Bottom Lock refurbishment

Bottom Lock – refurbishment

By 2006 it was beginning to be apparent that, in spite of patching, the original mitre gates at Bottom Lock were coming towards the end of their life and replacement was going to be expensive. Funding was therefore sought from Lincolnshire Waterways Partnership to completely refurbish the lock and work started in the Autumn of 2008. In addition to new bottom gates, the Trust had a wish list of projects that, for a variety of reasons, had either not been done when the original restoration was carried out or need to be improved. These included safety ladders, stop plank grooves, a new gearbox on the guillotine gate and floating landing stages.

First the old gates were removed so that the manufacturers, Hargreaves, could use them as a pattern for the new ones. The next operation, to drain the lock, was very difficult due to there being no stop plank grooves. The lock had to be piled, an expensive operation, especially as very long 8M piles had to be used to achieve a seal. Fortunately the guillotine gate was sufficiently watertight for there to be no need of piling above the lock. At the same time the crane drove in the stanchions to anchor the new landing stages. The landing stages and access ramps were lifted in later.

Work inside the lock chamber went smoothly with the grooves for the lock ladders being cut and the new ladders installed very easily. Transport of the new gates to the lock site was not so simple due to the remoteness of the lock, however, the local farmer was very helpful in allowing the Trust access across his land. The lorry could bring the gates to the edge of the farm and then they were carried separately to site by the farmer’s tractor and trailer. The onsite crane then lifted the gates into position, according to the crane operator each gate weighed in at 7 tons!

While the lock was drained the opportunity was taken to cut stop plank grooves below the bottom gates to make any future operations in the lock much easier. Also high on the Trust’s wish list was the alteration of the gearbox on the guillotine. The original gearbox was very low geared to make the operation of the gate a relatively easy operation. Unfortunately this meant that fully opening the gate required a staggering 350 turns! A replacement was sourced with higher gearing that, although making the gate slightly harder to raise, is much quicker to use.

The refurbished lock came into use at the start of 2009 cruising season.