Cargo boat veers out of control on Wisbech Cut

Published: Monday, 08 July 2024

A TIMBER Carrier veered out of control into the west bank of the Wisbech Cut while proceeding upstream to the Port of Wisbech. writes K Alexander-Duggan.

On the morning of the 25th June 2024, the timber carrier 'Baltic Arrow' fully laden with cargo from Riga in Latvia was proceeding upstream on the flood current with two local pilots on board with a planned arrival at Wisbech winding hole at slack water.

Ploughed into West bank

BalticArrowBowAt 8.49am the vessel sudden veered to starboard (right) and ploughed into the West bank, where it became fully wedged. (pictured) The force of the incoming tide pushed the stern into the east bank. Leaving the vessel aground at bow and stern when the tide went out, leaving the channel blocked.

This happened just before high water when the depth of the main channel would be over 45ft, tide range here being an average of 22ft (6.7m). This section of river is under the control of the Port of Wisbech and Sutton Bridge Authority (Owned by Fenland District Council) from Wisbech to the sea and not the Environment Agency.

Later that day, tugs from Sutton Bridge and Wisbech pulled the Baltic Arrow off both banks on the evening flood current and guided her to her berth in Wisbech where she arrived at 10.30pm. The shipping berths in Wisbech are classed as NAABSA berths, which stands for 'not always afloat but safely aground' so, technically, all vessels ground whilst moored here during low water and this has always been the case. Coasters of up to 2000 tonnes can be handled here.

When boats run aground above Peterborough

When boats do run aground on the river, it is often down to the inexperience of the person at the helm who steers as they would on a canal, keeping in the centre of the canal where the water is deepest. Rivers are a natural formation where the deepest part of the channel is rarely in the centre instead moving from side to side depending on the direction the river is moving. The course of a river is constantly changing very slowly as the force of the current erodes the banksides and riverbed while the silt is carried away by the current.

The inexperienced often ground on the inside of a bend when taking the bend too tight. Another area where the inexperienced get caught out, is running aground on the spit that forms downstream of a junction of two rivers when turning. A good example of this, is at Trent Falls at the junction of the Trent and  Ouse rivers. The constantly changing speed of the current and water levels can also be a problem for boats that are under powered.

The silting problems at Salter Lode

This year we have had a very wet Winter and Spring with all three rivers in flood conditions for most of the time. Apart from a few days of hot weather in June we had a great deal of rain. At the end of June this year, the Welney Washes were still flooded with water from the winter rains. In a normal year the Washes would be clear of water and the fields that are flooded in the winter months used for livestock. So where does the silt come from? It is a mix of matter washed off the land by the rain and what is eroded from the riverbed. While the river is flowing freely, the slit remains suspended in the water. When the flow is interrupted or blocked, the silt that is suspended instead falls to the riverbed. Which is why silt builds up behind dams and little used lock gates.

Salter LodeLockBoth Denver and Salter Lode (pictured} are rarely used in the winter months. Due to the location of the lock at Salter Lode, the sidewall at the entrance to the lock on the riverside interrupts the water which flows in. As a result some of the slit along the bank is pushed by the flow into the gap and stays there and builds up over time blocking the lock entrance.

Made conditions not safe

In the boating season, the daily use of the lock washes out any silt that has started to build up. Last winter and spring heavy rain washed more silt than normal into the river and the higher flow of the river down the New Bedford made conditions not safe for EA staff to remove the silt build up by the usual method of dispersing the silt into the main channel of the river using a plough towed from a motorboat, where it is taken out to sea by the river current. This method is less damaging to the ecological balance of the riverbed than the more conventional method of dredging which causes a great deal of damage from which in some cases it can take years for the ecological balance to recover and with the landfill tax very costly. The yearly licence fee for a 57ft narrowboat will just about cover the cost of landfill tax for 12 tons of silt.