An Andover business which makes classified materials for the military is set to expand if a planning application is approved by Test Valley Borough Council (TVBC).

Scientific Management International (UK) Ltd (SMI) has applied for permission to expand its manufacturing hub in Walworth Business Park, with two new “secure manufacturing areas” to be constructed at the rear of the building. Due to being a military contractor, the exact nature of their operations is a state secret.

The plans are currently being considered by TVBC, and will be decided on in due course.

SMI was founded in 1992 as Scientific Management Associates, and relocated to Andover in 1995. It opened its factory in 1997, and in the same year gained a qualification allowing it to supply submarine parts to the Ministry of Defence, which it has held ever since.

It was renamed to SMI in 2017 following a management buyout, with bases and work all around the world. It supplies a variety of products which are described as “the central nervous system for critical infrastructure including naval ships, submarines, aircraft, power generation and transport.”

Due to the nature of its work, it is a List X contractor, companies which work on UK government contracts requiring them to hold classified information on site. As a result, the plans for the interior of the building’s extension are vague in what they show.

Under the plans, two additional “secure manufacturing areas” will be created, while others will be extended. An additional temporary store outside is planned while work takes place, with additional work including connection to the sewer system proposed. The company will continue operating while the extension is built.

In its plans, SMI said: “Maintaining a continued presence in Andover through investment in the existing building is considered by SMI as a more attractive prospect than exploring potential alternative sites and/or locations.”

The plans are now being looked at by the council, with an environmental health officer raising concerns over a planned smoking shelter.

Mike Lee said: “It is not completely clear if the northern elevation wall to the shelter will be solid or not, but if both the northern and southern elevation walls and roof are solid then the proposed structure would be substantially enclosed and therefore not be sufficiently open to qualify as a shelter for smoking purposes.”

However, he added it was “a very minor element of the whole application and this aspect should not hold up determination of the application”, and could be rectified quickly.

The plans are under consideration by TVBC, and will be decided on in due course.