Measuring high in ports

Author:Arno Kijzerwaard

In a world where cargo transportation by means of intermodal containers keeps growing in volume, ship sizes show a steady increase as well. As a consequence, ports around the world have to invest in larger container cranes in order to handle these ships.

These container cranes are increasing in operating speed as well as in their level of automation. Trolley traveling speeds up to 240 or even 300 metres per minute are no exception anymore. On a track of 100 m, these trolleys easily travel more than 10,000 kilometres per year.

One of the key elements to crane maintenance at these high speeds is the wear, caused by the wheel-rail contact of the trolley. Effective prevention of this aggressive form of wear is realised by an accurate alignment of the trolley wheels. On a container crane with a girder height of more than 50 m, however, this alignment procedure puts extreme demands on measurement instruments.

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Staying on track

Though the alignment measurement of a set of steel wheels on steel rails seems a straight forward activity that could be performed by almost anyone in possession of a theodolite, this proves far less simple when located 50 m high on a moving steel structure in the wind. Not to forget one had to travel half the world to even get there.

The accurate alignment of trolley wheels on container cranes is such a specialty and niche market that the market area is simply formed by ports around world. Langeveld Cranes has almost a decade of development in this technique, bringing it to a whole new level. By now, their estimated amount of successful projects approximates 300 all over the world.

Langeveld has been using a Leica TS30 total station and recently added a Leica Nova TS60 total station to its equipment basket. The TS60 is used in combination with a Leica CS35 tablet computer and Langeveld’s own specially developed wheel alignment software.

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Working in the extreme

车轮对齐的公差可以追溯到1970年代。经典起重机设计标准均指定0.4 mm/m的最大允许轮角。但是，这与描述良好的跑步行为并不完全相同。通过从良好的跑步行为的一侧接近对齐，在实际的最终结果中实现了全新的精度水平。

This new accuracy level, though beneficial, puts higher demands on the accuracy and reproducibility of the measurements. The total stations have to measure up to the demands over and over again. The work of Langeveld’s trolley wheel alignment is so much more accurate than ever specified in the history of crane standards. This in itself is one thing, but it’s also significant that this result is always achieved on a height of more than 50 m from quay level on a moving crane in the wind.

Climate is another critical aspect to consider. The temperature working range of measurement equipment is usually one line in the data sheet. Hardly a difficult specification to meet when measuring close to Langeveld’s home base in the Netherlands. This becomes a less theoretical value, however, when winter projects in Scandinavia are asked for, followed by tropical destinations around the equator.

After dozens of these projects, the TS30 total station has remained stable. Of course, the instrument is acclimatised prior to each working day. Still, extreme variations of ambient temperature are no longer theoretical values in this line of work.

“在世界各地的每一个可思考的气候中，我们的莉卡地理系统总站都进入了几乎所有大洲的港口，并通过非洲，中东，亚洲和南美许多国家的定制官员的手中。bob apple”Langeveld项目管理所有者Casper Langeveld。“无论运输形式或环境条件的形式如何，这些总站都会继续工作，并为我们提供所需的测量。bob apple我们能够信任结果并确保为客户提供高质量的可交付成果。”

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New trends, new needs

Recent developments in crane automation have unexpectedly led to a complete new challenge. The classic crane driver was normally located almost directly above his load. Every move, shock and sound were immediately noticed and reacted upon. This could be anything between a radio call for a service engineer or, in a worst case, a full crane stop.

起重机自动化增加和遥控器的最新趋势有效地从起重机中移走了驾驶员。这意味着手推车行为中没有直接见证人的震惊或噪音。因此，手推车必须比以往任何时候都更加光滑，因为声音或震动的任何偏差都会在更长的时间内保持不变。

Meeting the international demands and work volume, the TS60 was an easy choice for the firm as a natural successor to the TS30. With ATRplus, the TS60 total station's ability to remain locked on the target is maximised, ignoring other distractions in the field, which can be plentiful in a port.

TS60 Langeveld自己的软件运行,阿龙g with the possibility of also using Leica Captivate 3D field software, this is a crucial feature for the firm. This enables the internal communication to the total stations for a cohesive work environment.

Langeveld说：“我们相信Leica Geosystems为我们的业务提供的整体强大解决方案。”“我们为起重机市场组成了一个强大的团队。”