Measuring and registering a new build 'classic' boat

[Gareth]

I am just starting to progress the build of an A class hull that my wife and I acquired about 3 months ago.  It is a 1970 John Lewis design, Phaedra 2, possibly one of the most beautiful A class designs ever, or at least I think so.  We bought the hull as a bare shell, no deck beams or anything above, and a nicely cast lead keel,  weighing 53 pounds.  I have been pondering whether to build the boat to be fully compliant with the A class rules and get it measured and registered on completion, perhaps with a view to competing in the classic group of some vane sailing events.  We had the same issue with a classic Marblehead last year, a Roger Stollery Daredevil design which had never been measured or registered prior to us restoring it.  The stumbling block was the bow bumper which could not be made compliant with the current Marblehead rules without major surgery to the stem, or ending up with a particularly ugly excrescence on the front.  Neither of these options was acceptable to us so we abandoned the plan to register that particular yacht,

Phaedra 2 is an even more 'pointy' design and I cannot see any easy way of making it compliant with the current A class requirement for the front 20 mm of the hull to be made from a resilient material.  On our other A class yacht Serica 3, we sail with a 60 mm sponge rubber ball fixed to the stem.  However I doubt that this would be considered compliant as, in the Marblehead discussion, it was suggested that the compliant section should extend down to the waterline, although the rules are not explicit in this regard. 

Are there any A class experts out there who have any experience of this problem and can suggest a possible way forward?   Must a previously unregistered boat be measured to the current rules or can it be measured to the rules as they stood at the time of its design?

Edited October 7, 2020 by Gareth

[tiggy_cat]

Would be interested to see the replies. I have the same issue with my unregistered 1970's Dambuster. Probably easier to contrive something for that , but won't be pretty. In a recent post to  a Facebook page, I queried whether the Dambuster ( or a nice "roundy" Clockwork Orange that I am looking at on Ebay)  could be registered under the current rules. The answer from the Class Registar was yes , as the difference was mainly in how the sails were measured.  Then another well known and respected yachty commented that as for Classics, he wouldn't be too bothered if they were  actually measured and registered , if it got them back on the water.  Some sort of general compliance with class when built notice perhaps?

 

Edited October 7, 2020 by tiggy_cat

[stevevw]

Well I for one would like to see them both sailing registered or not.

[Gareth]

During the Marblehead discussion we had last year it was apparent that there were two sides to the coin.  Owners of modern, measured boats may not mind competing with unmeasured 'classics' on the grounds that their significant performance advantage would probably outweigh the fact that the classic might have a bit more sail area or waterline length than the class rules allow.  However the owners of a lightweight,  expensive and relatively fragile A class boat might be reluctant to risk it being rammed by an old 67 pound monster with a less than ideal bow bumper.

[stevevw]

A 67lb monster going full tilt is going to do damage 20mm of rubber or not.

[Derek Priestley]

Accidents happen & most vane sailors accept this with good grace & there are always lots of people happy to help repair.

I'm sure that we'd all be happy to see a few vintage boats racing in the centenary A week (2023) and I for one wouldn't mind if the forward most part of the hull was not "elastomeric"!!

Good luck with your build & hope we'll see you at classic & vintage Marbleheads next year.

 

Derek

[fastwave]

You could always add a knitted bow bumper which might not be accepted by modern class rules but provides at least some protection.

 It really needs to be fixed well in place such that it does not get pushed out of the way.

 You can find them on ebay and model shops. It has a quite nice vintage look which does not ruin entirely the look of a Vintage yacht

[Gareth]

We have used knitted bow bumpers on a number of our restored vintage yachts (usually made by my wife).  I think it would work quite well on our A class, particularly with a small sponge rubber ball underneath, partially impaled on the point of the bow.  However, as you say, it probably won't be strictly in accordance with the latest class rules

We have found that a length of hook type Velcro stuck on the stem is quite effective at stopping the knitted bumpers riding up or down the stem.  It is not necessary to have a piece of loop Velcro on the bumper, the hook type alone will grip it.

Derek - I hope there will be a classic and vintage Marblehead meeting at Fleetwood next year,  if there is we will be there (and return the Mayoral Trophy)

Gareth

Edited October 9, 2020 by Gareth

[Bill Green]

If we are being strict about this,  if the boat has had a certificate issued in the dim distant past then the hull can be remeasured to the rule applicable at the time of certificate issue.  The certificate records will indicate whether one was issued or not. That’s called Grandfather Rights, however the rig has to comply with the current rule. If it has not been certified then it has to be measured to the current rule. There is absolutely no reason why the boat cannot be measured to the new rule however the boat does need to be in compliance with it. In your case it will need a compliant bumper, there is no depth requirement for the bumper only for it to project the required amount. 
 

Official stance over, let’s deal with the practicalities  You are not going to sail Phaedra in a National Championship are you?  so there is no need to get it measured .  If you are going to sailing it in a “fun” event, then if the organisers are happy with you not having a bumper or as suggested a nominal bumper then as Derek says ”crack on”. If you are aiming to sail it in a MYA sanctioned event then it will require a certificate  

I hope that clears things up for you

All the best

Bill Green

A Class Registrar

[Gareth]

Thanks for that Bill, it pretty well confirms what I thought was the situation.  I doubt that I will get Phaedra officially measured.  I will probably do what I did with Serica III and do some basic measurements myself, weight, waterline length, freeboard and draught and then work out the permissible sail area.  If it comes close to the John Lewis figures I might reduce the ballast weight a bit to get the design sail area.  I will leave QBL and all the other complicated stuff for someone else to worry about. 

Hopefully I wont have the same problem that I did with Serica III.  Norman Hatfield's Serica I was eventually able to carry about 1500 sq of sail after the keel weight had been reduced, allegedly necessary because Bill Daniels got his sums wrong.  Despite using the lighter keel design and repeatedly checking my measurements and sums, Serica III could only be allowed 1300 sq inches.  I eventually discovered that at the same all up weight, Serica III has a two inch longer waterline length than Serica I, but I never have found out why.

Regards

Gareth

Edited November 24, 2020 by Gareth

[Derek Priestley]

Hi Gareth,

 

Wow!  2" difference, that's some discrepancy>  Maybe needs some very careful re measurement!

 

Derek

[Bill Green]

Gareth. The QBL has significant impact on sail area so you can’t ignore it. If you can get the boat “in racing trim” ie:- on the right waterline as the design then you shouldn’t have a problem with sail area. However, I need to say it’s not just the right waterline length it’s sitting on the design waterline. That should bring all the dimensions into the right ball park. 
 
On  Serica, by the sound of it, the displacement calcs were either screwed up or more likely the builders either pushed or pulled the beam to alter the displacement, or both. This  will significantly alter the displacement and result in what you saw, but a 2” discrepancy is a lot. Also the shape of the hull may not be to the design and again this will have an affect. 
 

Bill

[Gareth]

Bill,

Thanks for that information.  I realise it's a bit cavalier to ignore QBL but Bill Daniels original calculations suggested the penalty was small so i decided to simplify matters and ignore it.  However maybe that was part of his original mistake as it seems to be well established that there was a major error in the original Serica design calculations that he did back in 1955/56.  I think the most likely explanation, as you say, is that either Arthur Levison or John Gale changed the hull shape of what became our Serica 3, or something else happened during the 45 years or so when it was in limbo somewhere.  Its not really that important now, as Serica 3 is now what it is and I don't plan to change it.  Its just one of those things that keeps niggling at me to try and understand the full story.   I have a partially written up description of the story as I know it and I could finish it and paste it up on here is anyone is interested,

Gareth

[Derek Priestley]

Hi Gareth,

 

I would like to hear the full story.

 

[Gareth]

The Serica rating saga

The saga of Serica’s rating measurements is complicated, confusing and in some cases contradictory.  It is not helped by the fact that there are three A class yachts named Serica.  However for Derek, Bill and any other A class anoraks out there I will try and explain the story as best I have been able to uncover it. 

The original Serica, henceforth to be known as Serica 1, registered as K750, was designed by Bill Daniels and built by Arthur Levison for Norman Hatfield.  When we acquired our hull in 2015, we were loaned the original Serica drawing, signed and dated 1955 from the Norman Hatfield archive and it indicates the design was to be a boat with a Loaded Waterline Length of 55 inches, displacement of 59 lb (44.9 lb lead)  and, by inference, a sail area of 1600 sq inches.  However, somewhere in his calculations, Daniels made a mistake and when the boat was built and measured it was seriously over rating and could not carry the expected sail area.  The keel was apparently modified to reduce the weight and a further note on the drawing states that the measurements after the keel mod were LWL 55.8 inches, displacement 56.5 lbs and sail area 1483 sq inches. 

We have another set of displacement calculations dated 6^th May 1956 which give a calculated weight of 62.2 lbs and waterline length of 58.05 inches but it is not clear what stage of the boats construction they refer to.  As an addendum on these sheets there is reference to a new lead weight of 38.5 lb compared with the original design figure of 44.9 lb.

After building Serica 1, Arthur Levison apparently went on to partially carve a second hull to the Serica design but it was never finished and went missing for about 45 years 

Some years later in the 1970’s, Jim Belton, an associate of Norman Hatfield built a plank on frame version of the design, which was registered as Serica 2.  He designed a lighter weight keel for this hull with a lead weight of approximately 35 lb and a copy of this drawing was loaned to us.  We know nothing more about this boat except it was registered as a radio A, K1000 in 1976.

Around 2009 the ‘missing’ partially carved Serica hull re-emerged.  It was progressed by John Gale and we acquired it as a bare wooden hull, without a keel in 2015.  We made a ‘light weight’ keel to the Jim Belton drawing and estimates during the build suggested our Serica 3 would weigh about 58 lb and we expected it to be able to carry about 1500 sq inches of sail, i.e. comparable to Serica 1.  When we measured it, to the best of our ability we found the displacement was 57.2 lbs but the waterline length was 58.6 inches.  Calculations showed it would only be able to carry about 1300 sq inches of sail.   This was a bit of a disappointment and I rechecked the measurements and calculations several times and had the rating calculation checked by a well respected A class measurer but the sail area for Serica 3 always came out at about 1300 sq, in.  At the time I was more concerned to make sure the Serica 3 measurements and calculations were correct, rather than knowing why the resulting sail area was so much smaller than Serica 1.

A couple of months ago a friend in the VMYG sent me a cryptic email asking if we had an A class yacht called Serica.  I said we did but why was he asking.  He sent us a copy of the October 1956 Model Maker magazine report on the Gosport A class nationals which mentions Serica and its rating problems.  It quotes Serica’s measurements as LWL 55.8 inches, displacement 55.8 lb and sail area of 1472 sq inches, which are close to the original drawing figures after the keel modification.  At this point my brain clicked into gear and I realised that the key factor was our Serica 3 has a significantly longer waterline length than Serica 1.  I measured the LWL of our boat at a range of weights so it was easy to estimate that at 55,8 lbs, where Serica 1’s LWL is 55.8 inches, Serica 3’s LWL would be 58.15 inches, a difference of 2.35 inches. 

I checked the weight of Serica 3 using two sets of bathroom scales and a luggage weighing scale and all tallied to within a pound.  I estimate the waterline length would not be more than +/- 0.25 inches in error so there must be another reason for the difference between Serica 1 and 3.  Either:-

The early modification to Serica 1 was more than just reducing the weight of the keel

The Serica 3 hull carved by Arthur Levison is not the same shape as Serica 1 and was modified in some way, although the overall length and beam tally with the original drawing dimensions.

Something happened to the hull in the 45 years when it was missing in limbo

When John Gale worked on the hull he changed its shape

I have made a silly mistake somewhere or there is some other factor I am unaware of.

In the end we fitted Serica 3 with a 1300 sq inch set of sails and it is what it is.  As Mervyn Cook said after checking our calculations, it should be really good (for its age) at Fleetwood in a blow.  The reason why I have suddenly taken an interest in this relatively academic issue is that we are currently progressing the build of another partially built A class hull to the John Lewis Phaedra 2 design and I am curious to see how closely it is going to match up to the original John Lewis drawing.

Finally, if anyone knows the whereabouts of Serica 1 and 2 we would be interested to know.

Gareth

[Derek Priestley]

Hi Gareth,

Very interesting read.

  I joined the Radio A fleet in 1979 and raced in the RA Nationals at Basildon (later Chelmsford) RYC .  The boat I used was Kami Sama which had been owned & built by Dennis Lippet, and went through various hands and ended up at Fleetwood & placed 2nd in our one & only World A class Championship in 1975 raced by Alec Lamb of Fleetwood.  Mike Harris won the event.  

In 1979 I was loaned the boat to use in the RA Nationals and off I went to Basildon with Kami Sama & my new wife Maureen (Auntie Maureen) . Kami Sama kept up to her traditions & I finished 2nd to a man from Woodspring John ??? racing a white (Bob Underwood built) Highlander!

But the point of this ramble is that in that race was Norman Hatfield with Serica!

Best wishes

 

Derek.

 

[Gareth]

Derek,

It would have been Serica 2, K1000, that Norman Hatfield was sailing in 1979.  Serica 1 was transferred to Dr J S Rix at Poole in 1974.  Serica 2 was registered to Norman Hatfield as owner in 1976, with Arthur Levison credited as designer and Belton/Hatfield as builders.

Best regards

Gareth 

[Gareth]

For those of you who are A class anoraks and have been lying awake at night wondering why the waterline length of our Serica III was so long , I now have the answer.  I have almost completed a second A class to John Lewis's Phaedra 2 design.  That had the same problem of excessive waterline length when measured in our garden pond.  I have now measured both hulls in a 6 foot water trough using the recommended technique of gently drawing the hull towards a metal 'weir' across the tank at the surface level of the water, measuring the overhang forward and aft and subtracting these values from the overall length of the hull.  This gave results much closer to the predicted design values and around 1.5 inches less than my pond based method suggested.  The answer, therefore, is that it was all down to my crap measuring process which was much more pessimistic than I thought.

 

 

Edited July 23, 2021 by Gareth
Better photo files

[Gareth]

[Derek Priestley]

Hi Gareth,

 

Following on from all of your experiences, I believe that you have now completed phase 1 of the A class measurer's training course!!

 

Just the draught, freeboard, QBL, sail area & formula (slide rule operation) reqd!!

hope to see you at our "Bill the milk" trophy classic & Vintage Marblehead event in 3 weeks?

 

Derek

[Gareth]

Derek

Does this exempt me from needing to do an RYA sail measuring course?

Draught and freeboard I can manage on my bench.  QBL I have also measured (roughly) and I think its ok.  I am putting m,y faith in Bill Daniels and John Lewis's skills as designers as their relevant drawings say the QBL penalty should be zero.

Slide rule still in the loft, I have progressed from inches, a calculator, pencil and paper to putting millimeters straight into the A class Excel spread sheet

Bill the Milk event looks doubtful due to the arrival of Elizabeth's latest trainee hearing dog puppy Elsie, younger sister of our last dog William who has just gone out to work this week..

Best regards

Gareth