This tanker blew up on May 27, 1979, killing three men.
Another drowned while trying to abandon ship by way of the after mooring ropes.
Earlier Atlas Titan had discharged cargo at Wilhelmshaven
and the tanks had been crude oil washed in the required inert condition.
En route to Setubal for drydock, her tanks received
a water wash and slops were collected in No 5 Center tank and the port slop tank.
When Atlas Titan berthed at Gaslimpo Tankcleaning on May 24,
the tanks were reported as properly inerted.
But there was a problem with a valve or line in No 5 center
which prevented that tank from being pumped down to the last 4-5 ft of sounding.
It was therefore planned to complete the job with portable pumps.
An initial attempt -- using hydraulic equipment with the power unit
situated safely on the poop -- failed due to a defective seal.
Efforts to repair the pump were unsuccessful.
As a result, it was decided to use five air-driven sump pumps,
suspended in the tank by means of a non-synthetic rope.
Air was supplied via standard compressed air hoses fitted with instantaneous
couplings of ferrous material and exhausted through a short stub pipe on each pump
and vented into the cargo tank.`
Discharge hoses of synthetic construction and fitted with aluminum
instantaneous couplings led from each pump through a single tank hatch
and then to below the liquid level in the port slop tank,
so eliminating the possibility of static generation through free-fall.
But none of the pumps was electrically bonded to the ship's structure.
The first pump was started at 1900 on May 26th;
by 0030 the next day four units were working.
The fifth pump was not started until 1600.
Less than two hours later, Atlas Titan blew up.
The explosion in 5C ripped open the decks
and caused crippling structural damage.
Later the tanker was declared a CTL.
The first four pumps operated each had an air consumption
of some 9600 cu ft/hr while the capacity of the fifth unit is still unknown.
However, simple calculation shows that air consumed and then exhausted
into No 5 center tank by the first four pumps alone totalled 792,000 cu ft
compared to the tank's capacity of 899,339 cu ft.
This indicates that almost a complete air change had been effected,
so negating the inerting operation carried out earlier.