What will it look like?

This is a picture of a bridge on the Chesterfield Canal which is similar to the B2133 bridge. The view is as it will be seen from the east side of the road. (Photo: Chesterfield Canal Trust)


This is a touched up version of the same bridge viewed from the other side, but with the image reversed.

Construction Pictures of the new lock.

Q Surely we can squeeze enough headroom out of the existing crossing without all the expense of a new lock to the west?

• Devils Hole Lock
• DHL mitre = 18.77 m AOD
• Required depth of water = 1.4 m
• Therefore:-
• Water level below DHL = 20.17 m AOD
• The B2133 Road
• Road Level = 21.74 m AOD
• Road thickness = 0.6 m
• Therefore:-
  • Underside of bridge = 21.09 m AOD
  • Water level below DHL = 20.17 m AOD
• Therefore:-
  • Headroom Available = 0.92 m
  • But the required headroom is 2.4 m
  • Minimum Headroom Required = 2.4 m
  • Headroom Available = 0.92 m
• Therefore:-
  • Lift road by 1.48 m
    or
  • Lower canal by 1.48 m

• Constraints on Lifting the Road
  • Maximum brow 1000 m radius
  • Maximum valley 500 m radius
  • Max permitted Road lift is 0.42 m
  • Required Lift 1.48 m
• Therefore:-
  • Lifting the road on its own is not enough, the canal has to be lowered as well.
    • Lift the Road
      
    • Additional Road Building Costs
      
    • Un-quantifiable Risks
      
    • Typically Greater disruption of the traffic
      
    • Placating the households on the High Street and the Onslow Arms
  • Lower the canal
    • Extra costs
    • Steel Piling
      
    • Excavation
      
    • All risks quantifiable

• The question was:
  • Can enough headroom be squeezed out of the existing crossing?
• The answer:
  • unfortunately not.

Q Wouldn't a lifting bridge solve all our problems?

• WSCC will not accept the cost responsibility to service and maintain the bridge or to replace the bridge when required, say after 50 years.
  
• WACT would be required to give WSCC a bond to the value of replacing the bridge should WACT fail in their responsibilities.
  
• WACT would have to employ full time staff to service and maintain the lifting bridge for the life of the canal.
  
• WACT would have to replace the bridge when required.
  
• Because there is no ready alternative route for emergency vehicles, WACT could well be legally responsible for consequential damages.

• Lifting Bridge Constraints
  • COSTS
  • Bond immediately doubles cost
  • Servicing and replacement over 120 years?
  • Legal implications of failure of the bridge to operate or malfunction?

Q Why can't the winding hole stay where it is?

• Filling the winding hole reduces the project costs by £20000.
• Reduced off site spoil disposal
• Reduced bank protection required
• Easier disabled access to walkway under bridge
• Winding hole is too small for boats larger than ZK

Q Why ruin Brewhurst Lock when we have spent so much effort restoring it?

• Yes, but why didn't the Trust get it right first time, as per Halcrow's 1993 Report?

• Brewhurst 1995
• Brewhurst Lock
  
• A lot of what can be seen is concrete!
  
• The largest cost £24,800 relates to fitting smaller gates

Q Why don't we avoid Brewhurst Lock altogether and take a low-level route through the car-park?

Q Will WSCC fund the towpath or bridleway under the bridge? No

Q Will the towpath be a permissive right of way? Yes