First trial – Liebherr MK 88 Plus over the River Main
Bridges carry, bridges hold and bridges connect. A report by Stephan Achenbach, passionate MK driver at Riga Mainz and an enthusiastic social media user.
Bridges do not build themselves. They must be planned, built and maintained so that they can connect people. Riga Mainz’s MK 88 Plus Liebherr mobile construction crane, which had just been delivered had a special role to play, namely bridge maintenance on a cable-stayed bridge in Frankfurt.
Bridge maintenance on a cable-stayed bridge in Frankfurt.
The Werksbrücke West built from 1970 to 1972 is on the edge of the Höchst Industrial Estate. This bridge was the first concrete bridge for railway and road traffic to take the form of a cable-stayed bridge and the first cable-stayed bridge with a parallel attachment pattern. Over the course of time corrosion has formed on the angled cables, which are positioned very close to each other, due to the influences of the environment.
The majority of the internal plant truck traffic between the north and south plants uses the road that passes over the bridge. It had to be ensured that this unique connection suffered no adverse effects. The road which goes away from the plant has been shut to motorised traffic for several years and has been used as a pedestrian and cycle route since then.
To ensure that the MK 88 Plus could reach the site, the plant security service opened the gate which has been shut down and is only used by the plant fire service team. Thanks to its variable steering concept, the active rear axle steering and there versing camera, the driver and vehicle managed to negotiate the 90 degree corner backwards and were able to take up their position. With a support width of 5.75m, pedestrians and cyclists were still able to use the bridge without hindrance.
Benefits in favour of an MK 88 mobile construction crane
One of the main benefits of the MK 88 Plus is its low gross weight of 48t. As it is a lightweight, the mobile construction crane is ideal for this bridge maintenance work, particularly since the road supports are made of full-width prestressed hollow concrete sections. In its 45-degree super luffed position, the mobile construction crane completed its job by enabling two erection engineers in the secured cage to inspect and repair the support cables and cross struts. The height-adjustable elevating operator’s cab meant that the driver and erection engineers could work at eye level. When the support cables were “checked”, the “level luffing” option was simply disabled at the touch of a button.
After just one week, the MK 88 Plus was able to move to the right-hand side of the bridge. The 50m pylon there had suffered environmental damage to its masonry, but it could be repaired.
However, the MK 88 Plus is not just a great partner for bridge maintenance, it’s also very adept at protecting birds. Two NABU (German Nature and Biodiversity Conservation Union) members took the opportunity to take a closer look at peregrine falcon nests on the top of the pylon from the secured cage. Since the mobile construction crane was too far away for nest observation, it was moved a short distance whilst fully setup– to the amazement of watching faces.
Late summer temperatures of up to35 degrees took their toll on both man and machine during this job. The work was finished one day earlier than planned to the complete satisfaction of everybody involved.
My summary: the MK 88 Plus mobile construction crane is the perfect crane for high handling capacities combined with sensitive movements at great heights with a large radius and in a constricted space. A simply fantastic machine!