Abstract: A safety apparatus adapted for retrofitting vertical enclosures is shown. The safety apparatus may include a support frame, a grate platform, and telescoping support legs adapted to fasten to an enclosure wall. The apparatus may also include a hinged hatch defining an opening configured to allow a person to be pulled through the platform.

Abstract: The present disclosure relates to a scaffolding and worktable apparatus with pivotally connected end legs, and in particular, to an apparatus that can be modified from a scaffold to a worktable by rotating collapsible end legs from a first position to a second position and an apparatus that can also be stored or used in a flattened configuration by rotating the end legs to a third stored position.

Abstract: A system for constructing a tank which is made up of a plurality of generally rectangular prism sections, which are hinged together on the back side to form a platform, having an end section hinged to a frame section, a cantilever frame extending from the end section, a counterbalance frame attached to said cantilever and extending parallel to the platform and opposed to the end section, with the end section and said counterbalance frame being separated by a pair of saddle wheels mounted to the cantilever frame. At least one additional saddle wheel is mounted on a frame section for cooperative operation with saddle wheels on the cantilever to support the system on the tank wall and to move the platform within the tank wall as it is constructed. The hinge connections between the sections allow the platform to be adjusted to the arc of the internal wall of the tank under construction.

Abstract: A scaffold system includes first and second spaced apart vertical posts. An upper support device mounts at an upper portion of each of the first and second vertical posts and includes spaced apart arms extending in a first direction from the associated vertical post for engaging the side of a building. A lower support device mounts at a lower portion at each of the vertical posts to support one or more planks and includes outriggers extending laterally and in a second direction opposite the first direction. The outriggers include a wheel mounted near an extended end of each of the outriggers to provide for rolling the system to a worksite. The outriggers may be vertically adjusted and combined in multiple combinations and with multiple arm configurations to adapt to uneven terrain.

Abstract: A device for positioning a rope access technician next to a blade of a wind turbine, including a rigid spine, one or more clamp assemblies with each clamp assembly connected to the rigid spine and each clamp assembly capable of clamping to a blade of a wind turbine, and a lower platform connected to a lower portion of the rigid spine with a substantially flat top surface on which a technician may sit, stand or place items.

Abstract: The present invention provides an adjustable ladder and scaffolding system wherein a scaffolding structure provides a support to which is attached a frame. The frame includes a pair of ladder clamps that enable the frame to be connected to the spaced apart risers of a ladder that is to be supported. The frame includes left and right plates and a base opposite the ladder clamps. Adjustable connections are provided between the left and right plates and the base so that the distance between the base and the clamps can be varied, thus enabling the ladder to assume a diagonally extending orientation relative to horizontal. The frame is adjustable so that each frame attached to the ladder shortens the distance between the ladder and the scaffolding structure as the elevation is increased.

Abstract: An aerial work platform apparatus includes a platform adapted to be attached to one end of a boom or a lifting system and a frame coupled to the platform. The frame has a plurality of vertical and horizontal rails, and a plurality of adapters, each adapter being integrally attached to one of the vertical and horizontal rails and receives and secures a tube to the rail. Each adapter includes a sleeve for receiving the tube, at least one fastener for securing the tube to the sleeve, and a connecting unit for integrally connecting the sleeve to the frame.

Abstract: A scaffold includes a first end frame assembly. The scaffold includes a second end frame assembly. The scaffold includes a first side brace assembly supported by the first end frame assembly and the second end frame assembly. The scaffold includes a second side brace assembly supported by the first end frame assembly and the second end frame assembly. Each end frame assembly has a first rail with holes and a caster assembly and a second rail with holes and a caster assembly, and a horizontal that is attached to each rail. Each side brace assembly has a locking pin in proximity to each end which engages with a hole in a respective rail, and an associated guard disposed about each pin. Each locking pin has a handle which has a length that extends below the associated guard on an interior side of the guard. A method for a scaffold.

Abstract: Disclosed is a modular platform comprising a horizontal frame that is made of four angle irons and is devised and sized to receive and support a grid on which one or more persons can stand. Four supporting legs, each made of an angle iron, are respectively connected to the four corners of the frame, and extend below the same in order to maintain it at a distance from the ground. Reinforcing pieces are positioned below the frame and connected to the supporting legs for reinforcing the platform. The platform also comprises at least two thin holding bars extending horizontally between two opposite sides of the frame, in order to support the grid on the frame while preventing it from staying directly on the angle irons forming the frame. Each supporting leg has a lower end provided with a supporting foot that is adjustable in height, and has a lower end of a round shape to reduce the contact surface with the ground. The platform structure makes the platform very easy to clean.

Abstract: A method of manufacturing a treestand platform is disclosed. First, a plurality of treestand components is provided. The treestand components are assembled together to form a treestand platform. The treestand platform is then brazed to bond the treestand components permanently together to form a brazed treestand platform. The treestand platform will generally include a frame having a top surface and a bottom surface and interior portion. A number of rail members are configured and arranged to form a grid pattern with a top edge and bottom edge. The rail members secured within the interior portion of the frame. A top plate secured the frame and the top edge of the plurality of rail members and a bottom plate secured to the frame and the bottom edge of the plurality of rail members.

Abstract: An elevator work deck for use during elevator construction including a first support having a top surface and a bottom surface, and a second support having a top surface and a bottom surface. There are means for positioning the first support and the second support in abutting edge to edge relation so that the top surface of the first support and the top surface of the second support define a planar horizontal working surface when assembled in an operative position. Fastener receivers are positioned on the bottom surface of each of the first support and the second support. There are clamping fastener assemblies engaging the fastener receivers to clamp the first support and the second support to elevator car sling structural beams.

Abstract: A platform assembly (10) is provided having a framework (12) comprising: a plurality of connector nodes (16), each of which has a single leg (18) extending downwards therefrom. A plurality of frame bars (20) extend between the connector nodes (16) and connect thereto by frame ends attached to either end of each frame bar (20). A plurality of platform boards (14) are supported on said framework (12). The platform assembly (10) may have a number of layers (A, B) of framework interconnected to one another in a vertical orientation through the connector nodes (16) and legs (18).

Abstract: A panel-type construction element comprises a substantially rectangular base panel (1), which is particularly suited, for example, for use as a covering for facade scaffolding. Numerous dimples (2) can preferably be configured on the upper face of the base panel parallel to the longer side of the panel and continuous transversal areas (3) that are devoid of dimples and that respectively run at intervals in the longitudinal direction of the base panel are configured over the entire width of the latter. In the areas (3), transversal ribs (7), which project downwards and are connected to the underside and the respective abutting areas of flange surfaces (4) provided on the underside of the base panel to project downwards from the two longer sides of the base panel. The combination of longitudinal and transversal elements permits a simple, rigid and light-weight construction element, which if configured in plastic exhibits excellent weather and corrosion-proof properties and is extremely stable.

Abstract: A coating unit (20), comprising a lift-off protection (25) that is fastened in a face end region (21) of the coating unit (20) and is formed by a securing pivot lever (26), which can be manually pivoted about a pivot axis (27), which in the usage position (22) of the coating unit (20) is vertical, from an open position, in which the coating unit (20) can be placed onto a horizontal carrier (30) or lifted off therefrom, into a closed or lift-off protection position (31), and vice versa, in which the coating unit (20) is secured against lift-off from the carrier (30) when it is placed on the carrier (30).

Abstract: The present invention relates to a method for manufacturing an endless, fibre-reinforced plastic element, wherein a granulate based on a thermoplastic polymer, fibres and possibly other additives are extruded into the element via an extrusion process. The present invention further relates to a fibre-reinforced plastic element obtained by extruding a granulate based on a thermoplastic polymer, fibres and possibly other additives.

Abstract: A scaffold plank and toeboard system provides a fully integrated system where toeboards are easily securable to provide perimeter protection about different working platform configurations. The scaffold advantageously includes a series of securing ports that allow male connectors of the system toeboards, or male connectors of generic toeboard securing brackets to be appropriately placed for maintaining wooden, metal or other toeboard material that is basically fabricated onsite according to the material available. The scaffold securing plank also cooperates with other equipment, guard rails, plank support intermediary ledgers etc. to use the securing ports to simplify installation and securement thereof.

Abstract: A scaffolding support platform for use with a scaffolding system including a fabricated end frame including a floor having a flat surface adapted to support a worker and a support frame including a base for supporting the floor, a plurality of anchors to releasably attach the support frame to a fabricated end frame and a plurality of support members extending between the base and at least one anchor.

Abstract: A scaffold system includes at least two essentially vertical support assemblies having an upper end and a lower end, wherein each essentially vertical support assembly includes at least two vertical support members connected by at least one horizontal member. A platform is attached proximate to the upper ends of the at least two essentially vertical support assemblies, wherein the vertical support assemblies are positioned to be proximate to a structure. One or more gap fillers are movably attached adjacent to the platform along at least a portion of the platform length and are configured to extend at least a portion of the platform towards the structure. One or more movable gates are attached to the essentially vertical support assemblies of one or more movable scaffolds, wherein the movable scaffolds are configured to be positioned on opposite sides of the structure to enable access to a top of the structure, and the movable gates may be connected to each other over the top of the structure.

Abstract: A ladder support and bracing apparatus includes a panel that has a top side, a bottom side, a first end, a second end, a first lateral side and a second lateral side. Each of a pair of lips is attached to and extends upwardly from the top side and each is coextensive with one of the first and second lateral sides. A vertical support is hingedly coupled to the bottom side and is positioned adjacent to the first end. The panel is substantially horizontally orientated when the vertical support is vertically orientated. The bottom side of the panel adjacent to the second is positioned on a step and the vertical support adjusted to horizontally orientate the panel. A ladder is then positioned on and supported by the panel.

Abstract: An adjustable, articulable platform, changeable to and from a “U” shape to an “H” shape, is attachable to the distal end of an articulable support arm of a transport vehicle. The platform is arranged to adjustably surround an elevated chimney on at least three sides thereof. The platform comprises: a lower anchor plate centrally disposed within an elongated lower support frame; a rear anchor plate connected perpendicularly to the lower anchor plate, the rear anchor plate centrally and connectively disposed within an elongated rear wall frame, comprising bridging portions of the platform. A right sidewall frame and a left sidewall frame is connected to respective end portions of the elongated rear wall frame.

Abstract: A climbing device having a main support member with a pair of ancillary support members connected to and extending outwardly at an angle from the main support member. The main support member has a brace at one end and a stop at the opposite end. A pair of cable supports are pivotally attached to the ancillary supports. The cable supports have slots that receive stops on a cable to releasably attach the cable to the climbing device.

Abstract: Self-closing, flexible trap door for access platforms, enabling its use as a work surface, consisting of a rubber body, fixed to the access platform, strengthened by a cross-directional rigid reinforcement, fitted with a tape to facilitate opening and a lock when being transported and assembled. Closing is caused by the pressure of the rubber. Additionally, the closing is caused by an externally-driven mechanism or by means of magnets.

Abstract: A movable scaffold (20) has one or more fixed work platforms (21). The scaffold frame element has four upright tubular corner members (1) connected by tubular cross-members (2, 2a, 2b). Each tubular corner member has a bottom end provided with a wheel (15) for allowing a displacement of the scaffold. The scaffold is provided with elements for adjusting its height. Between each tubular corner member (1) and the wheel (15) at its bottom end are provided vertical adjustment elements (5) to enable an individual vertical adjustment of each wheel relative to its associated tubular corner member (1) while effecting a displacement of the scaffold (20), the scaffold being thus safely movable even on rough foundation.

Abstract: The claimed work platform system, alternatively dubbed by the inventor as “Miniscaffold”, provides a compact, versatile, and portable method of supporting workers engaged in various elevated construction or maintenance activities. The claimed work platform rides upon a number of locking floor casters. Each floor caster is mounted to a removable, telescoping support which may be readily relocated inward to accommodate access through narrow aisles or outward to enhance the platform's stability. Each telescoping support is also fitted with an individual jack mechanism to compensate for the inevitable variations in ground or floor elevation typical at construction or work sites. The “Miniscaffold” is also constructed from interlocking square tube members which enhance the work platform's stability and thus eliminate the obtrusive and cumbersome diagonal supports found on most scaffolding.

Abstract: A rib bay platform for use in an aircraft rib bay, is adjustable in length (for example it comprises two telescopically mounted sections. The platform comprises a first end configured for mounting on a stringer of the rib bay (for example by an interference fit), and a second end configured for mounting on another stringer of the rib bay (for example on feet mounted on ball-and-socket joints). A method of operating in an aircraft rib bay comprises the steps of providing a rib bay platform of adjustable length; adjusting the length of the platform; mounting the platform between the two stringers; whereby a person may then operate inside the aircraft rib bay whilst being supported on the platform.

Abstract: An aerial work platform apparatus includes a platform adapted to be attached to one end of a boom or a lifting system and a frame coupled to the platform. The frame has a plurality of vertical and horizontal rails, and a plurality of adapters, each adapter being integrally attached to one of the vertical and horizontal rails and receives and secures a tube to the rail. Each adapter includes a sleeve for receiving the tube, at least one fastener for securing the tube to the sleeve, and a connecting unit for integrally connecting the sleeve to the frame.

Abstract: The support apparatus is principally directed to a planar structure which will support a workman when working above a ceiling with steps provided only by joists. The support apparatus is planar having handles at each side and each end. The apparatus folds about a hinge which is intermediate the ends. Notches at the bottom side are spaced to standard residential construction for joists to give the support apparatus greater stability when in use.

Abstract: A scaffold plank assembly for engagement to a scaffolding frame. The scaffold plank assembly comprises an elongate, non-metal plank defining opposed first and second ends and at least one interior cavity. Attached to respective ones of the opposed ends of the plank is a pair of end connectors. Each of the end connectors comprises a main body defining an arcuate body engagement surface, and at least two arms which are attached to the main body. Each of the arms also defines an arcuate arm engagement surface which is substantially continuous with the body engagement surface. Attached to and extending from the main body is at least one attachment finger which is extensible into the interior cavity of the plank. The body and arm engagement surfaces are sized and configured to be cooperatively engageable to the scaffolding frame.

Abstract: A platform (11) for use as a temporary support structure, said platform comprising an expanse of netting (13) having a border rope (15) fitted thereto around the outer periphery thereof, and at least one inner rope (19, 21, 23) fitted to the netting (13), extending around, inside and spaced from the border rope (15), and spaced from any other at least one inner rope (19, 21, 23).

Abstract: A scaffold securing device for securing scaffold boards. The device includes: first elongated arm member, an L-shaped second elongated arm member, a chain member, and an elongated connection member. The first elongated member includes two arm member end and an aperture. The L-shaped second elongated arm member is rotatably coupled to the first elongated arm member and includes: a pair of arm portions and an aperture. The elongated arm members are substantially flat. The chain member is coupled to the first elongated arm member. The elongated connection member, in the form of a swivel pin, connects the elongated arm members together by insertion through the apertures. The swivel pin includes an elongated body portion, a head portion, and an elongated lock portion. The second elongated arm member is rotatably coupled to the second arm member end of the first elongated arm member by hinging.

Abstract: An adjustable, articulable platform, changeable to and from a “U” shape to an “H” shape, is attachable to the distal end of an articulable support arm of a transport vehicle. The platform is arranged to adjustably surround an elevated chimney on at least three sides thereof. The platform comprises: a lower anchor plate centrally disposed within an elongated lower support frame; a rear anchor plate connected perpendicularly to the lower anchor plate, the rear anchor plate centrally and connectively disposed within an elongated rear wall frame, comprising bridging portions of the platform. A right sidewall frame and a left sidewall frame is connected to respective end portions of the elongated rear wall frame.

Abstract: The present invention relates to a panel comprising two parallel skin plates made of wood or a wood material, between which ribs extend for stiffening the panel, wherein the ribs are at least substantially made of wood or a wood material. The present invention further relates to the use of such a panel as a scaffolding board or a construction element and to scaffolding provided with such panels.

Abstract: A scaffolding plank includes a frame, a plank secured atop the frame, and hook members secured to the frame at a respective corner thereof. The frame includes a first longitudinal support, a second longitudinal support, and a third longitudinal support disposed between the first longitudinal support and the second longitudinal support. The frame further includes a first end support secured at first ends of the first, second, and third longitudinal supports and a second end support secured at second ends of the first, second, and third longitudinal supports. The frame still further includes a first center support secured between the first and third longitudinal supports offset from the midpoint of the frame and a second center support secured between the second and third longitudinal supports offset from the midpoint of the frame.

Abstract: A scaffold assembly comprising at least one pair of hook-on scaffold elements; said scaffold elements adapted for support of at least one builder's plank; each of said elements comprising a vertical main shaft provided with a hook structure at an upper end of said main shaft and a securing bracket at a lower end of said main shaft; each of said hook-on scaffold elements further comprising a braced hook-on arm; said hook structure adapted for engagement with a horizontal top plate of a building frame, and said securing bracket adapted for engagement with a vertical stud or a horizontal element of said building frame.

Abstract: A movable platform for supporting a load alongside a structure has an attached catch. The movable structure includes a base having an inboard side and an opposite outboard side, an inboard support extending away from the inboard side of the base, an outboard support extending away from the outboard side of the base, and a catch connected to both the inboard support and the outboard support and passing beneath the base, so that an object dropped over an inboard or outboard edge of the base will be caught by the catch. The inboard support is attached to the base so that a distal end of the inboard support is movable with respect to the base. The distal end is maintained to be in contact with the building exterior. Also described is an accessory for a preexisting movable platform that allows the arms and catch to be attached.

Abstract: An elevated work platform to support workers thereon comprising a plurality of support sections held in operative relationship relative to each other by a peripheral frame wherein each support section comprises a plurality of transverse support members held in spaced relationship relative to each other by a plurality of longitudinal members and the peripheral frame comprises a pair of side frame members each including a channel to receive opposite end portions of the transverse support members of each support section to hold the support sections in operative position relative to the other support sections.

Abstract: An adjustable, articulable platform, changeable to and from a “U” shape to an “H” shape, is attachable to the distal end of an articulable support arm of a transport vehicle. The platform is arranged to adjustably surround an elevated chimney on at least three sides thereof. The platform comprises: a lower anchor plate centrally disposed within an elongated lower support frame; a rear anchor plate connected perpendicularly to the lower anchor plate, the rear anchor plate centrally and connectively disposed within an elongated rear wall frame, comprising bridging portions of the platform. A right sidewall frame and a left sidewall frame is connected to respective end portions of the elongated rear wall frame.

Abstract: A composite scaffolding plank made from a plurality of wooden boards positioned in side to side parallel abutment. A plurality of spaced pins extend transversely through the wooden boards. A cam means on the pins pulls and holds the boards together. In one preferred embodiment where the plurality of wooden boards are from a single board that is ripcut, the strength of the wooden plank is increased by cutting the plank longitudinally, positioning the resulting sections in side to side parallel abutment with the wood grains alternating directions, and to subsequently embedding a plurality of spaced pins in the sections.

Abstract: Method for mounting a scaffolding board and scaffolding board (1) including a section (2) with a substantially flat surface for persons staying upon this surface, and including a fitting with hooks (5) at the end of the section (2), where the hooks (5) are provided with downwards directed recesses for securing the assembled scaffolding board (1) on a transverse beam. The section (2) extends approximately to the centre (9) of the recess (8) to cover half of the transverse beam (7) when the scaffolding board (1) is placed on the beam (7).

Abstract: An elevated work platform to support workers thereon comprising a plurality of support sections held in operative relationship relative to each other by a peripheral frame wherein each support section comprises a plurality of transverse support members held in spaced relationship relative to each other by a plurality of longitudinal members and the peripheral frame comprises a pair of side frame members each including a channel to receive opposite end portions of the transverse support members of each support section to hold the support sections in operative position relative to the other support sections.

Abstract: A step for temporary installation upon slopes, comprising a step board (1) pivoting around its horizontal axis and provided with tilting struts (9) for adjusting the angle between the plane of the board and the plane of the slope, bears at its rear side lateral pin joints (2) attaching rails (3) whose bottom side is provided with means for fixing to the slope.

Abstract: A step stool nestable for stacking is formed vertically tapered with the smaller end closed to form a horizontal stepping surface. The interior of the shell has attachment surfaces faces upon which the casters are attached for use. Initially the casters are mounted on the undersurface of the closed end to permit stacking of the stools for bulk transport or shipment in quantities. Upon separating the stools in the stack, the user removes the platform and casters from the undersurface of the closed end and attaches them to attachment surfaces in the shell. In the disclosed embodiment a platform member is attached to the shell and the casters mounted on the platform member. In the disclosed embodiment, the casters and platform member are enclosed in a container and releasably secured to the undersurface of the closed end of the shell for stacking.

Abstract: An assembly of portable platforms is mounted and connected together on a ladder to provide a working platform.

Abstract: A multilevel access platform comprising a plurality of stackable modules. Each module includes elongated column members that are generally parallel and coextensive, and a plurality of levels of elongated lateral members that extend transversely between and are connected to the column members. Each level of the lateral members is located at vertically spaced positions relative to the column members and each of the lateral members border a side of the module. At least one platform section is provided for each level and is supported by one level of the lateral members. The stackable modules include a staircase that extends between each level of the lateral members. The multilevel access platform includes a base assembly provided to stabilize and independently secure the multilevel platform. A method for erecting the multilevel access platform includes the step of stacking each module to meet a desired height of a building construction.

Abstract: An outrigger assembly includes at least one support unit including a first elongated support arm and a second elongated support arm cantilevered and secured to the first support arm. A joist-supporting arm is removably engaged with the front end portion. The assembly further includes an upper support arm cantilevered and secured to the first support arm. A support member having opposed end portions is secured thereto and to the first support member. The upper support arm includes a plurality of L-shaped members mated along an edge thereof. An elongated board is positionable between adjacently disposed rear end portions. The front end portion exerts an upward force against the work area joists while the upper support arm exerts a downward force against a top surface of the work area such that the forces become balanced.

Abstract: Holding hook for a mutual blocking position retaining of a first type of a scaffold elements (4) at a second type of scaffold elements (5) in a scaffold and consisting of a holding part 811) that relative to an axis (9) is pivotally applied to a fixed holding part (2). This pivotally applied holding part (11) is shiftable between a holding position in which the pivoted holding part is blocked and a releasing position for the scaffold elements. The pivoted holding part (11) is also displaceable along the axis (9) and is equipped with a blocking part (13), that at a first axial displacement position in the blocking position of the holding hook blocks the pivoted holding part in its holding position by impace towards a fixed blocking surface (27) in the fixed holding part. In a second axial displacement position outside the blocking surface (27), the pivoted holding part is allowed to be shifted to a releasing position.

Abstract: A platform structure has at least two articulated platforms that can extend end-to-end to form a bench type arrangement. For ease of portability, the structure includes wheels so that it can be carted when it is in a stow position. The structure can include a detachable canopy frame and a canopy, which provides protection from the element, namely rain, snow, sun, and wind. The canopy can have a camouflaged pattern so that it can blend into the surrounding. When the canopy is camouflaged, the structure is instantly converted into a hunting blind. In addition, a mounting mechanism is provided to mount the platform structure to another structure.

Abstract: A scaffold plank assembly for engagement to a scaffolding frame. The scaffold plank assembly comprises an elongate, non-metal plank defining opposed first and second ends and at least one interior cavity. Attached to respective ones of the opposed ends of the plank is a pair of end connectors. Each of the end connectors comprises a main body defining an arcuate body engagement surface, and at least two arms which are attached to the main body. Each of the arms also defines an arcuate arm engagement surface which is substantially continuous with the body engagement surface. Attached to and extending from the main body is at least one attachment finger which is extensible into the interior cavity of the plank. The body and arm engagement surfaces are sized and configured to be cooperatively engageable to the scaffolding frame.

Abstract: A scaffold plank assembly for engagement to a scaffolding frame. The scaffold plank assembly comprises an elongate, non-metal plank defining opposed first and second ends and at least one interior cavity. Attached to respective ones of the opposed ends of the plank is a pair of end connectors. Each of the end connectors comprises a main body defining an arcuate body engagement surface, and at least two arms which are attached to the main body. Each of the arms also defines an arcuate arm engagement surface which is substantially continuous with the body engagement surface. Attached to and extending from the main body is at least one attachment finger which is extensible into the interior cavity of the plank. The body and arm engagement surfaces are sized and configured to be cooperatively engageable to the scaffolding frame.

Abstract: An extensible, self locking platform includes a first assembly having a first plurality of substantially parallel longitudinally extending members and a second assembly having a second plurality of substantially parallel longitudinally extending members. The first and second assemblies are longitudinally, slidably coupled with each other. The platform may also include one or more catch devices. In one embodiment, at least one catch member is pivotably coupled to the first assembly with an associated stop member. The stop member is configured to maintain a rotation of the at least one catch member at less than a full revolution such that when the catch member is being abutted against an elevated support structure and the platform is being laterally displaced relative thereto, the catch member will also abut the stop member and prevent further displacement of the platform relative to the elevated support structure.