UK crane builder Granada Material Handling recently commissioned four cranes - two 60t and two 30t - at a Poole, Dorset-based firm which manufactures heat exchangers for the petrochemical industry. The cranes were part of an extension project to an existing fabrication bay

The order, worth £220,000 (Euros 320,000), was received last September, installed at Heatric Ltd in April and commissioned in May. Granada has worked with the firm on various projects over the last 10 years. The 60t cranes (13m span) each have two 30t grabs, which work in tandem, while the 30t units (12m span) have two 15t grabs, which, again, lift in tandem. However, maximum loads could weigh up to 96t, so the two 60t units can in turn work in tandem. There is a data communication device between the crab unit so if one fails it stops the operation of the other.

The new building is approximately 60m in length - about 20m longer than the old one. Granada replaced the busbar along the entire length of both bays to allow the old cranes to run into the new part. Due to the heavier capacities of the new cranes compared to the old (the old ones in the existing part are only 10 and 30t capacity), it fitted travel limits to ensure loaded new cranes cannot run on the old gantry. Additionally, an infrared anti-collison system was fitted to stop loaded cranes running into each other. An anti-collision over-ride was fitted to the pendant so the operator can run the cranes together.

Components will be built on one side of the new facility and then transported to the other to be prepared for dispatch. All cranes are pendant controlled and feature Mannheim, Germany-based firm SWF micromove invertor technology. Given that the company sells its products by weight, Granada installed an electrical weight display system that "gives an accuracy of +/-1% tolerance of the actual load," it said.

All cranes have full length maintenance platforms with under mounted 400W metal halide flood lights to illuminate work areas when the cranes are parked under the main factory lights. The facility sometimes operates 24 hours a day.

Due to height constraints above the 60t cranes, the crab units had to be lowered through the roof structure. Factory heaters mounted above the 60t cranes meant Granada had to install heat deflection shields on the crab units. The cranes could not be positioned symetrically in the buliding as there are offices on one side, hence a free standing gantry structure was built to accomodate the cranes.