A Light, Strong Light

A Light, Strong Light

“My father was the keeper of the Eddystone Light,

He married a mermaid one fine night.

From this union there came three:

Two little fishes, and the third was me.

Yo ho ho, the wind blows free,

Oh,  for a life on the rolling sea!”

Point Pinos light, built in 1855, the oldest continuously operating lighthouse on the US West Coast.

Point Pinos Light in Pacific Grove, CA, built in 1855, the oldest continuously operating lighthouse on the US West Coast.

Once upon a time, lighthouses were the far-flung outposts of civilization. Their locations on points of land that stuck out of the coast were often quite remote from population centers. Since the light needed to be maintained in working order at all times, a live-in light-keeper was often assigned. The lighthouse had living space in it. It was a little building with a big tower.

If that’s your image of a lighthouse, then the new light at the Port of Valencia might barely be recognizable. It looks like giant version of a child’s toy, a tower from a sci-fi play-set, made of bright blue and yellow plastic. Located on the long narrow breakwater that shelters the northern expansion of the port, it is a landmark both literally and figuratively: the world’s first lighthouse made entirely from composites.

The 32m (105 ft) tall open structure was installed in February, 2015, hoisted into place, fully assembled, by a fairly modest crane. It was designed by Ignacio Pascual, Infrastructure Director of the Valencia Port Authority, and built by a partnership between fabricators Acciona, Madrid, and Huntsman Advanced Materials.

Various parts of it are made of carbon fiber, glass fiber, and hybrid composites. Special processes were developed by Acciona to produce some of the parts, Huntsman supplied specially formulated resins.

The central column consists of eight pultruded carbon fiber tubes, 35m long. They are 250mm in diameter (OD) with a wall thickness of 20mm. Acciona developed a special pultrusion process that uses carbon tows and heavy carbon fabrics.

The floors are resin-infused glass fiber. They were specified as not more than 20cm (8 in.) thick, with chemical resistance requirements. Glass fiber steps, also 20cm thick, were made by resin transfer molding, a process that uses molds on both sides of the cast part to produce high-strength composites with two finished surfaces.

To meet both aesthetic and chemical resistance requirements of the project, metal fasteners were not used. Instead, Acciona created an all-composite system, which included glass and carbon fiber stiffeners, and Huntsman’s Araldite epoxy structural adhesive.

The project took 20 days to build, including the six hours it took to install the tower on the breakwater. (Compare that with 28 days just for a concrete foundation to cure before you can begin construction.)

The new lighthouse is also energy efficient. The light is supplied – not by monstrous arc-lamp or a huge glass bulb, but by an LED source that consumes just 70 watts and is visible for 25 miles. The lighthouse has 10 solar panels and a vertical-axis wind-driven generator to supply most of that power.

If you’re wondering what happened to the walls, they’re not needed. They don’t have to shelter a live-in light-keeper, and the composite materials themselves are weather resistant, so they don’t need to be enclosed.

“Yo ho ho, the wind blows free,

Oh,  for a life on the rolling sea!”

Images via Huntsman Advanced Materials and Acciona, as noted.