With regards to temporary fencing you can't get a much stronger panel than a round top panel which has a centre bar.
This Round Top Temporary Fencing Panel With Centre Bar is made from a 38mm thick steel frame with a 38mm thick steel bar going down the centre for increased stability. This provides the panel with added strength, durability and rigidity.
Visit the First Fence Ltd website for more information on Round Top Temporary Fencing Panel With Centre Bar