The 'Spiralveyor' is the registered trade name for a range of spiral elevators made by Amberflex Inc. in the USA, tel. 877 800 1624, email info@ambaflex.com. A reason that you may not have heard of the company is that they say that they only supply to equipment manufacturers and system integrators. Machines for handling unit loads are listed as 'Spiralveyor TM'. These are made in versions up to 32" wide and can do high rates of elevating, but are only rated for loads up to 35 kg per item so I would query their use for ship unloading.

I do not know of a manufacturer of heavy duty spiral conveyors for unit items but would expect there are a number of equipment manufacturers that can respond to your requirements. Scorpio Engineering, in Bangladesh, have experience with ship unloaders and specialised handling equipment and may be worth a try. ■