| Hobie Forums http://www.hobie.com/au/en/forums/ |
|
| Launching Tips http://www.hobie.com/au/en/forums/viewtopic.php?f=78&t=41493 |
Page 1 of 2 |
| Author: | mayfield6 [ Wed Mar 07, 2012 12:21 pm ] |
| Post subject: | Launching Tips |
Guys, I have been breaking in my new PA over the last 2 weeks and have a question regarding launching and in particular re-trailering. I launch alot of times at boat launches. Seems to me that getting it in the water is pretty easy. I am using the pool noodles with PVC through the center support method along the scupper line. The PA wants to stick sort of to the noodles though. Definitely doesn't slide right off like I thought it would. I am going to trade out the reinforced noodles for the 4" PVC to help with that. What I am taking a long time to say is, how are you guys re-trailering when you are solo? It seems clumsy to me to roll over my loaded boat and throw in the cart and roll to the truck. Are you guys tying off and then backing down the trailer? |
|
| Author: | MrGreen [ Wed Mar 07, 2012 2:40 pm ] |
| Post subject: | Re: Launching Tips |
I usually use a cart to wheel the PA back to the trailer. But that is because the main places I launch from are not boat launches. |
|
| Author: | Iceyak [ Wed Mar 07, 2012 3:12 pm ] |
| Post subject: | Re: Launching Tips |
That is a good question. When my wife isn't with me to help lift it from the water to the trailer (THANK YOU HONEY!!  ) unloading everything before turning it on its side to put the wheels under is at times a pain. If entering/exiting from sand is fine, but a concrete boat launch is tricky not to tear your boat to shreds on rough concrete!!
|
|
| Author: | TroutNoDoubt [ Thu Mar 08, 2012 12:31 am ] |
| Post subject: | Re: Launching Tips |
If I'm alone, I retrailer at ramps by backing up to about 6 feet short of the water. I pick up the nose of the PA and place it on the back bunk on the trailer. (My bunks run perpendicular to the long axis of the PA). I have a set of 3 pullies with 50 feet of rope that I attach to the back end of my SUV and the nose of the PA. This allows me to pull the rope and pull the PA on to the trailer w/o assistance. I dont have to roll the PA over on a cement ramp and scratch it up just to put the dolly on. I only have to drag the sacrificial tail pads of the PA to the edge of the water at the base of the ramp. Good luck! |
|
| Author: | TroutNoDoubt [ Thu Mar 08, 2012 11:06 pm ] |
| Post subject: | Re: Launching Tips |
Here's diagram of the process I described: 
|
|
| Author: | Patriot [ Wed Mar 14, 2012 8:10 am ] |
| Post subject: | Re: Launching Tips |
TroutNoDoubt, Your pulley system is just what I was looking for! And the sketches were very enlightening. I want to implement your system. Do you remember the size of the 3 pulleys for loading a PA? Is it 1 single sheave pulley for each side of the SUV & then a double sheave pulley for the front handle of the PA? What diameter rope did you use? Many thanks for sharing the know-how. |
|
| Author: | TroutNoDoubt [ Wed Mar 14, 2012 12:10 pm ] |
| Post subject: | Re: Launching Tips |
They are ~2" diameter pullies I got at the hardware store for a few bucks each - nothing special. The rope is 1/4" nylon rope/cord. Actually, my drawing is incorrect; I use one pulley at each location on the SUV/Truck and a one pulley on the front grab/carry handle of the PA. I made loops out of 12-18 inch lengths of cord so I can quickly loop-hitch them to the connection points, then attach the pullies via the small ring at the back end of each pulley (ID 3/8") via inexpensive, hardware-store carabiners. I pre-string the cord through the pullies with carabines attached so it's quick to set up in just a few steps. Takes two minuts to set it up. Next time I have it set up I'll take some pics or a video, but it's pretty straightforward. For this purpose, the diameter of the pulley doesn't matter. The mechanical advantage of the pullies is directly proportional to the number of times you run the line back and forth between the PA and the SUV. My set up has four runs, so it provides 4X mechanical advantage and only 1/4 of the force/effort is required vs. the force required for a direct pull w/o the pullies. If you need to reduce the pull force further, you can add a pulley or two and increase the number of runs of line. Obviously, a longer lenth of rope is required. I re-drew the drawing to correct it and labeled the runs and directions of line travel (below). Run #1: from carabiner @ PA nose to right pulley @ SUV Run #2: from right pulley @ SUV to pulley @ nose of PA Run #3: from pulley @ PA nose to left pulley @ SUV Run #4: from left pulley @ SUV to hand Hope this helps. Let me know if you have any other questions. Bob PS: There are a number of alternative solutions. You could simply buy a small hand winch made for boat trailers. One designed for small boats is pretty cheap, but you need a place to mount it. 
|
|
| Author: | Tom Kirkman [ Wed Mar 14, 2012 1:29 pm ] |
| Post subject: | Re: Launching Tips |
We use bare 2-inch PVC. We have to be careful and make sure somebody is holding the bow ropes or the boats will shoot off the trailer like the pipes were greased with lube. Same coming back on - we tend to pull them too far forward because they slide on the PVC so easily. I think your problem may be the pool noodles. Not sure they're at all necessary. |
|
| Author: | Patriot [ Wed Mar 14, 2012 3:44 pm ] |
| Post subject: | Re: Launching Tips |
TroutNoDoubt, You da man! Thanks for clarifications & making it simple for me. Understand the mech. advantage of the pulleys is 4X for four passes thru the pulleys, but still a little worried about the "cheap" carabiners. It would seem to carry any load, they would have to be a bit beefier. Right? .... say the load of a PA is 136 lbs; then 1/4th of that would be the load capacity of the carabiner....or 34 lbs each. Am I missing something? |
|
| Author: | mayfield6 [ Wed Mar 14, 2012 7:04 pm ] |
| Post subject: | Re: Launching Tips |
Changed out the noodles for PVC and she slides off just fine now. Thx for the help guys. |
|
| Author: | TroutNoDoubt [ Wed Mar 14, 2012 11:43 pm ] |
| Post subject: | Re: Launching Tips |
Patriot: Bear in mind that the load on the carabiners is NOT the total weight of the PA, but rather the "drag" weight/force - the amount of force required to drag the weight of the boat on to the trailer. This is much less that the force required to vertically lift the weight of the PA, and it is split between the carabiners. It will be a lot less if you change over to bare PVC bunks, which are very slick as Tom noted above. The carabiners I use are rated for 100# each. I wouldn't put more than 50# of force on them. I've never had any problems with the ones I use. It your concerned, you could eliminate tham altogether and just tie the pullies into each 12" rope loop used to loop-hitch to the connection points. Good luck. Let me know how it goes. Bob |
|
| Author: | Patriot [ Thu Mar 15, 2012 5:49 am ] |
| Post subject: | Re: Launching Tips |
Good point, TroutNoDoubt ... drag vs free weight! I have the Trailex trailer with the cradles for the PA. The drag would be higher than the PVC since I am told the cradles are carpet covered. (Ordered for delivery end of this month). I will give your solution a try & report results. Many thanks for the tutorial! |
|
| Author: | gotcha [ Thu Mar 15, 2012 6:05 am ] |
| Post subject: | Re: Launching Tips |
I was looking at the same thing. We have a place called primitive launch. It is kinda steep. I was tink of useing the same set up to lower and retrieve the PA. I found a strip of carpet 3ft. wide and 20ft. long. I roll that out and let it down or up without tear up the bottom. Also protection. |
|
| Author: | qualey99 [ Thu Mar 15, 2012 7:53 am ] |
| Post subject: | Re: Launching Tips |
Your mechanical advantage is only 2X with that set up. A single pulley provides NO mechanical advantage, only a change of direction. If you need to pull 100 lbs off the ground with a single pulley, you must apply 100 lbs to the other end of the rope, even though you have 2 lines running. When you add the second pulley is when you get the reduction on force. The 3rd pulley is again nothing but a change of direction pulley. So you are reducing your force by 1/2. Physics 101. |
|
| Author: | TroutNoDoubt [ Thu Mar 15, 2012 11:11 am ] |
| Post subject: | Re: Launching Tips |
Thanks Qualey99. I'm not an expert in pulley systems and I'm dredging up college physics from 30 years ago, which is pretty dusty! So, I apologize for any errors in my example. I looked at the example again and I partially agree with you. You're right in that the last run is a change in direction and I forgot to substract it from the number of lines used to calculate the mechnical advantage. However, I disagree that the first run is only a change in direction and doesn't contribute to the mechanical advantage. I don't think it matters whether the origin of the rope is attached to the load or the anchor. It still adds a line "supporting" the load, for a total of 3 lines. So I think it counts and the mechanical advantage in my example is 3. In any event, it's not something I want to argue about. So, if I'm wrong, I apologize in advance. Regardless, I think we can agree that block and tackle systems can be a useful tool for re-trailering the PA, or lowering the PA down a slope as Gotcha suggested. I think we can also agree that adding pullies will increase the mechanical advantage of the system and reduce the effort to accomplish the task. Tight lines, Bob |
|
| Page 1 of 2 | All times are UTC - 8 hours [ DST ] |
| Powered by phpBB® Forum Software © phpBB Group http://www.phpbb.com/ |
|