By Brian Milligan
Business reporter, BBC News, Portsmouth
The shipyard is taking on extra staff to complete the work
Putting together what is in effect the largest jig-saw puzzle ever made in Europe is not an easy task.
The two most expensive Royal Navy ships yet - HMS Queen Elizabeth and HMS Prince of Wales - will be partly built in Portsmouth, before they are finally assembled in Rosyth.
"Of course, the whole thing will shrink a bit when it goes to Scotland," grins a casual Phil Rood of VT ship-building, referring to the fact that average temperatures in there are a couple of degrees cooler than in Portsmouth.
Building yards in Barrow in Furness and Govan will also take part in the construction of the four huge cross-sections of the UK's next generation aircraft carriers.
Every pipe, cable and steel section will need to match up perfectly. Mistakes will be costly.
Shrinkage on the aircraft carriers is therefore a big issue.
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