International lifting equipment manufacturer Konecranes has been contracted by JSE-listed pulp and paper manufacturer Sappi to install two cranes at the paper manufacturer’s Ngodwana mill, near Nelspruit, in Mpumalanga.
The contract forms part of Sappi’s Project GoCell, an extension to the Ngodwana mill that will enable Sappi to produce specialised cellulose, a product similar to cotton. It is used in the production of textiles, cellphone screens and pharmaceutical and household products.
Konecranes started the R3.1-million contract for the installation of a double-girder bridge crane at the mill’s Uptake 3 building last month. The crane will be used for the maintenance of motors and rollers in the drying process at the mill’s new Fibre Line 3.
The crane has a 45 t capacity, a lift height of 16 m and a 20.4 m span. The crane’s travel- ling speed is 40 m/min and it weighs 26.1 t.
The crane’s hoists, end-carriages and electrics were manufactured in Finland and its bridge-girder structure was manufactured at Konecranes’ Alrode facility, in Johannesburg. Three trucks were used to deliver it to site.
Konecranes Southern Africa sales and marketing director John MacDonald says this installation was complicated, owing to the limited space for the crane inside the Uptake 3 building.
“A mobile crane, which is generally used when installing a fully assembled double-girder crane, was not an option, as the crane needed to be installed inside a closed building on a different floor from the access point. Therefore, the crane had to be dismantled into smaller pieces to fit through a 10 m × 5 m opening in the building’s roof.
“Each piece had to be lifted separately through the opening using electric chain hoists. The pieces were laid out, assembled and then lifted into position using chain blocks and forklifts,” he explains.
The erection, commissioning and load testing were successfully completed in mid- February, after which the crane was handed over to the GoCell project manager.
Meanwhile, Konecranes was also con- tracted by Sappi in November last year to install a R3.3-million 32 t double-girder portal crane at the Ngodwana mill’s new Fibre Line 3 for Project GoCell.
The crane will be used to move paper rolls from one stage of the paper manu- facturing process to the next.
Installation started in the first week of November 2012 and the crane was erected, commissioned and tested by the end of December that year, says MacDonald.
The 32 t crane has a 24.5 m lift height and features a total crane weight of 38.4 t. The distance that the crane will cover in the mill when in operation is 67 m, he adds.
The double-girder portal crane runs on 57 kg/m parallel rails, spans 21 m over the processing bay and travels at a speed of 32 m/min. It is supported by two portal legs 20 m above the rails to clear any processing machinery.
MacDonald says there were several obstacles at the Project GoCell construction site that hampered easy installation of the portal crane.
Konecranes could not use two standard mobile cranes to lift and hold the different crane pieces from ground level onto the operating level of the plant. To overcome the challenge, a 500 t mobile crane was used instead to lift the completely assembled double-girder portal crane from ground level onto its rails, which were 30 m above the upper level of the plant, he explains.