original blocks? suggestions to replace?

[SpeckledTrout]

Folks, thanks for your responses. It occurs to me that I don't know if the original jib tracks have a backing plate inside the hull (and if so, how are those constructed). Seems logical there would have some kind of backing plates given the strain on the OEM blocks (no ratchet, etc). Does anyone know?

[GreenLake]

Hadn't thought about that: the load on the jib track cars does change some based on whether you use ratchet blocks or not. Assuming the ratchet block is perfectly efficient and requires only minimal tension on the free end, the entire load from the jib sheet pulls forward.

For a regular, 90 degree turn around a block, there's the same force going forward as going sideways. The track will have to offset the tension in the part continuing to the CB trunk, so there's a net pull outward that matches the strength of the pull forward (which the track stop transmits along the track).

Now, ratchet blocks do require some tension on the free part to keep them engaged, and, more importantly, they act like free blocks whenever you pull in the jib, so you don't gain much in terms of required strength of the jib tracks.

In any case, yes, you do need backing, and you may need to cut holes for some inspection ports so you can get an idea what was provided for your boat and whether you can reuse that.

Inspection ports are covered in many DSII specific threads, just go back in time a bit.

Also, you can get neat little nets that make pockets inside the port, so you can stow things underneath the covers to keep them out of the water - (except that the bilge water can get at them). One guy I sailed with would stuff small plastic bottles in there as he was emptying it during long trips. At the end of the season, he would fish them out again.