How has technolgy changed sailing speed?

Could it be that mono's started using movable ballast on larger boats in the 90's?

[wet feet]

It could be movable ballast.It could be better use of composites.It could be more efficient sails.It could be CFD.It could be sailors with more experience of fast monohulls.It could be all of these things.

[rayk]

I think better communications technology allowed faster lighter boats to venture offshore for the ocean passage records.
Coastal speed increases follow the stages of technology very closely or even in step.
Once global communications caught up with materials, things took off for the off shore crowd. Prudence could be thrown out the window.
No one really wanted to die while setting records in the 'old days', but it is now possible to drive the boat till it fails, and then press the button for a rescue.

Sail area to displacement ratio has climbed of course, and higher initial stabilty with lighter rigs means more sail up, more of the time.
Weather routing is useful too.

A sailor from 100 years ago might be impressed by todays modern technologies, but may fail to be impressed by our dependence on them.

[RHough]

Doug, it is true that the monos in my BDR data since 1994 have used some form of movable ballast. However I think movable ballast was in use long before that. Could you look at what you have and give me some idea when ocean crossing boats started using ballast systems?

Wet, if it was a better use of materials, better sails, or better design methods, can you identify a major change in any of these area that could have caused the big jump in performance?

Rayk, Your comment that coastal sailing speeds have closely followed stages of technology interests me. I have not found a source for that data. Could you point me in the right direction or post some data that supports that conclusion?

Thanks all.

I've found the Trans-Pac records since 1906, I'm entering all the data I can find into a spreadsheet to look for trends. It is very interesting! The 1931 24 hour run made by Dorade at S/L 1.44 was backed up in 1936 with a Trans-Pac win ... first to finish, first in class, and first on corrected time! Her average for the 2225 miles was a S/L of 1.14. In the 1940's, under a new rule, her 38 foot LWL was rated at over 45 feet ... That was a fast boat!

More to come, thanks in advance for help with data sources!

My bad. It was 1953 that Dorade sailed the Trans-Pac at a rated length of 43.6 ... still for a boat that won a Fastnet and a TransPac in the 1930's to be raced in the 1950's is pretty neat, even though she finished the 1953 race 18th of 32 ... she was a fast boat.

This site says that movable ballast was first used in the mini-transat in 1983:
Gale Browning Ocean Racing
Address:http://www.galebrowning.com/minitransat/racehist.htm Changed:1:14 AM on Wednesday, August 6, 2003

[CT 249]

Movable ballast was used in the 1800s aboard yachts. Dixon Kemp writes of lockers behind settee berths which were used for storing metal movable ballast. LF Herreshoff's uncle had a catboat with sliding ballast, and a similar system was used in Australia.

Movable ballast is certainly not a new idea, it's just that it was banned for many decades.

[DGreenwood]

Ever heard of a sandbagger?

[rayk]

The best example I can think of regarding the connection between coastal speed and technology application is Doug Lord's rabid promotion of foiling moths.
Getting the hull out of the water is an evoloutionary step.
(If any one has read a defence of clunky old fashioned boats, think about how a foiler regards your hole in the water.)

Displacement boats:
Exceeding hullspeed is an effort to reach planing speeds.
Hullform must be suitable if you want to plane, surf, whatever.
Power to weight (SA:Disp) is next.
Appropriate weather is the final ingredient.

Ideally a boat that uses foils for lift and stability will be the fastest.
Ballast (weight) and form stability (hull drag) is hardly the future of speed on the water.

Not such a pretty picture of sailing in the future is it?
We should be careful what we wish for. :)

[RHough]

I've got over 300 data points so far ... I'm getting cross-eyed

Looking at race results, obviously the fastest boat should win. A problem comes up when boats are different sizes, some form of handicapping system must be used to evaluate performance. In 1906 it was Time Allowance: One-half hour for each foot of overall length. The longest boat gave time to the shorter boats. The race winner on corrected time got a 12 hour correction. The boat was 6 feet shorter.

Rating rules in evolved over the years, ostensibly to create handicaps that were more fair than the rule that was replaced.

Length based rule performance can be evaluated by using the S/L ratio of the rated length compared to race placing. The corrected time winner should have the highest S/L ratio. Sorting the results by S/L ratios should give the overall corrected finishing order.

What happens in racing is that rules work pretty well early in the cycle, When Dorade won in 1936 the rule was: Time Allowance: R = 45 * ((1/2 (LOA + LWL) + (SA)0.5))/2 This attempts to rate long overhangs and sail area.

In 1939 the Handicap Rule: Ocean Racing Rule of North American Yacht Racing Union was adopted.

Under the 1936 Rule Dorade had a 2 day, 3 hour, 51 min correction, under the new rule she got 3 days, 3hours, 6minutes. Same boat ... different rules.

By 1955 the holes in the rule were so big that the TransPac was run under: Ocean Racing Rule of North American Yacht Racing Union subject to certain limitations plus the Transpacific Yacht Club's Table of Allowances.

Indeed when results are compared with the rated length of the boats, the finishing order does not compare well with a S/L sort. As the rule cycle progresses, the rule has problems with smaller boats. Boats with higher S/L ratios for the course place behind boats that were not sailed as well. Two thoughts come to mind. If the rule is to be fair it can be used on random leg races, the TransPac is predominately downwind. Design changes that make a boat perform better off the wind that don't change the rating will show up first in small classes, since the time and money to experiment is less. The bigger boats are "behind the curve". The race results up through 1959 certainly show that the rule of the day tweaking had a large effect on the results.

Every set of data that I've been able to find shows this trend. Single number measurement systems do a bad job of handicapping boats when race conditions are different than the conditions the rule was written for. Races and race records go to the boat that best exploits the rule she races under.

Through all of this, the speed of the boats didn't change much. S/L 1.4 is remarkably fast, S/L 0.9 is pretty slow. Two set of rules govern sailing speed. Mother natures rules of physics (not subject to change), and the racing rules of sailing, which, until they were changed to allow moving ballast, prevented mono-hull speed increases with new technology (don't argue with Mother Nature). Multihulls on the other hand seem to be getting faster as technology is introduced and did not require a change of the RRS to allow that development, perhaps Mother Nature likes boats that don't have to haul lead around?

If speed across oceans is your goal, and technology your muse, I cannot think of a case for refining or developing boats with ballast. The only question that remains is that of safety (seaworthiness and seakindliness). If there is a market for boats that cruise at 10-15 knots instead of 5-8 knots with a crew of two, we will see more multi's and boats like the Pogo40.

[CT 249]

Like others, I think the 24 hour run has major flaws as a way of measuring speed. It largely measures only top end speed; not upwind speed, not light wind speed, not angles. Such things matter, as we all know.

One extreme example (not an ocean racing example, but nevertheless intersting IMHO) would be windsurfers; a board that comes close to 50 knots is about twice the speed of an early board, but the 50-knot board cannot actually be sailed at all until there's maybe 12-15 knots of wind. To say that windsurfer speed is doubling is to ignore the fact that the old board is infinitely faster in very light winds, 'cause the speed board cannot be sailed at all!

The "classic" racing mono, like an IRC boat, is built to accelerate fast, point high, move well in light winds etc, which aren't tested in 24 hours speeds. This is shown in big coastal races like the Fastnet and Hobart, where Open types are often beaten by IRC/IMS type boats of similar LOA but much smaller beam, LWL and rig. Look at the last Fastnet, or the 2005 (?) Hobart when Hugo Boss and another Open 60 raced.

A 1960s ocean racer is about 14-16% slower than a '90s ocean cruiser/racer, according to IRC and IMS rules. The 1973 S&S design Love and War, a Grand Prix racer of her day, is rated 13.5% slower than a Beneteau 47.7. Same with Swans, etc. So speed is increasing around 0.5% per year in the "conventional" boats.

[rayk]

Originally Posted by RHough

If there is a market for boats that cruise at 10-15 knots instead of 5-8 knots with a crew of two, we will see more multi's and boats like the Pogo40.

I agree with you RHough, there is a market for these boats right now.
Like any other cruising boat they will be blighted by live aboard paraphenalia.
The ULDBs will appreciate crew who travel light (think no book collection, stores for three weeks, no water tankage, rope instead of chain, no spare sails, anchors or 'useful old rope').
To truly enjoy the performance of these boats requires some dependence on shore services, and fast passages between marina facilities is the style of cruising that will be most enjoyed.
Providing that the crew of a Pogo 40 or a multi has the discipline to keep the boat in trim, and the nerve to set maximum sail area, 10-15 knots is the reward.
Overloading the same boats puts them in the 5-8 knot bracket, and most racer/cruisers end up over loaded and under performing for most of their life.

[RHough]

Originally Posted by CT 249

Like others, I think the 24 hour run has major flaws as a way of measuring speed. It largely measures only top end speed; not upwind speed, not light wind speed, not angles. Such things matter, as we all know.

A 1960s ocean racer is about 14-16% slower than a '90s ocean cruiser/racer, according to IRC and IMS rules. The 1973 S&S design Love and War, a Grand Prix racer of her day, is rated 13.5% slower than a Beneteau 47.7. Same with Swans, etc. So speed is increasing around 0.5% per year in the "conventional" boats.

CT, Thats why I looked at over 300 TransPac results. I wanted to get a feel for a passage that is common for cruising boats. Based on LWL, boats that sail the TransPac course do NOT show an incremental increase in speed. The new boats may well be 14-16% faster around the buoys, but that does not show up in the passages times I have been able to find.

Different rules have predicted different speeds for boats since there have been rules. The same boat can be rated faster or slower by different rules. The boat itself has not changed.

Dorade's rating in 1936 was 38 sec/mile faster than her rating in 1939. She didn't get slower, but if you judged her speed from her rating you would say she was. The boat did not change. Her Atlantic 24hr run was 1.44 S/L, she did one Transpac at 1.14, one at 0.90 and another at 1.01 Her passages are slower than her best days run as we would expect.

Where I think boats have gotten faster is on closed courses on day races. That's where rating systems have to work every weekend. Closed courses favour windward ability and a small change in windward ability forces a large change in rated speed.

If there is data that shows that the average passage speed of a 40 foot 2006 cruising boat or XYZ rule boat is 14-16% faster than it's 1960's counterpart, I can't find it. 0.9 to 1.2 S/L is where displacement boats have been since almost forever. This years S-H had Love&War at S/L 1.07, Wild Oats at 1.14, and Ichi Ban at 1.28. On a downwind course, W-O and Ichi would have been at S/L 2.4+ while Love&War would be doing well to hit S/L 1.4

A combination of boats with better light air performance and better weather routing has brought passage speeds up, but there have been no great changes that coincide with new technology. 1920-1939 boats are hugely different in material and hull form to 1960-1980's boats, yet passage speeds are remarkably similar. After about 1980 ULDB's and Multi's do better on passages that favour their unbalanced polar curves. On passages like this years S-H they post speeds that are no great shakes.

I would LOVE to find some data that shows modern hull shapes are significantly faster than those of the 1930's & 40's. that was my goal when I started looking ... it would be great ammunition in the seaworthiness thread. Fact is I can't find data to support the position that new cruising boats are faster than the heavy types that are the pets in that thread.

If you've got data from passages or races that support that thought ... please ... point them out to me!

[PI Design]

Good luck with your search for the figures Randy. Sorry, I can't help you. Anyway, I haven't researhed these thougts, but off the top of my head the step change in speeds since the90's could be as a result of:
Lighter and stiffer hulls due to the use of foam cores and carbon fibres.
Laminated sails replacing Dacron.
Increased stability allowing more power to be developed. Stability has increased through water/canting ballast becoming more commonplace, the use of beamier boats (Open 60 etc) and longer/deeper/heavier fin keels (which were not structurally feasible previously).
Shore based weather routers and better forecasting facilities feeding expert info to the boats, so they find the best winds.
The sheer increase in numbers of boats participating in an increased number of trans-oceanic events. This has two effects. Firstly, there is more chance of an individual boat finding ideal conditions. Secondly, many sailors have now done numerous such events, so their level of expertise, and the level of competition, is higher.

It strikes me that there are two fundamental reasons why speeds can have increased beyond S/L of 1.34ish (hull speed). Either hulls must be thin and light (so as not to make a bow wave), or they must have sufficient power to breakthrough the drag hump (and presumably, therefore, plane). The multihulls obviously take the former route, and have done since they first appeared. It is possible to make incremental improvements to multihull speeds, but there is no barrier to breakthrough to get big improvements. Monohulls have the hull speed barrier to breakthrough, and the reasons listed above have helped produce boats that can achieve this, at least downwind.

One other thought: A 36 footer will have a hull speed of 8 knots. In days gone by, a yacht may have needed winds of 12kts to achieve this, now 8kts is enough. But if the hull can not plane, or some other way break through the drag humpo, it will not go any faster in 12kts. So, looking at BDR will not show any improvement in top speed. Top speed is achieved sooner, but is not any faster.

[PI Design]

The excellent 'Rig Theory' by Ian Hannay (AYRS publication 113) has some intersting stuff that may be use. Firstly he ascertains that whilst a racer is keen to get any performance increae, no matter how small, the cruiser is only interested in measurable improvements. He suggests a 2% improvement as a minimum, which corresponds to about a half day improvement for trans-Atlantic crossings. This pragmatic approach seems sensible to me.

He goes on to split the factors that affect yacht performance into three groups - primary, secondary and tertiary.
The primary factors are stabilty, weight and length. These factors, combined with wind strength directly determine the maximum possible speeed of the hull, irrespective of the rig used.
The secondary factors affect the efficiency of the system. For upwind work he has identified these as: effective height of the rig, effective depth of the foils and sail area.
Tertiary factors are: foil shapes, the style of sails/ spars and rigging, hull lines, surface finish and drag from appendages (propellers, cabin tops etc). It is within these factors that the designer, builder and sailmaker express their individuality.

There is a hiearchy here, whereby to gain a fundamental increase in speed it is necessary to alter the primary and secondary factors before worrying about the tertiary. Careful design of the teriary factors will decrease the inefficiency of the system, but can not make the boat sail faster than the primary factors will allow.

This hasn't directly answered your question, but does give food for thought. The step change in performance in the 90's wouldn't have resulted from fiddling with the tertiary factors...

BTW, I recommend 'Rig Theory' to anyone interested in sailing craft. It is an easy to read, well thought out document. Amongst other things it contains an interesting modification to Lancaster's Course Theorem.

[CT 249]

Randy, I don't think the fact that Dorade's rating changed as a result of a rule change has a bearing on the ratings I was talking about, which are the same rating rule applied to two boats.

It is a fact, as we know, that old boats like late '60s/early '70s racers normally rate in the region of 15% slower than modern racer/cruisers. If the old boats were as fast as new boats on long races, then in the typical Bermuda, Fastnet or Hobart the top old boats would correct out by about 12 hours over the top new boats. In fact the old boats do pretty well, but they certainly don't have that sort of advantage.

I think the problem with looking at passage times is that they can vary so much according to conditions. When the boats sail together in a race, the conditions don't vary as much and the older boats are normally some way behind. For example using Love and War, we can look at the 2003 Sydney-Hobart, pretty much an all-weather race from memory. The 47' Love and War finished 8 hours behind the IMX 40 and Beneteau 40.7 across the line (but still finished a respectable 12th on IMS). So Love and War, 7 feet longer, was about 12% slower when she started at the same time, sailed well, and had similar conditions.

In summary, it seem perhaps better to look at races (where the good boats are pretty much similar on conditions of weather, boat and crew) rather than passages, and the races prove that the newer cruiser/racers are quicker.