Problematic with long stern tubes
First processed to the jack Well and keeps tight. Also with the vent is wonderful. When I was watering, I checked that water came out of the vent if I held the hose below the waterline. At my ship, the stern tube is about 1m long. Therefore, I was concerned that it pulls the bush dry over the vent. However, there were no problems during normal lullablock operation - There was always water in the breather hose. Yes - until today. On the way from Bornholm to Swienemünde we had a good 6 BF, until 15 m before Swienemünde the wind suddenly dropped to zero. Of course, the 1.5..2m wave was still unchanged. Sailing did not go anymore and did not wait, because you are standing across the shaft. So machine on and with 4kn slowly swallowed. Of course, the ship has always made a good drive through the waves. No 10 minutes later I had strong vibrations in the shaft system. So despite the swell machine and the floorboards opened. The socket was really warm. Fat was enough inside, so machine on - the vibration came clearly from the socket! So I once sucked on the vent hose and had the feeling that it has long balked, until water came. Suddenly, the socket was quiet. For the test, I have the vent hose then held in a glass of water, which was empty in 1min. So we put the Pütz full of water next to the bushing and put in the hose. Interestingly, the bucket began to refill as the sea calmed down. I suspect that the jack on my ship starts to run dry at a certain speed. Luckily, we noticed that in time and could prevent major damage from water leakage. I would therefore strongly recommend a check valve in the vent hose to install, or to supply this with water. In my case, I now have a flange in the seagrass filter (located below the waterline) through which the socket can get water if necessary.
