Raking masts

[boatmike]

Sweeping the shrouds back acts as a backstay, and stops the boom going out.
That's much the same regardless of rake.
Plenty of British fore and aft rigs had upright masts and booms extending over the stern.
I suspect the schooners evolved through a development process, what was fast locally got copied and taken further.
There may have been other influences such as availability of the right timber and a history of smaller boats with rake, such as 'cat' rigs.
Also perhaps fashion was as important then as now in determining what an owner would commission?
I've used running backstays short-tacking up the non-tidal Thames, racing in an A-rater. It's what the third man is for!
Although with many rigs you only need the runners down wind, as the leach tension does the job upwind.

No argument with any of that apart from the fact that raking the mast back creates a tripod effect with the shrouds and does in fact create more support than if the mast were vertical. You are still generalising. I didn't say all boats were the same. they are not. I have some experience of the Cape Cod schooners from which I believe the racing vessels like "America" were at least partly derived. Also there is a difference between an A-rater and a 220 tonne schooner. You need a bit more than a third hand at that size!!

 

[lw395]

..... I have some experience of the Cape Cod schooners from which I believe the racing vessels like "America" were at least partly derived. Also there is a difference between an A-rater and a 220 tonne schooner. You need a bit more than a third hand at that size!!

I would think a few more hands, yes!
But still easier than many of the rigs such as dipping lugs etc.
And worth it for the performance.
Which were the Cape Cod Schooners you have experience of?

Sure I was generalising, but for the shroud to pull the mast back, it must be behind the mast at deck level.
That's physics, not specific to classic boats.
So it restricts the boom going out. Or did they let the leeward aft shrouds off downwind, as is done on some dinghies?
I realise the weight of the mast is also pulling it back, but that must be small compared to the drive in the sails?
If the boat is wide at deck level, you don't have to let the runner off (much) when close hauled of course.... just need to dump it before bearing off (I learned this at someone else's expense in an X-yacht!)

Cheers,

 

[cliffordpope]

If the point is to increase the angled span length to reduce vortex, that would suggest that a long high-peaked gaff on a short vertical mast would be best?
Or a felucca rig, or those south sea boats with sails looking like crabs' claws?

 

[DJE]

Could it be something to do with the size and position of the hatches and the need to provide good access to the holds when loading and unloading? This sort of thing could fix the mast step position requiring the rake to balance the sail plan.

 

[Roberto]

If the point is to increase the angled span length to reduce vortex, that would suggest that a long high-peaked gaff on a short vertical mast would be best?
Or a felucca rig, or those south sea boats with sails looking like crabs' claws?

I think that such a comparison would be too far fetched IMHO.
If one compares a standard Marconi rig with upright mast to a standard Marconi rig with a slightly raked masts, there may be indeed -among other effects- a reduction in vortex drag, but most other important factors would show very little change, in particular lift on the sail and lift angle.

Taking a completely different sail plan form would yield a definitely different pattern of sail lift and drag vectors, which would be hard to compare to a standard Marconi rig, it might be better or it might be worse, I doubt it can be said with any certainty.

Besides, in other cases there are other factors that limit the application of airplane wing theory to sails: to name one, righting moment, in a Marconi rig one can only increase span up to a point where heel angle remains acceptable.
Other rigs may be more useful in boats with different characteristics (hull speed, righting moment, etc) or where the sail is used in a different way (for example by generally reaching instead of beating).

All imho of course :smile:

 

[TamarMike]

I don't know that much about the history of foreign rigs but I wonder whether these schooners with raked masts were developed from French vessels with standing lugsails which might have had the mast raked to keep the luff vertical. However looking at modern replica luggers the foremast tends to be vertical or even slightly raked forward though the mainmast on Grand Lejon and the mizzen on Cancalaise are certainly both well raked.

A factor for British schooners keeping to vertical masts might have been the retention of square topsails?

As I say all just a few random guesses on my part.