World’s biggest vessel (1,252' x 407') decommissioning Brent oilfield structures after 40+ years.

Time goes by fast in an oilfield’s life – in 1977-8 I sailed as chief mate on the 4,000HP tug “Gulf Ace II” (TG39129) owned and operated by Gulf Mississippi and later bought out by Zapata. Towed a 300’ x 90’ barge out of the Firth of Forth, Scotland with a flare boom for the Brent Alpha (rig below to right with the flare boom sticking out at 45 deg. angle). After numerous weather related delays hoisted it into position on the rig. Took us a couple of weeks – mostly standing by getting tossed around the wheel house waiting on site for weather to improve, but interspaced once by running with the barge for shelter off Lerwick in the Islands with the rig master screaming over the radio that we could not leave. Shortly after we had anchored, we discovered the whole fleet of construction vessels also packed it in and were dropping anchor behind us to hole up until weather improved. After the lift was finally completed (took abt. half a day trying to keep the barge in position) we delivered the barge to a yard just north of Bergen, Norway and the tug down the English Channel (dodging wayward northbound ships in the southbound lanes) and around to Cobh Ireland (another story) where we picked up another tug (either TG43001 or TG39144) which we sailed to Falmouth and dropped off.

http://www.hartlepoolmail.co.uk/news/world-s-biggest-vessel-is-set-to-appear-off-hartlepool-coast-1-8519804

Pioneering Spirit (formerly Pieter Schelte) is the largest construction vessel ever built. Inspired by the offshore heavy lifting pioneer Pieter Schelte Heerema (1908–81) and designed completely in-house, the vessel is designed for the single-lift installation and removal of large oil and gas platforms and the installation of record-weight pipelines. The twin-hulled vessel is 382 m long and 124 m wide. At the bow is a slot, 122 m long and 59 m wide, that enables Pioneering Spirit to straddle a platform and remove entire topsides – up to 48,000 t – in a single lift using eight sets of horizontal lifting beams. Two tilting lift beams for the installation and removal of jackets – up to 25,000 t – will be located at the vessel’s stern. Complementing the lifting systems is a 5000 t special purpose crane for additional lifts such as lighter topsides and jackets, modules and bridges.

The Brent field is an oil and gas field located in the East Shetland Basin of the , 186 kilometres (116 mi) north-east of Lerwick, Shetland Islands, Scotland, at the water depth of 140 metres (460 ft). The field operated by Shell UK Limited was once one of the most productive parts of the UK's offshore assets but has reached the stage where production is no longer economically viable. Decommissioning of the Brent field will be conducted over the coming decade Shell will this week unveil a plan to dismantle four enormous oil rigs in the North Sea, kicking off a vast and controversial decommissioning project.

The Brent field rigs were built in the 1970s and produced around a tenth of the UK’s . But three of the four – Alpha, Bravo and Delta – have now shut down, and this summer the company will embark on a multibillion-pound eight- to 10-year project to remove the vast drilling and accommodation structures. Production started-up on 11 November 1976, and on 13 December 1976 the first tanker was loaded. The Brent field oil is extracted by four platforms in an irregular SSW-NNE line.[3] The first in place was the concrete-legged "Condeep" Brent Bravo in 1975, followed by the concrete-legged Brent Delta, Brent Charlie, and steel-jacket Brent Alpha. As of 2004, the platform was still producing oil through a manifold (all Brent Alpha fluids are produced across to Brent Bravo). A fifth installation, the floating , served as a storage- and tanker- loading buoy and was installed early in the field's construction. The "spar" design of this installation led to the name by which it became the best known of the Brent installations (outside the oil industry). The field also included a remote flare, the "Brent Flare", which was used to flare off excess gas before gas handling and export facilities were installed in the field. This unit was decommissioned and removed using a heavy lifting barge in 2005.

Brent Delta below.

Link to videos https://allseas.com/equipment/pioneering-spirit/

A huge barge carrying an oil rig set for Hartlepool is due off the town’s coastline. The arrival of the Brent Delta Topside will provide a spectacular addition to the Hartlepool skyline.

The 24,200t structure has a footprint of 240ft x 150ft, is up to 430ft-high and is due to arrive at Able Seaton Port, Hartlepool on or around next Wednesday. The Topside will arrive as a ‘single piece’, having been lifted from its foundation and transported by the world’s largest vessel - the £2.5 billion Pioneering Spirit - which measures 1,250ft x 400ft. The Pioneering Spirit is due to arrive at a point around 5.5 nautical miles north east of Hartlepool. Able UK says the structure will be seen for miles.

The structure will subsequently be transferred to a barge – the Iron Lady (650ft x 190ft) – which will then bring the structure into the River Tees and to Able Seaton Port.Timings will be subject to tide and weather conditions but the process, which will be carried out during daylight hours, should afford spectacular views from the Hartlepool’s Headland as well as both banks of the river. Peter Stephenson, Able’s executive chairman, said: “The arrival of the Brent Delta Topside will represent a significant development for the entire decommissioning sector and is the culmination of a long and detailed process that has involved a wide range of partners.“For our part, we have invested £28m in developing a new heavy duty specialist quay to receive these types of structures.“The arrival itself should certainly provide fellow Teessiders with an impressive spectacle. “Of course the topside will not be a permanent feature and our ultimate aim is to recycle over 98% of the structure, a process that should be completed within the next 12 months.”It is hoped that dozens of jobs awill be created during a huge engineering project. Able UK has invested £28million in building Europe’s strongest quayside at the Seaton Port, to take delivery of the 24,200 tonne Delta oil rig topside, which will be transported on the Pioneering Spirit.Once here about 50 jobs will be created, along with two apprenticeships, as the company sets about dismantling and recycling the enormous rig.Neil Etherington, business development director for Able UK, said there were 131 companies, which wanted the contract, so it was a huge success for Able to clinch it, and the aim is to secure a lot more similar rig demolition work in the future.Mr Etherington said: “It will dramatically alter the Teesside skyline for a while. People will be able to see it from as far at Redcar and Peterlee.”