Two gates on my mast track - what for?

[Poignard]

My 44-year old mast has a single external track with a 'gate' for slides about one foot above the boom and another one about a foot above that.

Is that so a trisail can be fitted without removing the mainsail slides, or is it for some other reason?

ps I don't know if it's relevent but she used to be fitted with a roller-reefing boom.

 

[barnaclephill]

Yes for a trisail. So that the trisail can be bent on ready to deploy whilst you still have the main on its smallest reefing position.

The reason two gates with roller furling on the main: you might need to take the slides out of the track when reefing and rolling it around the boom.

I'm not personally familiar with these, being without personal experience. My boom has some provision for rolling at the outboard end, but the inboard end has been changed at the gooseneck. My sailmaker told me that for my size of yacht (26') a separate trisail was not necessary - a third reef in the main was enough. So no practical experience of them, but that is what I have read in books, etc.