Q & A - The B2133 Loxwood Crossing


What will it look like?

chesterfield bridge

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)

chesterfield bridge

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

 
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