Bath Rugby Union have signed van der Giessen and Fernandez-Lobbe in a double deal. Lobbe, 35, who has 60 international caps and has played in three World Cups, joins from Northampton Saints for the rest of the season.
Van der Giessen, 28, who spent last season with Top 14 side Albi, has signed a three-month contract. Bath were forced to seek reinforcements after an injury to Scott Hobson.
Head coach Steve Meehan said: “Both players will be a valuable addition to the squad at this time when we have injuries in the second row.
Prop David Flatman says that he is feeling the pressure on Bath to deliver. Bath have won just one piece of silverware in the last decade after dominating domestic rugby in the late 1980s and early 1990s.
“There’s more, of course there is,” the England international told BBC Bristol.
“We’re under very positive and ambitious new ownership, have great new training facilities and we have to live up to that.”
Flatman continued: “But I think the real pressure comes from starting another season as a Bath player off the back of a season where we haven’t won anything.
Bath Rugby Union have increased their ground capacity from 11,700 to 12,300 after getting approval from Charity Commission. The ground is owned by Bath & North East Somerset Council as a charitable trust and the commission must oversee the ground’s continued use.
Bath Rugby Union’s chief executive Nick Blofeld said: “We hope to improve the facilities a little each year.”
The rebuilding project is scheduled to start on 16 August.
Meanwhile, Somerset county cricket club have played their first game on a newly-laid wicket at the ground.
England hooker Lee Mears is backing Bath Rugby team-mate Shontayne Hape to shine when the dual-code centre makes his international union debut on Sunday.
Hape, who left Super League side Bradford Bulls two years ago to have a crack at the 15-man game, will start in the number 12 shirt when England take on the Barbarians at Twickenham.
Although a non-cap fixture, the call-up to the starting XV is just reward for Hape’s patience and endeavour.