Re: What Halyards go to the Masthead?
You didn’t mention the size and type of boat that you have. Jib and main halyards go through the masthead sheaves. Some people use the “spare” aft sheave (you have a four sheave set-up or two?) for the main topping lift. Although, this is not the only way to rig a “topper”. The spinnaker needs to be on a swivel block mounted above the headstay and will not be routed through a masthead sheave. Storm Trysail? You use the main halyard for this but you may want to invest in a separate track for ease of deployment. Are you thinking about a storm jib? If so, the halyard will be on its own block mounted below the baby stay. The baby stay will be mounted opposite of the head card of either a third reefed main or your Trysail. The purpose of that is to match the loads lower down on the mast.