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Cromwell to Keadby lock on River Trent

Navigating from Cromwell to Keadby Lock on the River Trent, personal notes by Eric McDowall, 2023

For Boats especially with draughts around three feet, and perhaps considered as ‘low power’.

Any of us familiar with River navigations know well that eddy currents occur on bends and at junctions; these can cause silt to be dropped by the river on the inside of bends, and sometimes in lock approaches, like Keadby.

Due to the lack of deep draught commercial vessels using Keadby, the silting in the lock entrance on the Trent side requires removal at least twice a year. This is currently done by a ‘plough dredger’ which drags the mud out into the main stream, which carries it away. Immediately after a dredging, you should have no issues entering from the river, but if you are unlucky enough to want to use Keadby when it needs a dredge but hasn't had one, the following additional guidance may help you.

1. Lock Keepers at Keadby know when it needs dredging, Cromwell and Torksey do not. You do need to book in advance for any of these locks. provide all the phone numbers you could need.   for Hull tide times.  to buy charts from their ‘Store’, although Cromwell Lock sold me the Chart I wanted.

2. Currently (November 2023),  have a drone photo on their web showing the silt build up in the approaches when it needed dredging. If I had seen this before we went down the Trent, I would have taken a very different approach line into the lock.

3. Keadby advised me that, due to the silt, to lay for a tide at Gainsborough Pontoon. Providing the flood is not going to produce an Aegir, this is a sound plan, depending on tide times. It was an easy three hours or so, with the ebb, from Torksey pontoon to Gainsborough. Equally you could do this from Cromwell.

3a. Keadby advised me to turn at Gainsborough and moor to the pontoon facing the ebb. I wish I hadn't!

3b. If you are not used to rivers and decide not to turn and to moor facing north during the ebb, you must be confident about steering whilst going astern, as preferably you will come to a standstill next to the pontoon, and get your stern line ashore first! This is important when mooring in a flowing river, with the current on your stern. (photo of Tug No 2 by Eric McDowall)


3c. The ebb lasts a much longer time than the flood: as a result, the flood has much faster currents and more force. This is not taken well onto the stern of a narrowboat. If you do end up laying head to the ebb, you would preferably find means of securing your rudder amidships, or else it is liable to bang from one side to the other due to the eddy current swirls that the flooding tide produces.

3d. I used four warps. The two ends of the pontoon dry at low water, sitting on the silt and then settling with a heel towards the river. Try to moor somewhere in the middle section of the pontoon. You need a BWB/CRT key for the gate at the top of the ramp to get at shops, pubs, etc.  The following organisations denied that the pontoon is their responsibility: Associated British Ports; C&RT; Lincolnshire County Council; North Lindsey Council;  The Environment Agency.  It is probably the responsibility of West Lindsey Council.

3e. Tell Keadby by phone that you have arrived at Gainsborough pontoon. They will advise when to leave there. It will be just before High Water Gainsborough, when the flood stream is slowing to a walking pace.

4. It took us 2 hours 50 minutes to get from Gainsborough to Keadby Lock. That’s with a 18 h.p, 1936 National 2DM. As I closed the junction with the lock, I came-about to head into the ebb stream. The bottom gates were open for me and I followed the approach advice shown in “A Skipper’s Guide to the Yorkshire and Trent Commercial Navigations” from  coming up to the entrance from down-tide of the lock, parallel with the side of the river, and turning into the lock entrance ready to increase engine power.   (Also at

5. We got about half way through the turn, when the boat touched the silt deposit on the corner. Still going forward, the heel (or list) on the boat increased to an alarming amount and the boat stopped turning. We struck the upstream wall much harder than I would have liked, never touched the cill, and the boat righted itself as it came off the shoal.

5a. I think that having established that the lock gates are open for you, a better approach would be to come down sideways on the ebb current, at right-angles to the river bank, so as to have a short and straight run into the lock chamber, and avoid the silt build up on both sides. The opportunity to practice this has not arisen!



This information is provided in good faith to assist boaters. Whilst every effort is made to give accurate and up-to-date information, the Club accepts no liability or responsibility for any problems or consequences of navigating these waterways.