In February 2025, an inland shipping vessel struck the lower doors of the northern lock of Lith. The northern door of the lock was severely damaged as a result. The restoration will last until November 2025.
Project manager Ivo Thuijls and project leader Pascal Olislagers from the contractor combination Mourik Swarco talk about the work being done.
Both doors of the lower head of the northern lock of Lith are currently with the company carrying out the restoration work, Pascal Olislagers explains. ‘A 3D measurement of both doors has shown that only the northern door needs to be restored.
The southern door was not affected by the collision, only the platform on the door is damaged. However, since both doors are being lifted from the lock for the 3D research and restoration process, we can combine this with the revision of the door and slide cylinders of both the northern and southern doors. A silver lining to a cloud.’
Restoring the Door
Together with Rijkswaterstaat, a decision matrix has been followed to determine the best approach for the restoration of the northern door. ‘The choice has been made to minimally restore the door,’ says Ivo Thuijls.
‘This is done very carefully and through a standard restoration process.’ He adds: ‘We will not be making a new door. The reason is that manufacturing a new door takes significantly longer than restoration and it is also much more expensive. This was decisive for Rijkswaterstaat.’
Blasting
The first step in the restoration process is the so-called ‘blasting’. ‘This means that we remove all paint from the door,’ explains Olislagers. ‘This leaves a bare door. To do this, all parts that should not be blasted have been removed from the door. Think of the slides, hydraulic cylinders, slide guides, and the woodwork, which also needs to be partially replaced.
After blasting, we carry out various investigations to definitively determine which parts of the door need to be restored. Only after the door has been stripped of all bells and whistles can we map the damage down to the smallest detail and know exactly what needs to be restored.’
Steelwork
Then the deformed pieces are removed from the door and replaced. Thuijls explains that the steel needed for this can only be ordered once you know exactly what needs to be replaced. ‘Moreover, this steel must meet specific requirements. There is a certain delivery time associated with that.’
It quickly takes a few weeks. Once the steelwork is completed and the damaged pieces have been replaced, a new 3D measurement will follow along with corresponding investigations into, for example, the welding to ensure that everything has been properly restored.
Preserving and Assembling
After that, the door is ‘preserved’. ‘At the beginning of the restoration process, the door was blasted,’ explains Olislagers. ‘At the end, all protective layers must be reapplied. We will also assemble all (revised) parts that were removed at the beginning. Lastly, the wooden sealing beams will be reattached to the door. These must be precisely made to measure for a proper seal in the lock.’
Olislagers states that the platform and the associated railings are completely new for both doors. ‘In the collision, both platforms – the walkways on top of the doors – were so severely damaged that complete replacement was necessary.’
Additionally, concrete repairs are being carried out in the lock itself. ‘In the collision, the anchoring of the door cylinder, which holds the door in the wall, was pulled loose. We will also restore that. This replacement and repairs are done during the restoration of the door to work as efficiently as possible.’
Reinstalling and Testing
Once the northern door is repaired, both doors will be transported to lock Lith and installed there. ‘Then we need to test the doors, of course,’ Thuijls indicates. ‘We also remove the stop logs from the lock, which currently take over the physical dam from the lock doors. Once everything is functioning properly, shipping traffic can be restarted.’