Efficiently Shorten Your Boat Trailer for Winter Storage | 5" Aluminum I-Beams

[pjm]

I want to shorten my boat trailer so that it will fit in my garage in the winter, It has to be able to be put back together for the summer. Trailer is built with 5" aluminum I-beams running down each side. My idea is to cut the two beams and splice back together with 4 pieces of aluminum channel about 15" on either side of the joints so two 30" pieces would sandwich each of the I-beams and be bolted together so they could be removed once a year. I beam material is 1/4 " and channel to be used just fits inside and is .29" material.
Coments or help would be appreciated.

 

[minger]

They say the two happiest days of your life are the day you buy your boat, and then the day that your boat trailer snaps in half doing 80 mph on I-75 on your way to Lake Erie.

On all serious though, I would be pretty hesitant to do this. You really don't know what kind of safety factor was used when designing the boat, and you really don't know what kind of stress concentrations will arise from doing this. If you have any loose fit in the connection, it will just amplify the problem.

If you must do it, then I first advise drawing a free-body diagram. Indicate your trailer as a beam, and apply your load to it. See where your shear and moment forces are minimal and break the beam there. Do not simply break it in middle. Chances are it will be towards one end or the other.

How much do you need to trim off? Perhaps there's some way to modify the hitch such that it's collapsable or something.

 

[eachus]

Or better yet, do some simple trigonometry. What is the longest object that can fit in your garage diagonally? Since I assume you are not thinking about cutting your boat and gluing it back together each spring, there may be a way to fit both boat and trailer in the garage without surgery. Even if your trailer is heavy enough to require a couple of jacks or whatever to get it in place, the overall effort might be much less than reassembling the trailer.

 

[turbo]

To add to the above, don't just think in terms of the horizontal plane. If you have rafters to suspend a come-along from you might be able to suspend your trailer in such a way as to make maximum use of the 3-D space. Make a lightweight "T" out of wood to approximate the dimensions of your trailer, and get creative trying to fit that into your available space.

 

[pjm]

Ok: I've actually thought about all the alternatives and short of building a new garage, this seems to be the best option. The trailer already has a hinged tung about 2' ahead of where I want to cut. The trailer has two axles so is pretty well balanced with only about 150 lbs of weight at the cut point about 2 feet behind the hinge and about 12' ahead of the first axle.
Does this help me, there really isn't much downward force at this cut point because of trailer balance, so most of load will be when pulling and breaking. I'm thinking that the material added due to splice bars is about twice that of original I-beam. Because the two I-beams are coming together about 18" ahead of the cut point we have a triangle between the two beams and the ball connection from the cut point forward. Hopefully this helps share the pulling force on the two splices.

 

[DaveC426913]

Ok: I've actually thought about all the alternatives and short of building a new garage, this seems to be the best option. The trailer already has a hinged tung about 2' ahead of where I want to cut. The trailer has two axles so is pretty well balanced with only about 150 lbs of weight at the cut point about 2 feet behind the hinge and about 12' ahead of the first axle.
Does this help me, there really isn't much downward force at this cut point because of trailer balance, so most of load will be when pulling and breaking. I'm thinking that the material added due to splice bars is about twice that of original I-beam. Because the two I-beams are coming together about 18" ahead of the cut point we have a triangle between the two beams and the ball connection from the cut point forward. Hopefully this helps share the pulling force on the two splices.

I would not trifle with these forces.

It quite likely voids any insurance you might have too.

 

[DaveC426913]

The trailer already has a hinged tung about 2' ahead of where I want to cut. The trailer has two axles

This is exactly what I have. Did the trailer come with the boat? What kind of boat is it?

 

[pjm]

Yes the trailer came with the boat, a 20' baja outlaw. The boat will fit in the garage with about 6" to spare but the trailer tung sticks out about 2' past hinge point. If I don't lock it up, I'll loose it.

 

[DaveC426913]

Yes the trailer came with the boat, a 20' baja outlaw. The boat will fit in the garage with about 6" to spare but the trailer tung sticks out about 2' past hinge point. If I don't lock it up, I'll loose it.

1] I'd alter the garage before I'd alter the trailer.

2] The trailer hinges. How far will it hinge? Enough to shorten it if you put the nose on blocks to make it high enough?


3] Baja outlaw? Where does the mast go?

 

[pjm]

So would I but garage is as big as allowed by city. Neighbours turn everyone in if they see something that doesn't comply. Can't go up that high because back of trailer hits ground. As I said, all options have been investigated. Can't find alternate indoor storage, and outside is not an option. I keep coming back to cut and splice. If we can put men on the moon, surely there is some method to splice safely. Kind of sound like a broken record, don't I

 

[DaveC426913]

So would I but garage is as big as allowed by city.

I meant cutting a small hole in the door for the tongue. Since the tongue hinges, you can cut the hole in the bottom edge, kind of like a cat door.

Or better yet, back wall, where your neighbours won't see it.


Why is the tail touching ground a bad thing? You know you're supposed to raise your trailer anyway when it's on storage? It's takes pressure off the tires. Unless you like square wheels come spring.

Build a cradle that supports the trailer off the ground, the rear brace just behind the axles.

 

[pjm]

OK I did a scale drawing and rotated the front up to clear the opening. The front of the trailer has to be 11' up which is higher than the ceiling and all four wheels are off the ground with the back of the trailer touching the ground. The back wall of the garage is concrete and has two large conduits inside for 400 amp power service. Don't want to go there. The garage door is a brand new insulated steel rollup so cutting a hole would compromise its integrity and be a shame to ruin. How do I send pictures- I'm new to this

 

[DaveC426913]

OK I did a scale drawing and rotated the front up to clear the opening. The front of the trailer has to be 11' up which is higher than the ceiling and all four wheels are off the ground with the back of the trailer touching the ground.

Even with the hinged tongue? Even if it's in the garage diagonally?

How do I send pictures- I'm new to this

Your posts have a "Go Advanced" option that will get you more features. Look for the paperclip. It allows you to attach a file.

 

[pjm]

Yes even diagonally, that's what I was trying because it minimizes the height requirement. If you get this pic you can see that I have to cut just behind the winch sort of in line with the bow of the boat. The 2x2 seen running down the middle would be unbolted from the crosssmember and pull out with the front being removed. This tube is bolted through the two beams where they terminate and has the hinge piece and hitch connected to it. I hope you can enlarge pic so you can see what I am talking about. Look forward to your comments.

 

[DaveC426913]

What if you moved the position of the boat on the trailer? Moving the boat forward 2 feet would give you the room you need.

'course now you've got the same problem with the winch post...

 

[pjm]

Boat can't go forward enough even with the winch removed mainly because the leg at the back hits the trailer. If I remove the leg, I still have a problem because the beds are designed to support the hull in that position and the hull would then not be properly supported. Ready to cut the i-beams yet?

 

[DaveC426913]

Boat can't go forward enough even with the winch removed mainly because the leg at the back hits the trailer. If I remove the leg, I still have a problem...

Your boat has a leg?

Well there's yer problem...

Ready to cut the i-beams yet?

Nope. I'm a thinky guy, not a buildy guy. You'll have to wait around for some buildy guys to come along.

 

[pjm]

OK: Thanks for the input, I've enjoyed the joust

 

[dr dodge]

I would consider cutting. but I would make 2 crossmembers out of channel, wide enough to go over the I beams. trim the web out so that the outside ends of the channel crossmember go over the Ibeam. then weld and bolt both crossmembers to the trailer so they sit back to back and bolt them thru. then plate the I beams, and weld and bolt one side of the plate. that boxes the ends of the frame at the point you cut it at. I would also put a diagnal piece in the rear section between the added crossmember, and any existing one. if no rear crossmember then a pair in a v shape. use large bolts, nylon head nuts and big washers (also preferably welded in place) on both sides of every bolt. and quite honestly, I'd use a dozen or so 6 on the sides of the splices, and 6 to hold the crossmembers together.

now, insert disclaimer here: I am not a structural engineer, marine trailer engineer, civil (or un-civil) engineer. material composition can vary significantly, and some alloys can NOT be drilled without starting cracking problems that can NOT be stopped. welding should be done by someone VERY GOOD. << deleted by berkeman >>
be careful, be safe, closed coarse, professional driver, do not attempt this at home, milage may vary with driving style

dr

 

[dr dodge]

opps you'd need 18 bolts

dr

 

[gmax137]

pjm - you're showing good patience. Just remember this is an engineering forum & engineers are very careful, and like to take a conservative approach to problem solving...

As the exception to the rule, there's another thread (in the Materials... forum) where people are helping a guy design a trailer hitch for his motorcycle - so he can pull a trailer with another motorcycle on it. Now that's crazy...

EDIT _ sorry, once again I replied after reading the first page of posts, not realizing that the thread moved along on a second page.

 

[pjm]

Thanx guys. In certainly open to suggestions

 

[DaveC426913]

<< quote deleted by berkeman >>

We try very hard here on PF to not advise members to do illegal things.

 

[turbo]

We try very hard here on PF to not advise members to do illegal things.

Good point, Dave. If the OP lived around here and cut his trailer, he'd be in trouble in fairly short order. We are trying very hard to prevent the spread of Eurasian milfoil in our ponds and lakes, and there are often official-looking people stationed at boat-launches looking closely at your trailer, boat hull, props, etc. Even very little pieces of the milfoil can propagate, so if your boat/trailer have been in a pond contaminated by that nasty invasive plant, the next pond you launch at could become the next one contaminated.

If the trailer cannot possibly fit in the garage, I'd build a cradle in the garage to hoist the boat onto, and find an inexpensive place to store the trailer for the winter. There are all kinds of places around here that offer winter-storage for boats, trailers, RVs, etc, and some are quasi-public places, like exhibit buildings at our county fair-grounds. Many people own old farms and they don't farm, but they have big barns with lots of storage room. I have a friend with a big old chicken-barn on his property, and he stores boats and airplanes for other people. Old metal-frame building with concrete floor, aluminum siding and roof... it's pretty fire-proof.

 

[Borg]

They say the two happiest days of your life are the day you buy your boat, and then the day that your boat trailer snaps in half doing 80 mph on I-75 on your way to Lake Erie.

The third happiest would be the court appearance for the trailer smashing into another vehicle. If you're lucky, it would just be a lawsuit for damages and not a manslaughter trial.

 

[dacarls]

After owning and successfully modifying about 20 boat trailers, I just don't get cutting the boat supports!
Just modify the tongue- It already is moveable with its hinge.
You can cut it at the garage-fitting length, then make a really strong inner sleeve to fit inside the 2 halves, and put a serious set of pins through these parts. Look at the trailer hitch receiver inserts: they are held together with large 1/2 inch or 5/8 inch pins. It has worked for farm tractors for 100 years.

 

[DaveC426913]

It has worked for farm tractors for 100 years.

Travelling 200 miles at 60 miles per hour??

 

[Jasongreat]

If I don't lock it up, I'll loose it.

If this is the only reason you are trying to put it in your garage, couldn't you just block it up and remove the axles? 4 bolts/ axle(spring hangers) and some wires if you have electric brakes seems easier to me than modifying the frame, that is if you have the space to park it outside. It could still be stolen with a flatbed trailer and a winch but if the hull of the boat extends below the frame a little, it would be damaged while dragging and might dissuade some perspective thieves. Or you might could build a stucture in your garage that would hold the boat off the ground so you could back in, unload the boat and leave just the trailer outside with a proper tongue lock. I would think the trailer alone might not get the same interest as a fancy boat and trailer. Someone already mentioned that you could just cut a hole in your garage door so the tongue could stick out a little, a little rednecky but it would be a simple solution, if you could get a replacement panel(door still being produced), I would use the replacement for the modifying so when you put the old panel back on the colors would match and no one would be the wiser since the new one wouldn't be sun faded. These arent the solutions you were looking for but they are other possiblities.

 

[dr dodge]

I was not advocating 'illegal" activity, just being quite honest about the potential corner that the OP could paint himself into. Never start modifting any vehicle for the road without knowing the legal impact on it. When I talked about stickers, I did NOT mean to make your own inspection stickers. I ment safety stickers as to how the assembly was bolted together (insert bolt here, torque to xxx ft lbs., this side up, etc) We do not have trailer inspections, and it is perfectly legal to build your own, of modify existing ones. from the picture, it looked like even if you shortened the tongue, it was going to be too long.

dr

 

[dacarls]

Travelling 200 miles at 60 miles per hour?
Yes- Think about how much bumping and stress get put on heavy farm equipment.
These clevis pins always have a keeper, that looks like a safety pin.
How do you think the trailer hitch ball is held to the truck's receiver hitch? A large pin thru a 2 inch square steel tube. If the inner tube fastenings make you nervous, add a large piece of chain the length of the trailer extension, dropped over a large hook at each end.
For this whole inner sleeve, NO WELDING NEED BE INVOLVED. A couple of big bolts, and one clevis pin.

 

[pjm]

How about traveling 5 miles at 30MPH. Look at the photo, the boat barely fits so there is only one place to cut and that is behind the winch where the beams start to flare out and head back to where the boat is supported. I agree that the whole package is being held with one receiver pin and in some cases on a homemade trailer hitch bolted thru the frame of the tow vehicle. The downward weight on the cut points is only 150lbs so the only stress is in the horizontal plane-pushing and pulling. Add to this the triangulation effect and the sandwiched I-beams (2) should be stronger than before.

 

[dacarls]

Loo! A shiny new photo of an expensive anodized aluminum trailer! I would remove the winch stand and bolt it to a flat plate which is then bolted to the curved horizontal I- beams to keep them stiff and keep them in the same position to each other. Then the center trailer tongue could be unbolted and pulled out, to be replaced after winter!
It looks like the wheel stand stays right where it is now, on the outside.

 

[DaveC426913]

How about traveling 5 miles at 30MPH.

Ah, but ever plan on selling this beast?

 

[pjm]

Hi guys: Been away for a few days (trying to find a hack saw) Anymore new ideas?

 

[dacarls]

Hi guys: Been away for a few days (trying to find a hack saw) Anymore new ideas?

yeah. we are arguing whether you can pull out or cut off the existing tongue- after fastening a 2 foot wide aluminum plate under your winch tower across the girders on the front of the trailer. This is my idea.