When the diesel engine of a deck crane failed, it caused major handling problems for an offshore platform operating in the Dutch sector of the southern North Sea, problems that were solved with the use of J D Neuhaus air operated hoists. The crane was operating at 40 metres above sea level and provided a lift capacity of 20 tonnes. Replacing the broken engine, which itself weighed-in at approximately 1750kg, presented some logistic problems. The diesel engine replacement operation was successfully undertaken by the Gerritsen On- & Offshore Services BV company from their base in Amsterdam, with the work being completed in approximately one week.
As the replacement engine was too large and heavy to be ferried by helicopter, a lifting device was needed, that met requirements such as explosion-proof, lightweight and easy to handle to lift the replacement safely from the supply vessel. The suitable lifting device was sourced from the J D Neuhaus range of air operated hoists available in the Gerritsen rental fleet. It was a Profi 2TI model which had a lift capacity of 2 tonnes. This model is available as standard with a 3 metre lift, having an overall weight of approximately 110kg including the control system. This product was easily modified to provide the 40 metres lift required on site, involving an additional weight for the twin chain hoist mechanism at approximately 2kg per metre run.
With the replacement engine and its lifting equipment being transported by a supply vessel (16 hours sea time), provision was required for a further primary lifting unit to handle the Profi 2 TI hoist and its 40 metres drop of twin chains utilised for the major lifting operation. Once again, equipment that was light enough to be delivered to site by helicopter was selected from the Gerritsen rental fleet.
This was a J D Neuhaus air operated Mini hoist, providing 980kg lift capacity to handle the larger and more powerful Profi hoist and its 40 metre chains. The Mini hoist plus an appropriate beam clamp for the hoist suspension support was helicoptered in (30 minutes air time) and mounted ready for the primary lift operation of the Profi hoist and chains utilising a big bag container. The more powerful Profi unit was then used to replace the Mini hoist, utilising the same beam clamp installation. The Profi hoist with a 2 tonne lifting capacity was then utilised to undertake the more difficult lift and location of the replacement diesel engine utilising a sling assembly. The work was undertaken with one rig personnel for safety inspection, together with one rigger and three scaffolders.
The J D Neuhaus range of air operated hoists are universally deployable, incorporating explosion protection and are suitable for use in hazardous areas. The Mini series is available in load capacities of 125, 250, 500 and 980kg together with a manipulator version providing for one handed operation of lift, lower and hoist traverse operations. These products are explosion protected and feature an Ex classification of Ex II 3 GD IIA T4.
The Profi series hoists offer a more rugged build quality for heavier duty operations, and can be supplied with lift capacities from 250kg up to a full 100 tonnes. 100% duty rating and unlimited duty cycles are provided as standard, ensuring no down time and low maintenance requirements, They are supplied as standard with classification Ex II 2 GD IIA T4 / II 3 GD IIB T4, with increased spark protection to Ex II 2 GD IIB T4 and for explosion group IIC : Ex II 2 GD IIC T4. These products are insensitive to dust, humidity and temperatures ranging from -20°C to +70°C. They also provide infinitely variable speed controls for the precise positioning of loads.