safty chain again

[Wahoo]

can someone please advise me if i did the right thing or not to the safety chain setup on my trailer :-/:-/

before and after

http://img.photobucket.com/albums/v647/4xgold0/boat019.jpg

http://img.photobucket.com/albums/v647/4xgold0/boat122.jpg

[FNQCairns]

Close Daz run the bridle again and move the bottom of the adjuster to it, keep the direction of the chain more or less following the bend of the bow upwards, badly explained I know:(

cheers fnq

[Tangles]

fnq,

mate if you could explain that a bit more as i couldnt follow it and am interested as was thinking of doing something similar...

cheers
mike

[FNQCairns]

Ok sorry I will try. Relating to the first pic this time - there is a bridle attached to each side of the trailer, if the turn-buckle in that pic is disconnected at the top and reattached to the lower hole on the boats plate it will give close enough to the correct angle to stop the boat running forward.

Then the typical smaller chain can connect as usual.

Cheers fnq

[Wahoo]

yeh sorry Scott, sort of dont understand also, i would like to do without the chain that runs back to the trailer, could it be done?

Daz

[Wahoo]

Ok sorry I will try. Relating to the first pic this time - there is a bridle attached to each side of the trailer, if the turn-buckle in that pic is disconnected at the top and reattached to the lower hole on the boats plate it will give close enough to the correct angle to stop the boat running forward.

Then the typical smaller chain can connect as usual.

Cheers fnq

would'nt that way be pulling the boat back?

Daz

[FNQCairns]

Daz not if you would like it to work well, the idea is that when adjusted firm and the boat tries to move forward under great force the chain will straight away force the direction the boat wants to move (straight ahead) into a downward force at the bow that tries to lift the bum of the boat up of which the straps will not allow and all stays put.

The further back you can anchor on the trailer the better.

cheers fnq

[FNQCairns]

would'nt that way be pulling the boat back?

Daz

Yes but the turnbuckle is tightened to a point only that takes up the slack then makes it firm (or better expressed as snug possibly) at best, enough to stop the chain bouncing is enough just a couple of Lb pressure.

You can if you like run another turnbuckle forward (directly forward of the plate to counteract but it's not strictly needed.

cheers fnq

[peterbo3]

Wahoo,
It is a problem with a lot of trailers. The builders do not seem to put the tie-down points in the right place & if you weld them on later the gal suffers. The ideal & most secure way to secure the chains is around the tlr frame but this is often not practical.
The safety chain has a number of functions.
1.To quickly secure the boat to the tlr after recovery & to keep the boat on the tlr when launching.
2. To keep the bow of the boat locked down whilst travelling at speed on the highway. Also to stop the boat moving to the rear of the tlr on the highway. You should not rely on your winch cable/strap to do this.
3. To prevent the boat hitting the rear of the tow vehicle in an emergency braking situation or accident. This happens because the winch support post is held on by U-bolts & is not designed to handle rapid load forces. Although if you are in a high speed accident there is probably no practical system to prevent the boat coming forward or rolling off the tlr.
The top pic addresses issue 3 whilst the second pic covers 1 & 2. The setup in pic 2 with a single V chain from the hard points on the tlr frame to stop forward movement of the boat should cover all bases. The shackles may need to go up a size though. Do you use a ratchet type tie-down strap at the rear?

[Tangles]

Great thread,

So has anyone have a pic of what would be a good setup, also dont have the luxury of a lot of free tie down points, only have one almost in the centre of the trailor

cheers
Mike

[SgBFish]

This is mine.
It prevents the boat going forward or up except of course under very extreme braking which I don’t want to think about. It also prevents the boat going more that a few inches backward should the Spectra break, which is unlikely.

The chain goes around the drawbar and is shackled in place.
Scott

[Wahoo]

Wahoo,
It is a problem with a lot of trailers. The builders do not seem to put the tie-down points in the right place & if you weld them on later the gal suffers. The ideal & most secure way to secure the chains is around the tlr frame but this is often not practical.
The safety chain has a number of functions.
1.To quickly secure the boat to the tlr after recovery & to keep the boat on the tlr when launching.
2. To keep the bow of the boat locked down whilst travelling at speed on the highway. Also to stop the boat moving to the rear of the tlr on the highway. You should not rely on your winch cable/strap to do this.
3. To prevent the boat hitting the rear of the tow vehicle in an emergency braking situation or accident. This happens because the winch support post is held on by U-bolts & is not designed to handle rapid load forces. Although if you are in a high speed accident there is probably no practical system to prevent the boat coming forward or rolling off the tlr.
The top pic addresses issue 3 whilst the second pic covers 1 & 2. The setup in pic 2 with a single V chain from the hard points on the tlr frame to stop forward movement of the boat should cover all bases. The shackles may need to go up a size though. Do you use a ratchet type tie-down strap at the rear?



thanks Peter, have been sitting and thinking on how i can better my setup, yes have a 3" strap at the rear when under tow, and will upgrade on the D shackles


Daz

[Chimo]

Hi Wahoo

Have just read this thread and I wonder if you need to change things very much to give a satisfactory result.

The original twin chains should stop the boat moving forward in most if not all all events. If you want extra "holding Power" where the chain is attached to the trailer at the welded link then add a short section of chain around the trailer frame and attach it to the ends of the original with the same or an upgraded "dee" then you are nor relying on a welded chain link to do much more than locate the end of the chain with he bulk of load taken by the steel tube.

Still on the original set up, up the front where the tail of the chain hangs "dee" additional chain from the end down and forward and extend the chain around the centre drawbar forward of the winch post so you no longer rely on a welded chin link or u bolts to secure the chain. All the winch post does now is locate the end of the chain which is secured with another "dee". Another turnbuckle could be included on this line but you should be able to get the length correct so the one existing "dee" tightens the whole chain for travel. See pic.

IMHO it is not a good idea to rely on a winch to hold a boat on the trailer. All it should do is get the boat to the position on the trailer and from that point chains, straps and turnbuckles secure it.

Have fun and good luck with it ;)

Cheers
Chimo

[Wahoo]

thanks Chimo, well might go back to the first pic setup again, but fix the turnbuckle
a little higher as Scott (FNQ) posted, i wonder how the insurance side of things would be if something did happen, would they assess the setup?

Daz

[Chimo]

Daz

I think the closer you keep the trailer to original the better from an insurance point of view. If there is an accident the argument is with the trailer maker / dealer whereas if you completely change it you would need some formal qualifications on the subject to have any sort of leg to stand on.

If you added a length of similar guage chain as per the earlier post and adjusted the length to suit I suspect you may not need to move the turnbuckle as you should be able to apply appropriate but balanced force to prevent forward or rearward boat movement preferably without any load on the winch. You place very high expectations of the ratchet and pawl set up on the winch which I suspect are not really up to the sort of trauma a sudden stop (crash) will impose.

Also I believe you are going to upgrade the ties at the stern so maybe you can feel more confident as you drive defensively and never need to test any of this.

Cheers
Chimo

[FNQCairns]

Daz I have a little different overall view, the winch should never be ratcheted greatly up, it's never even needed but it can handle many lb of ratchet pressure with ease (poor maintence, worn out and too small winches excluded).

The transom strap does much of the all direction holding in place but only under typical driving scenarios, it will not do squat under a sudden stop crash scenario as in a rear end etc, the boat sits on rollers....

The usual short safety chain can stay loose but not a U shape just to the closest link possible and will stop the boat from sliding backwards if the winch fails at any time, it's got an easy job.

Apart from these 3 typical arrangements the only other security needed is a stand alone heavy duty chain that connects to the trailer as far back as practical and this chain/turnbuckle/whatever arrangement must attach directly to the boats attachment point - this is very important as it should start working almost the instant the boat starts to bear force on the winch post.

Daisy chaining from a chain link anywhere as in your first picture means your boat is free to move forward near 1 full foot almost unhindered with only the transom strap and winch post as resiatance which is bugger all to a boat sitting on rollers - daisy chaining from links at wide angles doesn't cut it either, it introduces fulcrums that will magnify the forces exposed to the chain.

In that first pic your boat can move forward a whole foot or more before the big chain resists all further movement, 1 inch is acceptable less better again IMO, this way all boat restraints strap, winch post and chains are working together at precisely the same or very near to the same time.

cheers fnq

[oldboot]

I agree with much of FNQ's post.

We have to think about the what the chains achieve.

We want to prevent the boat moving back.
and we want to stop the boat moving forward and up.

It occurs to me that these two functions should be seperated as much as possible. So the two chains should be connected as close as possible to the bow eye if not individulay directly.

both the arrangements above have the major flaw of this slack link section.

I would think about one shackle thru the bow eye with the two chains connected directly to it.

better would be two seperate chains in two seperate eyes but that could be a bit difficult.

cheers

[oldboot]

Oh BTW the shackle sizes look a bit small.

remember that shackles have considerably lower ratings than chain similar aparant size.

I'd be thinking about rated shackles too. Common mild steel shackles can not be relied upon. same with the turnbuckle.

cheers

[MyWay]

this is i think should be done

http://i302.photobucket.com/albums/nn101/mywayphotos/boat0191.jpg


myway

[Chimo]

Daz

Given the trailer you have you will have to sort out just what you can do with it particularly with its attributes. Ie
Whats with the roller up the front nowhere near the boat? How come there is no central box tube member visible or is it further forward as this trailer is also used on much longer boats?

As there is no central box tube member (or is there?) they have fitted the 'Vee' chain to try and hold the boat from going forward. FNQ is probably correct about the slack in the system but with the trailer the way it is they probably had not too many ways of slowing the boat as it tried to "mount the car"

The Mayfair system on my Tinka (as in pic) is the same on most of their stuff and seems to work reasonably well.

On the other hand if we want our boats to survive rapid stops, crashes, roll overs and all the rest we better start ordering the trailers with full rops cages (which will need to be pretty high so we can get the boats off in the water) and use a lot more dog chains etc or just recognize the chain attachment is just a compromise and on some trailers a bit more of a comromise than on others.

I'll be interested to see what you end up with and really keen to see the crash testing results.;)

Happy trailering

Cheers
Chimo

[cormorant]

Those cheap gal bottle screws are a classic failure point as they are not designed for shock load.