What are some good numbers for making some preliminary estimates with regards to bunkers for the following?
Assuming the actual numbers are not known:
Convert DO or MGO metric tons to cubic meters?
Same for conversion for HFO?
What percent would would be consider a tank full while bunkering?
What is the maximum percent allowable remaining in a tank to avoid mixing issues with HFO?
Also temps - acceptable max / min for HFO?
This is all hearsay, but here’s what I know about bunkers.
The Chief always talks in metric tons.
Our company policy is 85% on HFO, 90% on diesel.
I have no use for a conversion to cubic meters. Everything here is typically done in barrels. Haven’t used HFO in years but the conversion would be different than MGO due to the different density.
We use 85% as a max tank level, shouldn’t have many issues with the fuels mixing in the tank but I would have it as empty as possible to avoid degrading the quality of the MGO.
Been too long for HFO but for MGO I used 310 gal per metric ton as a ball park guesstimate when density and temperatures were unknown. That comes out to about 1.17 M^3.
Full tank in theory would be governed by a few things. Does the system incorporate an overflow tank, do you need very last drop or want to take advantage of low price at a particular bunker port? Top up till it overflows. (That sounds bad doesn’t it) Should take into account loading temp and expected temps on the voyage too if no overflow tank to allow for enough head space.
I just got finished hunting around and converting.
For IFO 380: 1 cubic meter ≈ 0.991 MT
For MDO: 1 cubic meter ≈ 0.85 MT
Company policy was:
Full tank is 85 %
Max allowable to avoid mixing: 10% - this might have been ship policy, not sure.
I don’t have any temps
You must work for one of those companies who puts the Mate in charge of bunkering…
Only enjoyment I get out of it is telling the barge pic and gauger that the captain doesn’t trust the chief to load the fuel so they have to deal with me.
Haha. The only enjoyment I ever get out of bunkering is watching the 2 day preparation of the bunker manifold…
fuel sales calculated at temp 68F.
90% for DF.
i only used cubed metric on garbage tossed over the side. … there was something else but i don’t recall what it was for, just that i had to do the calculations, i think it was the oil log book?
this should help a lot!!
What are some good numbers for making some preliminary estimates with regards to bunkers for the following?
Assuming the actual numbers are not known:
Convert DO or MGO metric tons to cubic meters?
Ballpark? 306 gallons per MT for MGO/DO. Obviously it depends on the temperature and density. It’s ballpark… Cubic meter is always 264.2 gallons So… 0.863 MT/m3
Same for conversion for HFO?
HFO varies too much to be accurate but I remember, IFO380 I used to use 275 gallons/MT so that is 0.96 MT/m3. LSFO is obviously lighter and the new VLSFO is like dirty MGO.
What percent would would be consider a tank full while bunkering?
Depends on who your asking and the tank configuration, expansion from > temperature after bunkering if HFO. Above 90% and it’s tough to defend if it’s too much for the tank. I didn’t normally go more than 85% unless I had to.
What is the maximum percent allowable remaining in a tank to avoid mixing issues with HFO? HFO is cracked with different, sometimes non-compatible agents. This can cause separation of cat fines, lubricities or even have a violent reaction to one another. I believe DNV Bunker Master recommends no more that 20% by volume ROB. I never went more than 10% or your cleaning the auto filter regularly.
Also temps - acceptable max / min for HFO?
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Impossible to calculate without the BDN. Download DNV Bunker Master. There’s a free version that will do all of this for you.
Everything you need to know about Fuels:
https://www.chevronmarineproducts.com/content/dam/chevron-marine/fuels-brochure/Chevron_Everything%20You%20Need%20To%20Know%20About%20Fuels%20v3_1a_2012.pdf
That’s good stuff. I sailed with a Polish guy a few years back. Had a degree in organic chemistry and used to go wayyyyyy deep on bunkers. I learned quite a bit from those talks but this is a crazy good read for guys out here. Thanks for sharing.