Our longest stop so far was in Belfast where we ended up staying approximately two months. It was a great city, nice marina and very friendly people. However, the stay was not voluntarily chosen and I thought it was time to ponder a bit on why we got stuck there and what can be done to avoid future problems.
So, the reason why we got stuck is because our batteries were destroyed by sea water entering the boat. The way I see it there was two failures that caused the boat to flood. The first was that the buckle to the anchor chain locker hatch broke and allowed water to fill the hatch. Normally this hatch is completely sealed from the rest of the boat but in our case I had violated this property by drilling a large hole to fit the air ventilation hose from the compositing toilet. As long as the hatch remains closed this should not be a problem. But we discovered the hard way what could happen if it did not.
When we learned that the batteries were too damaged to use, one of our first thoughts was that should not batteries intended for marine use handle a bit of water? But, as described in the paragraph above the problem was not really with the batteries but rather that water was allowed into the boat in the first place. And for that, there is really nobody to blame than myself. With that acknowledged work begun to make sure water would not enter the boat again. Besides fixing the obvious like installing a new buckle on the hatch and a ball value on the air ventilation hose I also started to think about what other ways water could enter the boat? Here is what I found:
Breaking waves could crash the companionway doors leaving the cabin fully exposed to the next wave. Luckily it is very uncommon having breaking waves crashing into the cockpit and such weather conditions are best to avoid. But given the state of our old doors they could not withstand even a moderate hit and thus I thought we might fix them right away because sooner or later it is going to happen no matter how carefully we plan. After walking around the marina looking at all different kinds of companionway doors we decided to keep the current design with two swinging doors but reinforce them heavily. Water roughly weighs 1.000 kg/m3 and our doors have a surface area of 0.54m2. So if a big wave comes crashing it will be something like 500 kg of waters throwing itself against them. I have not bothered about calculating what force they need to withstand but simply figured quite a lot.
I found that our old doors suffered from two big drawbacks. First, the doors opened outwards towards the cockpit but if they are pushed inwards they are too weak not to swing inwards. Second, if they were supported from the inside and thus prevented from swinging inwards the small screws keeping the hinges in place would be ripped out from the doors and again they would be pushed into the cabin. Therefore, the new doors are made larger and rests outside onto the plastic of the deck of the boat spreading the load of a hit onto the entire perimeter of the doors. This way the hinges does not need to cope with any load at all. To prevent them from swinging the wrong way (into the cabin) two bars are placed across the doors giving the centre of the doors support. These bars will only be placed there during bad weather. For several reasons it would have been better to place these bars on the inside of the doors but there is simple nothing strong enough to hold the bar in place on the inside so instead I bolted some U-bolts, with big backing plates on the inside, through the door. So even if the bars are placed on the outside they will now prevent the door from opening inwards even if a big wave hits. The doors themselves have also been made a lot stronger. I used two 12mm marine plywood sheets and laminated them together with epoxy and a piece of glass fibre mat in between. The total thickness of the doors is now 26mm. The glass fibre mat is probably unnecessary but what the heck. Besides being stronger the new doors have a lot better fit, they are also warmer and, as a bonus, they even look better 🙂
Another weak point found was the front cabin hatch. When the hatch is closed it is held in place with a screw. This screw is old and the threads have been worn so occasionally it could no longer hold the hatch in place. This imposes a great risk of flooding the boat again. So, two new fasteners have been installed keeping the hatch securely in place.
Open for debate is whether the cabin windows are strong enough. For sure they are strong enough for most situation but again water is heavy and strong windows have been known to break even on big ships several stories up. If a massive wave should hit one of three things can happen; nothing (obviously the best option), the window breaks (do not think that will happen) or the frame breaks (believe this is the weakest point). The frame is built from two slender aluminium brackets screwed together with the window in between. When the window is pushed inwards it will push on the inner aluminium bracket. The inner bracket is screwed to the outer bracket which rests on the outside of the hull. If the force is too big the aluminium will deform and the two brackets separate and the window will fall into the cabin as a result. There is no documentation or test data available so there is really no way of knowing whether the current window setup is strong enough without doing a practical test. Such a test will destroy the tested window which is not preferred since these window frames cannot be bought anymore. Right or wrong, necessary or not? I do not know, but what I did was to custom order 3mm stainless steel sheets to cover all windows from the outside. These sheets will rest on the outside of the hull taking the first hit of the waves. They are not in place just yet but I imagine they will make the boat look somewhat like a tank. Maybe not the prettiest look but definitely strong. As a bonus I image they can also be used to shade the windows in the sun gets too strong. Given the weather for the last five months that would be a nice problem to have J
In the cockpit there are several hatches to access storage under the benches. These storage compartments are not sealed so if water finds its way into them it will continue down to the bilge. There are four hatches and they rest in place solely by their own weight so if the boat heels 90 degrees or more they will start to open by themselves creating a danger of water coming in. A properly designed ocean going yacht will handle a knock down (when a strong gust of wind pushes the mast down into the water) without water coming inside the boat. Due to the counter weight of the keel the wind can never heel a properly designed yacht more than 90 degrees. But, in combination with high waves it may end up with the keel pointing towards the sky and the mast down towards the bottom of the sea. This is a highly instable position so it will not take long before turning back up again. But, if this happens all hatches in the cockpit will open and seriously flood the boat in just a few minutes. So again, the probability of this happening is minimum but the consequence is too big to ignore the risk and therefore, in my opinion, this needs to be addressed before crossing the big oceans.
If there is anything else that I have missed that also needs attention all suggestions are very much appreciated.
Getting the new batteries approved by the insurance company and shipped to Belfast took quite some time so we could do a few more things on the boat as well. I am not going to bore you by describing them but simply list them so you can get a feel for the development in our home (pictures found further below).
- Fixing a leaking window
- Finding a 10m RG58 GPS-antenna cable
- Finding and soldering TNC connectors (a lot harder than it seems)
- Making a nice bracket to fix the GPS-antenna to the push pit
- Making another bracket attached to the backstay instead
- Installation the AIS, GPS-antenna and VHF to work together
- Installation of a remote microphone in the cockpit to the VHF-radio
- Installation of the radar reflector at the top of the mast
- Making templates and order stainless steel shutters to the cabin windows
- Changed both bowsprit chains to more heavy duty
- Adding a stainless steel mesh on the bowsprit platform
- Raising both starboard and port side berths 50mm
- Making new battery beds under the berths
- Making new power cables to the batteries
- Installing and programming of the new batteries
- Finally fixed the battery charger lid and reinforcements
- Made a custom sized cutting board that fits in the sink
- Added thermal insulation between the motor compartment and cabin
- Made a thermal insulation inner door to keep the heat in the cabin
- Adding carpet with a rubber backing to the hull sides by the berths
- Making a cover to the mattress (possible to roll it up to a long pillow back rest)
- Making a waterproof cover to the battery charger
- Added a floating switch with a buzzer in the old battery compartment
- Making a hatch in the galley to store pots and pans
- Various paint jobs in the cabin
Still plenty of more to do but slowly our home is getting transformed one project at the time and more and more fit for purpose. So two months may seem like a long time but for me I was fully occupied and time passed quickly.