Civil engineering and construction firm Decmil Group has won a $55 million contract to install a second 800-man camp at Fortescue Metals' Christmas Creek operation.

Fortescue is increasing capacity at its Karntama Village at Christmas Creek, in the Pilbara, as part of its broader expansion program to increase iron ore production from its Chichester Hub to 95 million tonnes per year.

Decmil's contract is for the installation of accommodation rooms, laundries, universal rooms as well as extension to the central facilities - including expansion of kitchen and diner facilities; installation of recreational amenities such as a lap pool, new BBQ areas, gymnasiums and cafes - and substantial landscaping.

Decmil designed the Karntama Village and completed construction of the 800-person capacity stage one earlier this year.

The group's chief executive, Scott Criddle, said it was pleased to be awarded the follow-up contract for stage two.

"It is further endorsement of the quality of work completed and demonstrates Decmil's ability to remain agile and responsive to its clients' needs and project timetables," Mr Criddle said in a statement.

Mr Criddle said Decmil has developed workforce capabilities which allow civil and building skill sets, including key trades, to be transferable across large projects.

The immediate start of this contract allows Decmil to deploy staff from recently completed projects to the Karntama project, he said.