MotoSuiveur® load arrest device

The revolutionary MotoSuiveur load arrest device from Siguren protects against mechanical or electrical hoist failures by bringing the hoist drum to a safe and controllled stop. It has recently been recognised by the Office for Nuclear Regulation as an applicable mitigation for uncontrolled loads.

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

MotoSuiveur: An innovative load arrest device

The revolutionary MotoSuiveur load arrest device protects against loads of inherent value or risk being dropped due to hoist or gearbox failures.

MotoSuiveur's capabilities have been identified by the Office for Nuclear Regulation as a mitigation for uncontrolled loads.

These capabilities are beneficial to lifting operations across all sectors of industry. SCX Special Projects has implemented MotoSuiveur devices into advanced mechanical handling solutions at nuclear licenced sites, manufacturing facilities, and in defence handling applications.

Download our brochure or read on for more details.


Integrated Mast & Crane Rig

  • 10m telescopic mast and 5m reach manipulator
  • 5t hoisting system with MotoSuiveur load arrest device
  • Remote control with full recovery


ILW Handling System

  • 32t bespoke twin-hoist design with 2x MS4 devices per crane
  • Fully independent recovery drives
  • Two tier rotating grapple
Fuel Handling System

  • 120t safe working load
  • Loose article control
  • MotoSuiveur MS7 load arrest device


Nuclear COTS Crane Solution

  • Cost-effective COTS crane solution for the nuclear industry
  • 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 dropped 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, excluding the rope
  • Overspeed - Protection, both mechanically and via firmware controls
  • Drop Height - Load is arrested within 30° rotation of the drum
  • 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°

A MotoSuiveur device 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 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. Dependant on rope and barrel configurations, this could translate to a load drop of as little as just 15mm 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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Our team will contact you very soon to discuss the MotoSuiveur load arrest device.


SCX Special Projects Ltd
Roman Ridge Road,
Sheffield, S9 1GA
Tel: +44 (0)114 262 6199