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Have just taken over as Skipper of a Hatteras 77 in Greece, generally in good condition and low hours on twin Detroit 975shp two strokes.The vessel has seven fuel tanks which feed a main engine/return manifold but no functioning fuel gauges. Can anyone give me a clue on the engine consumption at 12knots about 1200rpm in litres per hour. For the future any advice on a suitable tank gauge system would be appreciated.
Is there a ship’s log? I would start there. And are these 12 or 16V92’s?? Normally aspirated or turbos?Captain Chuck on ChartmakerQuote:
Originally Posted by vinnie
Hi Chuck
Not managed to find any log books, think either the first or second owner must have kept them. The boat has not really worked hard and was laid up for about ten years.
The engines are the 12V 92 TIC and hull number is HATCG301E585. Engine and generator hours are about 7500 hours which is not much for a thirty two year old boat. Have resolved most of the problems and updated much of the electronics. It is this issue with fuel consumption I need to resolve.
Vinnie
At 10 kts hull speed, you re probably burning 22/25 gph or 85/95 litres. At 12 kts, that s likely to be close to 40 gph / 150 liters. Fuel burns goes up exponentially once you go above hull speed.
Keep a fuel log with hours, rpm, speed, estimated burn and cross check when filling up. With keel mounted tanks you should be able to use a dipstick. When filling up the tank, you can mark the stick at regular interval like every 100 gallons.
Are the gauges not working or you can’t find them?Quote:
Originally Posted by vinnie
I had a 1989 CPMY with 12-92 engines. Our typical cruise was 11-12 knots. We burned about 26 gph with one genny running. My boat did not have tank mounted mechanical gauges installed. It did have a Hart Tank Tender. It was old and unreliable. I installed a Maretron tank level monitor. I could monitor 6 tanks. Look up my old posts on this. I could send the data to my Garmin and read two of those tanks. I could also see all 6 tanks on my smart phone or tablet.
I have a 61 Davis with 1040hp 1292's. I just ran from Stuart Fl to Ocean City Nj and I took a little over 1,100 gallons. I don't have my log in front of me but I ran at 1,000 rpm's which was about 10 knots. The trip took right around 80 hours so I am guessing I was burning between 12 and 13 gph including gen. I can't give an exact because i ran it up to cruise speed every 12 hours and I ran at cruise the last 40 some miles Into Morehead City Nc and I also ran at cruise for about the last 25 miles to let the motors clean themselves out. So you may want to slow it down a little, the extra 200 rpm's for 2 knots may not be worth the extra fuel burn.
Hi Seven,Quote:
Originally Posted by SEVEN
Out of seven tanks I have located 5 gauges, two of which definitely are not working. Then there is a automotive fuel gauge in the engine room but cannot see which tank if any its connected to. It also does not give a reading.
David
If yours are like mine the floats are stuck. Pop them out of the tanks and clean them up with 220 sand paper until the float is free. Be gentle with the rods they bend easily.
We had issues and then ended up installing some new WEMA sensors. WEMA can custom make them depending on height. They can also provide you with the sender curves depending on what gauges you want to use.