| Horizontal Cable Systems | Rigging Sleeves |Monorails | Roofcars |

Horizontal Cable Systems

cable spec

A horizontal cable system is a permanently installed fall protection system typically consisting of two terminating roof anchors connected by a galvanized steel or stainless steel wire rope. Summit Anchor Co. offers horizontal cable systems to provide fall restraint or that can be designed to be used for anchorage in difficult areas of a complete building rope descent system package.

Horizontal Fall Restraint Cable System

The ANSI/IWCA I-14.1 Window Cleaning Safety Standard requires fall protection whenever a worker must travel within 6 feet of a vertical drop. Fall protection may be in the form of a code-compliant guardrail or parapet. When such code-compliant perimeter guarding does not exist and cannot be installed, a horizontal fall restraint cable system may be the best option for providing fall protection.

This horizontal cable system is designed to restrain workers from reaching a roof edge, thereby preventing them from falling off an elevated surface. Summit Anchor Company’s horizontal fall restraint cable system can safely allow up to two workers continuous horizontal movement across spans of up to 150 feet when intermediate anchors are evenly spaced along the span. Below is an example of how a horizontal fall restraint cable system may be utilized.

Horizontal Cable for Rope Descent System

This horizontal cable system is designed to allow a maintenance worker to descend in areas of a building where anchorages cannot be placed so that the angle between independent ropes does not exceed the maximum 15 degrees allowed in the ANSI/IWCA I-14.1 Window Cleaning Safety Standard. As shown in the photograph below, when horizontal cables are used for rope descent, they must be installed in pairs so that a worker can attach a suspension rope to one cable and a fall arrest rope (lifeline) to another cable. One horizontal cable shall never be used to simultaneously secure a worker’s suspension rope and fall arrest rope. The anchors between which each cable spans may be placed no more than 30 feet apart. Because a total of four anchors are required for each descent, this system is generally not economical and therefore should only be used when unique building features do not allow a worker to tie a suspension rope and a fall arrest rope to independent anchorages and maintain the required 15 degree angle.

OSHA states the following concerning horizontal lifelines:
“Horizontal lifelines may, depending on their geometry and angle of sag, be subjected to greater loads than the impact load imposed by an attached component. When the angle of horizontal lifeline sag is less than 30 degrees, the impact force imparted to the lifeline by an attached lanyard is greatly amplified...For these and other reasons, the design of systems using horizontal lifelines must only be done by qualified persons.” (1910.66 App. C Personal Fall Arrest System, Section III(h)6)

NOTE:
Due to the potential for misuse of horizontal cables in day-to-day field operations, portable cables would never be used for this application. Workers shall only use permanent horizontal cable systems that have been specifically designed by a Professional Engineer with a background in such applications. These systems shall also be installed in the field by a qualified person, and instructions for proper use must be readily available on the site.

Rigging Sleeves

Building designers who want to provide safe access for the maintenance worker may encounter difficulties where certain building features make various areas seem inaccessible. Rigging sleeves can provide a solution when the following features exist:

Overhangs
Skylights
Rotunda ceilings
Sloped roofs
High parapet walls
High penthouse walls

Rigging sleeves are engineered to allow the maintenance worker to gain access through such building features. They accomplish this by providing a passageway through which the worker can safely feed his rigging suspension lines.

How they work...

After securing his lifeline to an independent anchor, a maintenance worker simply ties his suspension line to the steel rod on the top of the rigging sleeve, removes the rigging sleeve cap, suspends both lines through the rigging sleeve, then returns to a lower level where a platform is located to secure himself and the platform to the suspension and lifelines.

Typical rigging sleeve application for overhangs, showing suspension and lifelines safely rigged on the roof .

Safety lines have been fed through rigging sleeves and secured to a platform below, providing access to this area beneath an overhang.

Advantages of Summit Anchor Co. rigging sleeves:

Our rigging sleeves are designed with a steel cap and installed in a way to ensure the building remains watertight, despite roof penetrations.
Our rigging sleeves are completely hot-dipped galvanized after fabrication to resist corrosion.
Our rigging sleeves have been engineered and tested to comply with current OSHA and ANSI I-14.1 safety standards for fall arrest and suspended maintenance.
Many installation methods are available to suit reinforced concrete or structural steel structures.
In addition to our standard vertical design, curved, horizontal, and recessed rigging sleeves are also available to suit almost any application.

Monorails

Monorails offer an alternative to rigging sleeves to provide safe access to hard-to-reach building areas. Monorails provide continuous horizontal movement and may offer design solutions where the following features exist:

Overhangs/Cornices
Atriums
Interior curtain wall

Monorails can be used to support suspended powered platforms, one-man cages, or one-man rope descents. Monorails may be preferred where spaces do not allow for access through building features or where minimal penetrations are desired. Use of a monorail for suspended maintenance could reduce the number of times suspension and fall arrest ropes have to be pulled up and down the building face, reducing wear and the chance of hardware damaging windows or building facades.

Monorails incorporate a track, which typically runs along the facade of a building; a trolley, which can move freely along the track; and supports located at intervals, which secure the track to the building. The track can be straight or curved, with a minimum 3'-0” radius, to fit any space or go around corners. The design must be able to incorporate fall protection for maintenance workers to safely approach and rig to the monorail as well as an anchorage point to which the worker can secure his lifeline. Typically, access is gained to the monorail through an operable window, hatchway, or an adjoining safe surface such as a setback or rooftop.

A monorail used to gain access beneath an overhang

Roof Cars

Roof cars are a permanently attached, motorized building system designed to suspend a working platform and provide for both horizontal and vertical movement to working positions. They are individually designed around unique building features to access the exterior (and, in some cases, the interior) of a building. Powered equipment is required for use on new buildings over 300 feet in height, when rope descents are prohibited by the ANSI/IWCA I-14.1-2001 Window Cleaning Safety Standard.
On some structures, use of a roof car system can reduce rigging time in the building maintenance cycle; therefore, building height is not the only factor to consider when choosing the best exterior façade maintenance system for a particular building. However, above 490 feet, a roof car is essentially required, as the hoist motors for the powered platform must be located on the roof, as shown in this photo.

Summit Anchor Co. does not manufacture a roof car as part of our product line, but has chosen to team with some of the world's best manufacturers specializing in rooftop machinery to provide this solution where required. If your building's height exceeds 300 feet, or it has special architectural features that make other access difficult, we hope you will find the following information about roof cars helpful.

How they work:

A man-rated platform is suspended by means of cables from a boom that is connected to a roof mounted carriage. Powered roof cars have controls located inside the platform which allow the operator to position the platform directly above where it is to drop down along the building. The operator can use the controls to perform various tasks, such as the following:

Ascend/Descend
Telescoping and/or Luffing the boom
Horizontal Drive (along the rooftop to access vertical drop locations)
Swivel/Tilt
Emergency (non-powered) descent

Typically, a roof car assembly is self contained and does not require building maintenance contractors to bring additional suspension equipment to the roof. Roof car booms can be designed to clear terraces or lower roofs, eliminating the need for additional suspension equipment. As this equipment is really a building system, it must be regularly maintained by factory-trained and approved technicians. This maintenance usually requires a scheduled approach that usually involves a maintenance contract to ensure that all factory-required maintenance is completed as an ongoing practice.

Common roof car considerations:

Rooftop Support: Depending on roof surface and structure, roof cars may be mounted at a fixed point on the roof and swivel/telescope, or they may travel on runways or steel tracks.

Platform: Platform-mounted hoists may be used with a rooftop carriage (anchorage) up to 490 feet. This is allowed, but not required, as wire rope weight, voltage drop to the hoists, fall protection, and platform stabilization issues may make roof-mounted hoists a more reliable option at heights below the 490 feet requirement.

Roof-mounted hoists are required above 490 feet. This provides for a lighter weight platform gondola. Controls are commonly hardwired to the rooftop hoists so workers are in full control of the platform functions. As noted above, this system is commonly found to be more practicable on buildings below the 490 feet threshold as well.

Stabilization: To avoid dangerous swaying in the wind during operation, a stabilization system must be designed into the building facade, ensuring that the platform is engaged to the face of the building. Commonly, this is either a continuous track mounted on the building face, where the platform can engage when traveling vertically, or an intermittent system of buttons that can be attached to the suspension cables at approximately every three floors of vertical travel.

Fall Protection: Fall protection must be addressed in every roof car installation. Various state, city, and other municipality regulations must be known and complied with. Powered platforms commonly include either two wire ropes per hoist motor (requiring the operators to tie off to the platform structure), or single suspension ropes at each hoist motor and provision for independent safety lines rigged to anchors on the roof (See Summit Anchor Co. Roof and Wall Anchors). Roof-mounted hoist systems are designed with anchorages and suspension ropes with sufficient strength to provide for fall protection, and users must be tied off to the platform structure.