Why Cal ?

[roverhi]

Have heard the Cal 40's pound when hard on the wind. Supposedly a function of the CCA design parameters. Having owned a non Cal pounder, It's a bit unnerving. In the case of the Cal 40, it doesn't seem to hurt the boats at all. the Cal 40 is the most raced boat design ever built and haven't heard of any problems with the hull.

One thing to look for in any of the older Cal designs is the mast step. They were/are steel and are most assuredly rusty. Depending on the effects of the rustermites, the step will need replacing if it hasn't been done already. Not a cheap job but way way less costly than buying a new piece of tupperware.

The lighter the boat, the less it's carrying capacity. Weight added to a light boat tends to hurt it's sailing qualities a lot more than a heavy boat. ?The mass of detritus accumulated in a cruiser is a much higher percentage of boat weight in a light boat than a heavier boat. A Cal 40 has plenty of carrying capacity and the lower she is on her lines, the longer the water line. The new plumb bowed, fat assed boats will pick up precious little water line length as they are loaded down and a whole bunch of additional wetted surface. The new Beneteaus make nice condo's though.

[Cheechako]

The lighter the boat, the less it's carrying capacity. Weight added to a light boat tends to hurt it's sailing qualities a lot more than a heavy boat. ?

So.... I've been trying to logic this out for a long time..... ever since people told me I couldnt load my 42 ft cat like I did my 47 mono actually... I understand that a thicker, heavier struture is stronger. But theoretically.. let's say you have two identical shaped hulls. One is built of 1/8" glass and one is built of 1" thick glass. Why would the 1" thick hull be better when loaded with the same amount of cargo? (from a speed /handling etc standpoint) The lighter hull would have less weight and less wetted area.... so what would make it sail worse? (other than potentially falling apart!)

[roverhi]

It's not about the construction weight of a hull but the design. Lightweight mono hulls tend to have flat bottoms. Wetted surface goes way up as you add weight and the weight is a much greater percentage of the boats displacement. Light weight sleds biggest advantage is sailing DDW in surfing conditions. They are so light that they are easily launched off a wave. Start adding weight and they are no longer quite the surfing prodigy. Also, lighter boats have smaller sail areas. Less driving force to propel additional weight.

In the case of a multi hull, it's not only a matter of additional wetted surface but structural concerns. You start adding weight to a multi with the terrific mechanical advantage of those wide spaced hulls and things can get interesting. Have heard that most structural failures in cruising trimarans are caused by owners loading the Ama's down and good old Archimedes takes over.

[sarafina]

sorta like a Porche and a half ton. Ya don't buy a Porche to load up and go 4 wheeling.

Alternatively you wouldn't pull a Dodge truck up to the start line on a roadster ralley.

Different horse for different courses.

I don't know that for her size I would class my Cal28 as a lightweight cruiser...

[Cheechako]

It's not about the construction weight of a hull but the design.
Yeah, that's kind of my point I guess. People tend to use the word "Lightweight", but really what they mean is "Modern design" .... which always confused me from a technical standpoint. Still... not convinced in the wetted area argument. Will an old say.... Herrreschoff .... design with a narrow beam, very narrow transom, deep wetted hull, long overhang etc really stay higher in the water than a newer design that carries the beam well aft? hmmm... my intuition says no....

[CnC40sailor]

Originally Posted by Cheechako

. Will an old say.... Herrreschoff .... design with a narrow beam, very narrow transom, deep wetted hull, long overhang etc really stay higher in the water than a newer design that carries the beam well aft? hmmm... my intuition says no....

No it won't, but a newer "lightweight" boat isn't designed to sail with much boat in the water, the herrreschoff Im going to assume, is. It's design effectiveness isn't effected as much because when conceived, it was expected to sail with a lot of boat in the water; its hydrodynamics were not changed as drastically. The "lightweights" were designed to float high with little boat in the water, so the more a lightweight sinks into the water, the more it deviates from its original design; its hydrodynamics drastically changed.

Back to the example about the Porsche (a very good example), if you load up a porsche with 500 pounds of stuff, its still going to be faster than the truck, but its performance stats are going to deviate from its lightweight numbers more than that of the truck because it (the truck) was designed to handle heavier loads.

[Cheechako]

It's a fun discussion, sorry ... didnt mean to hi jack the thread. I remain unconvinced that a new Swan or Oyster with the same payload wont outsail an old design with the same waterline length.... :>)

[sarafina]

I bet the new one might, given that her rigging and hardware is going to be substantially lighter.

Every time we upgrade something on the cal28 we take off payload. The old boats had old heavy gear.

Any ideas on how much of a speed difference there is between the same hulls, one with old rig and one with new?

[Cheechako]

No increase in max speed due to lighter weight.... waterline defines that. there is an increase in acceleration up to that speed with a lighter boat though... probably only important to racers.... :>)

[Adelie]

Originally Posted by Cheechako

It's a fun discussion, sorry ... didnt mean to hi jack the thread. I remain unconvinced that a new Swan or Oyster with the same payload wont outsail an old design with the same waterline length.... :>)

So let's look at the Cal40 vs the Swan 40-2.
The Cal40 has a PHRF of 117 vs 81 for the Swan.
The Cal has a hull speed of 7.4kt which would get it 177nm in one day. Applying the PHRF time on distance correction would put the Swan 13nm ahead. This assumes wonderful sailing conditions and a full crew.

If the wind is lighter the advantage will be a lot less. Reality will be mix of conditions that the PHRF is not good at predicting outcomes for. This is because the ratings are compiled from outcomes of completed races. In very light winds races are called off. In really heavy winds the skippers pack it in and go home. So PHRF only does a good job of predicting outcomes for fully crewed boats sailed in the 'moderate' conditions.

On the other hand cruising boats don't pack it in and go home for the evening, they keep sailing. I like the formula that EvansStarzinger and BethLeonard came up with. They interviewed a large number of boats encountered while cruising and obtained a large history of actual boat passages. Using this history plus specifications for the boats on these passages the did a bit of mathematical hand-waving call regression and determined what the important parameters were in predicting average daily runs for various boats.

The formula they came up with was:

=24*(2.62 + 0.066*LWL+ 0.051*SA/D)

Based on this the Cal should make about 129nm/d and the Swan about 132.

Evans indicated that the results are only good to about +/-10% or so. Thus the actual difference could be a lot greater or the Cal could be making more distance than the Swan.

Why the disparity between PHRF and Beth&Evans:
As previously mentioned PHRF boats are fully crewed and doesn't represent the very light and very heavy wind conditions well. Also the period of most races is pretty circumscribed, hour or days for all but a few races. Cruisers are out for weeks or months so constantly pushing the boat to live up to it's rating is just a recipe for fatigue and the bad judgement that follow. Boats are loaded a lot heavier for cruising than racing. Skippers tend to sail a lot more conservatively when cruising, repair facilities are a lot harder and more expensive to find.

Lets assume the Beth/Evans formula is accurate, what do you get for that extra 3nm/d?

You get an extra 1ft of boat length and 2' of beam, that's an awful lot of extra cabin space and this is not to be disregarded. You also get a boat that is 1-1/2' deeper and has running backstays that need constant tending. Depending on how you view the CSF the Swan is not quite a resistant to capsize. And to top it all off you would pay an additional $200k, or about 5x what you would pay for the Cal40. After outfitting I would expect the spread to be down to about 3x-4x.

This is why the Cal's continue to be seen as sturdy, budget minded boats that still perform well.

[Azul]

Originally Posted by sarafina

Might be cause of a compromised steel beam? Or broken tabbing?

Almost certainly due to the lightweight forward bulkhead. Three engineers owned my boat a few years prior to me, they augmented the front bulkhead (along with upgrading almost every other critical system on the boat, part of the charm of older boats) which does seem a little skimpy to a non naval architect (maybe 5/16 inch thick) with 1 1/4 inch marine plywood through bolted and glassed in. BTW, my mast support is original and shows almost no signs of corrosion even though I have seen a picture of a corroded support on a smaller Cal that had unknown care, I am more worried that my anchors will rust out than the support. Of critical importance, an older Cal does seem to have an intrinsic value after being upgraded that makes people still see the value of investing money in them.

I have read somewhere that people jokingly put out sail while racing a Cal 40 until the V berth starts to come apart.

For bluewater use many of the original Cals had what is nowadays considered lightweight chain plates, an unprotected companionway hatch needing a spray hood, questionable height above cockpit companionway with companionway boards that need upgrading and excessive mainsail square footage causing weather helm. Mine has been modified to the shorter boom, taller mast rig of later models with a traveler and mid-boom sheeting instead of the end boom sheeting. An Edson wheel was placed (the tiller can be remounted in seconds as backup) as the original tiller setup was considered awkward.

Not only are the Cal models so varied in their design, but over the last 40 years so many of them have been heavily modified that it is hard to make blanket comparisons. Even on the same model, progressive generations had lots of changes.

Sarafina, thanks for your post back in 2011. When I was researching Cals I saw that post about the Craigslist cheap Cal. That day I looked up and down the east coast on Craigslist and found a Cal that was posted for the first time that same day which was an incredible deal, much less than the usual 25K- just karma I guess!

[sarafina]

The little advantage of having the 28 instead of the 40 is that they used the same materials, so the strength to weight ratio is better.

But even given that I spent last week making 1/2" sheathes for the chain-plate bulkhead area which will bring up the strip of bulkhead that the chain-plates tie into up to almost 7/8"s, and total sheathes for the main bulkhead (with the companionway hatch) the same.

I hadn't considered bulking up the forward bulkhead (the one that would be the anchor locker, if there was an anchor locker?) or the second bulkhead (between the v-berth and the head) but am thinking if I feel the need to go that far.

I picked up 6" glass tape for redoing all the tabbing in the v-berth. On one side it is totally split and on the other it's squishy.
Our girl was raced like a bitch. She has hard miles on her, chips and fine crazing in the hull from impacts. The fiberglass around hatch has a deep crack, almost down to the bend at the bottom. A few "rode hard and put away wet" docking damages. Some minor wood rot around the edges from bad window seals.

I don't think that hull 181 is one I would do RTW in. She is better suited to coastal cruising and bay sailing these days, so I don't want to go overboard on reinforcing her structurally. Just more weight to haul, at some point.

And our steel beam is sound, but we have a bit of seperation in the beam the mast is stepped onto. She dioes show her years, but gracefully...

[Barney Post]

Originally Posted by nylajo

Cal 40 Old flat top in Swiftsure

Wow!
A one of a kind!
Someone sent me a Email about this boat a while back.
The only raised deck Cal 40 ever built. I quoted the story here:
CAL 40 sailboat specifications and details on sailboatdata.com

[justwaiting]

This thread started me thinking,

came across this site Cal Sailboats