Procesos judiciales y condenas por blanqueo de capitales

Container terminals are increasingly using Automatic Stacking Cranes (ASCs). In this field, Europe Combined Terminals (ECT ) in Rotterdam

Fig. 6.7.1 Automatic stacking crane

is well known. Since 1990, eight huge Over-Panamax Cranes and 25 ASCs, all of them built by Nelcon – Rotterdam, plus a great number of Automated Guided Vehicles (AGVs) transport more than 500 000 containers per year over the Delta兾Sea-Land terminal of ECT.

Very few personnel are needed, in relation to the high throughput, resulting in increased efficiency. The DDE-terminal ‘2000-8’ of ECT is now also equipped with even more and larger Over Panamax Cranes and ASCs. Transport over the terminal is also done by AGVs.

The unmanned and fully automated working stacking cranes receive their orders from a central point via a Main Computer System (MCS).

This MCS tells the ASC to pick up a certain container and bring it exactly to a certain position. For the ASCs, the commanding MCS and positioning systems can be schematized as follows in Fig. 6.7.3.

Encoder systems

Incremental encoders can count very accurately the numbers of revolu-tions which rotating systems like the motors, wheels or measuring wheels of a crane or trolley make. The number of the counted revolu-tions indicates the distance over which the crane or trolley has travelled.

However, if there is slip or ‘creep’, the measurement is no longer accurate.

Fig. 6.7.2 AGVs and ASCs

Fig. 6.7.3 The main computer system

Therefore, absolute setting points along the track are necessary.

These setting points check the precise position of the crane and are used as a resetting point. These absolute setting points can for instance be detected via flags. These flags are positioned exactly along the track.

An infrared sensor on the crane detects the flags.

Sensor systems

Only a few field-proven and fool-proof systems are discussed.

Hall magnets with electronic measuring rulers

The stacking area of an ASC (Automated Stacking Crane) is divided into blocks of 3,25 metres. A container of 20 feet (length 6,05 m) needs two blocks; a container of 40 feet (length 12,1 m) needs 4 blocks. Also 45 feet containers can be stacked.

As each second Hall magnet is laying on a different distance from the end, each block has its unique distance (L₂AL₁), through which the Hall sensors can identify the exact position via the PLC in the crane.

Fig. 6.7.4 Container positioning with Hall sensors

Detectors with linear absolute encoders

In this case, the build-up of the stack is somewhat more flexible. The route of the ASC is not divided into blocks. So-called Omega profiles, each with a length of 2,33 metres, are filled with small magnets which give a unique response to the signals of the measuring positioning detec-tor, which is fastened to the crane that is running over the rail-track.

This detector is connected to the PLC in the crane, and indicates the

Fig. 6.7.5 Detection with Stegmann Omega profiles

position of the crane accurately, due to the Omega profiles which lay over the full length of the crane-track. (Patented by Stegmann.) Antenna–transponder systems

In such a system electromagnetic radiosignals are used as well as a tachometer system; the sender兾receiver is mounted in an antenna on the crane. The sender transmits a signal down to a precise line on the railtrack. A number of transponders are installed along the full length of the railtrack. When the crane runs over a transponder, the transpon-der receives the signal from the sentranspon-der, and reflects a unique signal back towards the antenna. This unique signal indicates the exact position of the crane.

The antenna sends the unique signal to the extra PLC, which decodes the signal to the position of the crane and can send information on to the main computer. The antenna also measures the relative distance∆y between the centre of the antenna and the transponder. The exact posi-tion of the crane is then y₁GyC∆y.

The small transponders bedded-in along the whole crane- or trolley-track, are the fixed points over which the crane with the antenna can fix its position, within a very small tolerance. This system should be immune to radio-disturbances; however, a nearby high-tension or

Fig. 6.7.6 Antenna–transponder system

medium-tension feeding cable of a crane can influence the working of the system.

Radar systems

A radar system on a terminal can send out radar waves to, for example, an Automated Guide Vehicle in order to guide and position this AGV.

Fig. 6.7.7 Antenna block for transponder system

Laser systems

Laser beams can also be used for exact positioning. Fog, dirt and the travelling distance can influence the accuracy of the positioning. On a stacking crane, a laser beam can be positioned above each sillbeam, giving a horizontal laser-beam parallel to the crane track. The two laser beams can also then control the exact length that each crane leg system has travelled; thus checking the skew of the crane. In case of skewing too much, the laser system blocks the crane travelling mechanism, after this resetting has to be done.

If a laser camera is mounted on a trolley, with its laser beam directed vertically downwards, this system can be used to detect the distance of the trolley from stacked containers or to sillbeams etc. After a practice run this system can then be used as a way of measuring and detecting the protected areas underneath a crane.

The influence of wind and eccentric loading of the container The measures, mentioned above indicate some of the methods by which the exact position of the crane and trolley can be found. However, this does not necessarily mean that the container is placed in exactly the right position. If there is a strong wind pushing the containers aside, or

Fig. 6.7.8 Nelcon ASCs with anti-sway system