[Peter Eccleson]

Seeing the Shell Tankers thread jogged my memory of my first trip as 2R/O on the Mitra.
On passage from Singapore to Muscat in 1971 (June?) we had a complete engine failure in the Indian Ocean. I think it was something to do with contamination of water in the boilers and tube collapse or something like that - the engineers amongst you will know!
We were drifting for days towards some of the outer islands within the Maldives and had the German deep sea salvage tug 'Albatros' circling like a vulture for a couple of days.... with Shell in London telling us not to use him unless the situation got really desperate.
There was no powers at all - emergencvy generators failed. Also, to make matters worse, we had total failure of our emergency radio requipment (batteries went flat!!).
The engineers eventually (four days or so) managed to get an aux boiler going and got up a head of steam and off we limped to Muscat for repairs..... closely followed by the Albatros for a day or so until they decided that we were no longer fair game.
All this was about the time when there was a heightened awareness of safety on the new brand of 'supertankers' following the explosions on Mactra and the loss of ships like the Kong Haakon.
A good introduction to life at sea for me!
Anyone remeber the incident?

[istabraq]

Hi, I have just checked my discharge book, I signed off the "MITRA" On June 20th 1971 in Liverpool. I cannot remember that incident. Maybe your dates are wrong? According to my discharge book the captain's name was Bedford.

[Peter Eccleson]

Hi
Just checked my discharge book..... I signed on in Lisbon 27.6.71 (she had come from Ellesmere Port) and signed off on 13/10/71 at Grangemouth (Methil) the Captain was G.Lomax
Looks like it was the trip after yours!
Cheers

[mikeg]

Hi Peter,

I didn't sail on the Mitra but we had a very similiar incident on a Shell v/l where we were adrift in the Indian ocean for a couple of days with only the emergency diesel for power. Apparently one turbo alternator failed and the second one just wouldn't go on line. Ran up okay but nothing from the exciter of either alternator so no output. Everything was in order, rpm was okay but whatever we did it just wouldn't come on line. Eventually after hours checking every possible circuit, windings and busbar etc. it was discovered that there was not enough residual magnetism in the exciter field to start generation. The problem was solved by using a 1.5V torch battery to give it the kick required and it came back to life again.
I can't for the life remember which ship it was now..but I was so knackered after 18 hours in ER that I collapsed on my bunk, boiler suit and all.

Mike

[istabraq]

Originally Posted by Peter Eccleson

Hi
Just checked my discharge book..... I signed on in Lisbon 27.6.71 (she had come from Ellesmere Port) and signed off on 13/10/71 at Grangemouth (Methil) the Captain was G.Lomax
Looks like it was the trip after yours!
Cheers

Hi again,
Just checked my discharge book again, and it was captain Lomax, Bedford was obviously the shipping federation guy, who always signed under the captains name.

[Peter Eccleson]

Originally Posted by istabraq

Hi again,
Just checked my discharge book again, and it was captain Lomax, Bedford was obviously the shipping federation guy, who always signed under the captains name.

Think it was 'Gerry' Lomax (an Australian?) - from what I remember as a first tripper, he was not very popular all round. The reason I joined her at Lisbon and not Tranmere was that she had a load of engineers onboard from cammell Lairds I think and there was no spare accommodation for me. They all left in Lisbon. You must have had some mechanical problems on the previous trip or was it to do with modifications for tank cleaning??
Regards
PE

[istabraq]

it's all so long ago. But from what i can recall we did not clean tanks at sea, after the explosions on two of the 'M' ships. The board of trade came to the conclusion that the explosions were caused by static sparks from the tank cleaning "butterworth" gear. What I do remember from that trip was that we had to bring out welders and equiptment from Cape Town by hellicoptor to repair a Broken guage glass holder on the main boiler. Strange what you can recall when your memory is jogged.

[Peter Eccleson]

We took on a 'new' breed of Shell safety Officer (ex Chief Officers) especially for tank cleaning - created lots of radio traffic for us. Strange that you had a boiler problem previous trip.... perhaps it was common for that type of steamer.
Got a couple of piccies of her on my gallery.

[mikeg]

Originally Posted by istabraq

it's all so long ago. But from what i can recall we did not clean tanks at sea, after the explosions on two of the 'M' ships. The board of trade came to the conclusion that the explosions were caused by static sparks from the tank cleaning "butterworth" gear.

My recollection was of hot wash causing a build up of static charge and that tank cleaning at sea was still possible with butterworth by enforcing cold wash.

Mike

[Tom Logan]

I was Chief Officer on Mitra at the time of the incident refered to. As I remember, we stopped at sea for a minor repair, with the boiler shut down( there was only one main boiler and an auxilliary) and power supplied by the only diesel genie. The genie decided to throw a piston, but the emergency cut in, and as this provided enough power to restart the main boiler, the origonal repir for which we had stopped, carried on. Unfortunately, the emergency geniue then failed as well, leaving us with no power. We eventually got going again by a bit of inventive engineering. If the auxilliary boiler could be fired up, then we could get going again. By placing a couple of 45gall drums on a walkway above the boiler front, and feeding diesel by gravity to the burners, step by step we got going again. I think we were dead for about three days, certainly two nights with our only lights torches, and an aldiss lamp on the bridge in case other ships approached.
When we got going again, Capt. Lomax sacked the Ch. Engineer on the spot, and promoted the 2nd. to Chief. Told the Chief that as he no longer had duties, he should retire to the bar, get drunk, relax, recover from the strain of the last few days, and then he would be reinstated as Chief! As I remember, the Chief took full advantage of the oppertunity, helped along by Capt Lomax. Capt. Lomax was actually a very understanding captain!

[ian fears]

was on medora as junior r/o when the marpessa sunk and the mactra blew up remember getting the message to stop tank cleaning and the concern by all , i dont remember names from that long ago but the om from mactra relieved the om on medora some time later , he was the most objectional om i sailed with , had a habit of coming in radio room every pm about the time the mactra blew up and just sitting in a chair without saying anything, i think perhaps the experience had unhinged him somewhat, i eventually just ignored him and got on with the cowboy books but it wasnt pleasant had almost 2 months of it , as an aside from the time he came onboard the feeding went down hill fast we were served tripe 3 times a week even had in sweet and sour sauce went to BI afterwards what a change

[mikeg]

Originally Posted by ian fears

was on medora as junior r/o when the marpessa sunk and the mactra blew up remember getting the message to stop tank cleaning and the concern by all

Shell sent a GZWF (All Shell ships) message regarding tank cleaning but I believe the Mactra didn't receive it because the Master was using the R/T at the time. This seemed very odd to me at that time as there was daily Shell radio schedules where this message would have been easily relayed. Please correct me if I'm wrong in my recollection..

[ian fears]

Originally Posted by mikeg

Shell sent a GZWF (All Shell ships) message regarding tank cleaning but I believe the Mactra didn't receive it because the Master was using the R/T at the time. This seemed very odd to me at that time as there was daily Shell radio schedules where this message would have been easily relayed. Please correct me if I'm wrong in my recollection..

i think you are more or less correct it was a long time ago and i cant remember exactly, but im pretty sure it was due to rt calls by the om at the time the group message was sent [ it was the midday transmission ] and she blew up a couple of hours later ,there was intership shell schedules cant remember the times now but sure there would not have been one before she blew up ,

[mikeg]

Originally Posted by ian fears

i think you are more or less correct it was a long time ago and i cant remember exactly, but im pretty sure it was due to rt calls by the om at the time the group message was sent [ it was the midday transmission ] and she blew up a couple of hours later ,there was intership shell schedules cant remember the times now but sure there would not have been one before she blew up ,

Really unfortunate timing. He could have told the Master that he could have his R/T call after checking the GKA traffic list but thats not too easy with some I do recall the R/O concerned was vilified generally and made pretty much a scapegoat for the whole incident.

[K urgess]

After this happened I was instructed to remove all aerials that crossed the main deck.
Most VLCCs at this time had a main aerial that ran from the monkey island to the derrick post almost at the manifold.
Because the RO had been using the transmitter at or just before the time of the explosion it was thought that it was a build up of static in the earth path under the aerial that had caused the explosion.
I was on the Esso Northumbria at the time and there was suddenly no lack of help rigging aerials.
A similar situation arose when using wire halyards for wire aerials. If the halyard was the same length as the aerial, which was quite easy now that aerials were limited to above the accomodation, then, if it wasn't earthed properly, it would radiate in sympathy with the aerial. This caused sparks to fly, no pun intended, if it had rubbed the paint away from it's anchoring point. The 2nd mate noticed this one night and almost ripped the door off the radio room in his haste to stop crazy sparks from blowing up the ship. A proper earth and regular tests cured the problem.
It wasn't until later that large whip aerials were introduced.

[mikeg]

Originally Posted by Marconi Sahib

After this happened I was instructed to remove all aerials that crossed the main deck.
Most VLCCs at this time had a main aerial that ran from the monkey island to the derrick post almost at the manifold.
Because the RO had been using the transmitter at or just before the time of the explosion it was thought that it was a build up of static in the earth path under the aerial that had caused the explosion.
I was on the Esso Northumbria at the time and there was suddenly no lack of help rigging aerials.
A similar situation arose when using wire halyards for wire aerials. If the halyard was the same length as the aerial, which was quite easy now that aerials were limited to above the accomodation, then, if it wasn't earthed properly, it would radiate in sympathy with the aerial. This caused sparks to fly, no pun intended, if it had rubbed the paint away from it's anchoring point. The 2nd mate noticed this one night and almost ripped the door off the radio room in his haste to stop crazy sparks from blowing up the ship. A proper earth and regular tests cured the problem.
It wasn't until later that large whip aerials were introduced.

I suppose also ground free halyards of multiple or submultiple lengths would also radiate to a degree. Do you know if there was any research carried out in this direction? I do know Shell did extensive research into tank washing and static (Thornton Research??) but I'm not aware of any concerns regarding induced charges from RF emissions.
On an aside I remember on one ship transmitting on a particular frequency in the 16Mhz band caused sparks to fly between the metal headphone band and the top of my head (Never been the same since )

[K urgess]

I think it was a knee-jerk reaction without any scientific back up. After all until someone came up with the thunderstorm inside the tank idea the only thing that they thought could cause that sort of static was the main transmitter. Especially since the VLCCs usually came with at least a Crusader, Commander or such.
I can't actually remember when they started fitting inert gas scrubbers. My photo of the Universe Patriot was taken from the Esso Northumbria and we sailed out of drydock without any scrubbers. I don't think anyone had a clue at that time what was going on.
I also remember the burnt ears. I started using my own earphones after the metal band on the standard issue sparked to the tips of my ears. I can't remember which frequency it was. Probably 16 or 22mc/s.
When you think about it if the constant 500kc/s watchkeeping didn't drive you mad then all that radiated R/F inside an earthed metal box called a radio room certainly would.

[ian fears]

Originally Posted by Marconi Sahib

I think it was a knee-jerk reaction without any scientific back up. After all until someone came up with the thunderstorm inside the tank idea the only thing that they thought could cause that sort of static was the main transmitter. Especially since the VLCCs usually came with at least a Crusader, Commander or such.

im sure it was tank cleaning wot done it , the medora was fitted with all whip aerials the main transmitting one being mounted on the funnel we did have a crusader , not sure of aerials / transmitter on mactra believe it was a imr contract

[mikeg]

Originally Posted by Marconi Sahib

I think it was a knee-jerk reaction without any scientific back up. After all until someone came up with the thunderstorm inside the tank idea the only thing that they thought could cause that sort of static was the main transmitter. Especially since the VLCCs usually came with at least a Crusader, Commander or such.
I can't actually remember when they started fitting inert gas scrubbers. My photo of the Universe Patriot was taken from the Esso Northumbria and we sailed out of drydock without any scrubbers. I don't think anyone had a clue at that time what was going on.
I also remember the burnt ears. I started using my own earphones after the metal band on the standard issue sparked to the tips of my ears. I can't remember which frequency it was. Probably 16 or 22mc/s.
When you think about it if the constant 500kc/s watchkeeping didn't drive you mad then all that radiated R/F inside an earthed metal box called a radio room certainly would.

I'm with you on the 'knee jerk reaction' bit, it did seem that Shell had made up their collective minds rather quickly after the event that it was the 'mini thunderstorm' so hot wash static was to blame. I wonder if Thornton Research were actually able to simulate the critical conditions inside a tank that would cause an explosion or was it just a unproven scientific assumption?
I'd assume that RF induction would only affect areas outside a tank due to it being a EM screened box as would natural phemonema like St. Elmo's fire, lightning etc. Normally vented areas are protected from ignition by mesh.

Mike

[K urgess]

At a later date I'm sure I saw a very technical explanation of what they decided went on in a tank during washing.
First I think they reduced the pressure to try and avoid the build up of statically charge droplets leaving the nozzle but that left dirty tanks.
The distance from the washing nozzle to the double bottom gave some phenomenol voltage gradient a la thunderstorm especially if the washing nozzle was moving fast and not properly earthed. With a draft of 80 plus feet it was usually 100 feet from deck to tank bottom.
This built up until a lightning strike ignited the vapour in the tank. If it was at exactly the right proportion. big bang! I don't suppose anybody remembers the treacle tin full of gas that the chemistry teacher used to explode to demonstrate explosive mixtures?
If the mixture is explosive it'll bang so wash the flue gases and fill the tank with that first.

[Tom Logan]

As I remember,the problem was caused by the structure of the tanks rather than just the static build-up. The centre tanks, where the explosion occured, was divided up with two wash-bulkheads, into three sections. These bulkheads had large openings in them so that the cargo could flow through them freely, they were really there to reduce surge. When tankwashing, the very powerful jets from the guns swept over these bulkheads, and if they passed over one of openings a slug of water was formed, which falling through the tank picked up a very high static charge. If there was any sort of a probe from the tank bottom near where the highly charged slug was falling, a spark could occur. And there were plenty probes, mainly the hand-rails along the top of the keelson walkway. All this was found by experiment at a disused gas-works where the old gas tanks were used as a test-bed.
For a while we stopped tank-cleaning until an answer was found, which was great for me on ballast trips, but then cold washing was tried after a very extensive gas-freeing programme and continuous monitoring of the gas levels in the tank from five or six sample points. But then we tried 'over-rich' washing. During discharge of cargo, the tanks to be cleaned on the ballast voyage were wased with crude oil from the cargo. this helped clean the tank to some extent, but greatly INCREASED the gas level in the tank to well above the explosive band. For various reasons, this was a dangerous operation if not carried out properly, and for this reason safety officers, ch.officers specially trained in the job, were sent to each ship when tank-cleaning. This carried on until the ships were retro-fitted with inert gas systems.

[mikeg]

Originally Posted by Tom Logan

As I remember,the problem was caused by the structure of the tanks rather than just the static build-up. The centre tanks, where the explosion occured, was divided up with two wash-bulkheads, into three sections. These bulkheads had large openings in them so that the cargo could flow through them freely, they were really there to reduce surge. When tankwashing, the very powerful jets from the guns swept over these bulkheads, and if they passed over one of openings a slug of water was formed, which falling through the tank picked up a very high static charge. If there was any sort of a probe from the tank bottom near where the highly charged slug was falling, a spark could occur. And there were plenty probes, mainly the hand-rails along the top of the keelson walkway. All this was found by experiment at a disused gas-works where the old gas tanks were used as a test-bed.
For a while we stopped tank-cleaning until an answer was found, which was great for me on ballast trips, but then cold washing was tried after a very extensive gas-freeing programme and continuous monitoring of the gas levels in the tank from five or six sample points. But then we tried 'over-rich' washing. During discharge of cargo, the tanks to be cleaned on the ballast voyage were wased with crude oil from the cargo. this helped clean the tank to some extent, but greatly INCREASED the gas level in the tank to well above the explosive band. For various reasons, this was a dangerous operation if not carried out properly, and for this reason safety officers, ch.officers specially trained in the job, were sent to each ship when tank-cleaning. This carried on until the ships were retro-fitted with inert gas systems.

There must have been some point using 'over rich' washing before the gas level was raised above the exposive band, obviously frequent monitoring of the gas build up levels would have been critical. Did washing with crude oil have any static charge issues linked with it at all?

Mike

[Tom Logan]

The tanks were crude-oil washed during discharge,when the gas levels in the tanks were to rich anyway, so no problems. It crude-washed tanks became Very over-rich, and as the tanks were closed up as soon as they were emptied the over-rich condition was maintained until we were ready for normal washing at sea. As I remember, we always over-riched one tank more than we planned to wash. This was because during water washing we connected the tank being washed to the 'spare' tank by means of flexible pipes connected between the butterworth plates. this was because if for any reason the hot washing in the tank suddenly stopped (say a pump failure) the rapidly cooling tank could draw down a vacuum which could pull in the deck if the tank was not vented. So if there was a breakdown the tank would be relieved through the hose from the other 'over-rich' tank, hence maintaining the safe atmosphere. Fortunately in my experiance that never happened!

[mikeg]

Originally Posted by Tom Logan

The tanks were crude-oil washed during discharge,when the gas levels in the tanks were to rich anyway, so no problems. It crude-washed tanks became Very over-rich, and as the tanks were closed up as soon as they were emptied the over-rich condition was maintained until we were ready for normal washing at sea. As I remember, we always over-riched one tank more than we planned to wash. This was because during water washing we connected the tank being washed to the 'spare' tank by means of flexible pipes connected between the butterworth plates. this was because if for any reason the hot washing in the tank suddenly stopped (say a pump failure) the rapidly cooling tank could draw down a vacuum which could pull in the deck if the tank was not vented. So if there was a breakdown the tank would be relieved through the hose from the other 'over-rich' tank, hence maintaining the safe atmosphere. Fortunately in my experiance that never happened!

Thanks Tom for explaining the mechanics of crude oil washing during discharge, you've taught me a lot that I didn't fully appreciate at the time. The use of flexible pipes was a very well thought out solution to cover any unfortunate eventualities.
Tank washing under such conditions was a hugely responsible undertaking even with Safety-Chief Officers specially trained for the job. I'd like to raise my hat to all those who worked so hard to preserve the safety of the vessels and the personnel aboard, self preservation not withstanding

[BarryM]

Originally Posted by mikeg

Hi Peter,

I didn't sail on the Mitra but we had a very similiar incident on a Shell v/l where we were adrift in the Indian ocean for a couple of days with only the emergency diesel for power. Apparently one turbo alternator failed and the second one just wouldn't go on line. Ran up okay but nothing from the exciter of either alternator so no output. Everything was in order, rpm was okay but whatever we did it just wouldn't come on line. Eventually after hours checking every possible circuit, windings and busbar etc. it was discovered that there was not enough residual magnetism in the exciter field to start generation. The problem was solved by using a 1.5V torch battery to give it the kick required and it came back to life again.
I can't for the life remember which ship it was now..but I was so knackered after 18 hours in ER that I collapsed on my bunk, boiler suit and all.

Mike

Mike, failure of gennies to power up because of loss of residual magnetism was not uncommon - especially after extended dockings when shore power only was used. Another "remedy" other than the 1.5V battery was claimed to be hammering the bedplate. I never saw it work but maybe I didn't use a big enough hammer!

BarryM