Darlington Works, United Kingdom

The new Darlington Works for Cleveland Bridge was opened in 1982. Built on a Greenfield site on the eastern edge of town, it replaced the hundred-year-old works at Smithfield Road. As the most modern steel fabrication works in Europe, it was designed for the manufacture of steelwork for bridges and structures. Continual investment has kept the Works up to date and abreast of the market for constructional steel. Today it is the only large works in the UK for fabrication of higher added-value plate products.

Aerial view of the Darlington Works

A 100 x 240m factory building houses the main facility. The Works layout ensures efficient flow of steel from delivery into the stockyard through treatment, preparation, fabrication, assembly, protective treatment and despatch. Material for section and plate products follows the route appropriate to the work processes for the size of each finished item. The main building comprises three transverse preparation bays (110m x 36/30/25m) and four longitudinal fabrication and assembly bays (each 150m x 27.5m). Self loading transporters carry blast cleaned material from the treatment line into the preparation bays which are equipped with magnetic 15T EOT cranes. Rolled section can be processed through one of three saw and drill lines and a plasma notching machine. Combined beams can also be processed. Tubular work up to 1200mm diameter can be processed on a pipe profile machine. For plate products there are a range of machines that undertake all burning processes, CNC drilling/milling, mechanical edge preparations and presswork. Each fabrication bay is serviced by EOT cranes and contains machines and welding equipment for specific product ranges – assemblies up to 82t can be accommodated with tandem lifts, with transporter capacity up to 96t. Large scale trial erections are carried out in two outdoor areas (8000 and 5000 sq m) covered by travelling cranes and with mobile cranes in support.

Finished work is transported into the protective treatment facility that has five cells 11m wide x 7m high and up to35m long, with controlled environment. Blast cleaning, metallisation with zinc or aluminium, glass flake enamel and paint systems are applied to meet the client’s specification.

The Works has immediate access to the motorway network – girders up to 50m long have been transported – and it is only 25km from the docks at Teesport for shipment worldwide; it has its own connection to the national rail system. Teesside airport, 5km away, provides ready access for visitors from abroad.

The particular facilities of this works include:

Treatment Line - all material from the stockyard passes along a roller track through the treatment plant for blast cleaning, and priming when appropriate. Material u to 1 t/m length, 3m wide and 450mm thick is processed.

Burning Machines - the three burning machines can process plates up to 27m long, 4.5m wide and 1800mm thick through the processes of flame stripping, flame planning and profile cutting.

Tube profiling - the robotic tube profile machine can prepare tubular work from 75mm – 1200mm diameter including cut-outs and weld preparations using oxy or plasma cutting.

Presses - levelling rolls, a 250t pin press and a 700t portal press are used for straightening, bending, pre-setting and cambering. A 640t brake press bends plate components, including trough plates up to 16m long for bridge decks.

Saw, Drill and Section Notch Lines - the three lines take sections up to 24m length, 1200mm width and 500mm depth, including cambered beams. The section notch line makes all common cuts on H‑sections, channels and plates.

T&I Section Fabrication - automated equipment produces parallel, cambered and tapered Tee and I Beams, welding flanges to webs in the vertical position, up to 35m long and 3.04m deep. A 10mm fillet weld can be achieved in one pass.

Panel Assembly Machine - a hydraulic clamping portal and a 6 head sub-arc welding gantry operate over a hydraulic retaining bed to produce stiffened plate panels. The bed is set to pre-camber the panel plate to allow for weld shrinkage effects. This machine produces precise high-quality orthotropic deck panels efficiently up to 32m long x 3.6m wide.

Machining - the bays are equipped with a variety of drilling, boring and milling machines to cover the full range required for bridge and heavy structural components.

The capacity of the Darlington Works is about 50,000 tonnes per year depending on the product mix. Some recent achievements include:

· 26,000 tonnes of heavy welded truss and deck panels for Tsing Ma bridge

· 14,000 tonnes of stiffened plate panels for Jiangyin Bridge

· 700 tonnes a week of complex heavy plate girder work for the Broadgate Plaza Raft

The production staff in the Works are supported by Welding Engineers, Quality Control and Quality Assurance specialists. Quality Management Systems, third party accredited to ISO 9001, are used throughout.

First Class Fabrication