A special weekend-long convention in Newcastle will mark the milestone in September, including a tour of locations used in the series.
The comedy followed a group of British construction workers overseas, launching in November 1983.
It ran for two series on ITV from 1983 to 1986, before returning on BBC One in 2002. A fourth series followed in 2004, along with a two-part finale special.
Timothy Spall, Kevin Whately, Jimmy Nail and Tim Healy led the cast, along with Gary Holton, Christopher Fairbank and Pat Roach.
Healy - who played team leader Dennis Patterson - is confirmed for the event, along with creator Franc Roddam and writers Dick Clement and Ian La Frenais.
Several other cast members are expected to confirm their attendance in the coming weeks.
"Thirty years, I can't believe where it's gone," said Healy. "We're having