A “triple play” Boat Project

Boat projects can sometimes be fun and satisfying (OK, at least satisfying).

There are three conditions that must be met for this to be the case.

1. Having the right parts on hand
2. Having the right tools on hand
3. Having the project be in a (relatively) accessible location

In my experience, the confluence of these three factors, which I call the triple play, is very rare. Well, yesterday it happened.

The project at hand was replacement of the sea water pump for the stabilizer heat exchanger. The stabilizers are powered by a hydraulic pump running from the main engine, and the fluid moves the fins. This fluid is at high pressure and gets hot, so it needs to be cooled. On our boat this is by means of a heat exchanger that is cooled by seawater. A 120V pump circulates this water, and it runs all the time that the boat is underway. If the pump dies, no more water circulation, and soon, no more stabilizers, which will shut down when the fluid gets too hot. So it is a pretty important piece of equipment, and it is one of those single points of failure… there is no backup pump installed.

I have been suspicious of the pump for a while. It runs pretty hot, and in fact, part of underway engine room checklist is checking the temperature of that pump. For that reason, I bought a spare pump before we came down to Mexico. I did not install it, however, following my new “ain’t broke don’t fix” rule. Well, coming back to the boat I discovered that it now is broke, so its gotta be fixed.

Getting the old pump out was pretty easy. It was clear that the line from the pump to the heat exchanger needed to be changed, but as it happened, I had some spare hose of the proper size and almost exact length. One small complication was that the new pump has the motor control unit mounted on top of the motor instead of the side. In the picture you can see the unit on the old pump on the left side of the motor. That makes it easier to access the mounts, but interferes with the 90 deg elbow for the water output, seen in the middle of the picture.

Putting the new pump in was straightforward save for running the hose. I had to angle the elbow off the centerline in order to get the hose and clamps attached and then had to make sure it didn’t rub against the side of the compartment. Of course, the mounts were laid out differently from the old pump, so I had to drill new holes, and it was a bit of a tight fit getting the screws in. After it was mounted I just had to wire it up to AC power. Once installed, all I had to do was open the through hulls for the inlet and outlet and prime the pump – a simple matter of loosening the bolt to the left of the elbow until a little bit of water flowed out. A quick test confirmed that we had good water flow. Success!

I was surprised when finished to find that the job had taken most of the day – about 5 hours or so. Things just take a long time on a boat, due to a combination of tight spaces and rummaging for various tools and parts. When it all comes together, though, it sure is satisfying!

Special Bonus!

I had a little bit of apprehension this morning. The plan was to start the main engine… after sitting for 9 months. I primed the fuel system, Gwen pulled off the stack cover, and I turned the key… YES, it fired right up!!

I love the old Lugger!