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My new to me boat trailer has a huge crack right in the center beam just in front of the axels. The only thing that was holding it together was the bolt going through the beam that holds the bumper pad in place. When I removed that bolt, the beam pretty much split in half about 80%. I have added some steel to hold it together but this is temporary. I am going to buy a solid beam to fully encase the break and hope it will hold up. Has anyone else seen this type of break? I assume it must have been cracked already but I didn't discover it during inspection. Tried to add image below, not sure it worked.

Tim from Texas

Mystery solved . We figured out how this happened.

When I loaded the boat from at ramp the very first time, I didn't have it anywhere near deep enough in the water. When I approached the trailer to load on, I felt a really hard hit. I thought is was the trailer hitting the front pad head on and not riding up on top of it. However, after reviewing the whole set up, I am pretty confident that thud was the bow hitting the bean as it would have been far too high for the boat to properly get on top of it without contact. I think it hit real hard and then went on up the trailer after that. Lesson learned, get that trailer well under water next time.

My new project this week is repairing my Wally on the water mistake

I believe that was the easiest & quickest problem solved I have see on this forum.

I have not had a trailer cross member split, but I have had extensive rust. After consulting with my son, a welder, who lives in California, I elected to have a mobile welder cut off both the stern and midships cross members plus the V shaped supports for the bow. He, then fabricated new replacements and welded them into place. Total replacement of all three steel support pieces for the trailer were replaced with new for only $700. So, it is not "an arm and leg" to have a new crossmember replaced.

Tim - can you get a pic that shows more of the trailer? I'm having a hard time getting oriented with that closeup shot of the crack.

While you may have finished cracking it with your power load, it's unlikely that you actually put enough force on it to break a correctly sized structural part of the trailer. Possibly a poor design or a metal fatigue issue. Of course, I'm assuming you weren't planing when you hit the trailer.

Jimmyt wrote: ↑Thu Sep 10, 2020 5:00 am Tim - can you get a pic that shows more of the trailer? I'm having a hard time getting oriented with that closeup shot of the crack.

Yea, I can't visualize this either. I'm thinking this isn't original. My aluminum trailer doesn't have a cross beam in FRONT of the axles.

Below is my trailer after I added a second axle and before adding fenders.



The trailer should be able to withstand poor loading.

Thank you all for the feedback, I will have to get the boat off the trailer and take a few more pictures for perspective. Here are some responses below;

Trailer is aluminum, and is not aftermarket. It was purchased new with the boat in 2012.

I did come in a little hot for a first load in, a little over confident I guess. It was windy and I was worried about drifting sideways a bit.

I too think it is unlikely the boat was able to break this beam on the hit I made, it likely had some sort of stress crack that just needed a hit.

It split right at the bolt holes as you can see so it was a weak point already. I did hit the bumper pretty hard and it is attached where the beam broke.

My trailer is very similar to what you pictured, it is the beam just in front of your axels there.

I'll post a couple of pictures once I repair the break.
Thanks all,
Tim

Those are the axles in Russ's pic.

The piece in your photo appears to be aluminum, but the axles should be steel, factory were galvanized, so I'm not sure what's going on.

Don't know if there were any factory dual axle trailers. Maybe someone else knows.

My bad, you are correct. I thought I was looking at a beam in front of the axels in his pic. It is actually his axel. The beam I broke is just a few inches forward of that front axel and is a little higher but just slightly. Thanks for the catch. I will share a photo once boat is off the trailer in a couple of days.

If your boat is sitting on an aluminum tube, instead of the steel axle tube, that could be a problem.

Look very closely at the break. And post pics of the surfaces of the fracture if you can. You're looking for a very smooth area, like fine wet sand, with rough areas around it. Probably right at the bolt hole. That would be a fatigue failure, with the crack starting at the hole (which is a stress raiser), then the beam or tube failing due to overstress once the fatigue crack took out enough metal.

Or it could just be due to severe overload during that loading mishap.

If you want to know why it happened, at least. Which I would, so I could take measures to prevent it in the future.

Thanks guys, more interest here than I expected but helpful none the less. Here are a few more pictures. It is sitting on the beam but also has a cradle strap that connects to the trailer main rails that sits on on top of the beam that broke. Also looks aluminum though but should be holding some of the weight. The steel 18in L metal on the beam is a temp fix to hold things together until I can get the final fix completed.

Tim,
You may have a problem with that trailer. It may have been adapted from another boat, or the trailer builder may not have understood the boat. That aluminum cross member appears to be inadequate to carry the load. You very well may have broken it loading, which may save you a future disaster down the road. Hopefully you have a good trailer company nearby that can help you straighten it out.

The factory trailer uses the steel axle tube to carry the center of the boat. Additionally, there are cheek bunks that transfer some of the boat weight to the i-beams directly. The rear cross member of the trailer is aluminum (3x3x3/16)- again with cheek bunks that transfer weight out to the I beams. These subtle differences in bunk arrangements can make significant differences in how the various members are loaded.

Could you measure the square tube that failed and the thickness? How many other support points are holding the boat up? The factory trailer has the V-bunk at the front (directly on the I-beams), a cross-bunk at the axle, and a cross bunk at the rear of the I-beams. If I was a betting man, I'd bet the bulk of the boat weight is carried by the axle bunk.

Thanks for the advice Jimmy, I guess I need to have someone take a look at it for me with some expertise. I may be able to add a bunk on top of the axel to lighten the load once I fix the beam issue. I added a couple more pictures to show all bunks.

Beam is 3" with a 1/4" thickness. I'm going to add some steel inside the tube and encase the outside as well so it should be the strongest point on the trailer after that all be it a little heavier than before.

The way your center bunk is set up, transfers the load to the center point of the cross beam. The strap is not really taking much. If you extend the bunks out over the rails and block up from the I-beams. That would help distribute some of the load away from the center of the cross beam and put it out on the I-beams.

Not sure that slipping a smaller steel tube inside of the aluminum would do it. Ran a few numbers on the 3x3x1/4 aluminum tube, and it looks questionable. Nothing in depth, but it needs close scrutiny.

Good luck with it! Hate you have this to deal with. Shouldn't be too bad if you find the right person to help.