1. Field of the Invention
The invention relates to a device for transporting people by a spreader having a vertically movable head beam with horizontally extendable long bars.
2. Description of the Related Art
When unloading containers transported on ships, at first the containers have to be unshipped which are positioned on the hatch covers. In order to protect them against falling off during the journey the containers are locked against each other and relative to the hatch covers by means of so-called “twistlocks” (interlocking elements to be provided at the corners of the containers). Prior to the unloading procedure, said twistlocks have to be unlocked manually. In the case of twistlocks which must be handled completely manually, they are put first, also for the loading procedure, on the hatch cover or on the containers already loaded, whereupon they are also manually interlocked. As the containers are often stacked up to five layers on the hatch covers, it is extremely difficult to reach them from the deck or from the gangways between the container stacks. The lower two layers are locked or unlocked by rods from the deck or the gangway, whereas the upper layers have to be unlocked from above, using the afore mentioned rods. As in many cases salient containers hinder accessibility, the before mentioned operations are extremely dangerous and often result in fatal accidents. This is why in many States legal provisions have been issued generally prohibiting any operation from the upper surface of the containers. However, said provisions cannot be followed in practice because, up to now, suitable devices are missing which could safely transport the staff on the spot to open the twistlocks.
In view of these problems various producers are trying to find a solution and offer appropriate devices. Said devices (so-called personnel cages) are used to transport the staff as near as possible to their point of intervention. Personal cages are known which—when hanging under the spreader—are positioned on the uppermost container. From here, the staff operates using the already mentioned rods. In a further known device, two cages occupied by operators and also hanging underneath the spreader, hang down along the front parts of the containers, such that they make it possible to safely reach at least the twistlocks of the uppermost layer. A further known device facilitates, by means of three personnel cages interconnected through ladders, the locking and unlocking of the three uppermost layers. However, this device, due to its overall height, is only fit for limited use (necessary hoisting height and salient containers). A further important requirement to facilitate an efficient routine of loading and unloading is the necessity to mount said device directly on the bridge crane use for ship loading. Due to the specific construction of these very expensive bulk devices there is no place suitable for such a device.