What made Pilot Cutter so fast? Just rumors?

[NewAlexandria]

I"m looking at WestSail32 let's say, and I'm looking at Pilot Cutters from Bristal, and I don't see the speed difference in the design. It's basically the same boat. Physicals can't be overcome. There is optimal design for everything and anything close to it, will also be close to it in speed let's say. So how come WestSail32 is known for being slow and Pilot Cutters are known to be super fast. I don't buy it. The only difference is the rigging, but in that case most designers would simply select Gaff setup. What am I missing here?

[TrentePieds]

You are missing quite a lot :-)!

Pilot cutters were only "fast" for their time and in relation to other working craft. Subject to the minimal differences in STW ("Speed Through the Water") that existed between them, "winning the race" (for that is what it was) and glomming on to the commission of bringing in the ship "lying off" awaiting a pilot, it all had to do with the skipper.

Differences in hull design and rigging were the least of it. Skippers' competence and guts was the best part of it, for the skipper of a pilot cutter was NOT the pilot, but a "waterman" who made his living essentially by the same means that 'Uber" drivers do today.

Now if you would like to gather some of the bits you are missing, read The Proper Yacht by Arthur Beiser and Francis Kinney's Skene's Elements of Yacht Design. When you have "internalized" the tons and tons of information made available to you through those two books we can begin to talk technicalities, tho' when you've done that, we may not need to do so ;-)!

All the best to you.

TrentePieds

[sanibel sailor]

I am assuming you are referring to Lyle Hess's Bristol Channel Cutter.
SA/D BCC 18.6, W32 16.7
D/L BCC 346 W32 419
An extra 5500 lb displacement on only 1.5 longer WL
Far better hull shape, benefitting from 50 years newer design.
PHRF Lake Ontario says the BCC has to give the W32 10 secs/mile.

I had a BCC and she performed OK at best to windward but was quite fast off the wind as well as in light air as she could set a lot of sail and her weight gave her momentum thru the lulls.

[Bowdrie]

Originally Posted by NewAlexandria

It's basically the same boat. What am I missing here?

They are certainly not the "same boat".
Lyle Hess didn't invent that hull shape, his designs borrow a lot from the original working craft of the 1800s.
William Atkin designed the wood version of the W32 in ~1927.
A perusal of the lines drawings for each will show large differences between them.
The W32, with its bluff bow and steep buttock lines uses a lot of its sail power in pushing the water aside.
The BCC has a finer entry, flatter buttock lines, and with good drag to the keel the wineglass stern sections have a better "release" of the water.
The W32? Atkin was approached by some guys that wanted a scaled-down version of a Colin Archer rescue boat.
He obliged them.

[Don C L]

Waterline, displacement and how big a furrow yer trying to plow.

[NewAlexandria]

Originally Posted by Bowdrie

They are certainly not the "same boat".

I was never talking about any Lyle Hess.
I said Pilot Cutters in general are all advertised as 10 knots but WestStail32 is 7 knots. It is the same boat, the minor differences in hull design do not create 3 knots difference. As a matter of a fact in order to push above 7 knots is limited physically, hence my question.

I don't see why a tiny difference in hull design would create 3 knots. More, why would someone designing a boat 100 years later not know which hull design is faster? Every boat would be doing 10 knots 100 years after Bristal mania.

No where online or anywhere it is explained how come they were faster.

[Don C L]

They really advertise 10 knots? For the 28? Well in any case the BCC has a much greater SA/D, less displacement and all that sail area is a bit lower to the water, which all help. Still, as you say, that can't account for 3 knots. I can certainly imagine 8 or pushing 8.5 kts on a beam or broad reach in a good breeze though I bet. The W32 has such a full bow that really has to move a lot of water out of the way. I say this not from sailing one, but only from sailing next to one for one long afternoon and wondering why he wasn't going faster.

[NewAlexandria]

Yes they say they are going 10 knots on any boat 28 to about 46 which I think is not possible. Then Southern Cross 31 would do it too, it's a smaller bow WestSail 32.

[Adelie]

For non-planing vessels, the only way you are going to get to 10kt is with waterline, and that will be the max speed off the wind in heavy winds. For 10kt max you need about 55’ LWL.

Pilot boats needed 2 things;
A. to be sea kindly in heavy weather and seas.
B. Better than normal speed.

A. Was because they spent a lot of time waiting hove to on station for a steamship to arrive needing a pilot to go in to dock.
B. Was to minimize the amount of time getting the pilot from dock back to station.

Because they weren’t hauling significant cargo, hull shape was optimized for speed compared to a fishing vessel: finer bow, less beam, relaxed stern shape.

With a given length of hull bow sprit and bumpkin allowed them to carry more sail in light air leading to a faster average. The gaff rig helped carry a lot of sail too with a shorter mast.

WS32 is actually a decently fast boat if it isn’t overloaded and has good light weather sails. Won the TransPac 1 year even though they bumped its rating part way thru the race.

[NewAlexandria]

^ I like the answer above. Especially A and B. I arrived at those same conclusions as that's the only logical way.


In the video below in the description they are sailing 11 knots on a 43 water line. This just made me wonder. I still think 8 knots max. More like 7.

https://www.youtube.com/watch?v=Fadj84jz2Tg

Same thing with that famous boat Agnes. No way it's 9. It's all 7 I think.
I am really busy restoring motorcycles, but once I will be free to design my dream boat I will post everything with calculations and modeling.

[Don C L]

Originally Posted by NewAlexandria

^ I like the answer above. Especially A and B. I arrived at those same conclusions as that's the only logical way.


In the video below in the description they are sailing 11 knots on a 43 water line. This just made me wonder. I still think 8 knots max. More like 7.

Same thing with that famous boat Agnes. No way it's 9. It's all 7 I think.
I am really busy restoring motorcycles, but once I will be free to design my dream boat I will post everything.

Well, of course that is a longer boat so it will go faster.
My waterline is 22.5 feet. My theoretical hull speed is about 6.4 kts. But once heeled I have a little more waterline and I know I have had her at over 7 knots STW steady on a beam reach and I wasn't trying too hard. The hull speed is not a hard and fast limit. I'd guess that is right, 9 - 10 kts for the boat in the video, especially if she has a 43 foot waterline. 11 knots? Maybe once in a while.
https://www.omnicalculator.com/sport...-is-hull-speed

[Don C L]

Hull shape does matter too. Imagine a 40 foot barge vs a 40 foot proa or catamaran.

[NewAlexandria]

Maybe you guys are correct. I know nothing about boats, I only visually do not see much difference in hulls between Bristals, Southern Crosses, WS32s. I plugged in the numbers into calculator and for the most optimal scenario 44 water line is 8.8 knots. So Maybe. You could call them 9 knot boats. Maybe I'm wrong.

[Don C L]

This is kind of an interesting article.
https://www.dmsonline.us/the-truth-o...g-speed-limit/

[NewAlexandria]

Just read it. I feel 3 times smarter.

Btw, from that article one can conclude double ender is faster as you can extend the wave length by 5 feet at full hull speed (both waves line up with the boat at maximum separation - long peak to peak) .

This article also explains WestSail32 hobby horsing at slow speeds. She is wide and has hard time surfing the bow wave. She can't break through unless more speed comes in.