Boat + Tralier max lateral tilt

F

ferret30

New member
We live on a street that has a 12 degree slope (measured with a smartphone app). Our driveway is perpendicular to the street and is flat in both directions, but at the point where the driveway meets the sidewalk, it's up to 14 degrees. I've always thought it would be a bad idea to try to park the boat at our house because of the possibility of tipping the boat/trailer when making the turn. It's been nerve wracking getting a moving truck in the driveway, and that's a pretty low center of gravity.

Anyone had experience moving the boat/trailer on this kind of slope? Are there any guidelines or rules of thumb? I doubt I could ask C-Dory or King Trailer since the answer really depends on the combination of the boat and trailer specs.

I'd love to park it in the driveway for the winter, but I don't want to wind up "in the news". Thanks for your input!
 
The biggest concern would be bottoming out the back/front of the trailer when the tow vehicle was on one slope and the trailer on the other. You didn't say whether it was an up slope or a down slope from the road to the driveway. 14 degrees is a lot! I bottomed out my previous trailer once on a steep slope turning from one road to another. Best to test it out SLOWLY with an empty trailer and someone watching as you back in. However, it might just be better to find an alternate place to park the boat or continue with whatever is the status quo.
 
A 14 degree slope equals about a 28% grade! (100% grade = 45 degrees) Consider that most interstate freeways max out at 7% grade, or an angle just slightly under 4 degrees.

Most likely you will not tip over the C Dory. But I am not sure I would try it. I would also be concerned about the bottoming out of the trailer/truck, depending on the geometry of the drive and street.

(Generally max grade is 12% for residential streets--this is close to 6.8 degrees....so your street is about twice this) There are a couple of other streets in Calif which are close to this--3rd Street in Laguna Beach is 30%, A couple of drivable streets in San Franscisco are in the 31% range, and it is written that Baxter in the Silver Lake District of Los Angeles is close to 32%. I used to go up and down that 30% grade in Laguna with my car--once only with an RV...I would not try it towing a trailer, and I have done a lot of steep grade mountain driving....
 
ferret - ditto on what Roger said. My driveway is steep, narrow and I have the same problem at the bottom. It helps if you have a swing jack. Make sure your wiring is up out of harms way, make sure your rear tires are at full pressure, go slow and have somebody watch or listen. If you have a lot of tongue weight, a weight equalizing hitch might help.

As for the trailer tipping to one side when the inside wheels hit your driveway and the outside wheels are still on the road - you could try lowering the pressure on the inside wheels or installing smaller dia. tires. Make your turning arc as wide as possible(from the other side of the road) to lesson the lenght of time your wheels will be on different planes.

Good luck, it is nice to have your boat at home over the winter.

Regards, Rob
 
I had my boat on the trailer at my sisters last year and it bottomed out on about a 10 - 12 degree up slope driveway from a nearly level street. The 2 foot skid mark is still there. Thought about putting landing wheels of some sort on the back of the trailer, but haven't done it yet. Park the other way so the rain drains out now.

The guy who might have some practical insight on this might be Cory the C-Dory transporter. Dr Bob has the numbers down, and it's hard to argue with those. I think I would be looking at remote storage, without seeing your situation first hand, or maybe getting that moving van back :twisted:

Good luck and stay safe,

Harvey
SleepyC:moon
 
So the bottoming out probably won't be the major problem. We've had a flat bed about the same length as the boat trailer (a lot lower CG, so no tipping worry). The driveway is almost completely level to the street, it just kind of twists like a helix to meet the street slope. It is definitely a steep street -- there are treads cast in to the sidewalk and the street surface has grooves cut in to it like a washboard for traction. When it snows it becomes a popular ski/snowboard area. It's fun to live so close to downtown, but when there's a snow in the forecast, the parking spaces on the level streets are hard to come by!
 
I think that people are confusing the angles. Just to be clear your drive way is flat and the road, at a 90 degree to the drive way is on a slope. When I drove concrete truck in the Seattle area I can across this a lot. Its all depends and I can't say to what degree its going to fall over. I would have to come look at it and I can if you want. I drove propane and concrete for 10 years both here and in the sierras. Both are top heavy loads and I drove in a lot of hill country with out ever losing a load or rolling over. I would be happy to come give it a once over and give you my thoughts on it.
 
Sounds like we might soon hear about the first "low rider" adjustable pneumatic suspension being added to a C Dory trailer as a mod! :smiled
 
ferret - the low rider idea got me thinking, is there some way you could stiffen up the suspenion on the low side(where any tipping will be adding more weight)? Maybe a couple of small jacks pumped up between the frame and leaf springs?

On construction sites years ago to get equipment into a site before the city came to cut the curbs we would dump dirt or gravel to make a temporary ramp over it. What if you marked out the projected path of the wheels on the low side and where the road meets your drive - dump some sand or gravel to even it up a bit(temporarily).

Round up as many heavy set buddies as you can and get them to hang off the side like a sailboat! :lol: seriously though, I did a lot of 4 wheelin when younger and if we had to traverse a section where there was a risk of tipping - we would go thru 1 at a time and 2 or 3 guys would stand on the running board and hold on to the roof rack leaning out. It worked and wasn't a real risk because if the Jeep did tip it would be away from the riders and they just had to let go of the roof rack and jump off. Only tipped my Land Cruiser 2 times! Drivers side both times. :amgry

Just some crazy ideas - I hate seeing a guy not being able to get his boat home for Christmas! :cry:

Regards, Rob
 
There is an easier solution than hanging big guys off one side, smaller tires etc---that is using a portable plywood ramp on the street in the transition on the down hill side of the street to the driveway. This could be in several sections, and contoured to the street--not expensive or difficult to make. I can PM details if you wish.

An equalizer hitch hangs down below the trailer frame with equalizing bars, and would probably make it more difficult.
 
If it isn't compensated pneumatically (adjustable air shock) it could be handled with anti-tip torsion bars like the "Rock Crawler" 4X4'er use. Complicated rigging for a trailer.

Two adjustable pneumatic shocks would do the trick! They even have the type that have electrical switching that can be adjusted from inside the vehicle on the fly.

Or then you could follow the style of the Skate Boarders and BMX Bikers and build a portable ramp to compensate for the angle.
 
Sorry for the delay -- these days it's dark when I leave for work and dark when I get home. But with the magic of Google and their roving fleet of camera cars, I can show my situation with street view pictures.

(PS Tom: Thanks for the offer! Hopefully these pics will be helpful enough that nobody has to drive over to consult! :) ).

Looking up at our street from the bottom of the block:
driveway4.jpg

Half way up the street looking at the driveway entrance:
driveway2.jpg

Looking straight down the level driveway:
driveway1.jpg

Looking down the street from the top of the hill:
driveway3.jpg

Other considerations:

a) The street isn't usually this empty except weekdays during work hours.

b) My truck is only a 1/4 ton (4WD) and I'm not sure how it would handle pulling the boat up the hill in the first place!
 
The issue would be only a short distance where the street transitions to the driveway--the plywood ramp would work very well there. I assume that you would go uphill past the house, and then back into your driveway. I think this would be easier than trying to back up that steep hill.
 
It looks doable but I would back up the hill not drive up it. reason is that if you drive up you are then backing down the drive way. then as you turn the trailer you are pushing the trailer from the uphill side with the most force on the down hill side trailer tires. If you back up the hill then you will be pushing the trailer up the hill on to the up hill side trailer. Its more work on the truck but with 4x4 low you should have no problems. Thats the way I do it at my house. Which is also on a hill with a drive way like yours. I have a 27 that is heavier then yours and I have no problems.
 
starcrafttom":26xb1pkv said:
It looks doable but I would back up the hill not drive up it.
Click to expand...

I was thinking that too. Backing up to the driveway means that when the boat is at a 45 degree angle to the driveway, it's going to be tilting less than 14 degrees. If I backed down the hill, the part where the driveway slopes from the sidewalk height to the street height will contribute to even more tilt.

Also, if I'm backing down the hill with the trailer oriented with the driveway and the truck more pointing up the hill, if something happens like the surge brakes locking (for whatever reason), then the truck's push on the tongue could actually increase the tipping forces.

The thing is if I did it and it worked, I'd have free storage, and wouldn't have to take it up to Lummi Island (my other free-ish option).

But if it doesn't work, it'll be an expensive experiment! Also, it's always questionable how many cars are going to be on the street on a given day, so that can make maneuverability a big concern!
 
starcrafttom":2ol01rg1 said:
Its more work on the truck but with 4x4 low you should have no problems.
Click to expand...

I was thinking about this too, and with all that sharp turning I may have to do, 4 low might not work, or may damage the truck. Turning on dry pavement in 4 low isn't good...
 
Either way, I would lock out the surge brakes mechanically when backing with that steep an angle and the turn. I would double that 4x4 is necessary, unless there is some slippery material (snow or ice--and then I would go for another day). The low range of a 4 x 4 might be an advantage, but usually a low gear will handle this. The reason I prefer backing down hill, is that you are not having to push as hard on the trailer frame as you make the corner.

Traffic--just get some friends out to stop the cars. We routinely block our street when I back the 42 foot RV onto our drive, which only has about an 8% grade.

We always use two way radios when backing boats or RVs in tight or difficult areas.
 
I have always lived on hillsides, often having to turn while backing trailers uphill while doing all sorts of neck wrenching and stomach churning maneuvers. If you have a hitch on the front of your vehicle you can "thread the needle" with ease. I had a reciever welded to the front of my truck and now have one on the front of my tractor. I haven't had such a lateral grade as you have, but control is greatly enhanced with this set up.

Bruce Cassal
Carpy
 
you dont have to lock in the front wheels to use 4 low. And yes turning with the fronts locked in will cause damage. But using the gear ratio in 4 low is what you want. easier on the tourqe converter and more power. I have backed down really steep , standing on the tail gate when you get to the bottom steep, by putting the truck in foward and letting the truck roll back and using the gas to stop it because the brake will not hold it in reverse. it works. I have even used a wench cable to back down a hill to get to another road/trail/rut to get to a fishing hole. If there is a will there is a way.
 
Our truck has 2H-4H-N-4L settings (not push button), and it doesn't have the manual locking hubs, so I don't see how to get 4L ratios without being in 4WD. I have some nice low gears (PRND321), but unfortunately no reverse low.

I do like the idea of having a second hitch on the front, but on this hill there would be no way of switching from one configuration to another -- I'm not trusting wheel chocks on this hill! :)

If we bail on this plan, we'll be taking it up to Lummi Island Thursday. I don't have lots of experience (as in miles) with that trailer, and the spare tire doesn't include a spare hub. The grease looks fine, and it's only a 100 mile trip.

One way or another we're putting this boat to bed for the winter!
 
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