Has anybody worked out what sort of load the crew has to deal with on the spinnaker sheet in say, a Force 4?

This information might help in discussions we're having with the nedical proffession.

Well its that old argument about the division of labour - the helm will say not enough and the crew will say too much.  I am unaware of strikes or lock outs in Merlin Rockets but some may know differently.

Seems quite well balanced in our boat - but it was a serious question re the sort of loads to be dealt with to assist in dsicussions ith doctors who don't all understand what our sort of sailing is about.

David, could you go for a test sail with a spring balance and fix it between your and and the sheet in a range of wind strengths and directions?

The set up was a simple Tee Bar with a spring balance that ended in a hook. The buttock clenching bit was tying a loop in the sheet to measure the load, if you got a gust you saw some great readings just before the water closed over you!

But it is an easy enough experiment to conduct - no wonder that there is a high incidence of wrist problems in later life for long term dinghy sailors!

D

I thought that wrist problems were mostly due to another activity which also supposedly makes one blind

Rather than forming a loop, use an arrangement utilising a cam cleat mounted on a small board in conjunction with the spring balance, then it is easy to adjust and release quickly.  We used this system on testing small anchors, and sea anchors. You pull a doubled part of the sheet through the "hooped holder", and then cleat the direct sheet . Obviously you have to fix the end of the spring balance.

I am sure there must be a mathematical formula to work it out - all to do with the force on the area of the spinnaker.

I am sure the loads on the spin sheet are relatively low compared to that of the guy. Its not the wrists that get injured, but the knees that take a bashing.

Surely relies onb how fast the boat is going, when the boat is moving fast the loads will be less, bit like why you should gybe when going fast, which is often easier said than executed!

They work bloody hard!!!!

Old Fart - There's no correlation between cider drinking and Merlin sailing.

The Pages tried 2:1 kite sheets - ask Phil or Lizzie D about success - seems feasible for the jib too.