Trailer Failure

[SW Boat Transport]

Originally Posted by Anchorhandler

In this case you never know what the trailer was carrying before this particular boat or even how it was loaded up in this example. If the drawbar was overloaded and subjected to a cyclic 'bouncing' effect then its inevitable that something was gonna give....at some point or another.

This trailer was brand new and had only had only carried the one boat a total of five miles. It was loaded by QAB, who have loaded numerous boats for me in the past and are always very careful.

Looking at the fairly central position of the axles (see below) and the fact the boat had 2 hefty outboards on the back, I cant see how the nose weight can have been excessive. Even if the nose weight was a bit high, I have towed numerous steel trailers in the past with excessive nose weight and never had any problems.

[Anchorhandler]

Originally Posted by SW RIB Charter

This trailer was brand new and had only had only carried the one boat a total of five miles. It was loaded by QAB, who have loaded numerous boats for me in the past and are always very careful.

Looking at the fairly central position of the axles (see below) and the fact the boat had 2 hefty outboards on the back, I cant see how the nose weight can have been excessive. Even if the nose weight was a bit high, I have towed numerous steel trailers in the past with excessive nose weight and never had any problems.

Hmmm, the plot thickens....

If there are snapped welds the length of the trailer it would suggest to me an overloading problem or a defect in the welding process. Visually the welds look OK from what i can see but visually eyballing a weld is hardly conclusive.

As AMac already suggested, the dimensions of the profiles used dont seem to correspond with a trailer designed to carry nearly 3.5t...

If the trailer is genuinly designed to carry the coresponding load, is it possible it was shock loaded when the boat was loaded onto it?

I wouldnt expect to see weld failures on the swing beam clamp from any kind of cyclic stress as that area shouldn't be flexing as much as say, the main longitudinals....

Simon

[PeterM]

Originally Posted by SW RIB Charter

Here are a couple more photos taken this afternoon. The first one shows the front of the trailer where it broke away. It looks to me like the weld has just failed. The second shows another weld on the rear swing beam, which also looks to have failed. There are several other split welds right down the trailer.

Could always be the welds failed due to it 'connecting' with the LR that was pulling it , or the shock loads the whole front end hit the floor ? Just an option ...

[eilean mor]

sad times
yep, just reading it, I was thinking the same as PeterM, if there has been catastrophic failure of one part, then has that carried through to other bits?

[Poly]

Looking at their website none of their designs have the double box side rails meeting at a point, so unless this was a new design the whole trailer is totally out of shape.

[Kernow Buoy]

This is mine (albeit a single axle) those top rails are at least 18" apart

[Kernow Buoy]

And this is a pic of a larger twin axle much more similar to the damaged one

[willk]

Do we know the unfortunate driver?

It might have happened if the towball wasn't engaged properly, hopped on the first big breaking run and the frame hit the road...

...just a possibility?

[Nos4r2]

After a quick gander on their website,it looks like one of their Kittiwake range to me.

To me,the drawbar arrangement looks like a fracture waiting to happen at exactly the points that one's failed at.

[Anchorhandler]

IIRC, the website seems to suggest that Gullwing only produce 'multi roller' type trailers up to 2600kg..........? The 3500kg ones all seem to be of the 'roller ramp' type.

The pictures posted clearly show stickers saying 'multi rollers' and the fact it has swing beams seems to support this.

Was the trailer acvtually plated at 3500kg?

If i havent mi-understood and the trailer was only 2600kg then there probably wasn't much room for error.

.
1700kg boat + outboards + gear etc.....?



Simon

[Nos4r2]

Originally Posted by Anchorhandler

IIRC, the website seems to suggest that Gullwing only produce 'multi roller' type trailers up to 2600kg..........? The 3500kg ones all seem to be of the 'roller ramp' type.

The pictures posted clearly show stickers saying 'multi rollers' and the fact it has swing beams seems to support this.

Was the trailer acvtually plated at 3500kg?

If i havent mi-understood and the trailer was only 2600kg then there probably wasn't much room for error.

.
1700kg boat + outboards + gear etc.....?



Simon

Does it have swing beams or have the roller carriers failed when the trailer gave way?

<edit> In the first pic it does appear to have swing beams, though it's not that clear. I'm also quite shocked that the recovery guy pulled something that much of a mess on a speclift with ratchet straps. It needed a flatbed.

[Anchorhandler]

Originally Posted by Nos4r2

Does it have swing beams or have the roller carriers failed when the trailer gave way?

<edit> In the first pic it does appear to have swing beams, though it's not that clear. I'm also quite shocked that the recovery guy pulled something that much of a mess on a speclift with ratchet straps. It needed a flatbed.

Hey Nos4r2

Something SW Rib Charter mentioned sparked my curiosity....in post 20 he posted a pic of a failed weld on the rear swing beam carrier....

To me it does seem that it was a multi roller trailer but i suppose the real question is "what is it plated at?"

Your right about the recovery guy though, very brave considering many other welds had failed further down the length of the trailer

Simon

[randski]

Here's mine 3500kg... hope it's ok, it's off to Sweden later this week

[Anchorhandler]

Originally Posted by randski

Here's mine 3500kg... hope it's ok, it's off to Sweden later this week

I'm sure it is....

There could be a number of reasons why the trailer failed, not properly hitched as Wilk said, incorectly loaded somehow, maybe the driver didnt see and slow down for a speed bump traffic calming measure (although why they call them "calming" is beyond me as they make my blood boil...especially when your towing something big )

Still, your picture shows that the trailer in question was plated at 3500kg.

Simon

[SW Boat Transport]

Originally Posted by Anchorhandler

To me it does seem that it was a multi roller trailer but i suppose the real question is "what is it plated at?"

The plate on the trailer (well actually on the detached drawbar!) says 3500kg GVW, 2850kg Capacity

[Nos4r2]

Originally Posted by Anchorhandler

Hey Nos4r2

Something SW Rib Charter mentioned sparked my curiosity....in post 20 he posted a pic of a failed weld on the rear swing beam carrier....

To me it does seem that it was a multi roller trailer but i suppose the real question is "what is it plated at?"

Your right about the recovery guy though, very brave considering many other welds had failed further down the length of the trailer

Simon

I suspect not all of the failures shown were present 'til the recovery guy winched it all down to the spec lift.

It looks to be the same model as Randskis-the roller ramp model.

[Paul Cannell]

Originally Posted by Kernow

This is mine (albeit a single axle) those top rails are at least 18" apart

Are you missing a bolt or 2 from that pic? there no stop bolt in the sliding bar.

[Kernow Buoy]

Originally Posted by Paul Cannell

Are you missing a bolt or 2 from that pic? there no stop bolt in the sliding bar.

Hi Paul,
Yes indeed, the stop bolt is sat on the drawbar out of shot. Whenever I go away I remove the drawbar for a bit of added security. Thanks for the headsup

[Rokraider]

The design looks weak IMHO. It is a long stretch from the axles to the towball. Most of the trailer length it has dual rails, which would imply that it would not be strong enough to have just singles. As you get towards the drawbar the dual rails finish and it goes down to a single rail, which does not appear to be beefed up other than an additional piece of box section down the middle, that wont contribute much to the up and down flexing that is going to occur at the point where the dual rails finish. Personally I believe the dual rail should have continued right to the front where the tow ball coupling is attached. Problem is , it would make if more labour intensive to fabricate and push the price up.
I am also not a fan of using extruded materials in this situation. It all depends what the quality of the extrusion mix is.

[Tino]

Originally Posted by SW RIB Charter

Here are a couple more photos taken this afternoon. The first one shows the front of the trailer where it broke away. It looks to me like the weld has just failed. The second shows another weld on the rear swing beam, which also looks to have failed. There are several other split welds right down the trailer.

This damage would suggest that the unfortunate driver may have hit something with the trailer which caused catastrophic damage to the trailer. Even a speed bump at high speed? Was there any damage to the Tyres or wheels?