One for the Tanker men

[James Curry]

Big Bang.jpg

I am sure I saw her when I was on the Blue Flu Autolycus may have been as we were arring or leaving Durban. Certainly an oh tish moment

[Doc Vernon]

MACTRA (2) | Helderline.com

[vic mcclymont]

I believe she was in Durban neatly year undergoing repairs
Vic

[James Curry]

Did Shell not have another one that went bang in a big way? did a google search, Marpessa. 15 days apart Mactra was the second one.
The Marpessa actually sunk and sadly 2 were killed on her as well.
I seem to remember seeing a Tanker of the West African coast that had a massive explosion looking at the damage. We passed her at a reduced speed and it seemed that the main deck plating had peeled back as if it had been opened by a tin opener. The plating was just infront of the accommodation block and it seemed to extend up as high as the bridge, cannot remember her name, this would have been about 1970/71 it was certainly after the Shell tankers explosions.

[Colin McClelland]

Here is the OCEAN BRIDGE , one of BIBBYS OBOs, I was in the engine room when she blew up, it punched a hole in the foreward bulkhead,
We blacked out, a steam line broke , so the egineroom was full of steam and in darkeness and sea water was pouring in,
By the time we got the lights on and the steam shut off the water was up to the main engine crankcase doors.
With the ship on fire it was time to leave.

The full story later

Coln

[vic mcclymont]

when the Mactra was in Durban for repairs you could see right through her.
When repairs were complete she had iron beams weld to the hull n bot port and starboard as well as the deck. She was probably stronger than when she was built.
LLoyds insisted that a deep sea tug escorted her to Japan.
Vic

[Tony Taylor]

Did Shell not have another one that went bang in a big way? did a google search, Marpessa. 15 days apart Mactra was the second one.
The Marpessa actually sunk and sadly 2 were killed on her as well.
I seem to remember seeing a Tanker of the West African coast that had a massive explosion looking at the damage. We passed her at a reduced speed and it seemed that the main deck plating had peeled back as if it had been opened by a tin opener. The plating was just infront of the accommodation block and it seemed to extend up as high as the bridge, cannot remember her name, this would have been about 1970/71 it was certainly after the Shell tankers explosions.

Kong Haakon I think was the third one, we were en route Venezuela to La Spezia and diverted to assist but were stood down as several other vessels were there before us.

[John Arton]

Prior to the introduction of MARPOL in 1974? On crude oil tankers it was common practice when tank cleaning between cargoes to just pump the washings directly to sea and then fill the required tanks with sea water ballast that would be discharged during the next loading port.
The first thing that was introduced was dedicated slop tanks where the tank washings were pumped too. These washings would be allowed to settle in the slop tanks whilst the crude oil would naturally settle out from the water forming a layer on top of the water. The depth of the crude oil layer could be determined by using the oil/water interface tape which was a metal hand tape fitted with a brass bob attached to its end. Lowering the tape into the liquid slops once the bras bob reached the seawater a tiny electrical current would be formed which could be read on the meter attached to the tape, which had a grounding wire which you attached to the slop tanks ullage port opening through which the tape was passed. This would give you the depth of seawater in the tank who you could then pump out to sea without any of the crude oil being pumped to sea. The remnants of crude oil in the tank was then loaded on top with the next cargo.
It was found that if this grounding wire was not correctly attached to bare steel on the ullage port without any paint preventing proper contact, then upon lowering the bob into the flammable gas atmosphere in the tank, a static charge could build up on the bob and if the tape was not correctly earthed, then a static electric discharge could occur resulting in an explosion.
This later led to the mandatory introduction of inert gas generators on board using exhaust gases from the main engine to reduce the oxygen levels in the cargo tanks to below the lower explosion level, along with dedicated ballast tanks, or alternatively by fitting dedicated inert gas generators on deck around the accommodation
The slop tanks were usually located port and stbd wing tanks at the aft end of the tank deck
Rgds
J.A

[Tony Taylor]

After tose explosions Shell suspended all hot washing. They carried out extensive research into what caused the explosions and came to the conclusion that static discharge fron the tank wasing machines was responsible for the ignition source.
One of the other findings was that Telcon bronze tools were found to accept and dicharge a static charge more readily and of higher intensity than the steel equivalents. Every vessel was ordered to ditch all bronze tools ove the wall, it must have cost thousands of pounds.
Imagine my dismay when many years later in the early 2000's on a business visit to Stanlow refinery I saw those same tools in daily use on the plant.