Hendriks precon supplies precision moulds for Alfen transformer stationsTransformer and mould specialists join forces

In a world that is working hard on the energy transition, transformer stations play a huge role. Electricity is becoming increasingly important now that gas use is reducing in the Netherlands. The many transformer stations spread across neighbourhoods and business parks are vital elements in the chain from energy producer to user. Alfen has specialised in this area for over 60 years. The company uses moulds for the production of prefab transformer stations. Three new Hendriks precon moulds were recently added here.

Special challenges

In recent years, Alfen has produced and supplied many tens of thousands of transformer stations to grid operators, industrial companies, businesses and the horticulture sector. This long-term success is partly a result of continuous innovation and using the latest technology. This makes Alfen transformer stations suitable for all situations and types of users. For the construction of the stations themselves, the company has relied on Hendriks precon for many years to supply the moulds for the concrete station fabrication. They’ve recently added a mould for a new type of compact station.

Martin Pieterson from Alfen described the mould: ‘The new mould was quite challenging and demanded considerable engineering expertise from Hendriks precon. The transformer stations produced with this mould are modest in size. But at the same time, the interior must be extremely flexible as this is divided into three rooms that may need different configurations. We addressed these challenges together with Hendriks precon. We’ve already been working with them for years and they were the obvious partner for this project.’

Monolith unit of interior and exterior walls

The mould is raised somewhat from the floor and comprises a core with mobile exterior walls. ‘The exterior of the transformer station is finished with vertical fluting. As well as a beautiful aesthetic, the fluting is also a match for the anti-flyposting policy of many companies and municipalities’, stated Martin Pieterson.

The finish on the interior section that comprises three separate rooms is striking, as this ensures that the transformer and low and medium voltage equipment are separated. And yet, the interior and exterior walls of the transformer station are produced as a monolith. ‘For this, the core of the mould comprises three sections that are formed by openings. Installing steel openings enables various versions of the stations to be produced with one mould.’

Complex hydraulics on compact size

As the core and the exterior walls are slightly raised, the core with hydraulic cylinders can be moved downwards at the bottom. ‘Two of the three core elements can be unloaded downwards separately from each other before the station is pushed upwards as a unit. Special air openings in the core prevent the formation of a vacuum.’ Combining three separate hydraulic units for the inner core on a modest surface posed specific requirements on Hendriks precon’s inventiveness. ‘One of the inner formworks can also be pulled away at an angle to make the core easily accessible for cleaning, maintenance and the introduction of cast-in elements.’

Martin Pieterson continued: ‘The exterior walls of the mould are on wheels and can be opened and closed using hydraulic cylinders. All walls are provided with an axle that protrudes through the perpendicular wall when closing. The exterior bulkhead is then automatically fixed using the mould’s 12 hydraulic wedges. As the exterior walls have a working platform on all four sides, casting work can be carried out in a safe and reliable way.’ The roof is supplied as a separate element with the station. All stations are installed on site fully setup, but the separate roof enables elements to be exchanged on site via the roof, where necessary.

High level of precision

When asked about the cooperation with Hendriks precon, Martin Pieterson responded enthusiastically: ‘Working with Hendriks precon was great. We needed a high level of precision and considerable engineering expertise to ensure that these moulds work well. Hendriks precon is the best there is. And they were again able to develop a fantastic solution to incorporate the vast hydraulic system needed to unload the core, in the core elements. A major challenge and a world-class performance.’