Abstract: A stringer for a modular scaffolding system. The stringer has a lower base, a web extending upwardly from the lower base, and a channel extending upwardly from the web, the channel having at its upper edge a pair of base flanges extending outwardly therefrom and having along a length of its inner wall a flange, wherein an insert shaped complementary to the channel and having a recess disposed along its length complementary to the flange is slidable into the channel.

Abstract: A hoisting apparatus (10) for use at a manhole (1), comprising a supporting mast and a jib crane (14) connected at an angle to an upper end portion (16) of the supporting mast (12). The jib crane (14) has a front member (18) pointing upwardly and extending on one side of the supporting mast (12) and a rear member (20) having a rear end section (22) extending on another side of the supporting mast (12). A linking rod (24) is connecting the rear member of the jib crane (14) to the supporting mast (12). The apparatus further comprises a winch mechanism (30) mounted onto the jib crane (14) and having a cable (32) cooperating with the front member (18) of the jib crane (14) for hoisting an object from the manhole (1). In a preferred embodiment, the apparatus comprise a security fence (40) for surrounding at least partially the manhole (1) and preventing accidental entry therein, the supporting mast (12) being part of the fence.

Abstract: A hoisting apparatus (10) for use at a manhole (1), comprising a supporting mast and a jib crane (14) connected at an angle to an upper end portion (16) of the supporting mast (12). The jib crane (14) has a front member (18) pointing upwardly and extending on one side of the supporting mast (12) and a rear member (20) having a rear end section (22) extending on another side of the supporting mast (12). A linking rod (24) is connecting the rear member of the jib crane (14) to the supporting mast (12). The apparatus further comprises a winch mechanism (30) mounted onto the jib crane (14) and having a cable (32) cooperating with the front member (18) of the jib crane (14) for hoisting an object from the manhole (1). In a preferred embodiment, the apparatus comprise a security fence (40) for surrounding at least partially the manhole (1) and preventing accidental entry therein, the supporting mast (12) being part of the fence.