New Cement Ship On Way To N.Z.

Press, Volume C, Issue 29520, 23 May 1961, Page 14

New Cement Ship On Way To N.Z.

(From the London Correspondent at “The Press”)

LONDON. May 10.

The single-screw cement carrier. John Wilson, built at Leith for Wilsons (N.Z.) Portland Cement Ltd., of Auckland, is now sailing for New Zealand through the Panama Canal. The John Wilson is a technically interesting ship and thv first bulk cement carrier to use a combination of a screw conveyor and air-slide connexions for both loading and discharging. After machinery and ballast trials on the Firth of Forth the cargohandling equipment was tested in Kent.

Three tandem generators supply the electric power to propel the ship and also the power to drive the selfloading and self-discharging gear. A centre tunnel runs through the ship and contains the airslide connexions with which the cement is transferred from the holds to screw conveyor tubes running on cither side of the tunnel and feeding aerated

cement into pumps to get it ashore. Tire floors of the holds are divided into transverse valleys. At the base of each valley is a canvas-topped duct.

Air is pumped into the duct at a pressure of 41b a square inch and this, as the engineers describe it. “fluidises” the cement. The cement then flows down and along the ducts, up pipes in the central tunnel to the screw conveyor. This in turn directs the aerated cement to the Fuller Kinyon pumps which push it ashore.

Fluid cement will continue to flow for a considerable distance along a shore pipeline. The John Wilson can carry 1750 tons of cement. It is 268 ft. long and has high class crew accommodation. The consulting naval architects, Sir J. H. Biles, designed her and the builders were Henry Robb, Ltd. She was launched on January 18. just three months before completion.