Hounded by Stenoses
12 April 2013 | Aberdeen Typhoon Shelter
David C
If I only had an angioplasty balloon!
This boat business is way too much like the Interventional Radiology practice I just retired from. Case in point:
Symptom: Secondary Autopilot was blowing fuses and showed high voltage as the rudder turned to port (to the left, for you farmers)
Our master electronics guru, Berry Ng from Skywave Electronics in Hong Kong, was evaluating the situation. He was testing the autopilot by activating the hydraulic pump which moves the rudder back and forth, all controlled by a computer which is linked to navigation devices. Suddenly the rudder stopped moving and Berry ran down to the aft stateroom and I heard him utter an oath. CODE RED!!! The main seal on the pump had ruptured and there was red hydraulic oil sprayed over the aft bilge and running forward in red streams. We stemmed the flow by turning off the valve on the hydraulic reservoir and placed oil absorbent rags to soak up the bright red fluid. Way too much like work!! The pump was toast, however—useful only as a source of spare parts for the new one which Berry fortunately accessed via a short sampan ride. Berry thought it was a problem caused by blocked internal valves in the pump. After hooking up the new pump, however, the voltage asymmetry persisted. Using his best diagnostic acumen, Berry deduced that the problem had to be in the tubing from the pump to the ram (the device which turns the rudder). He removed each hydraulic hose and voila, one was blocked. Above picture shows, at autopsy, the tube cut in half and a light shone through the affected side with only a pinhole of lumen visible. This likely resulted as the connector fitting (metal piece to connect the tube to the pump) was being swaged (compressed with a machine) onto the tubing and the lumen was inadvertently narrowed—the high voltage was a result of the pump working against the stenosis and the code red occurred when the high pressure pump overcame the integrity of its own gasket seal and self destructed. The oath uttered has common usage in the English language and is ideal for situations such as this.
So I suffered the consequence of a stenosis in the vascular tree, but the whole thing reeks of medicine. Need a degree in boat neurology to sleuth out problems with the electrical AC system which has both 220V and 110V systems and the DC system which has both 12V and 24V components. Throw in multiple battery banks, charge controllers, alternators and inverters, not to mention isolation transformers and miles of wiring and you can see the possibilities for nervous problems—and I use that term broadly. Essential diagnostic tool is a multimeter and amp clamp which allows one to check voltage, current, resistance, and connectivity. Good we have Wade aboard who has seen it all.
One needs no imagination to link gastroenterology the boat life! One sobering episode involved our holding tank, which I thought had been effectively pumped out the day before, but was actually up to its limit and when the toilet flushed just one more time, its foul contents sprayed over the dock. Picture this scene:
Our lovely boat neighbors, Kevin and Irina, on their 50’ gorgeous sailboat….bright sunny Sunday morning, drinking coffee and serving brunch to a group of friends and family, laughing and enjoying the lovely day. You get the picture! He was a prince about it and called it a rite of passage of boat ownership but I was not easily consoled. “Howdy neighbor!”
Will post again before shoving off to describe final preparations and give details of the first leg.