ContraRoll Marine is a specialist bespoke roller shutter system specifically manufactured for incorporation within the latest transfer at height, walk to work (W2W) offshore access solutions.

Lift cursor towers are increasingly being retro-fitted or designed onto offshore wind service vessels. These towers provide stepless, variable height access for the transfer of personnel and cargo via fully adjustable and in some instances, motion compensating, walk to work gangways.

The ContraRoll Marine Shutter is a unique solution for providing a weather-resisting closure to varying voids created at the top of the cursor as it travels up and down the tower. This method of movable closure significantly assists in protecting the internal lift mechanism and operating controls mounted within the tower.

As the cursor or adjustable pedestal raises and lowers in its vertical transit, the two shutter curtains within the ContraRoll system are connected allowing them to simultaneously follow the movement, travelling up and down with the cursor, providing a highly-effective and robust closure.

A specifically designed torque-based control system is included. This allows for a seamless interface with the cursor and vessel management controls.

The ContraRoll system uses heavy-duty but lightweight insulated steel laths secured in place using vertical guides. The inherent strength of the curtain system provides an alternative solution that is more suited to withstand the offshore weather conditions when compare to vinyl or fabric type curtains.

Performance characteristics 

  • Resistance to wind load: Class 5 as standard

  • Vessel acceleration

  • Operational up to 3m/sec²

Key attributes

  • High wind load capabilities

  • Fully adaptable to suit a range of cursor travel heights and opening widths

  • Compact but robust design requiring minimum side room

  • Shutter curtain and head box fully factory-assembled allowing for easier installation or retrofitting at yard

  • Produced by a UK manufacturer with over 100 years of experience in providing quality engineering solutions

Applications 

Designed specifically for use on offshore lift cursor towers.

Operation 

A bespoke, torque monitoring control system is provided. Integrated variable speed drives will ensure that both shutter motors operate simultaneously with the cursor drive.

A project specific Functional Design Specification is generated to ensure the correct interface and outputs are agreed.

  • Two 440v, 3ph, 60Hz direct drive motors are provided:

  • IP56 motor; IP66 gearbox; IP66 enclosure

  • Integrated safety brake

  • Nitrate oil seals

  • Lubricant to suit –10°C and +45°C as standard

  • Manual override facility

DNV-approved heat tracer cables and termination kits are provided for mounting behind the side guide channel. Various temperature ranges and supply voltages are available.

Curtain

The shutter curtain is formed using heavy duty but light weight 95mm foam bonded insulated laths complete with a white plastisol Colorcoat LG finish. The laths are secured into position using nylon endlocks. Where necessary, fixed curtain panels are provided at the ends of the cursor travel.

Curtain / cursor interface

A grade 316L stainless steel interface mounting block is provided to allow the shutter curtain to be connected to the topside and underside of the cursor. This will vary depending on the cursor design.

Side guides

The shutter curtain is prevented from lateral movement by full height G316L double rebate side guide channels.

These also include twin brush seals mounted to the internal face, integrated tracer cable channel and structural mounting angle.

The side guides are provided in manageable sections of approximately 3m in length to aid installation.

Headbox assembly

Constructed from G316L stainless steel, the headbox assemblies incorporate the endplates and structural mounting angles, the roller barrel, shafts, bearings and motor mounting brackets all within or around a reinforced subframe support structure.

A G316L stainless steel casing is provided to enclose the headbox assembly and also the motor.

Each assembled shutter curtain will be rolled on to the respective barrel prior to despatch. Removable M12 swivel lifting eye bolts will be fitted to the headbox to allow the whole assembly to be lifted into position as a single unit.

Finishes

The curtain is provided in a white plastisol finish as standard. Other colours are available from the Colorcoat LG finish. Where ever possible, the remaining components are supplied in G316L stainless steel.