Securing methods for boat onto trailer for travelling

[oldboot]

I can see that.

Apart from making one chain dependent on the other for its effectivness, cross chaining also puts the tie down at a mechaincal disadvantage.

cheers

[PinHead]

I can see that.

Apart from making one chain dependent on the other for its effectivness, cross chaining also puts the tie down at a mechaincal disadvantage.

cheers

want to expand on that..give some point loadings..sheers factors etc.
We are talking about a boat on a trailer not a bloody silo..I bet the silo is on a flat bed..totally different to a boat sitting on a trailer.

[oldboot]

The point is that there are a lot of "tried and true" methods of securing loads that simply prove to be ineffictive and possibly dangerous.

And lots of people simply wont be told.

cheers

[PinHead]

so you cannot give point loading and sheer factors for a boat on a trailer and the chains holding it ?

as I said..winch strap and safe chain..strap over the rear works a treat...there really is no need for anything else.

[fairpractice]

Hi. have had a winch post tear its weld, winch hook straighten, winch strap bust.
Now use chain and turnbuckles at front AND a length of telecom type rope wrapped from bow to trailer frame about 10 turns. great shock absorber and insurance on thousand km. road trips.
The degree of tie down depends on the distance i travel, with the obvious safety factor for traffic accidents.
cheers john

[nautimax]

Ok some further information about this whole bolt strength thing.


Now who knows what steel the "U"bolts are made off AND consider the threads are mostly rolled not cut and thus are not full depth and not all that strong...so the 300KG aint all that unrealistic, particularly if you calculate from "proof load" (the strength before the bolt starts to stretch).

cheers

...rolled threads don't need full depth (to retain strength) as opposed to cut threads. The advantage of rolled threads over cut threads is they are less susceptible to fractures because the metal (grain) is made to flow and shaped into the threads...as opposed to cutting across the natural grain of metal when dies are used to cut threads...anyways, most commercially available threaded fasteners have only 75% thread depth unless you spec otherwise it will cost a bit more....