Thanks Arne I saw the similarities with your Frøken Sørensen write up so that's a great start.

For a regularly trailered boat I'm trying the keep the rigging real simple.

With the timber tabernacle however, the parrels will need to be unclipped somehow to drop the mast.

Checked the Junk Rig calculator again and a 21 sq/m sail gives me my target 7 metre mast in a tabernacle

At 1000kg that's a SA/Disp ratio of 21  - fair for a mono hull novice. ( Have raced cats)

Re the mast size I see the reduction in weight David if the diameter is increased on 3mm.

The options for Ali tube (using 4 metre plus hoop pine) in Brisbane that I'm seeing include:

Diam mm	Thickn mm	Weight kg	Strength kpm
100	6	19.1	1202
127	4	16.7	1410
127	3 (actually 2.8)	12.6	1083

At 1000 kg the estimated righting moment is 533 kpm

At 1100 kg the estimated righting moment is 587 kpm

So was targeting 1200 kpm at the partners (2 times the righting moment)

In this case moving to 127mm diameter will require the forward facing portlights in the cabin to be modified to allow the base of the mast to swing through the 200mm or so of the front of cabin into the tabernacle. The tabernacle itself may then need to be constructed from steel as my hoop pine stock for the tabernacle is 120mm x 50mm. So needs some thought.

Thanks again.

Peter, I think I'd stick with 20 sq m, on a fairly lightly ballasted boat.

Is it possible to get a mast tube with 3mm wall at a slightly larger diameter? Would that fit without taking up,too much interior space?

Hi All

Firstly thankyou to everyone who has contributed to the resources on this site.

I had never heard of a yard hauling parrel 2 months ago.

Just looking for any feedback on the following junk project.

So here we go again.

All the ideas here are based on contributions from this site.  

Currently fitting out a Hartley 21 in Brisbane Australia, that was built maybe 10 years ago and has never hit the water.

I have most of the original plans, the original builder made a few reasonable mods that I plan to continue. ( like a big hole in the bottom for an outboard well)

The project was purchased with no rig, centre board, rudder, cockpit or trailer.

It will be trailered to boat ramps so a quick setup is required.

I have not sailed for a number of years (been 4 wheel driving and extensive power boating on the main sail areas) but plan the following cruising fitout and love a small adventure:

• Tabernacle mast
• water ballast (approx 250 litre)
• self draining cockpit
• junk rig
• Outboard Well
• Foam flotation
• composting head
  

Winds on average are medium, but it rips in regularly on Moreton bay after lunch.

Boat Specifications

Length overall	6.4 m (21 ft 0 in)
Length at the waterline	6.035 m (19 ft 9.6 in)
Beam	2.4 m (7 ft 10 in)
Draft (board down)	1.52 m (5 ft 0 in) steel swing keel
Draft (board up)	0.31 m (1 ft 0 in)

 

Sail Area – From Hartley 21 Plans

24 foot mast   or   7.3 m

Main    157 sq/ft

Jib        65  sq/ft

Total    222 sq/ft   or  20.6 sq/m

26 foot mast  or  7.9 m

Main    186 sq/ft

Jib        90  sq/ft

Total    276 sq/ft    or  25.6 sq/m

Displacement

Min 907 kg – Wikipedia

1043 kg - hartley-boats.com

Ballast

3 – 5 cwt depending on conditions and weight of cruising gear

or  150 to 250 kg

Centre Board

The weight of the standard 10mm steel plate centreboard = 75.5Kg

Planned Mast

At a target displacement of 1000kg (most likely slightly more applying raffety’s rules) we get an approx righting moment of 533 kpm

I plan to use a 100mm Ali tube and timber composite mast. (picked up some 80 year old Hoop pine 2x4’s and 2x5’s for the tabernacle.

Trying to keep this real easy to pop up

Using 4 metre of 100mm x 4 mm Ali (get it cheap) and Hoop, the weight for a 7metre mast is approx 22 kg.

Strength at partners 852 kpm

OR

Using 4 metre of 101 x 6 mm Ali and Hoop, the weight for a 7metre mast is approx 28 kg.

Strength at partners 1202 kpm

Tabernacle

The overall length of the boat is 6.5m. I was looking at keeping the mast mast a maximum 7m overall.

The mast will sit in a clamp attached to the tabernacle. The mast is slid forward horizontally about a metre into a travel position and slid back into a mast raising position and clamped for raising.

The tabernacle will be constructed from Hoop pine (Similar the Douglas Fir) 5x2 and some steel hardware.

There will be no holes or welds in the ali mast

Mast Position

Using a scaled drawing from the plans have determined the centre of effort of the Bermuda rig at the centre of the rear most portlight. (Approx 3040mm from the transom or 840mm from the rear of the cabin) The CE is a fair way back.

Using Junk Rig Calculation Tools I started with a sail area of 20 sq/m (Conservative for novice) and the Joanna Sail type.

This gave a 1.85 AR approx sail, 7 m overall mast and boom length of 3.74 m. This places the mast near the front of the cabin top (1525mm forward of the centre of effort and 600mm forward of the Bermuda mast give n 10% boom forward of the mast)

While a taberbacle here is a bit of work (Tabernacle tied to the keel, deck and cabin top, protrudes 400mm), it means that 300mm of the base of the mast would need to pass through the front of the cabin. (Just ply here, means the tabernacle is fully sealed from water and the overall trailing, storage height minimised)   

Mounting the mast on the front deck like a Hartley ts16 would need a boom of 4.14 m, so I think the AR would be too low if I understand correctly

 Still need to draw up the sail

Regards to all