MotoSuiveur® load arrest device

As part of a new lifting solution, or retrofitted to existing equipment, the MotoSuiveur load arrest device from SIGUREN technologies provides unparalleled protection against multiple causes of dropped loads.

MotoSuiveur is not a hoist brake, it's something revolutionary and innovative. It transforms your approach to crane safety.

MotoSuiveur: An innovative load arrest device

MotoSuiveur protects against uncontrolled loads caused by hoist brake, gearbox, motor or control system failures, including overspeed and overhoist scenarios.

The MotoSuiveur load arrester meets the recommendations of the Office for Nuclear Regulation's ONR Technical Assessment Guide 56 (TAG 56) for Nuclear Lifting Operations in addressing a range of lifting challenges.

Download our mini brochure, find technical information in our MotoSuiveur catalogue, or read on for more details.



Integrated mast & crane rig

  • 10m telescopic mast and 5m reach manipulator, fitted with MotoSuiveur load arrest device
  • 5t hoisting system for nuclear size reduction tasks
  • Remote control operatoin, plus independent load recovery paths


2x 32t nuclear box-handling cranes

  • Bespoke rotating grapple with semi-automated remote control
  • Two MotoSuiveur load arrest devices per crane
  • Multi-layered functional safety designed to IEC 61508 standard
125t bespoke nuclear crane + 10t auxiliary hoist

  • Bespoke high integrity crane with MotoSuiveur (MS7) load arrest device
  • Full loose article control plus stainless steel walkways and cabinets
  • Designed to IEC 61508 functional safety standards


Nuclear COTS Crane Solution

  • Cost-effective COTS + MotoSuiveur solution for nuclear lifting
  • Proven commercial design combined with failsafe technology
  • Supports multiple hoists for a wide range of applications

The elements of a MotoSuiveur load arrest device

Annotated diagram of a MotoSuiveur® unit


In the case of uncontrolled loads, safety concerns which arise from traditional hoist safety brakes can all be solved via the integration of the MotoSuiveur load arrest device. The concerns solved by the MotoSuiveur unit include:

  • Load Arrest - Protection against any hoist or gearbox mechanism failure, bar the rope
  • Overspeed - Protection, both mechanically and via firmware controls
  • Drop Height - Load is arrested within 30° rotation of the drum, as little as 30mm of drop
  • Overload Protection - Allows incorporation of a torque limiter
  • Independent Recovery - Optional independent recovery mechanism

A MotoSuiveur can replace multiple safety systems to deliver permissive safety in a single independent device, reducing complexity, implementation time and cost. And, because it isn't a friction-based calliper brake, its response times are significantly faster.

As the exclusive supplier of the MotoSuiveur device, SCX Special Projects has not only installed them on numerous nuclear licenced sites, but also for aerospace and defence applications too.

A MotoSuiveur® unit with a diagram showing load arrest rotation of 30°


Load arrest within 30° of drum rotation

The MotoSuiveur load arrest consists of a worm and wheel gearbox mounted directly to the hoist drum. The worm is a permissive system that only operates if fully functional and healthy, and which allows the wheel and barrel to rotate at any speed within the hoist’s normal operating parameters.

Any large differential acceleration between the worm and wheel will cause the system to mechanically lock, safely arresting the load. This provides mechanical failsafe protection in the event of any electrical or mechanical failure.

Should an arrest situation occur, hydraulic damping of the worm absorbs any impact force, bringing the load to a safe stop within 30° rotation of the drum. Dependent on rope and barrel configurations, this could translate to a load drop of as little as just 30mm before arrest. Compare this to traditional hoist safety brakes and the difference can be substantial.

A commercial hoist upgraded with MotoSuiveur

The incorporation of a MotoSuiveur load arrest device means the reliance on the integrity of the motor, gearbox, drum or shaft is reduced. This allows for the incorporation of a torque limiter between the motor and gearbox which provides mechanical protection against any overload, such as in the event of a snagged load or double blocking.

When an arrested load is being held by the worm and wheel, an optional integrated independent recovery motor can drive the worm to remotely recover the arrested load.

Come and see the MotoSuiveur in action

We actively encourage people to see for themselves how the innovative design of the MotoSuiveur load arrest device has revolutionised hoist safety. Please use the contact form below to request a demonstration.

MotoSuiveur® mobile demonstration kit

MotoSuiveur® mobile demonstration kit

Let's talk more about the MotoSuiveur load arrest device

We always find that the best outcomes are achieved by talking with us sooner. That way, we can explore all the possible solutions before committing to a course of action.

The MotoSuiveur could change the way you approach crane safety. If you'd like to see the MotoSuiveur in action, we'd be very happy to arrange a demonstration.

Call us on +44 114 262 6199, email us at, or complete the contact form below and we'll be in touch.

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SCX Special Projects Ltd

Roman Ridge Road, Sheffield, S9 1GA, United Kingdom

t:  +44 (0)114 262 6199