Bilboes were long iron bars which were attached to prisoners legs to stretch them apart and making it impossible for them to run away and escape.
Because they had a sliding shackle it made it almost impossible for the prisoner to stand not alone walk. The word ‘Bilboe’ derived from Bilboa, as this country was best known for it’s steel.
The bilboes were also known humorously as ‘Garters’ but they obviously having nothing to do with women’s lingerie!