Designing a pathway for dollies and "trax" from a Dry Storage Lot to the beach. What would be a suggested slope for two persons to easily transport up to 500 pounds of vessel?
Downhill.
Next?
Gee thanks Matt! Just let her go, weeeee...I'm talking about the return trip 
Assuming 200lbs of force to drag it up the slope, 23.5 deg from horizontal.
Angle = asin(drag force / weight)
If you want to only pull with 100 lb of force then 11.5 deg slope.
This is of course assuming no friction as using a set of beach wheels on a prepared surface will be close enough to zero friction for this purpose.
If you really want to get it dead on, determine your coeeficient of friction and use this formula:
Pull Force = Weight[Fcoeff * cos(angle) + sin(angle)]
But again, for practical purposes you can assume no friction. If you want to be sure multiply your desired pull force by 1.1 to "build in" a safety factor.
Maximum recommended slope for cars (short distance) is 20%, meaning you go up 20 for each 100 of horizontal distance.
Maximum recommended slope for cars (road) is 5%, meaning you go up 5 for each 100 of horizontal distance.
Anything in between will work.
Actual, the answer is as flat as possible. Sure dont want to have an easy path to take the vessel down to the water in the morning, then after a hard day of sailing have to drag 500 lbs uphill 
. ADA requirements want about a max 5% slope, but you can get by with a greater slope for less distances, but have landings in between. Just cause water is usually down the beach, you are going to have it downhill somewhat. I would try and shot for around 1-2% for your slope. That is roughly what you see on a cross slope in a road (from the centerline to the curb/gutter). But like I said, the flatter the better.
Jonathan Grant
Mesa, AZ
Boatless
I launch from a ramp that moves up and down with the tides. At a very high tide it is inverted, but at a low tide it can be as much as a 45 degree grade. There is no way that my crew and I can get it out by ourselves if that is the latter case. We have always found at least one other body to help, thank you very much. If we could not we are ready to use the gas powered Mules in the yard that move the 30 foot boats around the yard. We will tie a line to it and keep the Mule on level ground.
Dan
I have found that even getting up a small 3" lip in my storage unit is tuff. I have to get a running start at it, even with a dolly on the front of the trailer. Will be a little easier on CatTrax, but ruff after a long day of sailing.
Thanks to all for the replies.
Dan, I'd kicked around the idea of something motorized and a track. We will eventually build a seawall and install a crane for bigger OD's (J22), but that is down the road. Representing the beach launched boats I wanted to make sure we didn't compromise expenditures on our end, to help them get going sooner (i.e. phased project/phased funding) and be disappointed for not "stretching" out and asking for all the proper room.
John:
Have everyone chip in an buy a cheap 3 wheeler are one of the two sheet go carts like things that Wallmart and Pep Boys sells. Know what I am talking about?
Doug
Doug,
Yes I do. Then it becomes a liabilty concern we don't really need, but thanks.
Just an added note - Handicap ramps are a max. 1 in 12 degree slope . That is one inch rise per foot {12 in} length.
Take a laser level and note the total grade difference .
If it is 36 inches IE you need 36 ft of ramp .
Hope that and this helps http:/