A portable safety rail system includes one or more railings inserted into one or more stackable rail bases. Each rail base can include a plurality of apertures for receiving end rail posts of railings through a raised hub defining an open region between the bottom of the hub and the surface on which the rail base rests. Each end rail post can have a stop flange that engages an upper surface of the hub when inserted therein and an aperture through the end portion that extends into the open region beneath the hub for receiving a pin to lock the post while allowing rotation of the post. The system can also include toe boards that are attached to railings with a mount having an aperture through which railings are extended, allowing the toe boards to also be rotated to be aligned with railings.

A method of operating an incursion warning system for a work zone, the incursion warning system comprising: a plurality of sensor units arranged about a perimeter of the work zone; and a plurality of alarm units each comprising one or more of an audio, visual or haptic alarm operable to warn a workforce of a potential danger in response to a detected breach into the work area; the method comprising: establishing a geo-zone delimiting a geographical area that includes at least part of the work zone; and a set of rules associated with the geo-zone; deriving an instruction for one of the alarm units determined to be in the geo-zone from the set of rules based on a characteristic of the alarm unit and a characteristic(s) of one or more other alarm units determined to be within the geo-zone; and wherein the instruction is derived in response to a change in a characteristic of the alarm unit and/or the one or more other alarm units and/or one or more of the sensor units within the geo-zone.

A method of operating an incursion warning system for a work zone, the incursion warning system comprising: a plurality of sensor units arranged about a perimeter of the work zone; and a plurality of alarm units each comprising one or more of an audio, visual or haptic alarm operable to warn a workforce of a potential danger in response to a detected breach into the work area; the method comprising: establishing a geo-zone delimiting a geographical area that includes at least part of the work zone; and a set of rules associated with the geo-zone; deriving an instruction for one of the alarm units determined to be in the geo-zone from the set of rules based on a characteristic of the alarm unit and a characteristic(s) of one or more other alarm units determined to be within the geo-zone; and wherein the instruction is derived in response to a change in a characteristic of the alarm unit and/or the one or more other alarm units and/or one or more of the sensor units within the geo-zone.

A retractable cylindrical safety marker is provided. The retractable cylindrical safety marker includes a base, having a middle section defining an upper planar surface and two opposing edges; a first end section rotatably attached at an end to one of the opposing edges; and a second end section rotatably attached at an end to the other of the opposing edges, and a vertical riser, having a lower riser having a lower end attached to the first end section and the second end section, the lower riser having a slot extending along its interior surface in the longitudinal direction; and at least one upper riser concentrically positioned within the lower riser, the upper riser having a tab positioned on an outer surface thereof, the tab being mateable with the slot and configured to permit the tab to translate along the slot.

A retractable cylindrical safety marker is provided. The retractable cylindrical safety marker includes a base, having a middle section defining an upper planar surface and two opposing edges; a first end section rotatably attached at an end to one of the opposing edges; and a second end section rotatably attached at an end to the other of the opposing edges, and a vertical riser, having a lower riser having a lower end attached to the first end section and the second end section, the lower riser having a slot extending along its interior surface in the longitudinal direction; and at least one upper riser concentrically positioned within the lower riser, the upper riser having a tab positioned on an outer surface thereof, the tab being mateable with the slot and configured to permit the tab to translate along the slot.

There is provided a structure support arrangement for supporting a structure, the structure support arrangement comprising: a body member; a nesting formation defined on the body member and configured to prevent lateral movement of the structure support arrangement in at least one transverse direction when the structure support arrangement is nested with a further structure support arrangement; and a post receiving formation defined on the body member and configured for receiving a support post to support the structure.

A retractable cylindrical safety marker is provided. The retractable cylindrical safety marker includes a base, having a middle section defining an upper planar surface and two opposing edges; a first end section rotatably attached at an end to one of the opposing edges; and a second end section rotatably attached at an end to the other of the opposing edges, and a vertical riser, having a lower riser having a lower end attached to the first end section and the second end section, the lower riser having a slot extending along its interior surface in the longitudinal direction; and at least one upper riser concentrically positioned within the lower riser, the upper riser having a tab positioned on an outer surface thereof, the tab being mateable with the slot and configured to permit the tab to translate along the slot.

A retractable cylindrical safety marker is provided. The retractable cylindrical safety marker includes a base, having a middle section defining an upper planar surface and two opposing edges; a first end section rotatably attached at an end to one of the opposing edges; and a second end section rotatably attached at an end to the other of the opposing edges, and a vertical riser, having a lower riser having a lower end attached to the first end section and the second end section, the lower riser having a slot extending along its interior surface in the longitudinal direction; and at least one upper riser concentrically positioned within the lower riser, the upper riser having a tab positioned on an outer surface thereof, the tab being mateable with the slot and configured to permit the tab to translate along the slot.

A base for a subterranean fence post which includes a body with a ground-engaging surface and a mechanism for mounting a lower end of the fence post to the body wherein a footprint of the surface is sufficient to provide lateral support to maintain the post in an upright orientation and a mass of the body is sufficient to stabilize the upright post.

A base for a subterranean fence post which includes a body with a ground-engaging surface and a mechanism for mounting a lower end of the fence post to the body wherein a footprint of the surface is sufficient to provide lateral support to maintain the post in an upright orientation and a mass of the body is sufficient to stabilize the upright post.