Blog 94 - "We Do Not Have Sufficient Fuel To Reach Next Bunkering Port" - The "Roaring Forties"

“Marine Musings 29” “Thornhill”

11th Nov 1994 Vittoria. Brazil ~~ 15th April 1995 Vancouver BC, Canada

A long flight saw the two of us - the new Captain and me - reach the ship in Vittoria, Brazil, just a few hours before she was to complete loading, giving us hardly any time for a proper inspection, prior taking over.

At first glance itself, the ship did not seem to be in good condition.

More than anything else, as far as I was concerned, there was a feeling of deja’ vu, as I found that the ‘Thornhill’ had started life as “Chennai Perumai”, which was the name of my first ship (as Fifth Engineer) in Sisco in 1970, exactly 25 years ago.

It was the second generation of the ‘Chennai Perumai’ - I had served on the first generation one.

Were the omens trying to say something?

Within the hour of my joining, I was plunged into a severe crisis with the fuel quantities on board.

Both the old Captain and the old Chief Engineer were to sign off just before the vessel sails out - a few hours at most. Both were busy packing and saying their goodbyes.

Meanwhile, I had taken the Fourth Engineer with me for taking all Fuel and Diesel Oil soundings. On calculation, the figures were nearly in accordance with the Engine Log Book figures. No problems there.

We were carrying iron ore from Vittoria, Brazil (latitude 20.3 degrees South) to Japan, a pretty long voyage, with an interim call at Singapore for bunkers and fresh provisions.

The passage / voyage plan was to take the Great Circle Route, go south to around the 40 degree South latitudes and then make our way up in a slightly northerly course to Singapore.

I asked the new Captain to check on distances, estimated speeds etc.

I checked the Chief Engineer’s calculations of speed, consumption, quantity bunkered in Vittoria etc. As per his calculations, all seemed fine.

The outgoing Chief Engineer was getting nervous about my invasive questioning of the bunkers, speeds and distances and told the outgoing Captain that I was being unrealistic.

But an old memory had triggered me, that the further south you go, the more the winds, either on the tail or on the head. Something known as the “Roaring Forties?” The seas were supposed to be always choppy, wave heights rising and falling day to day.

Courtesy JKOSM

Courtesy Wikipedia

I then asked some pointed questions to both of them.

When coming in on ballast across the same stretch of water, what speed had they averaged?

I found that they had taken the same average speed for the outbound fully loaded passage.

On checking some of the older voyages’ abstracts, loaded voyage speeds were found to be much lesser, with good weather conditions.

A quick calculation at the lesser speed revealed that all fuel oil double bottom tanks would be empty, leaving the unpumpable quantities, before we reach Singapore. And all the quantities in the settling and service tanks would be zero about a day and a half away from Singapore. This was subject to not making any allowances for bad weather, high winds, choppy seas.

The seas in the Thirties South latitudes were expected to be choppy although, supposedly, with a tail wind.

There was no chance of taking on additional bunkers in Vittoria before we sailed, as the vessel was down to her marks.

The take over was fraught with danger.

We were flouting all kinds of rules as per the Safety Management directives of the company.

As per Company regulations, our fuel oil calculations should be such that the vessel reached the bunkering port with a reserve of at least 5 days consumption for long voyages and 3 days consumption for short voyages. The reserves were meant for eventualities such as unexpected bad weather, deviations etc.

I made the statement that I am not taking over, as I felt that the safety of the vessel will be compromised when we run out of fuel mid sea, at least 3 days before we reach Singapore. I also stated that, on this voyage, the only port of refuge we can seek is South Africa, which was impractical given the passage plan.

New Orleans was looking after this vessel. A message immediately went out from the old Captain that I was not willing to take over, listing my objections.

New Orleans were already well aware of my bringing to light serious problems on previous ships. There was probably a collective sigh of “Here we go again”.

After a rather heated telephonic conversation with the Office, they asked me to take over and they will support any decision that the vessel makes for any deviation or other eventualities. I asked them to send us a message stating so. Surprisingly, they did send it.

We took over and sailed. From day one, my concentration was on accurate fuel oil consumptions, speeds, distance to go and weather, along with the new Captain.

Sure enough, we started hitting high swells and winds from day two of the voyage, sometimes favourable, sometimes causing pitching which led to reduction in rpm and, consequently, speed. To take advantage of the supposed tail winds, there were constant course corrections.

With the vessel rolling or pitching, accurate soundings of fuel oil tanks were well nigh impossible. We had to wait, in suspense, for a good day.

Usually, with suction from fuel oil double bottom tanks being good, the tanks can be pumped down to about 3 to 5 cms of oil, which may result in about 5 to 10 tons of oil remaining in the tank. If an average of 7 tons were to remain unpumpable, with 8 double bottoms meant 56 tons unpumpable, which would not aid the ship’s cause.

As in all ships, the suctions from each tank is located on the last and aftermost inward bay of the solid floor of the tank.

As each tank neared becoming empty, we had to adjust ballast in two ways.

First was to give enough of a stern trim in order for the oil to collect in the after portion of the tank.

Second was to give a deliberate list to either port - for starboard tanks, and starboard - for port tanks, to get the oil to flow to the aftermost and innermost bay in the tank, where the suction is located.

Using the above combination of ballast, whenever each tank level was coming down, we added the next step of transferring the remaining oil in the tank to one of the after tanks in one operation, till the pump lost suction completely.

Checking the tank sounding, we found the sounding to be 0 cms or 0.5 cms.

To our advantage, the sea temperatures were mild, as it was summer in the southern latitudes. Using steam heating to heat the fuel to ease the pumping capability till the last possible moment, we successfully managed to bring each tank to almost zero.

The 50 odd extra tons of oil that we were able to extract from all tanks - the so called ‘unpumpables’ - proved to be the tipping point in our attempt to reach Singapore with only the fuel in hand.

We reached and anchored in Singapore with all our double bottom tanks nearly bone dry, with about a maximum of 1 ton in each tank.

Both our Settling Tanks were empty, each brought down to a level of 2 cubic metres, before being shut off.

Of the two Fuel Oil Service Tanks, one Service Tank had 2 cubic metres remaining and the second had 7 cubic metres remaining.

Looking back, we had started the voyage about 140 tons short of what would have been considered a 'safe' limit.

Why did we shut off the Settling and Service Tanks when there were 2 cubics inside? If we had used the last dregs inside the tank, we would have had to cope with very thick sludge in the bottom of these tanks, as none of the tanks had any record of having been cleaned. (It is usual to stencil the date of cleaning on the tank itself which, then, leads one to Maintenance Records for more details).

We would have run out of fuel if

We had had to steam for one more day

If we had not taken the extreme measures of listing and trimming the vessel by stern in order to take out the last drop from each tank.

New Orleans were not particularly favouring me, as I caused some flap or the other on each ship that I join. In the last one - the Atlantic Erie - I had said that we will not sail without getting the needed spares for a hydraulic pump for the Controllable Pitch Propeller.

In this one, the Thornhill, I had stated that I will not take over as we did not have sufficient fuel for the voyage.

In both cases, I was justified in my actions.

In both cases, I could have just taken over and accepted the risks involved without making a fuss about it - but certain factors had to be brought into the limelight.

In the case of the CPP hydraulic pump, where the requisition had been pending for 8 months, my action of not sailing without the hydraulic pump working, showed up the lackadaisical attitude of the involved Superintendent and his inability to judge the seriousness of a situation.

In the second case, that of shortage of fuel oil for a particular voyage, it showed up the rather carefree approach taken by the outgoing Master and Chief Engineer in calculating and ordering sufficient bunkers for the next voyage, a voyage that they will not make.

But there was one ace up my sleeve that none of the others thought of or took cognisance of. The ship had more than 140 tons of Diesel Oil in stock, which gave an additional 4 days steaming time. But it meant additional cost, three times the cost, if I were to consume diesel oil for the Main Engine instead of fuel oil.

I made sure that the arrival Singapore Fuel Oil conditions were prominently emphasised in a letter to the NOLA Office. I also sent copies of this letter to the previous Captain and Chief Engineer, adding in a postscript how they nearly put us all in serious danger by their callous approach to calculating the requirement of fuel for a particular voyage.

For the benefit of my non-seafaring friends, I am elaborating how the fuel system is organised on board a ship.

Fuel oil is taken into - or ‘bunkered’ - into (mostly) Double Bottom Tanks which, as the name itself implies, is right at the bottom of the length and (nearly) the width of the ship. There could be a total of anywhere between 2 to 12 tanks spread around the bottom layer of the ship.

Depending on factors such as stresses, trim, arrival draft, a plan is formulated between the Chief Engineer and the Chief Officer as to the sequence of tanks from which fuel is to be consumed.

Over a period of days each tank is used up and then the next tank - as planned - is put into use.

For ease of pumping, steam is opened to the tank(s) in use, the steam coils fabricated and secured into the bottom of each tank. The object of steam heating of the heavy fuel oil is to reduce the viscosity of the oil for ease of flow from the tank to the pump. The steam and the oil do not or, at least, not supposed to mix - the consequences of such mixing can have disastrous consequences.

The Fuel Oil Transfer Pump, which is located in the Engine Room, is then used to take suction from the nominated tank and pump the oil up into a Settling Tank.

(The Fuel Oil Transfer Pump used to be operated manually before the advent of automation. Now it starts and stops automatically, depending upon the levels in the Settling Tank(s)).

Many problems occur if this ‘automatic’ filling of the Settling Tank is not monitored properly.

The Double Bottom Tank may be empty and the Transfer Pump will be running without pumping up any oil. If not monitored, the Engineer will only come to know when the Settling tank Level comes down and the ‘Low Level’ alarm sounds. If this alarm is faulty, it could lead to the Fuel Oil Purifier losing suction. With no oil going to the Fuel Oil Service Tank, the ‘Low level’ alarm of the Service Tank is activated. For this reason, all alarms are checked in rotation every 3 months.

The Transfer Pump also is likely to get damaged, especially the shaft seals.

Now oil is filled in the Settling Tank, upto the auto trip point of the Transfer Pump.

75% of the ships I have sailed on had 2 Settling Tanks. This is really advantageous, as it allows a lot of leeway in improving the quality of fuel before it is used.

In the Settling Tank, the fuel is heated (using steam coils) to around 90 to 95 degrees C. Some of the water in suspension evaporates. Most of it settles down to the bottom. A drain valve, right at the bottom of the Settling Tank, is just ‘cracked’ open every 2 hours or so for a few minutes to drain out this accumulated water. The bottom of the Settling Tank is sloped to facilitate this as well as to deliver oil to the Purifiers through other valves. A lot of sludge also drains out.

In fact, the first indication of quality of the fuel that we have bunkered is from this drainage.

===== "Marine Musings 29 continues =====