Tie Down Blog

What is a Mobile Fall Arrest System?

A worker on a roof tied off to a safety harness and anchorage point

Mobile fall protection utilizes tools or equipment that provide temporary fall protection solutions. A mobile fall arrest system allows workers to comply with OSHA Fall Protection standards even when a permanent anchorage point is not available.

Anyone in the construction industry knows the leading cause of death and serious injury on the job site is falls. The need for practical and reliable fall safety solutions has established traditional fall arrest features like anchor points. The evolution of fall protection systems introduces convenient and flexible options, like mobile fall protection. 

Two workers attached to mobile fall arrest system
Falls and Facts From OSHA

Employers hold the responsibility of providing a safe working environment for employees. One of the many ways employers ensure fall safety for employees is with a fall arrest system. Fall arrest systems work in areas that expose workers to vertical drops of six feet or more.

Workers use personal protection equipment (PPE) to restrict their range of movement as a way to prevent close proximity to a leading edge. This system prevents falling from occurring, instead of stopping a fall as it happens.

Each worker constructing a leading edge 6 feet or more above a lower level must be protected by guardrail systems, safety net systems, or personal fall arrest systems.
OSHA 3146 – 2015


The personal fall arrest system offers a level of required protection for workers exposed to a leading edge without physical edge protection. The active parts include:

Parts of a fall arrest system
  • Attachment Location
  • Body Harness
  • Vertical Lifeline or Lanyard
  • Webbing
  • Anchorages
  • Horizontal Lifeline
  • Connectors

Anchorages act as an independent structure that attach to a building structure and the worker ties off to the device.

An anchor point needs to be fixed to a structural surface, which has to be strong enough to hold the sudden weight and force of a falling worker. Anchors can be removed or left in place for future use.

The anchor acts as a temporary or permanent system, but it creates a hole in the roof substrate.

 A metal or steel anchor is the most common method for the anchorage component, but many rooftops and surface don’t allow penetration of the roof membrane.

The demand for a completely temporary anchorage system led to the development of mobile fall arrest.

Anchor point on a roof

Because penetrating the roof is not always an option, the introduction of mobile fall protection emphasizes flexibility and mobility on job sites.

System such as Mobile Fall Protection Cart can hold multiple workers on one device. A mobile fall protection cart with four anchor points provides a way to improve productivity and keep workers safe on a jobsite.

The common anchor point only holds one worker and acts as just fall arrest. Mobile systems hold multiple workers and are often designed for both arrest and restraint.

Close up of mobile fall protection

This provides workers fall safety at all times without compromising on a high level of safety confidence and flexibility.

Traditional Anchor Point
Mobile Fall Arrest

Choosing the right system will depend on a number of factors:

  • Crane load: A qualified person determines the set-up and rated capacity of a crane before using it to load or anchor a system to the crane.
  • Surface Type: Employers assess the walking and working surface to determine if it will safely support work activity, including a personal fall arrest system.
  • Surface Compatibility: Because not every roof is built out of the same material, not every anchorage system is compatible. If compatibility is not determined, the performance of the fall arrest is negatively affected. A qualified person verifies the type of surface an anchor system can attach to.

A safety coordinator will determine the best tool to make sure his or her team is safe and compliant all times while on the jobsite.


Tie Down’s Penetrator Line of Mobile Fall Protection Carts, like the Multi-Plus, works on various surfaces and provides protection for two workers in arrest and two in restraint.

However, there are other options, like the Penetrator Sentinel, that hold three workers in arrest and two in restraint on surfaces like TPO, ISO, PCV, and EPDM. The Sentinel also includes a material toolbox and a built-in material rack.

Mobile Fall Protection systems are becoming more popular in the construction industry today. Mobile solutions set up in minutes, giving an advantage to more fast-paced job sites. Reducing the time and labor on a job site is a key metric for any job site foreman.

Tie Down Penetrator Mobile Fall Protection Cart

As the construction industry evolves, ingenuity becomes a more important feature for products every day. Tie Down offers a variety of mobile fall protection systems, many offering both arrest and restraint, that fit different job site requirements and needs while meeting OSHA standards.

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