The Diesel Oil Service Tank Vent

6th January 2011, 23:54
The Diesel Oil Service Tank Vent Pipe..
MV Braer. Generator shutdown due to a sea water ingress into the DO service tank. Caused by heavy weather and the base of the vent pipe, situated in the upper deck scupper being rotten.

I have also experienced this on the MV “Antilochus”, 4th Engineer, sludged the DO service tank twice a day. Singapore , massive monsoon storm, rain cascading down the sides of the ship. Cargo loaded, Moved off on DO, stopped dead, the DO service tank was part full of water. On investigation it was found that the vent pipe to DO service tank had rotted away at the base.
Even in modern times, if the vent pipe lies in a scupper, it is worth a check, the diesel oil fumes are highly corrosive.

Possible, the fisher boys should check, rusty scab at the base of the vent pipe. All the best.


7th January 2011, 01:09
Mmm, another good one is DO Service Tank sounding pipes which pass through Ballast Tanks... I took over a ship about 4 years ago; anchored for 2 days to allow the Master & myself, who'd had 3 weeks on board with the previous owners' crew, to train up our own lads. Just going round the ship with a Surveyor; all seemed OK, when the lights went out... Investigation revealed the Service Tank having lots of sea water in it - where'd it come from? Found out that the Mate, being a conscientious chap, had decided to fill & empty all the ballast tanks to check that the remote gauges worked OK. We found a 10mm diameter hole in the sounding pipe when we started looking

We were lucky it happened when it did; at anchor in a safe location, good weather & not working cargo...

7th January 2011, 16:42
On the QE (1) in the bakers shop an oil fuel vent pipe went from floor to ceiling level thro' the shop and the shop was washed down twice a day, and the obvious happened, one day the oil went further up the pipe than usual and popped out all over the bakers floor, it was only 2"deep.Gave the lads plenty of overtime.

uisdean mor
8th January 2011, 12:36
Another difficult one to figure out after the first instance.
Main day fuel tank vents led as high as possible and on this occassion protected "inside" emergency generator flat next to funnel. EGen room had usual watertight door and jalousie venting. Over time the practice was to keep door and jalousie closed off - wrong on a few fronts but we all know how easy it is to "get used" to what seems normal without thinking too much. Come the day when emergency generator needed in earnest it cut out soon after start up. Problem was fresh water in the fuel? Where was it coming from? Condensate from the atmosphere as warmer day tank vents drew it out of the air. A sore lesson learnt and needless to say proper ventillation and check procedures instated after the event.
Uisdean Mor

Malky Glaister
13th January 2011, 03:33
I've had a several water in fuel tank problems both salt and fresh. What peed me off no end ?
It was usually laid at my door. Salt contamination of heavy fuel does the engine no good at all. Blame the Chief. (It costs a lot to debunker a ship you see but fuel injection gear well that can go on next years bill) I packed it all in after a couple of blame layings

regards Malky