What is the force exerted on a C-30 BSTR jib sheet

[Mark Hudson]

The jib cars on my C-30 BSTR do not work well. The angle of approach and departure to the winch bind while using the 155 roller furling. My solution is to purchase two after market blocks with stand up springs and attach them to the two free slides on the track. As I look at block Safe Working Loads, they all seem to max out around 1500 lbs, with the exception of a few. I have looked at replacement cars that are rated 2000 to 3500 lbs SWL, but are a bit pricy and I'm not sure they will solve my problem (they only pivot lateraly across the beam) So how many lbs of force are placed on our jib sheets? Any comments?

 

[Tim S.]

Clew Loads

Wind Strength will have alot to do with it, but you probably are looking at max clew load of 1500-1700lbs, straight line. Your block is seeing a deflected load which will be far less. Most marine hardware safe working loads are rated about half of the breaking strength.Keep in mind that the tighter the angle of the line in and out of the block has a bearing on the load. The load is greater when the line is taking a 90 degree turn vs a 30 degree turn. Conversly the load is greater at 180 degrees.So, a block rated at 1500lbs safe working load, should be plenty strong, unless you are making a 180 degree turn.I hope this helps shed some light.

 

[Jim]

Clew loads 2

If Tim is right and he probably is at least close and it sounds as though you will be using the new blocks as turning blocks than you need to double the actual load on the line for the load on the block. Several years ago I replaced our turning blocks with new Garhauer blocks two months later we had gone through two sets of them. After some discussion with Garhaur they built us a custom set that are holding up to date. They are about twice the size of the regular Garhauers. In fact the hole in the center where the bearings are is just the perfect fit for a beer can to give you an idea as to the size of them. I guess all I am saying is there is a lot more load there than most would imagine. You might call them and check on the price of a set light ours.

 

[Gary Jensen]

Check Gaurhaur Out

My blocks are over kill on my 380. They are from Garhaurer and are the very best priced blocks BY FAR!!!!!!!!!