Precast concrete has been produced at Tallington near Stamford for a very long time. Conveniently located between the East Coast Main Line and a source of good concrete-making aggregates, the 13ha site was first developed by Dowmac in the 1940s.
It has its own modest footnote in the history of concrete in that the first pre-tensioned prestressed concrete railway sleeper was produced there in 1943, an achievement commemorated by a brass plaque near the main entrance. Now, with the local quarry long since worked out and converted into 'leisure lakes,' Tallington is under new ownership (see box overleaf) and preparing for the challenges of the next decade.
Tarmac Precast Concrete structures director Norman Brown says Tallington is already the largest multi-product precast factory in the UK. 'We turn out everything from bridge beams to agricultural panels, including a lot of sleepers and other rail products.
'Now we're looking very hard at the architectural market - especially structural components with high grade architectural finishes.'
Purely architectural concrete such as cladding panels currently forms only 5% of structural production. Brown explains: 'This is a very specialised market and hard to break into.
But attitudes are beginning to change. Developers can see the advantages of eliminating site trades by using structural panels which are factory- finished. A recent £2M plus investment in new production facilities has contributed to enhanced quality, especially on large panel units. One of the key elements in this investment has been a special German-developed magnetic formwork system, where powerful magnets not only hold the steel forms together, they allow boxouts to be firmly located without welding or drilling holes through the steel.
'This is safer, as well as helping to keep the formwork in top condition,' says Tarmac production manager Paul Fry. 'It's also very flexible and efficient. We can cast wall panels in it one day, floor slabs the next.'
Close by sit some distinctive, large Y-shaped steel moulds which feature hydraulic operation and integral heating elements to speed curing. These are producing units for the new Onley prison, and complement the modular pods that Tarmac developed in its PCSL JV.
Some of Tarmac's plans are based on revivals rather than innovations. In the Dowmac days Tallington turned out a significant number of long span Double Tee flooring units, many going into multistorey carparks. 'But during the Costain period these were rather neglected,' says Brown.
'In the last three years, however, we've turned the situation round. Double Tees now form a healthy 25% of structural production, along with their cranked access ramps.'
Brown is particularly proud of Tarmac's recent successes in the grandstand and stadia sector. Over the last six years the company has supplied structural precast elements to projects ranging from Lord's cricket ground to the Nottingham Ice Centre.
One of the latest is the Millennium Grandstand at Newmarket (see page 31). With casting of the Newmarket units now complete, production of elements for the new grandstand at Warwick racecourse is under way.
These days most of the concrete uses crushed granodiorite aggregates from Cliffe Hill Quarry in the Midlands. The three batching plants which serve Tallington's seven separate production areas are due for a £300,000 upgrade very soon.
But, while new products are developed, Tallington's roots have not been neglected. There is still a rail link into the plant, and train loads of precast sleepers still roll out of the gate. With the current boom in rail infrastructure, Tarmac appears to be covering all the angles, and Tallington looks set for a prosperous future.
Architect: The Goddard Winsor Practice
Structural engineer: Jan Brobowski & Partners
Main contractor: John Mowlem
Quantity surveyor: Davis Langdon & Everest