Troll A platform is a condeep offshore natural gas
platform in the Troll gas field.
A view from the South East of Troll A
It is the tallest construction that has
ever been moved to another position, relative to the surface of the
Earth, and is among the largest and most complex engineering
projects in history. The platform was a televised sensation when
it was towed into the North
Sea in 1996, where it is now operated by StatoilHydro.
The Troll A platform has an overall height of 472 metres and weighs
656,000 tons and has the distinction of being the tallest structure
ever moved by mankind. The platform stands on the sea floor 303
metres (994 feet) below the surface of the sea and each of the
National Geographic Channel production, documentary 2007(?),
rebroadcast 2009-10-02, 12-13:00 hrs EDST (Comcast Cable Television
system)Slip forming) and each is mathematically a joined composite
of several conical cylinders that flares out smoothly to greater
diameters at both the top and bottom, so each support is somewhat
wasp-waisted viewed in profile and circular in any cross-section
(see picture at right). The concrete legs must be able to withstand
intense pressure so are built using a continuous flow of concrete,
a lengthy process that takes 20 minutes per 5cm laid.
The four legs are joined by a "Chord shortener", a reinforced
concrete box interconnecting the legs, but which has the designed
function of damping out unwanted potentially destructive wave-leg
resonances by retuning the leg natural frequencies.(Not present in
the picture at right.) Each leg is also sub-divided along its
length into compartments a third of the way from each end which act
as independent water-tight compartments. The legs use groups of six
holding it fixed
in the muck of the sea floor.
Troll A was built by Norwegian
for Norske Shell
with base construction beginning in July 1991.The base and the deck
were built separately, and were joined in 1995 while the base was
partially submerged. The base is a Condeep
gravity base structure
from reinforced concrete
platform was towed over 200 km from Vats, in
the northern part of Rogaland, to the
field, 80 km north-west of Bergen.
tow took seven days.
Troll A is scheduled for an expansion of living quarters to
accommodate the increasing number of workers needed to operate new
compressor modules. These modules are needed due to the dropping
pressure in the wells.
Gas rises from 40 wells, and is exported through a number of pipes
at more than . Troll A is scheduled to receive two additional gas
compressors to increase production volume and compensate for
dropping gas pressure in the wells.
In 1996 the platform set the Guinness World Record for 'largest
offshore gas platform'.
In 2006, the 10th anniversary of Statoil's operatorship of Troll
gas production was celebrated with a concert by Katie Melua
held at the base of the Troll A
platform. As well as entertaining the workers on the rig, the
concert set a new world
for the deepest underwater concert at 303 metres below