New bow roller, what is important?

[Twister_Ken]

In your shoes I wouldn't want to make off a preventer on the stem head. Any strong point on the foredeck would do.

Spinnakers don't come into what I was suggesting - this is for a cruising chute or asymmetric which is flow with its tack on a strop from as far forward on the boat as possible. The further forward you can get it, the better, so that the strop and the sail clear all the junk on the bow - like anchor, nav lights, pulpit, etc. Some boats go so far as to have an extendable 'bowsprit' or 'prodder' which pushes the cruising chute tack even further forward. If I were making up a custom bow fitting, I'd be tempted to see whether there was a way of designing it to take a prodder.

Here's a picture of a chute, conventionally set

And here's one on a sprit.

 

[PeterGibbs]

The strain that is most likely to casue you grief, and which has to be protected against in your design, is lateral snatch, not so much the vertical tension arising from a set anchor.

The further out the roller is set from the hull the greater is the lateral strain, as the boat shears in gusts.

So my advice is keep the structure as contained as possible,
double rollered of course, and laterally strengthened - the stresses that can be encountered are not to be sneezed at!

PWG

 

[rogerthebodger]

Thenks Ken got it now.

The preventer I was refering to would not be cleated at the bow but would run from the cockpit up the port side to the bow around a snatch block and back down the starboard side with snap shakle on each end.

With the boom on the port side the port shakel attached to the boom end and the line cleated on the starboard side at the cockpit and the other way with boon on starboard side.

Idea picked up some time ago on this forum.

 

[ShipsWoofy]

I have saved this thread for reading later, a quick flick through shows that the roller I have will be adequate, but I do need to replace the actual rollers, they are ss but have worn down and now wobble, stopping a nice free roll out. They appear to be on pins, so just how difficult to replace or even remove I have no idea.

 

[Poignard]

[ QUOTE ]
They appear to be on pins, so just how difficult to replace or even remove I have no idea.



[/ QUOTE ]

Just keep epeating: "They went in so they must come out"!

Seriously, have you considered having a bronze roller made? As far as I know the one on my boat has been there for 40 years and it still works fine.

 

[kds]

I am suprised that noone has mentioned the advantage of a roller of large diameter. I have only come across one once, but the ease that the chain came up with was an eye opener. I Couldn't fit a larger one on my bow - but if your fitting overhangs ( as in the photo) - you could easily go to double or tripple normal diameter.
Ken