Key build stage for next Astute class submarine gets underway

Anson is the fifth of seven, £1bn Astute class nuclear submarines that the Ministry of Defence has given approval to build. At 97 metres and 7,400 tonnes displacement, like all the Astute class subs Anson has a nuclear propulsion system which means she will never need to be refuelled.

Yesterday (Thursday) Gerald Howarth MP and John Hudson, managing director of BAE Systems Submarine Solutions, revealed the keel unit, the first pressure hull unit brought onto the build line in the main hall, at a ceremony at the shipyard in Barrow-in-Furness.

Known traditionally as ‘laying the keel’, a submarine’s keel is not physically fabricated or laid, so the ceremony marks the transition of the submarine’s construction from fabrication of the pressure hull units to full assembly of the hull in the main build hall, the Devonshire Dock Hall.

John Hudson said: “Today we embrace that [keel laying] tradition but with a modern twist. Anson’s keel is being laid vertically to enable more cost effective submarine production. It will be safer and easier for our engineers to install material and equipment into the hull in this orientation.”

Suppliers to the programme, children from 10 local schools, VIPs, local and national press and many of the engineering and support staff attended the ceremony. John Hudson stated that Boat 4, Audacious, is expected to take 20% less time to construct than the first boat, Ambush, owing to the manufacturing and supply chain efficiencies that the programme has fine-tuned in the last 12 years.

The early part of the Astute programme ran over-budget and behind schedule. Asked whether the Astute programme is back on track, John Hudson said: “Astute had a difficult early history. We baselined the programme two years ago, and since then it has been very, very stable we are delivering the programme to a high degree of predictability. It is a very complicated programme and things do go bump in the night – there are so many components to co-ordinate and so many different things that we need to do in order, but since we rebased it has been very stable.”

The Astute programme has developed the SEP supply chain collaboration programme with its key partners, including Babcock Marine and Rolls-Royce. Head of Programme for Astute Boats 5, 6 and 7 Nick Warburton says it encompasses several things, including the build methodology. “It has led to a more modular build of the boat, with larger components and numerous multi-mounts that speeds up assembly. The vertical assembly allows us to speed up the construction and is a lot safer because we don’t need as much scaffolding orientation.” For vessels with a lead time of nine or 10 years, Mr Warburton says, changes in technology and commercial off-the-shelf equipment also greatly help to reduce costs. “As time ticks on, we take advantage of whatever innovations come up – for example, as the revised mission systems and sonars in Boat Four.”

Nineteen-year old Tom Milson, one of the company’s apprentice welders nearing the end of his second year, recently was runner up in the national final of the BOC Apprentice Welding Competition where he had to demonstrate stick and Realtrack welding, as well as the MIG type he was more used to. Next week he will represent England in the UK finals in Cambridge, where success might lead to EuroSkills or WorldSkills competition. “I would recommend the apprenticeship 110 per cent. BAE Systems gives full support to what you do, you learn a trade and see how a nuclear submarine is put together.” Tom has recently enrolled on a foundation degree in Business Management.

Anson is the fifth of a series of seven Astute class submarines being built in Barrow in a contract with the Ministry of Defence that dates back to 1997. The second-of-class, Ambush, underwent trim dive and incline testing over the weekend of October 1. The first boat, HMS Astute, was handed over to the Royal Navy in November 2010. Soon after, the submarine briefly ran aground in the Kyle of Lochalsh during shallow water trial manoeuvres. It recently completed an extensive package of work known a Base Maintenance Period at HM Naval Base Faslane. Following sea trials that included an unbroken 46-day period at sea, Commanding Officer of Astute Commander Iain Breckenridge, described the vessel’s capability as “exceptional”.

It takes about 18-months for the Royal Navy to assume control of the submarine from BAE Systems Submarine engineers and complete all the systems tests. When the handover is completed, the submarine can spend more than two years doing sea trials including deep diving, weapons systems tests and countless safety drills.

The BAE Systems’ submarine programme involves an extensive supply network of over 500 companies, with more than £4.4bn spent across the UK alone since 2000. BAE Systems submarine business employs about 5,000 people and is the largest employer in Barrow-in-Furness.

Quick facts

  • Anson will never need to be refuelled
  • About 110km of cabling and pipe work will be installed on board
  • There are about 40,000 general welds and 50,000 pipe welds on the submarine. Each has to signed off, and each weld is registered, to track the operator and date of inspection.
  • The Sonar 2076 sonar suite that will be fitted to Anson has the processing power of 2,000 laptops.
  • Three chefs feed up to 130 crew a day. The submarine’s operational range is limited by stores and the human factor – the boat can run for maximum 90-days before needing to restock with food.
  • Some sleeping areas accommodate 32 men in one space. Each bunk is about two metres, by 1m high by 1m wide. Only the Commanding Officer has his own cabin.