Dredger in Action

Dredging on the Thames & Severn Canal

The Cotswold Canals Trust Dredger ‘Augustus Gloop’ is now in action on the Thames & Severn Canal between Ham Mill Lock and Hope Mill. The vintage German built machine has been part of the CCT maintenance fleet since it was purchased back in the 1970s.

Upgrades & refits

It has undergone a number of refits and upgrades over the years. Most recently it has been fitted with new flotation tanks, a diesel fired cabin heater, renewed hydraulic pipes & pump and hydraulic legs.

The machine is pictured right as it was craned out of the Stroudwater Navigation at Ebley to be placed in the weed choked Thames & Severn Canal east of Ham Mill. (Photo by Steve Pickover)

Gloop

The machine has certainly been living up to its onomatopoeic name. Its task is to remove some 15,000 cubic metres of very gloopy material from the canal channel.

Weed & reed raft

But first it has had to dig its way down through generations of weeds and reeds filling the entire width of the channel.

Dredging Project Manager Robin Payne explains… “When it was lowered into the channel by Ellis Cranes it simply sat on top what amounted to a large raft of vegetation. We had to dig our way down through that in order to get afloat”

Robin adds that he is nevertheless reassured by the depth of water to be found beneath the raft of vegetation.

“The thing to remember is that the process involves going through three different layers… 
1. The raft of reeds
2. The water beneath and then…
3. The generations of silt beneath that.”

Supportive landowner

This prompts the obvious question…

Where will the silt go to? The answer is provided by the generosity, understanding and support offered by the landowner of the ground on the offside, or southern, bank of the canal. That is where the nutrient rich material will be deposited, drained and levelled. The restricted reach of the dredger arm means that this cannot be achieved in one swing of the bucket.

The process explained

Robin explains…”We shall be dredging the pound in sections. The method will involve a number of ‘passes’ along the length of each section. We are currently travelling from west to east on the towpath, northern, side of the channel. We lift the material and deposit it back into the channel to the right of that run as it were. We intend to do the ‘return pass’ from east to west when we shall lift what we have just deposited and move it again onto, or at least, towards the offside bank."

Click on the images to view larger versions

Click here to view Mike Gallagher's Bagpath Bridge Album

Click here to view Robert Paget's video of the dredger in action
 

The photos show Robin training CCT volunteer plant operator Austin Smith. The pair made some good progress on Sunday bearing in mind that an early dusk brings an early end to their activities. Robin aims for the dredging team to operate for at least three days a week.

Taking the positive approach the winter solstice will soon be upon us so those days will be getting longer after 22nd December.