation and other tools to study flow, drag, pressures, and interactions around propellers and propeller safety devices.

Feedback

If anyone has any comments, suggestions for areas of study, or would like to help in these efforts, please see our How Can I Help page or contact us.