Research Project

Conclusion

The fender designed in this project appears to work much better than those currently available with the added benefit of taking up much less space. It is also easier to deploy and position onto the available dock poles. I intend to continue developing the design in the future and will be keeping some of them on the boat as a permanent addition to the fenders we have. Depending upon the amount of interest from other recreational boaters I may also make a few more to sell.

Update 2

Procedure:

Another prototype was created using a foam pool float with some 3D printed pass-throughs for the belt. The foam was cut to the same dimensions as done previously and 4 slits were cut vertically in each corner for the pass-throughs. The 3D printed parts were then installed and a belt with a buckle was threaded through two of them and sewn to the buckle.

Findings:

The upgraded design worked better than the first and was easier to secure to the test pole than the first. It held on tight and had the advantage of the stickiness of the thin rubberized coating to prevent it from sliding up and down the pole. Other findings:

  • The rubberized coating is too thin on the outward-facing side and could be easily torn.
  • The foam isn’t quite as tough as that used previously and probably won’t last as long under constant wear.
  • The cut edges should be sealed to prevent waterlogging
  • a different type of buckle should be used as the current one is challenging to tighten around small poles.

Next steps:

A few modifications could be made to the current fender to improve some of the issues shown such as applying a rubberized coating to the outside and replacing the buckles used.

Photos:

Cutaway design of inner and outer strap connectors:

 

3D printed pass-throughs (right) and bird guards for bow poles (left):

 

Raft foam used to make prototype:

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Cutting raft foam to size:

Closeup of strap:

 

Testing of the finished fender on pole:

Update 1

Procedure:

After some research and design, I came up with a basic bumper design that I could build from materials I had and some basic fasteners from a local store. I started with a roll of 1/2 inch thick closed-cell foam that I cut into two 2 by 1 foot rectangles. I then sewed the two pieces together using paracord. To protect the boat from rubbing directly against the black foam and potentially rubbing color off or tearing the foam I sewed a cover made from a few yards of fabric and a zipper. Once the foam was in the zippered cover I tested it at home by wrapping it around a pole with a nylon belt and dual-sided release clasp as a fastener. Once I determined that the belt could hold it around a pole I tested it a few times on the boat so see how well it performed at keeping the boat off the dock.

Findings:

The prototype performed spectacularly for what it is. It was dense enough to prevent the boat from squishing it flat against the pole but was easy to stow and use. it took up considerably less space than the bumpers and was far easier to attach to the poles. A few improvements that could be corrected in future designs:

  • It should be made of a single piece of foam as water can get between the two rectangles and make it smell if not properly dried
  • A lower density foam could be used so it’s lighter and potentially make it a bit thicker so it is softer for the boat to push against
  • The belt and clasp should be sewed onto the cover or better yet pass through the foam to be more secure and easier yet to attach to the pole
  • Closed-cell foam works well but isn’t too visually pleasing potentially a foam with a rubberized coating could be used in its place

Next steps:

For the next prototype, I plan to choose a different type of foam and will implement some of the design improvements noted above. In the meantime, the current prototype will continue to be used and tested and other potential improvements and flaws will be noted.

Photos:

Sewing the cover for the prototype:
Without the prototype fender (notice the lower fenders fail to keep the boat off the pole):
The prototype fender in use:

Research Project Planning

The goal is to create a product that can be strapped to poles in marinas to protect boats from damage due to rubbing against docks. I am going to make a prototype of the fender from some 1″ thick closed-cell foam I had with a fabric casing and a buckled strap. I will evaluate how well this bumper design protects the boat by testing it compared to the large bumpers we have or as a supplement to the current bumpers. Then from the results of testing, I will create a second iteration of the prototype that addresses the issues I have with the first.

Research Project Intro

I have found products similar to what I want to create but they are meant to be mounted permanently to the owners dock instead of being removable to take with the boat to other docks that may require that type of fender. The following articles highlight damage done to boats by docks and examples of current types of fenders.

http://www.svsarah.com/Sarah/ewRubRailDamage.html -details damage and repair steps taken to fix damage to a boat due to a pole.

https://www.whiskeycreektrading.com/fold-go.html -This is similar to what I want to create but this only works on 4”x4” square poles and only covers the front face of the pole. The issues with this is because if its attachment method it can be pushed around the side of the pole if the boat rocks up against it and if a marina has different size/shape poles it would be useless. It is also 40 inches tall so it would be difficult to store on most boats.

https://www.anchoring.com/blogs/anchoring/dock-bumpers-and-fenders-protecting-your-boat-from-the-dock -list of several current fender types. My design is most similar to the piling fender but it would be removable and able to fit any size/shape pilings.

-A method we’ve used at one marina to keep the boat off the pole. Note that not many docks have a nail driven into the top of them like this one. If it was rougher in the marina or the wind was faster he bumper could easily be pushed around the side of the pole.

-another way of tieing the fenders to the pole but the disadvantage is the shape of the boats hull makes it difficult to keep it away when the bumpers are placed down lower.

-Here’s an example of how the shape of a boat makes it difficult to use fenders near the waterline. Because the boat tapers away from the dock as it nears the waterline the lower a fender is the wider it must be. in the photo above the fender is around 1.5 feet in diameter but the boat still rubs against the dock pole.

-Example of some damage to a boat from rubbing against a dock pole.