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Steel ballast, motor, and "how waterproof is PocketShip?"

PostPosted: Mon Oct 04, 2021 1:47 am
by ManInBlack
A couple weeks ago I lowered my new PocketShip into my small pond to do an initial test in water and it was mostly good. There were some small issues with the hatch fit, cleats, battery and outboard mounting points, etc. So we took the boat out and made adjustments, and just recently tested it again, doing a bit more this time. First, I thought I would share a few pictures of the steel rebar ballast we used, since it might be a bit unusual.

We used 20mm diameter steel rebar cut into 30cm lengths, and then welded into flat packs of 6 bars. We then coated it in 2 coats of grey anti-rust paint, followed by 4 coats of white silicone for both anti rust, antislip, and softness when it bumps up against the hull. Each flat pack of 6 is about 4kg (9lbs), so I'm starting with 16 packs for a total of 64kg (140lbs) + the 50kgs of LiIon outboard motor traction batteries, for a total of about 115kg (250lbs) of ballast+batteries. BTW, I know that the lead ballast is recommended to be about 150-200lbs, but does anyone know what the normal battery weight is? I'm going a little lighter on the ballast to compensate for what I assume is a much heavier battery. But I'm not really sure what size batteries the rest of you are using. We made an additional 10 packs in case they are needed in the future.

Re: Steel ballast, motor, and "how waterproof is PocketShip?"

PostPosted: Mon Oct 04, 2021 1:48 am
by ManInBlack
Here is a picture of the boat with the ballast and half of the batteries installed

Re: Steel ballast, motor, and "how waterproof is PocketShip?"

PostPosted: Mon Oct 04, 2021 2:36 am
by ManInBlack
We also tried out the new electric outboard motor we ordered. It is a Caroute N300 24V 2000W with 160lbs thrust.

The pond is small so I don't think we got up to full speed before we needed to turn around, but it handled well, accelerated quite quickly, and based on the relatively large bow wave the emerged just before turning, we may have reached hull speed, even in this short distance (about 20-30m). The other thing I should mention is how incredibly silent this outboard is.

If anyone is interested, I can try to post a "motor power in watts vs GPS speed" table/graph in the upcoming months when I get the boat out to a larger pond or canal to test it. I'm not sure if seeing this data on this particular boat is useful to anyone. (I found that my 5kWh battery pack fits easily in the compartment in the fore area of the cabin, so I should be able to cruise for 5 hours at 1kW, but I'll have to test what speed that actually is.)

Re: Steel ballast, motor, and "how waterproof is PocketShip?"

PostPosted: Mon Oct 04, 2021 3:07 am
by ManInBlack
Finally, I remember when I first was exploring building the PocketShip, I saw a few questions about how waterproof the cabin is when it rains. So I thought I would mention an accidental test in this regards that I've performed as part of the ballast and motor tests mentioned above.

Short version, the PocketShip cabin is _extremely_ waterproof.

Construction note: I am a first time builder, and didn't make any intentional modifications beyond what was described in the manual. So this should be read as a test of a "stock" PocketShip, and not anything special that we did to waterproof it.

I've temporarily docked my PocketShip in my pond up against my house (which is also floating on the pond). I'm experimenting with camping aboard the PocketShip a few days like this, which seemed like a good idea for testing it since extra pillows, blankets, cushions, night-lights, and DC fans, etc. are all readily available right there in my home if needed aboard the PocketShip in the middle of the night. But what I didn't consider is that the roof of the house extends out just far enough to funnel the rain onto the dock side top of the PocketShip. (Picture attached.)

And boy has it rained. I am in Bangkok, Thailand, and if you've happened to catch it in the news recently, there has been extremely heavy downpours flooding large parts of the country, with the flooding having just reached the outskirts of Bangkok. This is the monsoon season, when the heaviest rains of the year normally come down, and this year's rains are exceptionally heavy.

So in the past few days, I've measured rains where my pond's water level has risen about 10cm (4in) in about 1-2 hours of rainfall within a single day. And the roof of my house is funneling a larger area of this downpour right down on top of the PocketShip. So the right side of the PocketShip is probably seeing about 30-40cm (12-16in) of rainfall over the course of an hour or two. I didn't happen to be inside the PocketShip for this, but when I swung by afterwards, the deck drained all the water on deck out with nothing more than some wet surfaces, I couldn't see a single drop of water inside the cabin anywhere.

So in summary: I accidentally took one of the heaviest downpours of the past 5 years in one of the wettest countries in the world, and funneled a large area of that water onto my PocketShip increasing the amount of water hitting it by several times. And the deck drained it all without a hitch, and the cabin stayed perfectly dry.