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Dracula1
Posted: Mar 5th, 2010 at 23:42   |   Subject: Design 012 - the journey
Hello George,
I have enjoyed reading the plans for the 23' Design 012 which I purchased in January. The plans and instructions definately speaks the right language for the first time boat builder. For this I am most greatful. I do not plan on starting the build untill mid autumn due to the humidity which may have an adverse effect on the West System and the timbers. This is giving me time to familiarise myself with the various disciplines of boat engineering and will aid in programing of the build.

I must be honest here and say that initially, I dismissed this design for a number of reasons however, I couldn't stop from visiting the study plans time and again. It was an education in getting over my preconceptions of the boat I would be satisfied with.

I think the turning moment was when I discovered myself at the kitchen table, a print of the study plan in front of me, a pencil in my hand numerous sketches on the page. Lets just say that the boat now has a chart table from folding up the port side seat backrest and a sizable double berth from reconfigured hinges utilising cam lift-off hinges on a sectionalised starboard seat backrest. All while maintaining the original fold-up function for the quarterberths.

If I may, can I ask for your assistance in understanding this boat (this is probably best done in separate, topic specific threads). I have been trying to educate myself, however, some questions relate specifically to your concepts and general reasearch still has not yeilded substantial solutions.

Once again, thanks for understanding your market audience (me being one of them). Study and the build are part of my journey to enjoying sailing, and I am enjoying myself enormously.


Regards,

Gary
debenriver
Posted: Mar 8th, 2010 at 00:51   |   Subject: Design 012 - the journey
Hi Gary

Sorry to be a little late replying to you - I've been away for the weekend.

I would be very happy to answer any questions about the design - practical or conceptual – and to assist you in any way I can.

And the changes you are considering for the interior sound pretty interesting and practical too.

So –– fire away!

George
Dracula1
Posted: Mar 8th, 2010 at 11:59   |   Subject: Peak and throat Halyards
Hi George,
Hope you had a great weekend. It is I who thank you for your prompt reply. The world may be caught up in its acronym based language tailored for mobile phones but I still remember snail mail. I suppose that is why I want to build a sailboat. Escape! In stately fashion of course.

I would like our first conversation to be in relation to the halyards and sheets. The first focusing on the foot of the mast. If I interpret correctly, you have a design philosophy that the boat is operated from the safety of the cockpit. This appeal’s to me, as much of the time, I will be sailing alone.

I apologize in advance if my questions are somewhat naïve. Learning to build and sail from books is limiting. My reading has left me with gaps of a specific nature. The books tend to be generic with the information they provide, and understandably so. Thank you for your offer to assist me.

Q 1 :-
The deck plan (sheet 012/012/01). I can trace the main halyard, which I interpret as being the peak halyard. I have assumed the throat halyard is at the mast itself. Is the assumption correct?

Q 2 :-
The main halyard block at the foot of the mast (assumed peak halyard) seems to be too far aft for it to pass through the sheeve at the head of the mast without a quarter turn around the mast to enter the sheeve. This configuration would provide ample clearance between the staysail boom as to not interfere with the passage of the boom. Is there an additional block or blocks on the mast to guide the peak halyard to enter the mast head sheeve more square on, to reduce friction on the lace for the main, the rotation of the perrel beads and angle of attack to the sheeve. Or am I being overly concerned?

Once again, thank you for your assistance.


Regards,
Gary
debenriver
Posted: Mar 8th, 2010 at 15:41   |   Subject: Peak and throat Halyards
Hi Gary

The downside of bringing control lines back to the cockpit is extra friction, additional loads on the area around the mast, and rope clutter in the cockpit. But I do think that the advantage of being able to largely work the boat from the cockpit well outweighs this.

However, as drawn, the halyards are not logically or properly organized – and that needs to be addressed. So I am very glad indeed you have raised the issue.

Both the throat halyard and the peak halyard should go back to the cockpit. When you are hoisting a gaff or gunter rig you need control of both halyards in one place – either the cockpit or the mast, but not one at each. And it is usual for both to be on the same side of the mast (or in this case the same side of the coachroof) so that you can conveniently pull both up at once in the first instance.

So we need a reorganization of the leads.

On the Stbd side:

The swivel block currently labelled "Spinnaker Halyard" should be moved forward, onto the tabernacle base fwd of the side web, and converted to a double. This will take the fall of the Peak Halyard, to run through the middle sheave of the triple turning block, and the fall of the Jib Halyard to run through the outer sheave of the triple turning block.

The swivel block currently labelled "Topping Lift" should in fact take the fall of the Throat Halyard. To run through the inner sheave of the triple turning block

And the swivel block currently labelled "Main Halyard" should in fact not exist.

On the Port side:

The swivel block currently labelled "Staysail Halyard" should take the Topping Lift. To run through the inner sheave of the triple turning block.

The swivel block currently labelled "Jib Halyard" should be moved forward, onto the tabernacle base fwd of the side web. This will take the fall of the Staysail Halyard, to run through the middle sheave of the triple turning block.

If a lightweight "Ghoster" or a Cruising Chute is going to be set, then we wouldn't bring these lines back to the cockpit, because these are essentially light weather sails and are can reasonably be set from the mast.

The other thing about the deck plan is that the fittings list is out of date (I don't think Main Marine fittings exist any more). So I will redo the plan to show more up-to-date hardware and the reorganization of the lead fittings around the mast.

What is important with these fittings is they are bolted to the coachroof structure in strong places, as close to the mast as possible, so that in effect the resolved loads are as nearly as possible transferred back into the mast, rather than carried by the coachroof structure.

Once again – I am very glad that you raised this issue as it is not correct as shown.

George







debenriver
Posted: Mar 8th, 2010 at 19:33   |   Subject: http://www.classicmarine.co.uk
Gary -- the updated deck plan is on the website. You should download this. George
Dracula1
Posted: Mar 11th, 2010 at 08:25   |   Subject: Ballust weight
Hi George,
The new arrangement at the mast is quite an elegant solution. I noted well your comments about transferring the uplift loads from the halyards back to the mast and reduce uplift loads on the coach roof where possible. Speaking as a person who has very little experience with sailboats, the logic of the arrangement sits easy in my imagination. Many thanks.

If I may move on to the next subject, may we discuss the ballast and expected trailered weight.

Q1.
I have not been able to find the design weight for the cast iron ballast on the drawings or in the instructions. I would like to use this information for a more comprehensive specification for the foundry. If I have missed something, I apologize. The specification on the boat’s web page indicates 0.718t and the General Arrangement drawing indicates 0.590t. Can you please advise the design weight I should specify?

Q2.
Can you please provide the actual weight of the boat so I can arrange for a trailer which meets with regulatory requirements? All I need is a reasonable approximation of the empty weight of the hull. I have collected some examples of sailboat inventory from other forums. I can extrapolate the weight of the loaded boat. Thankfully, most manufacturers provide data sheets.



Thank you in advance,

Gary
debenriver
Posted: Mar 11th, 2010 at 15:15   |   Subject: Ballast weight
Hi Gary.

The volume of the iron ballast keel is calculated at 0.09968 cubic metres. At 7,200 kg/m^3, this gives the calculated weight of 718 kg. This is the figure on the specification, and these are the figures that you should give the foundry. The calculated volume (and thus the weight) take account of the reduction for the centreboard slot.

The General Arrangement (GA) plans are drawn at an early stage and are intended to give a general idea of the boat pre-design. They really should be updated as the design progresses, but often they are not, because they get overtaken by the actual build plans. There is some discussion of this scattered about the website. "Info - Study Plans" popup and also "New Designs – 152 – GA" popup, touch on this subject. I will go back and bring the specification of the GA up to date however, as it is rather confusing.

The ballast keel in particular has multiple functions. It has concentrated weight to give stability. On this design, it provides longitudinal stability in conjunction with the deadwoods. In other designs with a fin keel it provides longitudinal stability and lift. It helps to reduce leeway. It balances the centre of lateral area with the centre of effort of the sails. And finally it provides the balance so that the boat trims properly. So it has a lot of things to do! Which is why it is often one of the last items to be finalized.

The displacement of the boat as quoted on the specification, includes the ballast keel, all structures, all the furniture, the spars, rig, sails, fittings, plumbing, electrical installation, battery, engine and engine installation, sink, taps, WC, cooker, gas bottle, tanks (empty), and an allowance for epoxy, fastenings, sundries etc. At that displacement, the vessel floats on the dwl. So at that load, the LWL is on the DWL (see "Info – Specification Data" popup for a discussion of this).

This figure, 1730 kg, would be a reasonable trailer weight. Not included would be your personal gear, water and fuel, consumables, stores and so on. You could lighten the trailer weight by removing the sails, battery, gas bottle – and I suppose the spars and rig – if you needed to.

George
Dracula1
Posted: Mar 22nd, 2010 at 09:30   |   Subject: Icebox
Hi George,
sorry for the belated acknowlegment of your last response. I finally get some 'me' time.

Thanks so much for the answer. I will copy the specs from the boats web page and add all this to the design folio.

I am currently reasearching the black and grey water regulations for Queensland and New South Wales waters. Requirements for blackwater retention seems fairly straight forward. I was given a bit of a 'heads up' that there may be an issue for grey water retention around the Barrier Reef areas. The Tourist Operators Handbook suggests best practice is to retain the grey water and only dump it when at a shore facility or as far away from the reef as possible. Most of the problem with reef degradation seems to be sulphates from the mainland and bilge water from larger vessels. Currently, it appears that the choice of soap will be the only issue, as the boat can retain any black water produced. Anyway, I will keep working on the plumbing layouts so that it does not look like something the 'Cat in a Hat' would be at home with. The forward section is a buisy part of the boat.

Take care George. Thanks for the help with issues I floundered on. I am mulling over a few other items, however, I think I have most of it sorted out. Just have to commit to a single course of action and most should become clear.

Best regards,
Gary
debenriver
Posted: Mar 26th, 2010 at 10:00   |   Subject: Icebox
Hi Gary

I'm very happy to have been of help.

Blackwater tanks- however necessary - are such a pain to organize in a smaller boat because of space limitations. On larger boats I like simple tanks above the waterline because then you don't need very complicated plumbing:

Outlet valve for natural drainage to the sea where permitted.
Air vent with valve.
Inlet from the WC discharge.
Deck pump-out arrangement.

The you have two modes of operation:

Outlet valve closed; air vent open = waste storage.
Outlet valve open; air vent closed = discharge to sea.

And two modes of emptying when in waste storage mode:

Discharge to sea.
Discharge to shore station.

The good thing about this arrangement is that the tank is always in use – the WC always discharges via the waste tank. So when you are well out at sea and permitted to discharge waste, the tank get lots of seawater pumped through it and so it tends to stay fresh. And in storage situations, after shore pump-out, you can pump plenty of sea water through it (just pump the WC), again to help keep it fresh.

Hard to do this on the smaller boat though!

Best regards -- George
Dracula1
Posted: Mar 29th, 2010 at 09:23   |   Subject: Plumbing
Hi George,
I agree. The more simple, the better. Constant flushing of the black water tank, as you have suggested, is sound advice. I am strangely comfortable with the mechanics of the affair. I have been reading a lot of blog sites and taking special interest in the opinions of sites hosted by those who engage in serious sailing. I do have to thank all of these people for sharing there experiences. It helped me enormously with understanding the idiosyncrasies of plumbing on board a sail boat.

It is time for me to stop over analyzing this. It seems that the best way forward will be to wait till the hull is turned over and use cardboard mock-ups of commercially available tanks to see what works and what doesn’t. The unfortunate side is that most of the tanks on offer are for power boats or larger sail boats where these space devouring, power hungry gizmos are right at home. It may come down to a special order tank to place it in an elevated position.

Other options -
A well sized diaphragm hand pump arrangement may be worth considering should the tank be positioned too close to the waterline.
A loop back circuit through the macerator for pump-out purposes seems viable, household power permitting at the time (Hmmm, there is that ‘Cat in the Hat’ design rearing it’s ugly head again). I am sure the WC would end up atop the mast if that design ever eventuated. I will work on elevating the tank at the point. Stay with the KISS principle.

Once again George, many thanks for your time.


Regards,

Gary
debenriver
Posted: Mar 29th, 2010 at 15:53   |   Subject: Plumbing
Don't forget you can always make a ply/epoxy tank – assuming that it is just a passive tank that can empty to sea by gravity when permitted.

Make all the ply parts and pre-coat them. Best to make the corners with cleating (say 15 x 15) on the outside and a good big fillet joint on the inside. Fit the top last – screwed and bedded – so that you can fillet the inside and roll a final epoxy coat on it. Fittings can be epoxy bonded in – or conventionally with a backnut on the inside. 12mm ply is best for this job. You can design (say) the back so that it extends beyond the top and ends, to give a flange for fixing.

George