SOME of the world's biggest manufacturers, who have plants in Tai Po Industrial Estate, say the infrastructure, cheap land, transport links and quality amenities have prompted them to set up operations there. Electronic component manufacturer Motorola; injection moulding machine-maker Chen Hsong, and construction materials firm Daido Concrete are among companies that have benefitted from the facilities in the estate. Motorola selected Hong Kong as the site for its design and manufacturing centre to serve electronics manufacturers in Asia. ''Unlike Yuen Long, it [Tai Po Industrial Estate] is close to higher education institutions, such as the Chinese University and the Hong Kong and City polytechnics, with their professional and engineering capabilities,'' Tam Chung-ding, Motorola's senior vice-president and general manager, said. Land was the decisive factor in choosing the site. Motorola's factory, the Silicon Harbour Centre, is a 326,000-square-foot, three-storey facility on a 7.2-acre site. Mr Tam said he could not have obtained a more suitable plot of land, considering the waste disposal needs of the factory. ''The industrial estate is unique with its really low-cost land,'' Mr Tam said. ''The estate is good; we began construction in 1988, moved into the building in 1990 and expanded faster and invested more money than originally planned.'' Mr Tam said Motorola could not expand any further in Tai Po, and was pleased that Tseung Kwan O Industrial Estate would provide space for future plans. Another company that has outgrown its operation in Tai Po is Daido Concrete. It moved to Tai Po about 12 years ago. Executive director Masao Suzuki said the main attraction had been the cost of land. ''In 1991, when there was no room left for us to expand in Tai Po, we bought 25,000 square metres for a second factory in Yuen Long at a price that would have cost four to five times more on the open market,'' Mr Suzuki said. Daido Concrete manufactures concrete piles and steel pipes at Tai Po and, at Yuen Long, it produces aerated concrete using a fully automated process. Daido Concrete centralised its operations when it moved to Tai Po. Mr Suzuki was satisfied with the working environment, although he believed the Hong Kong Industrial Estates Corporation was inflexible. ''Even if we wish to change the layout or office area, we need to apply for permission, and may not get approval,'' he said. Benelux, manufacturer of eight-millimetre video cassette tapes, microcassettes and 3.5-inch floppy discs, has not centralised its operations. Apart from 120,000 sq ft of production facilities in the Tai Po Industrial Estate, it currently has plants in Tai Ping and at Chai Wan. Benelux selected Tai Po because of its proximity to the border. Managing director Henry Chow said operating on the estate created a good image for foreign customers. A typical Hong Kong success story is Chen Hsong, which began in 1958 as a small maintenance workshop and now is the world's largest manufacturer of injection moulding machines. The company philosophy is to produce machines that match those of the Japanese in quality, but at low cost. More than half the production is exported.