Boat Ramp, sink or swim!

[Neo]

I have found the best place to launch my Mac in a local waters....
It's an easy tow
Not well known, quiet suburb.... Not on the state government list.
Lovely parklands, flat firm gravelled car park.
Plenty of tree shade for prep and pack up .... But too many trees to raise the mast.
Has a jetty by the side of a wide, steep ramp.
Minimal tide variation into calm water.

It sounds like a dream but it has a major problem. The concrete ramp has warning signs saying it's steep. It doesn't look that bad, so I'm not so worried about that. But the concrete part of the ramp is actually quite short then drops off (an inch or two) to medium size pebbles in firm mud .... It slopes about 15 degrees runs down around 5 meters from the top of the water line to the bottom edge of the concrete. I have a 4 wheel trailer so I'm thinking I could reverse the rear axle off the end of the concrete but I'm worried about putting all 4 wheels onto the pebble slope past that point.

Just wondering if anyone else uses a short steep ramp like this and how they get on?
Would the pebbles take the weight of the whole rig on 4 (225/15) tires?
Will I have trouble driving back up the step?
How much of the stern needs to be submersed before the mac will lift of the trailer?

Any other ticks I could use to launch and retrieve?

Many thanks.
Neo

[Tomfoolery]

A couple of thoughts on steep ramps.

Remember that your trailer doesn't carry any weight beyond its own when submerged, and even then it's light due to the four tires, and the bouancy of all materials under water (and aluminium is less dense than steel). Some have reported their dual-axle aluminium trailers actually float. So fully submerged to where the bow can get onto the front vee bunk, there little weight on the tires.

With the bow on the vee bunk, the boat is still floating except for what bit of weight is on the front bunk. Most of the boat is still floating.

By the time the boat stern ends up in the stern bunk, the wheels are quite some distance up the ramp, though I have no idea how far in the case of your particular ramp, and for that matter, the trailer and boat combo. Draining the ballast before loading would mean the trailer is higher up the ramp before the stern lands in the bunk, and will also make it easier to get onto the front bunk, so you don't have to dunk the trailer quite as deep to start with.

So the full weight of the boat isn't taken on the wheels until the last bit of hull bottom is out of the water, which is pretty far up the ramp. But a steep ramp is still a steep ramp, so you still need something that can pull it up without slipping and sliding. I actually use low-range in my Jeep GC to pull it up the steep ramp at my marina, mostly so I don't have to rev the heck out of it. But it drops off like a ski jump.

Remember that if it was a typical power boat and trailer, you wouldn't have to dunk it as far, and you'd be winching it up the rollers instead of floating it onto the front vee bunk. If you add a couple of wide rollers further back, you could probably leave the trailer higher and dryer, and winch it up the last 10 ft. The rollers can and probably should be low enough that the hull doesn't touch them when the boat is nestled in its bunks - but they'll help ramp the bow up to the vee bunk without dunking the trailer as deep.

I would probably take the trailer there empty and dunk it to see how far you have to go to submerge the goal posts and get the vee bunk to the water line, and how the tires hook the edge (if at all) and where, so you can get a feel for whether you'll be fighting to get it back out with a boat on it's back. Note the point where the rear bunk starts to clear the water - that's where the tires start taking any real load. Anything before that is on the hitch mostly (via the little vee bunk), and the winch line pulling as the tow vehicle drags the bow up hill, tilting the boat up in the process.

But an inch or two (or more) drop off hasn't been a problem with my 2-axle steel trailer. As I said, it's not loaded when the tires had to climb onto the concrete. But that would depend on how shallow the edge is.

Here's the ramp I use for the Erie Canal. Talk about steep. It's actually quite shallow from the break on up, but it drops steeply at the break. It was taken in the winter when the water is drained, so you can see the scary part. My tires do go over the break, as I can see the trailer suddenly submerge like it's the Red October (it was pretty scary the first time - I didn't know what it looked like under the water), but there is no edge that anyone's tires can reach. But even if there was, the tires would easily climb it with no load on them. The water is normally just under the cantilevered wood walkway on the wall, covering the rocks (gotta use only the outside rudder, and just a little CB).



But as I said, the wheels have very little load on them until the trailer comes up and starts taking the boat weight. The bow weight when you first start pulling the boat up the ramp is almost completely on the hitch, as only the vee bunk has any load on it, and it's very light to start. It obviously increases as the boat is pulled up hill, but it's still mostly on the tongue. Once the other two bunks start taking weight, it's only a few feet more until it's completely on the trailer and clear of the water. You can even feel it as you pull it up the hill.

Sorry for the diatribe - the coffee is flowing freely, and it's quite strong to-boot.

[Neo]

Great response Tom, some really good points, I'm starting feel like I'm "up for this" experiment ....Thanks
The Erie Canal ramp looks like something from a horror movie

[Tomfoolery]

The Erie Canal ramp looks like something from a horror movie

It is, in large part due to it being exposed to the current. And yes, there's a very strong current sometimes. Like when they drain a lock. It's a LOT of water coming downstream when they lock someone through from high to low. The old guys step the valves open in three steps, opening a bit each time as the pressure drops with the water level, but the young-uns open them all the way right off the bat (I guess when no one is looking), sending a torrent downstream.

When hauling, the boat is almost completely sticking out into it, which makes it hard to get onto the trailer. I have to leave a rudder down, and the CB halfway down, and take a long run at the trailer, crabbing into the current as I go. I usually have to hit it a few times to get it into the vee bunk, at which point I leave it idling in forward, steeing the OB to center the stern, then go forward and hook and crank.

Some better guides up front would certainly help.

Go try the empty trailer thing and see how it goes. Nothing to lose, and the trailer (if aluminium) probably weighs about 10 lb under water, so you can mess about as much as you like to feel comfortable about how deep you need to go, and how far up the ramp you need to be for the rear bunk to start breaking the surface.

Bring a buddy in a pickup truck with a tow strap, if it makes you feel better.

Say, isn't it past your bedtime down there?

[Bayou]

This kinda reminds me of when I had my Hobie Tandem island. After we launched I was having trouble finding a parking place so I backed the trailer tires off the edge of the bulkhead in the swamp next to the launch, I thought that I would drive off when we were ready to leave, but I was wrong. When we got back from fishing I tried to drive forward but when the tires on the trailer hit the edge of the bulkhead my tires started spinning. No problem I will just put it in 4wheel drive.( My wife at this time is starting to voice some concerns) So with the truck in 4 wheel drive I gave it gas and the tires started spinning ,who would have thought. And no I wasn't drinking ,that would have been a good excuse for my overload of stupidity/testosterone. So now for the good part my next cleverly calculated move was to back up a couple of feet and then pull forward and this is what happened. When the tires hit the bulkhead and the truck somewhere in the neighborhood of 5000 rpms the trailer shot up about level with my wife's 5.5 height and came right on out... with my axel relocated approx. 13 inches rearward. I had to use ratchet straps to hold the axel on while driving the 45 minutes home while listening to my wife laugh at me and make remarks about idiot redneck YouTube videos So the reason for this long detailed explanation is to let everyone know that if you back your trailer off the edge of a concrete ramp Don't worry just back up alittle more put the truck in 4 wheel drive mash the gas peddle to the floor and it will come right on out .. just make sure you have some ratchet straps

[Neo]

It's days like that that make you say "OMG!!!" and "WFT!!! but it's memories like that that make you laugh
People ask me why I have have a Mac (or such a big trailer boat) where there's so much to do and so much to contend with. But I my answer is clear. Other boats (any type) are just too boring for me

Thanks for sharing that Bayou

[mrron_tx]

Nice long grade ramps work for Me....... steep ramps makes Me think water is going to come over the stern

[Neo]

Nice long grade ramps work for Me.

So you're placing your own metal ramps in the water? ....

[Tomfoolery]

Nice long grade ramps work for Me....... steep ramps makes Me think water is going to come over the stern

Funny you should say that - water does come over the stern when I launch or haul the boat up my marina's ramp. It's so steep, the angle is great enough that the stern sinks pretty far before the bunks start lifting it. I haven't noticed if the water is high enough to get into the steering and control cable hole, but it was a bit off-putting the first time I saw that. I make sure to drain the ballast before hauling it now, but don't remember looking to see if it sits as low as it comes up the ramp.

And the ramp actually does have steel tracks. But they're not shallow.

[Flmeadows]

I launch from the shoreline, in the new mexico mud sand, never had a problem.
Most of this has little to do with the boat, and more to do with your tow vehicle.

[Neo]

...water does come over the stern when I launch or haul the boat up my marina's ramp. It's so steep, the angle is great enough that the stern sinks pretty far before the bunks start lifting it. I haven't noticed if the water is high enough to get into the steering and control cable hole...

I don't think my ramp is as steep as the Erie Canal ramp but what about your outboard?... I guess it's jacked up while launching so is the front of the cowl being submersed? .... right at the cable entry holes, where the air intake is and much of the electrics are positioned.

[Tomfoolery]

The OB doesn't go under, at least not more than the transom mount and tilt hydraulics. The stern of the boat goes under, flooding the engine well, which then drains out as it levels out. I just don't know how deep it goes. It may get up to the cable entry point of the OB, but a little water in there won't hurt it as it's also drained. As long as it doesn't go too far under.

I should take better notice, though, and if the OB is getting too deep, tilting it partway down would be prudent, so it's essentially vertical when the boat is most tilted.

OK, so now you're getting me nervous. And it will be a while until I launch. No sleep.

[Neo]

OK, so now you're getting me nervous. And it will be a while until I launch. No sleep.

Opps .... Sorry Tom

[mrron_tx]

Nice long grade ramps work for Me.

So you're placing your own metal ramps in the water? ....

not quite..... I just have to be very choosy where I launch

[mrron_tx]

Nice long grade ramps work for Me....... steep ramps makes Me think water is going to come over the stern

Funny you should say that - water does come over the stern when I launch or haul the boat up my marina's ramp. It's so steep, the angle is great enough that the stern sinks pretty far before the bunks start lifting it. I haven't noticed if the water is high enough to get into the steering and control cable hole, but it was a bit off-putting the first time I saw that. I make sure to drain the ballast before hauling it now, but don't remember looking to see if it sits as low as it comes up the ramp.

And the ramp actually does have steel tracks. But they're not shallow.

I'm just not willing to let any water in the interior that I didn't bring aboard Ron.