Ramp Design

Dear friends,<br /><br />I will build a ramp at my home, on a river bank. What is the dimension and angle of a ramp that is good for a boat up to 23 feet ? The water here is almost 1.5+ meters different between highest and lowest ( more some day ).<br /><br />Thank you.

Re: Ramp Design

i can say that's a hard question to answer.. got to consider what you have in the way of a tow vehicle an such .. guess best answer is as wide an as less incline as possible.. a floating dock is nice .. a deck that floats via foam blocks or empty sealed barrels ( plastic ones prefferd ) or whatever.. install 4 poles in the river bed , 1 at each corner of the deck/dock,, but not tite, give room,, latch deck to poles with a loose rope loop with short cut pieces of pvc pipe to act as rollers ,, so deck moves up an down with the tides.. it's a beautiful thing..

Re: Ramp Design

Do you already have some local ramps you use and like? why not mesure them? Are you doing it yourself of having it done?

Re: Ramp Design

My .02$ check the ramps out in the area, once you decide om the grade and length,and the area is cut out use 3/4" stone(temporary),see how it works with respect to the tides,etc. Later on have black top or concrete installed. You are going to need a foundation anyway.

Re: Ramp Design

There will be an optimum ramp angle and length to suit your boat, trailer, vehicle and tidal variation. Ideally you will be able to back in deep enough, without having your car in the water. This is the requirement that sets the perfect angle.<br /><br />Crab bait made a good suggestion about the floating pontoon / dock - if your budget can extend to that.<br /><br />Below is a picture of my local boat ramp (Half Moon Bay, Auckland) which has long floating pontoons (Obviously you'd be looking at a scaled down version for a private ramp). These are great for loading people in and out without getting their feet wet. As Crab Bait said, they float on the water, so are always at the correct level.<br /><br />

Re: Ramp Design

For my :02c worth, our local ramps in West Auckland are all listed in the local map guide as between 7 and 10 degrees angle. The floating dockside is a great idea. I know, take it from someone who launches solo sometines and without a poontoon to tie up to there can be difficulties. Thinking back the 10 degree ramps are noticeably steeper than 7 degrees. A 20'+ boat would require a good tow vechicle for that one.<br />Good luck. Going by your posts you're getting very serious about boating. Keep us posted.<br />Ross

Re: Ramp Design

i would call the lake office nearest you and ask them to provide the name of the contractor they use when building new ramps on the lake. that would be a great start for you.

Re: Ramp Design

that's the best refferance picture,there kiwi!! this pictures worth a 1,000 words. wish i was backin' downer rite now for a day on the water .. LOOKS GREAT

Re: Ramp Design

Dear friends,<br /><br />Thank you very much for your advices. I love boat since very young and just made my dream come true. Right now, I have made a temporary ramp with ready made concrete sheets that normally used for house construction. My father, who is an engineer, do all calculations and constructions. We can do it at a very low cost and can change it if we have to. Right now it is 15-20 degree (a little too steep but OK), 12 meters long, approx. 2.5 meter deep (when high tide). I use my Jeep Cherokee 4.0 Liter to launch my 17.5 feet boat. It was easy launching when high tide but a bit difficult when low tide because the trailer's wheels almost reach the end of the ramp. I may have to extend the length a bit more into the water. After finding the proper length and angle, I will lay a permanent concrete layer on top of the concrete sheets. The main problem is the water level here vary a lot. If the angle is not steep, the ramp length would be too long to fit my house. I plan to make a winch or rail (like a mountain train in Switzerland) to launch & retrieve the boat instead of using a car. What do you think ?<br /><br />Thank you very much.

Re: Ramp Design

Re: Ramp Design

Pannet <br /><br />Another option which may be easier, is to get a winch for your Jeep. These are a standard accessory that attach to the front of your vehicle - very popular with off-roading enthusiasts. You should be able to get one from your Jeep dealer. Then you only have to find or make a good anchoring point at the top of the ramp...

Re: Ramp Design

As far as the winch idea: watch the weight of the boat/trailer and the angle at which you tow it up. The rolling coefficient of anything on pneumatic tires is 0.030. In order to make sure your winch you will need to make sure that it does not exceed cable and winch capacity. There is a formula we use in the USAF to figure rolling coefficient for the aircraft winch we use to pull vehicles (among other things) up the ramp into our aircraft, but it is quite complicated and you need to know the sine/cosine of your ramp angle. Loadin' airplanes is my forté -- being a loadmaster and all Some of it applies here too. Just be careful - would hate to see bumper/winch part from the Jeep.