Fastening device for ground protection mats

A fastening device to releasably interconnect ground protection mats comprising:

• a first part of a connection mechanism having a male part;
• a second part of the connection mechanism having a female part with a bore to receive the male part and configured to connect at least two neighbouring ground protection mats side-by-side by rotation of the male part relative to the female part;
• the male part comprises a first helical rib projecting radially outward from a shaft and the female part comprises a second helical rib projecting radially inward at the bore configured to receive the shaft, the ribs configured to abut one another, an axial length of the first helical rib being in the range 70% to 150% of a pitch of the first helical rib;
• an axial and radial lock having a first element at the rib of the male part and a second element at the rib of the female part, the first and second elements configured to engage one another by the rotation of male part relative to the female part;
• and
• a bias lock actuator to impose an axial force to the first element to force the first element in engaged contact against the second element and to provide frictional resistance to further rotation of the male part relative to the female part.