The surprise discovery of more lock gate damage has put Bremerhaven’s giant new Kaiserschleuse lock out of action until at least the end of the year.

The 305m long and 55m wide Kaiserschleuse had been due to re-open in June after being closed since last October for repairs to its outer lift-and-slide gate. However just two weeks before the scheduled completion of those repairs, port management company Bremenports reported damage had also been discovered on the lock’s inner gate. It announced that the facility would have to remain closed until at least December while fresh repair work took place.

Bremenports explained that its divers had discovered the latest recent damage during a routine inspection in early June, just as the earlier repairs were completed. Robert Howe, Managing Director of Bremenports, said the latest defects were “similar to those detected on the outer lock gate last autumn” and included track deformities on the gate’s undercarriage as well as cracks in concrete foundations.

Spokesman Rüdiger Staats told Maritime Journal “the deformations on the inner gate do not appear to be as extensive as those on the outer gate. Nonetheless we are obliged to have the inner gate repaired as well”. Robert Howe added “a thorough restoration of the inner gate is now called for”.

The new work involves the same procedure as just carried out for the outer gate. The giant 305m long and 55m wide lock was being emptied to create a dry working environment, the deformed undercarriage tracks were being removed and new tracks installed while new concreting work was to be carried out. Howe pledged: “We will not lose any time and we are doing all we can to ensure that the repairs can begin in September” with re-opening now planned for December.

The Kaiserschleuse was first closed to shipping last October after divers doing earlier inspections on behalf of bremenports discovered the outer gate defects. They found deformations and damage on the lower gate carriageway tracks and damage to rail anchorage points. Robert Howe said detailed refurbishment plans were drawn up in consultations between Bremenports engineers and the companies that built the new lock – a consortium headed by Hochtief Construction and also involving August Prien and Strabag.

A construction pit was drained by lowering two of three available 56m wide, ca 2,200 ton lock gates directly beside the working area - one on the River Weser side and the other on the lock chamber side. (Three gates were built at the Crist shipyard in Poland with one as a reserve unit in case of emergencies.) The two gates used in the repair of the outer gate sealed off the construction pit. Water was pumped out and silt cleared. The deformed rails were removed and the new rails installed and concreting work was also carried out.

Howe said early this year “We cannot yet state the cause of the damage (at the outer gate) with any certainty” and Staats told this correspondent in August it was still under investigation by independent experts. Staats told Maritime Journal that a 2.7m long section of the lower gate rail had been removed for analysis along with a 20 cm track end section and that materials testing in Bremen had not identified any faults in the quality of the rails.

The overall costs of repairing the damage to the outer gate and now also the inner gate as well, are uncertain, Rüdiger Staats said. Horst Rehberg, Commercial Director of Bremenports put the estimated cost of the first, now completed, gate repair at €2-3 million. According to Bremenports, the lock construction consortium is liable for that bill as part of a warranty which expires at the end of April 2016. It will presumably also be held liable for the latest repair. The warranty came into effect in April 2011 when the €233 million enlarged new Kaiserschleuse was inaugurated. It had been due into operation two years earlier but was delayed by severe winters.

One main reason for its construction was to provide easier access for carriers of up to 270m moving to and from Bremerhaven’s car terminals. It replaced a 114 year old, 215m long lock which had only a 28m passage width and could handle ships of maximum 185m.

The new lock was the biggest project of its kind in Europe at the time and officials described it as “a guarantee for the future of the port”. The first of the big ships to pass through it was the 230m long car carrier Fidelio.

Until the latest repairs are completed at the Kaiserschleuse, Sea-going ships will continue to use Bremerhaven’s only alternative big lock - the Nordschleuse, now itself more than 80 years old. One of the reasons for enlarging the Kaiserschleuse was to ease pressure on the Nordschleuse. It has however handled all the big ships since last autumn while proving the wisdom of the ‘alternative’ Kaiserschleuse investment at the same time.

The Nordschleuse was also the only lock for big ships during the four years it took to enlarge the old Kaiserschleuse. Built in 1931 and with a length of 375m, a chamber width of 60m and a passage width of 45m, The Nordschleuse is still one of the world’s biggest locks.

Without the two lock alternative – hopefully available again by the end of the year, Bremerhaven – Germany’s second biggest universal port, handling nearly 80 million tons a year - would face the loss of serious business. Not only giant vehicle handling facilities lie behind the locks: the inner berths are also home to leading shipyards like Lloyd Werft and German Dry Docks which need access for big cruise liners, tankers and other ships seeking repair, refurbishment or completion.

By Tom Todd