450: Main Halyard / Mast head pin

[arsenelupiga]

Originally Posted by meirriba

The blocks on the sailhead, as supplied by Lagoon, have the option to stop swiveling. Usually it with a smal Allen (hex) key.

i have done first what you suggested and noticed twisting force on block especially when broadreaching.

Additional soft shackle is used between block and sail, to twist and relieves block from these forces.

[Bean Counter]

We removed the shackle and spigot and formed a 5mm dyneema strop between headboard and pulley. This allows the head to rotate about 90 degrees each way, but not allow a 180+ twist, this takes side pressure off the pulley and also has a more dampening effect on the system vs s steel. The only down side to this is that if you need to disconnect the halyard from the mainsail, you have to untie your strop, a shackle would obviously be much quicker. This is why I replaced the topping lift with dyneema, (a) as we use this to go up in the bosuns chair, (b) It can substitute as a main halyard. Some say you should use the main halyard for the bosuns chair, the trouble is that you can not see the condition of the shackle at the top of the mast till you get there.

[Lambretta]

Originally Posted by Bean Counter

We removed the shackle and spigot and formed a 5mm dyneema strop between headboard and pulley. This allows the head to rotate about 90 degrees each way, but not allow a 180+ twist, this takes side pressure off the pulley and also has a more dampening effect on the system vs s steel. The only down side to this is that if you need to disconnect the halyard from the mainsail, you have to untie your strop, a shackle would obviously be much quicker. This is why I replaced the topping lift with dyneema, (a) as we use this to go up in the bosuns chair, (b) It can substitute as a main halyard. Some say you should use the main halyard for the bosuns chair, the trouble is that you can not see the condition of the shackle at the top of the mast till you get there.

Great info and also the replacing the topping lift with Dyneema when sailing downwind on a cat with either a code zero or spinnaker you can tension the topping lift, center the boom (without the main up) and tension the main sheet (like crazy) and then you materially reduce the load on your rig as your dyneema topping lift acts like a running back stay.