View source for CNC training facility, Sellafield, Cumbria

==Article in [https://www.newsteelconstruction.com/wp/wp-content/uploads/digi/NSCApril2017digi/pubData/source/NSCApril2017digi.pdf#page=16 NSC April 2017]==
{{#image_template:image=File:CNC_Sellafield-1.jpg|align=right|wrap=true|caption=View of the office block and the 50m-long range|width=400}}
'''Nuclear patrols with steel'''<br>
A bespoke [[Braced_frames|steel-framed]] training complex is being built for the Civil Nuclear Constabulary near Sellafield.<br> 
''By Martin Cooper''<br>

Charged with protecting the UK’s civil nuclear sites and materials, the Civil Nuclear Constabulary
(CNC) employs more than 1,500 armed police officers and members of staff whose primary task is to deter any attack or sabotage on these important assets.

To help better train its officers, a new CNC training facility is under [[Construction|construction]] near Sellafield in Cumbria, which consists of a series of inter-connected [[Braced_frames|steel-framed]] structures. They include a three-storey hub with classrooms, operational stores, gym and [[Multi-storey_office_buildings|offices]], alongside communal use areas. Further connected [[Braced_frames|steel-framed]] structures house two live fire training ranges – 50m and 100m long respectively, and a live fire skills area where various training scenarios can be played out within a three-storey building.

The facility will be owned and developed by the Nuclear Decommissioning Authority (NDA) and leased to the CNC. Morgan Sindall has been appointed to construct the facility with Deloitte Real Estate providing project management and cost consultancy support.

Commenting on the project that began last May, CNC Assistant Chief Constable Chris Armitt, says: “The new training facilities represent an important and necessary step forward for the CNC, ensuring we continue to effectively deliver our mission of maintaining public safety and protecting civil nuclear sites. It will allow us to continue to meet the most stringent armed policing standards set by the College of Policing and UK Government regulatory standards for the protection of nuclear sites such as Sellafield.”
{{#image_template:image=File:CNC_Sellafield-2.jpg|align=left|wrap=true|caption=Steel [[Modelling_and_analysis#Modelling|model]] of the entire facility|width=300}}
Work on the project started in May 2016 with the previously greenfield site, which is adjacent to the main Sellafield nuclear plant, undergoing a cut and fill operation. This work was undertaken to form a level footprint for the buildings on the sloping site. Once the pad foundations were installed, the [[Construction#Steel erection|steelwork erection]] progamme kicked off in July, with all of the main structures [[Construction#Steel erection|erected]] by November.

“A [[Braced_frames|steel-framed]] solution was chosen because of the [[Long-span_beams|long spans]] required for the ranges, while cost and [[The_case_for_steel#Speed of construction|speed of construction]] also played a big part in the decision,” says Morgan Sindall Project Director Paul Limb. “Configuring the [[Braced_frames|steel frames]] so they best fitted the site, especially as one of the ranges is 100m-long, was one of our initial challenges,” says WML Project Engineer Emma Hackney.

The biggest building is the hub that will accommodate the main entrance and it sits at the western portion of the site. Behind this structure are the two [[Braced_frames|steel frames]] housing the ranges, sitting either side of the live fire skills zone. At the end of 50m-long range and the live fire zone, two smaller connected frames house soft skills, which means training without live ammunition. Beyond these structures there are two further small, and completely independent, steel structures accommodating a workshop and a store.

As well as [[Fabrication|fabricating]], supplying and [[Construction#Steel erection|erecting]] the project’s structural steelwork, Border Steelwork Structures (BSS) has a large remit on this project as it also installed [[Floor_systems#Precast units|precast floor planks]], windows, [[Building_envelopes|cladding]] and roofing louvres. “We had to sequence our programme to allow access for our floor installation which had to follow on behind the [[Construction#Steel erection|steel erection]],” explains BSS Senior Contracts Manager Stuart Airey.
{{#image_template:image=File:CNC_Sellafield-4.jpg|align=right|wrap=true|caption=The main entrance and the completed [[Multi-storey_office_buildings|offices]]|width=300}}
The sequencing meant the two parallel ranges were [[Construction#Steel erection|erected]] first, followed by the connected three-storey hub building. Finally, BSS [[Construction#Steel erection|erected]] the live fire skills area which sits between the ranges. This area contains [[Floor_systems#Precast units|precast flooring]] units and in order to gain access for the crane it had to be built last,” adds Mr Airey. “We were able to position a [[Construction#Mobile cranes|mobile crane]] in the gap between the two ranges, installing steel and planks, working its way out sequentially.”

For its entire programme, BSS used four 80t-capacity [[Construction#Mobile cranes|mobile cranes]] for the steel and flooring programmes, and two self-erecting [[Construction#Tower cranes|tower cranes]] for [[Building_envelopes#Building envelope installation|cladding and roof installation]]. 

[[Construction#Steel erection|Erecting]] the two ranges required BSS to assemble on site a series of 24m-long [[Trusses|trusses]] that form the two column-free spaces. These were [[Fabrication#Handling and transportation|brought to site]] in two sections that were then spliced together and lifted into place as one large piece. Supported on perimeter columns set at 7m spacings the [[Trusses|trusses]], which have a maximum depth of 4.5m, taper to form the sloping profile of the roofs. The two ranges are independent structures that gain their [[Concept_design#Structural options for stability|stability]] from [[Braced_frames#Vertical bracing|bracing]] positioned within their perimeter walls. The live fire skills area gains its [[Concept_design#Structural options for stability|stability]] from the ranges on either side.

A series of 14m-long Westok [[Steel_construction_products#Cellular beams|cellular beams]], supporting [[Floor_systems#Precast units|precast planks]], form the live fire skills areas floors.

Structurally the ranges are separated from the hub building by a double column movement joint. The hub is a [[Braced_frames|braced frame]] with [[Braced_frames#Vertical bracing|cross bracing]] located in perimeter walls. One row of internal columns creates two internal spans measuring 7.5m-wide.

A [[Bridges|steel bridge]] connects the hub building’s main entrance at first floor level directly to a [[Car_parks|car park]].

[[Construction|Construction]] and fit-out is due to be completed by the end of the year and the facility will be operational by January 2018.

==Ballistic steel walls==
{{#image_template:image=File:CNC_Sellafield-3.jpg|align=right|wrap=true|width=300}}
“This is a bespoke building as it is the only one of its kind in the UK to have all of the training facilities within one large building,” says Morgan Sindall Project Director Paul Limb. As the name suggests, live ammunition will be fired in the live fire skills area as well as within the two ranges. Consequently, these areas have some special cladding to prevent bullets from leaving each of the three isolated zones, and to prevent dangerous ricochets.

The [[Braced_frames|steel frames]] support concrete wall panels that have a series of hardened bullet-proof steel (also known as ballistic steel) [[Steel_construction_products#Flat products - plates|plates]] bolted to them. Timber batons placed onto the [[Steel_construction_products#Flat products - plates|plates]] then support a further layer of rubber matting that creates a 500mm void. Bullets penetrating the rubber will hit the [[Steel_construction_products#Flat products - plates|steel plates]] and then drop down through the void into collecting trays placed on the floor.

{|class="wikitable" width="400"
|-
|'''Architect'''||Capra Architects
|-
|'''Structural Engineer'''||WML Consulting
|-
|'''Steelwork Contractor'''||Border Steelwork Structures
|-
|'''Main Contractor'''||Morgan Sindall
|-
|'''Main Client'''||Nuclear Decommissioning Authority
|}

[[Category:Case studies - Education buildings]]