Sperro is an automatic tying machine for fish. In the production of stock fish two fish are tied together and then hanged outdoors to dry. This is a traditional Norwegian product and mainly exported to Italy.

The process of tying fish is called “sperring”. Sperring is a heavy and labor intensive task and especially hard on the shoulders, since each fish weighs between 3 and 6 kg. Sperring is a seasonal job, normally done in February to April.

Sperro can tie 6 pairs of fish per minute (12 fish). In a typical production line setup one person will arrange pairs of similarly sized fish, while the machine operator will feed the fish into the Sperro machine. The finished tied pair is delivered to a bin. The production capacity is approximately 30 tonn per workday.