Episode 49 The Ballast Pump and the Boat’s First Hole

 It took about three hours to drill the boat’s first hole. 

Not all of that was drilling, of course. There was a lot of measuring, then re-measuring, both inside and outside the cabin with significant sessions of boat-yoga as I got in and out of position. Then, with much fear and trembling, I drilled a 3mm pilot hole to see if it came out the other side where I thought it would. It did, or, near enough. Then there was a great deal of further chin-scratching and arguing with myself about whether the pilot hole should be moved up or down or left or right, followed by a majority vote to keep it where it was. Then, I reamed out the hole with progressively larger drill bits to get to the 12.5mm diameter the hole needed to allow the lugs on the wire to get through.

I used a piece of wire inherited from somewhere for no better reason than that it was there, and it was, coincidentally, almost the right length at about 2.6m. I think it was 13Amp wire, which was oversized for a pump that said it needed a 5Amp fuse. My electrician friend assured me that oversized wires were unlikely to cause problems, unlike undersized wires that could overheat and, possibly, set the boat on fire. Oversized wire is good, especially when you don't have to buy it.

The switchboard got connected to the wire, which got connected to the pump, which produced a highly satisfactory whirring noise when I flipped the switch.

I couple of days’ later, when I had recovered sufficiently from my extended sessions of boat-yoga, I filled the ballast tank again and tested the pump’s ability to empty it. This it did, with some further, satisfying noises of water steadily dribbling out of the outlet, followed by visual confirmation and the obligatory photos (just to prove to everyone, including myself, that it worked). Before it would pass water, the pump needed to be primed, which was easily done with a crank or two of the hand-pump lever. I’ll need to remember to re-prime it if ever I drain it in future. This consequent operation, which included the addition of some labels, took about an hour.

Whilst pumping, the pump drew up to about 1.2 Amps (according to my digital readout) and emptied the partially-filled tank in about 10 minutes. The printing on the side of the pump says 11 litres per minute, or 3 gallons per minute. The capacity of the tanks is 250 litres, but they usually don’t get filled to capacity. According to these numbers, it should take no more than about 23 minutes to empty the full tanks, which equates to a little less than 0.5Amp-hours. The capacity of my battery is 12Amp-hours, which means it has plenty of capacity to drain the ballast. This is good news as it means that, whatever I use the battery for a day-sail, there should be enough juice in it to save me hand-cranking the hand-pump. It also gives me the option of emptying the tanks whilst under way and sailing solo, which could save time when I am returning to the ramp.

First hole through the bulkhead for the ballast pump cable

The ballast pump works!

Switchboard and meter for the pump in operation