Raked or Straight?

[Ransom]

I've been reading "Sail Tall Ships - A Directory of Sail Training and Adventures at Sea" comparing the various rigging configurations of schooners. Ransom's ship, the Rakehell is a gaf-rigged schooner with raked masts, mainly because I like the look of it.

In this book it gives specs for the various ships, such as length, LAWL, beam, draft, total sail yardage, minimum crew, maxumum day passengers, etc. But it does not make a distinction between raked masts or straight.

The choice doesn't seem to be tied to sail configuration, as gaf-rigged, gaf topsail, or square topsail can have either type of mast. So, besides the obvious, what is the difference between raked vs straight masts? Is one more advantageous than the other?

[MorganTyre]

Mast rake changes the driving centers of the sail plan affecting balance and performance at difference points of sail. It also changes the dynamics of the standing rigging. Also, a heavily raked mast can be used as a crane of sorts for loading or unloading cargo.

[Coastie04]

It's mostly looks. Sure, it affects the performance of the sail, but so does size, how deep the belly is, if it's loose footed or not, etc. Overall, the speed of different angles of rake were comparable. For the baltimore clippers, the highly raked masts were fairly standard. It was mostly for the appearance of speed. The baltimore clippers were extremely fast boats, but they were small and had little cargo space-major design aspects that allowed them to be fast.

There are a couple of other factors that are associated with the raked masts that can be either good or bad. The boom tends to center itself in light wind. This can be prevented with the use of a preventer, though it can be nice when setting/dousing sail. The shrouds and weight of the spar eliminates the need for running backstays. The boom on a raked mast raises up the farther out it goes, so it stays out of the water a bit better when sailing off the wind. Also, some say that square tops'ls can be braced around sharper, though I haven't really noticed it that much. Plus, the sharply braced square sails usually don't give a whole lot more speed. One of the disadvantages is that the rig will not stand up on its own if rigging gives way or is shot away, especially the headstay. Last year (maybe the year before?), the Pride of Baltimore II was completely dismasted when a single piece of rigging, the bobstay, gave way.

When it comes down to it, they really look cool.

Coastie

[Coastie04]

Then again, raked masts can look rather goofy.

I was thinking more about it, and it would seem that a raked mast could not support as many spars. So, for the larger clipper ships and giant windjammers of the late age of sail, that's probably why they went back to straight masts. However, the schooners eventually went back to straight masts as well in the late 19th and 20th centuries, and I'm just not really sure why, except if there were significantly more dismastings due to rigging failure than with straight masts.

Coastie

[Coastie04]

OK, I was getting curious and doing some of my own research online. I came across this in a wooden boat forum that they were talking about raked masts:

I am fairly certain that Lars and Elliason's Principles of Yacht design has a section on why masts are raked. I'll try to look it up. The reasons are partly aesthetic and partly performance and are actually related.

Having recently designed a sail plan (follows) I can say that raking the mast (both forward and aft from nominal design position) provides a way to move the lateral center of effort (CE) to achieve a design "lead" relative to the laterial center of resitance (LCR) which ensures proper helm response. Since setting lead during the design process is an inexact science, once the boat is actually built and sailed it may be necessary to adjust the lead. Some boats adjust the lead depending on weather conditions and some race boats adjust the lead depending on the point of sail. If you can't move the mast fore and aft, your only way to adjust the lead is to adjust the rake. If your mast had no rake and you found the boat had lee helm you would have no choice but to rake the mast forward which would look quite goofy. Hence, I beleive that during the design process you start with a rearward rake to ensure you'll never have a positive rake after tuning the boat. Over time this has become an accepted aesthetic.

Therefore, on my boat at least (and on a lot of other boats I think) you start with a rearward rake so that you will always have some rearward rake after the rig is tuned. As you can see from what follows I've designed 8" of rake which give me around 7.5" of lead (around 3% of LWL) by design. In practice I expect to rake the mast forward by a few inches but we'll see.

I think this is right but welcome corrections if I'm spouting BS.

I thought this perspective, although just one person's speculation, was rather interesting and as good an explanation as any; especially since the raked masts did disappear in later years when presumably more 'scientific' means of calculating the rig balance in a boat.

Coastie

[Ransom]

Thanks to you both for the info. Coastie, I have been on the Lynx and the Lady Washington, and loved them both. It was the Lynx that first got me wishing for a schooner. Yeah, the raked mast looks really cool. Looks like you both answered my question. Gramercy!

BTW, in your web surfing, have either of you come across anyplace that would give a cut away schematic of a schooner? While on the Lynx, we were only allowed on the deck, or in the gift-shop room. I'd like to get a better idea of the construction and layout below deck.

[Desert Pyrate]

Below deck, on almost every period schooner, she'd be as open as possible. No sole or excessive bulkheads.