Guy putting his hands under the garter should not place his hands under it. Use safety at all times.All these years and I’ve been using hand signals or a walkie talkie. Learned something new.That guy putting his hands carelessly under that beam is nuts.It will be more appropriate to mention name of bridge and name of country.The gap between two girders are very small but in india we use I type girders where the gap is 2.10 m. It is big scaffolding reauires to cast slab, where as inyour case it is very easy.