Built for world-wide ocean trade by Canada Steamship Lines (CSL), the CSL Innovator is a Panamax-class self-unloading vessel. (Panamax-class refers to a ship that has a dead weight of between 60,000 and 70,000 tons and is capable of traversing the Panama Canal.)
CSL’s new vessel had to be capable of transporting and discharging a wide range of materials. Typical free-flowing products include grain, iron ore pellets, and aggregates. Cohesive products include wet ores, concentrates, and cohesive coals. Fine, dry, dusty products include alumina and possibly cement. Products that cake include salt, potash, and sugar. Many products are single sized, but others, like gypsum, can contain large, slabby lumps.
The configuration of holds and hoppers had to maximize the useable volume in a Panamax-class vessel. In order to maximize useable volume, it was necessary to use a three-belt withdrawal configuration rather than a conventional two-belt system. Also, the hopper slopes had to be kept as shallow as possible, yet be capable of handling cohesive/adhesive cargos.
The vessel was designated with 240 gates. Gate configurations had to take minimal headroom. In addition, each gate had to provide good flow control for a wide range of free-flowing and non free-flowing cargos. Finally, it had to be cost effective, easy to construct, and mechanically robust.
The Solution
Personnel in Jenike & Johanson’s office in Toronto, Canada, worked closely with CSL designing viable hopper and gate configurations.
Flow property results obtained for a very cohesive iron ore concentrate were used as the design basis material. Jenike & Johanson considered many gate design concepts, constructed working models and performed flow pattern tests. Eventually, we developed a new gate of the “basket” or “swing” gate type in conjunction with Consilium CMH Marine AB.
The Result
The new ship, aptly named the CSL Innovator, has been in continuous service since September 1988. To date, the performance of the new hold configuration and gate design has been exceptionally good and has far exceeded industry expectations.
