Transshipment of coal was - and still is - big business in the Rotterdam port. One part of this business was the import of German coal to be used as fuel for steam driven ships. Leading in this business in Rotterdam was the so called 'Steenkolen Handels Vereniging' (to be translated into 'Coal Trading Company') which had the monopoly of trading German coal. To lower the costs of labour needed for the transshipment of coal, the company invested in this coal bunker machine. It was especially designed to provide seagoing steamships with a large amount of coal in the shortest possible time. The machine, called 'Pluto', was able to transfer 250 tonnes of coal per hour. The machine was manned by seven persons. If done by hand it would have cost no less than 250 dockworkers to do the job in the same time. At left in the picture of the model you see the so called dredger transporter which dredged the coal out of the hold of the lighters that transported the coal down the river from Germany. After that the coal passed through a funnel and ended up a conveyor belt - right in the picture. At the end of it there is a chute to deposit the coal in the seaships bunkers. Measures of the model (lxwxh): 164 x 73 x 107 cm.