Redwood City Built an Ocean Ship out of Concrete

A Shipyard on Redwood Creek

During World War I, merchant ships were being lost faster than they could easily be replaced. Steel was in heavy demand. William Leslie Comyn, a businessman with shipping interests, proposed using concrete for ocean-going vessels and established the San Francisco Shipbuilding Company to try it.

The work took place on Redwood Creek, south of San Francisco. Designers Alan Macdonald and Victor Poss developed the ship, and construction began in 1917. Workers built a reinforced framework and poured concrete into forms to produce the hull. By the following February, Faith was complete.

Concrete itself is heavier than water, but a hollow ship displaces a much larger volume of water than a solid block of concrete of the same weight. The hull’s shape and enclosed space allowed it to float with machinery and cargo aboard. The challenge was making that structure strong and watertight enough for service at sea.

A Short Commercial Career

Faith was steam-powered, with a reported speed of about ten knots. It carried commercial cargo after its launch, demonstrating that the proposal could work beyond a shipyard test. It was the first American ocean-going concrete ship, although concrete boats had already been built elsewhere.

The experiment arrived at an awkward moment. The United States pursued a larger concrete-ship program, but the war ended before those vessels could provide the wartime service originally envisioned. The urgent shortage that had made unusual building materials attractive was easing.

Faith’s own career lasted only a few years. By 1921 it had been taken out of service in Cuba.

Photographs published in 1918 show its masts, cargo gear, and funnel above a hull with the proportions of a conventional freighter. The ship’s unusual construction drew publicity while it was new, leaving a photographic record even though the vessel itself did not survive.