Wanderer Dinghy – buoyancy compartments

One of the issues with leaky buoyancy compartments is that you need to bail them out from time to time. This is a real hassle when they are filled with 40-year-old expanded polystyrene – the water comes out with lots of plastic bobbles in it. These need to be removed before the water can go over the side.

Port side buoyancy compartment looking forwards – now empty!
Continue reading

New Daggerboard for Owl – Part 1

Owl needs a new daggerboard. The current one is plywood and might be getting weak. Given I might need to stand on it to right Owl after a capsize this needs sorting.

Owl’s daggerboard – a big slab of plywood

Plywood is generally a bad idea for centreboards, daggerboards and rudders on dinghies as half the wood grain is running in the wrong direction. Once the thin outer skin buckles there isn’t much strength left to hold it all together. In any case it looks like Owl’s daggerboard has the outer skin of the plywood running across the board rather than down it – unconventional although this might be deliberate to put the load into the thicker underlying plys.

The board is 16.6mm thick, 410mm wide and overall 912mm long including the handle on the top. The part within the boat (dagger board casing) is 345mm.

Design considerations

The daggerboard is currently too far aft. I don’t think this hull was ever really designed as such – the fact that the original rudder only just touched the water is a hint – and the daggerboard case is too far back. If I taper the back edge of the daggerboard somewhat this will help a bit. Making the daggerboard longer will help the aspect ratio but also making the board harder to handle. Still a bit longer should be ok.

Given how thin the board needs to be, the profile is going to have to be Neil Pollack’s design for a parallel sided foil. I’ve put this into a spreadsheet for ease of use.

Other Owl Jobs

I need to re-finish the woodwork – this was done in Woodskin so that shouldn’t be too hard once the weather warms up.

I would like to get more buoyancy into her – I don’t have a huge amount of confidence in the built-in buoyancy given the design standards of the rest of the boat – so a couple of buoyancy bags under the seats wouldn’t be a bad idea. I will need to mend one of the seat supports and make sure everything is strong enough to take the load.

Wanderer Dinghy – buoyancy and ballast

Overall I’m very happy with the stability of Custard – my Wanderer dinghy. I’ve never had any concern about capsize. The junk rig helps with this – it is very easy and fast to reef as the gusts are coming in. It is also easy to put up full sail again when the gusts have gone through so there is no temptation to avoid reefing.

However. there are times when capsizing would be a really bad thing to do. For example, when older people are in the boat who would be impacted by immersion in cold water and would find getting back on board very hard.

There is a version of the Wanderer equipped with a steel centreboard. This apparently makes the dinghy very hard to capsize. However, it also increases the weight of the dinghy by about 38kg making the boat much harder to pull up a slipway and move around on land. Online opinion seems to be that while this works, one might as well get a Wayfarer and sail it heavily reefed.

The Wanderer does have floorboards, and it occurred to me that there is enough space under the floorboards for about 40l of water; i.e. about 40kg of water ballast. This could be pumped out before trying to get the boat up the slipway, or just when the wind was light.

Alternatively, I have a pile of old bricks at the bottom of the garden. Each brick weighs about 3.2kg so I’d only need 12 bricks to get to 38kg. Again, the bricks would be easy enough to put in and take out as necessary.

I sanity checked the question on the DCA forum and people seemed very supportive of the idea, so when I get time I’ll have a go and see what happens.

I’m also planning on getting some buoyancy bags for under the side-decks. The existing buoyancy is under the side seats. This works ok at keeping the boat afloat and limiting the amount of water sloshing around, but doesn’t help stop the boat capsize once water is coming over the side. If the top of the sides was buoyant this would help the ballast pull the boat upright.

I’m still working on getting Custard waterproof so this isn’t going to happen soon – I’ve got to get the front rubbing strip back on and sealed up first. Owl – my other boat – needs a new dagger board so that also needs doing. The current board is about 40 years old and plywood so I suspect it will snap off, particularly if I needed to use it to recover from a capsize.

New Parrels for Custard

As mentioned before I need to sort the effort involved in raising the sail. This was forced on me by injuring my hand while on holiday.

The sail on Owl is easy to pull up; that on Custard is too hard. They should be about the same as, while Custard’s sail is almost twice as heavy as Owl’s, Custard has a pulley system that should negate the extra weight.

The first thing to tackle are the batten parrels. These were ultra-short – normally junk rig parrels are quite long allowing everything to move around. The main reason for them being ultra-short was that I didn’t build them into the sail early enough but left them as something to sort out at the end. By that time I didn’t have much option but they seemed to work ok.

Continue reading

Andersen Self Bailer Repair

As I mentioned before Custard leaks a bit – not enough to be a real problem – I just need to make sure she is bailed out every day if she’s afloat. However, this isn’t ideal.

First step was sorting out the self-bailers. These are Andersen/Elvstrom Super Medium bailers made in stainless steel. My original idea was to remove them and blank the holes; however I thought it might be easier to repair the original bailers.

Repair kits are readily available although not cheap. I got mine from Force4. They include the two gaskets I needed plus rivets and thicker gaskets.

At first glance it looks like it is necessary to drill the old rivets out to get the old gasket out. However, this isn’t the case – the old gasket can be pulled out of the recess by prising with screwdrivers and pliers.

Continue reading

Problems pulling the sail up

Over the summer I injured my hand pulling the sail up. I’ve got an old trigger-finger injury and the high load on the halyard meant that this re-occurred: one finger couldn’t be straightened for a week or so. This is irriating rather than a big issue but I don’t want it to get worse. Thus I clearly need to sort the halyard load out.

Continue reading

Tesla Model 3 Towing Dinghy – Actual Energy Consumption

Having now been on holiday I’ve got some real figures for energy consumption:

Energy consumption over the last 30 miles of the journey home

The average seemed to be around 290 – 310 Wh/mile. This was for a fully loaded car, two adults, two children, towing a Wanderer dinghy with lots of stuff inside it and a towing cover. Speed was around 55mph(90km/h) on motorways and A-roads.

Continue reading

Tesla Model 3 Towing Dinghy

I wanted to get an idea of energy usage involved in towing Custard – a 14′ Wanderer sailing dinghy – so I could work out our range when towing the dinghy.

Update: I’ve now got the actual figures.

A Better Route Planner provides an easy way to work out how to get somewhere with charging stops along the way. You can also tweak your car’s energy usage. Their base figure is nominal usage at 65mph.

Custard’s trailer has higher drag that I would expect – in my Mazda 6 it looks like petrol consumption goes up by 25%. This doesn’t appear great for something that is fairly aerodynamic (boat shaped) and not particularly heavy (I guess around 340kg). When I used to tow a Jaguar 21 – 1100kg plus trailer – it seemed to double petrol consumption so for something much smaller 25% seems high.

Anyway, first guess was that the energy consumption in the Tesla would go up by 25 – 33%. The nominal energy consumption per mile is around 255Wh/mile at 65mph according to A Better Route Planner. This seems close to what we get on a normal local journey. So this would mean consumption of around 320 – 340 Wh/mile.

Continue reading