Westpile's history is inextricably linked with its shell pile system. For more than six decades it was the main source of income, but over the last two years, as Westpile has diversified into a broader range of mainstream piling techniques, it has consigned the system to the history books.
The shell pile system was originally developed by Alexander Rotinoff, a Russian marine engineer who fled his homeland to escape the Communist revolution in 1917. He patented his 'Cylindrical Shell Pile System' in 1923 and a year later sold the patent to West's Gas Improvement Company, a Manchester-based family-run construction company serving the gas industry.
West's saw the purchase as a way of expanding its activities and with Rotinoff on board set up a new firm, West's Rotinoff Piling & Construction Company. Initially based at Wilmott's Yard, Twickenham, in the mid-1930s the firm moved to Harmondsworth.
One of West's Rotinoff's earliest successes with the shell pile system was in the foundations for Guildford Cathedral. Piling work - 778 piles driven to 15m and loaded to 50t - was officially completed in April 1937, with Queen Mary pulling the hammer rope to drive the last pile. The cathedral was finally finished in 1957.
In 1942, the firm dropped the Rotinoff name. By this time, Alexander Rotinoff had died and his son George, who joined the company before the war, had left to join Dowsett Engineering. He died in 1959.
In the post-war years West's Piling & Construction Company went from strength to strength, benefiting from the building boom in the late 1940s and 1950s. The shell pile really started to come into its own.
'At that time in certain ground conditions the shell pile had no real competitor,' says Westpile estimating manager John Gedge.
Its main rivals were cast insitu piles and precast driven piles, the latter being heavier and more difficult to handle than the modular shell pile, whose length could easily be adjusted to suit the ground. The end- bearing piles were simply driven through the soft alluvium to refusal in stronger underlying strata.
Infrastructure and the power industries accounted for much of the construction - new roads and railways as well as steelworks, gasworks and oil refineries.
As Gedge explains, much of the work for the power industry was in estuaries because of the need for large quantities of water and good sea transport connections for raw materials. The shell pile was ideal for this sort of work because its permanent casing stopped the soft estuarine deposits squeezing in and acted as a water barrier to ensure pile integrity.
As a result, West's Piling was involved in many such projects. In 1948, it installed 18,000 shell piles for Llanelli Steelworks for the Steel Company of Wales, at a rate of about 1,000 to 1,500 piles a month. Gedge says the work was labour intensive, with rig outputs being only 100m of piling a day. Piles were installed by mobile rigs that were basically old railway carriages mounted on tracks operated by between five and seven men (today it is more usually two or three). All the concrete shells were cast on site, further increasing the workforce. That same year, the company put down more than 4,000 piles to depths of 6m to 7m for Salford Gasworks.
By the mid-1950s, West's Piling and its shell pile system were firmly established, installing the foundations for high-profile projects such as the Fawley oil refinery near Southampton in 1951. Nearly 1,000, 0.5m diameter piles up to 17m long were installed for the facility, then the largest refinery outside the US.
In 1955 West's put down nine 450mm diameter piles to 12m for the 195m high radio mast at Crystal Palace. In 1956, it began installing 10,000 piles, between 6m and 17m long, for BP's oil refinery on the Isle of Grain in Kent.
In the summer of 1958, it launched the Century Pile, a 0.6m diameter shell pile named for its capability of carrying a load of 100t after being driven to 30m.
West's continued to expand, moving to a new office and works complex at Colnbrook near Windsor in 1963.
One of its major contracts of the 1960s was Thamesmead, the vast suburban development on London's eastern edge, where West's installed 250,000 piles for the project using about 30 rigs (output was still relatively low).
Other large projects of the period included the original Seabank power station (6,000 piles) and Llanwern steel works (40,000 piles), the latter involving more than 20 rigs.
In 1973 the firm's parent company West Group Inter- national bought Economic Foundations from Robert McAlpine and incorporated it into West's Piling & Construction.
That year, the company also introduced its driven precast piling system, the hard drive system, and set up a casting yard at Colnbrook. It soon developed and patented its interlocking joint to rival main competitors of the time, Balkan and Hercules, which both had their own precast systems.
But the shell pile remained the company's main source of income, as there was still no real rival in soft soil, despite the fact that many of the piles installed were only 15m to 18m long.
In 1979 West Group International acquired Dowsett Piling & Foundations which Gedge says was the first to introduce continuous flight auger (CFA) piling using grout to the UK. But the two companies were treated as separate entities until 1986, when West Group International was bought by Tilbury Douglas, which merged the two foundation contractors to form Westpile.
But by this time shell piling was in decline. The advent of integrity testing meant that for the first time, the continuity and completeness of driven cast insitu piles could be checked. Gedge says that engineers had considered driven cast insitu piles to be 'suspect' in soft soils but these new techniques could prove the piles were sound. 'Integrity testing was the death of the shell pile,' Gedge says.
As a result, driven cast insitu piling became increasingly popular. CFA also benefited from the building boom of the late 1980s and early 1990s.
The shell pile really suffered in the recession of the early 1990s, mainly because it was slow and involved high mobilisation costs compared with other systems.
With the writing on the wall for the system, Westpile decided to change direction and go into the rotary bored market. After an unsuccessful bid for a competitor in 1990, the company decided to build its own rotary business. This began by converting the bases of driven machines into cranes and with some investment for new equipment (Tilbury paid for two new Watson rigs), Westpile entered the fray.
The decision proved a wise one. In 1990 turnover from shell piles was about £9M to £10M but by the mid-1990s it had plummeted to less than a fifth of that.
But the company still had an identity problem, says Gedge, as clients still associated it with shell piling and other precast driven work. In fact, at that time 80% of its work was bored piling.
Today, Westpile's aim is to stay multidisciplined. There is continuing development of CFA, with investment in new equipment, including the company's Cased Flight Auger Pile system introduced last year (Ground Engineering June 1998) and increasing pile diameter, now standing at 1.2m.
'In 1996, 750mm diameter was considered to be the limit,' says Westpile contracts director Pat Deighan. Further improvements in environmental aspects of the method and instrumentation for quality control have increased confidence and the popularity of CFA, he adds.
Deighan believes that CFA will continue to dominate the piling market, 'although rotary boring is still the only viable option on a lot of jobs'.
The drive for technical innovation and diversity has been crucial in the company's survival during the hard times of recent years. 'The reason the recession didn't catch many piling companies out is the fact that the industry is very robust,' Gedge says. 'The price per linear metre has not really changed since the 1980s. This, and the fact that our competitors are very good, means that to stay alive we have to be multidisciplined, versatile and have to perform once we turn up on site.'
The security of a large parent company has also helped, he says. 'We've been given strong and continuing support throughout.'
Today, Westpile employs about 200 people, including 20 engineers. Head office has been in Uxbridge since 1982 and the company is in the process of combining its northern operations at a new site at Hovingham in Yorkshire.