BW’s Isis Lock Consultation

BW posted 2 consultations on its website about the boom and lock landing at Isis Lock, where the Oxford Canal meets the River Thames. After consulting with members, we have sent this response:

"Because the boom and lock landing pontoon installations are inextricably linked, we are sending the same reply to both consultations, as we believe they should be just one consultation. We have also referred to the automated red light warning system and Duke's Cut signs.

"We have uploaded a set of pictures to a Picasa album to help illustrate the points. They were variously taken in January, March and November 2011.  This can be viewed here.

  1. The Boom

    1. "Its purpose is to reduce the risk of boats being swept down the stream onto the weir at Hythe Bridge in times of strong water flow, and to prevent unauthorised mooring along the banks of the stream."
    2. Pictures 1-8 show the boom in context.
    3. Before answering the latest consultation, we feel it is vital to discuss the Boom's position.

      1. As it is, the Boom presents a safety hazard because it has been installed too close to the Pontoon, because it severely restricts the turning area available to a boat being carried downstream by the current in distress conditions. It must be expected that a full size narrowboat will take time to turn and needs the space to do so without bow thrusters
      2. As applies to the whole situation, there is not a major problem when the flow on the stream is low. Even when the Red Boards for the Thames were up at Isis Lock in January 2011, careful, slow manoeuvring of a 57' narrowboat was relatively easy for experienced boaters following the sort of instructions now proposed.
      3. However, inexperienced boaters, both owners and hirers, would not find winding easy after heavy rainfall. Hire boats up to 70' in length are "available for reunions, hen and stag parties" and it would be easy for a boat to be pinned against the boom without easy means of release.
      4. If the boom had been located 70' (21.33m) downstream of the downstream end of the pontoon (excluding the ramp), a boat would be able to use its engine to go upstream after turning.
      5. We believe the piles and boom must be moved downstream to make the situation safe.
    4. To deal with the consultation:

      1. "HEIGHT RESTRICTION PROPOSAL
        To install a height restriction between the centre two piles of the boom.  This will allow the passage of small craft but prevent access by larger boats.  The height restriction would consist of a rigid steel wire with a cleat on each end connected to the pile and padlocked at each end to enable access by Environment Agency and British Waterways staff. The height restriction set at 1.5m above normal water level would be highly visible and feature plastic floats at 0.5m intervals along the wire.  This would prevent injury should a person be struck by it.   A ‘Warning Maximum Height 1.5m’ sign would also be hung from the height restriction."
      2. Pictures 1 & 2 show a small cruiser that has been anchored (not moored) downstream of the boom. Does the fact that it has passed the "Danger" sign mean that the owner has done so at his own risk?
      3. One of the criticisms of the boom is that has already spoilt the visual amenity of the area. However, the health and safety issues are far more important.
      4. Putting a rigid steel wire across between the two piles sounds very dangerous, because it would not be readily seen, even if the plastic floats at 0.5m intervals were reflective. The wire would also be susceptible to being cut with bolt cutters. We suggest the steel wire should be completely encased in a plastic, high-visibility reflective tube at least 100mm in diameter. This should be fixed at one end, with a padlock at the other end to allow official access.
      5. Consideration should be given to making keys to this padlock available not only to EA and BW but also to the Fire Brigade, Police, College Cruisers and any other local trustworthy person who might be available in case of emergency.
      6. The addition of "a sign hung from the height restriction" is considered visually undesirable. It would presumably only be seen as a small craft was about to pass between the piles, which, when the flow on the stream is significant, may be too late. We suggest a yellow sign with black lettering should be affixed to the upstream pile, facing upstream, saying, "Warning: Maximum Height between booms 1.5m".
  2. The Pontoon

    1. We don't like the way the pontoon has been installed.
    2. If we had been consulted before this was installed we would have pointed out that you have removed a considerable amount of "dead water". The bank could have been piled properly and boaters could have pulled into the side in quiet water all without the expense of the pontoon.
    3. For the pontoon to be effective, it is essential that a means of taking a rope from the lock onto the pontoon, and conversely from the pontoon to the lock, is provided. At present it is impossible to take a mooring rope between the lock and the pontoon – because the ramp to the bank is at the wrong (downstream) end of the pontoon. In strong stream conditions, it may be almost impossible to bring the bow in to the pontoon without a rope when leaving the lock, because the stream naturally pulls the boat towards it and away from the pontoon.
    4. Pictures 7,8,11 & 15 show that the bows of a boat leaving the lock become progressively further from the pontoon and further into the flowing streams before it can pull in to the pontoon – the longer the boat the more this is exaggerated.
    5. A ramp should be installed from the upstream end of the pontoon to the bank, in line with the current pontoon. This need not be the full width of the pontoon, thus allowing the safety ladder to be repositioned on the offside end of the pontoon, instead of the inside end.
    6. If this is not feasible, a ramp should be provided at the upstream end of the pontoon, immediately downstream of the first pile, at right angles to the bank and pontoon length. A step (or steps) on the bank would be necessary to accommodate this. Such a step would be as safe as any of the steps at many Thames locks. See Picture 9 for location.
    7. This is particularly important for the many single-handed boaters that use the canal and turn here, but still an important safety requirement for multi-handed boaters.
    8. We recommend taking action on one of points 5 or 6, in descending preference.
  3. Isis Lock Landing Consultation

    1. "BW has developed a set of instructions demonstrating to boaters how to turn using a rope system. The set of simple set of instructions has been developed to cover all users and a copy of the instructions are attached."
    2. We have posted your proposed instructions as Picture 14.
    3. Picture 15, an aerial view of the location taken before the lock landing was installed, has been annotated to show that the diagram with your instructions should be redrawn to scale. Reasons are as follows:

      1. Lines A-B and C-D show the alignment of the lock. Compare this with Line E-F, the alignment of the pontoon. It would be helpful to novice visitors if the pontoon was shown at the appropriate angle in the diagram.
      2. Line F-G shows the line that a 60' boat (approx) would be at in your diagram 4 when at 90º of its 180º turn. It can be seen that there is adequate length to turn through 90º, which is not evident in your diagrams 3 and 4. The river is wider than drawn.
      3. The legend "Turn through 180º" between stages 3 and 4 is misleading – it should perhaps read "Turn through 90º", if stage 4 is "Release rope and complete turn."
      4. Lines H-I and J-J show the width of Castle Mill Stream alongside the lock. The overhanging trees in the aerial picture mask the width at water level and the diagrams show the width as much narrower than is the case. Picture 11 shows some of this extra width.
      5. In all four diagrams the booms are illustrated with four piles. The diagrams should be amended to show the parallel booms and the piles. To inform any small craft boaters, there should also be an note to indicate that the maximum headroom between the piles is 1.5m.
      6. For all the above reasons, the instruction diagrams should be redrawn – to scale to help boaters turn in safety.
    4. There should also be a note on the diagram: "When exiting the lock to go onto the Thames, boats may be advised to turn to face upstream using the pontoon as in this diagram, before pushing the bows out into the strong current."
  4. Red Boards at Isis Lock

    1. "We are also currently looking into the viability of installing an automated red light warning system with the red light illuminating when the Environment Agency issue strong stream advice on the River Thames to replace the current manual signs."
    2. Picture 18 shows the Strong Stream notice board in January 2011. It is a completely sufficient means of indicating the danger.
    3. At a time of financial stringency we are surprised that you are even considering expenditure on this. The red boards have been adequate over the years and the cost of replacing them with new ones if they are damaged would be minimal compared with your proposed expenditure. Our earlier suggestions should have first demand on your budget.
    4. We recommend continuing with the existing system of red boards.
  5. Warning signs at Duke's Cut

    1. Until sometime this year there was the option of displaying a red board on the bridge at Dukes Cut, as a Thames Strong Stream warning.
    2. Pictures 19,20 & 21 show these.
    3. It appears that this has been replaced as part of this project, but we are dismayed at your alternatives, shown in Pictures 24 & 25.
    4. Firstly, in November 2011 the sign incorrectly showed the Strong Stream warning as in Picture 24 – this at a time when the Osney Lock Keeper had expressed dismay at the low levels on the Thames. A padlock should be used to prevent this occurring. We are aware of at least one boat that turned around unnecessarily at Dukes Cut as a result.
    5. The sign gives no clear indication of danger, being black rather than red. This should be remedied.
    6. The sign has been positioned away from the bridge, so, for a boater without experience or knowledge, it is unclear whether the message "No turning for Boats Over 52ft In Length Beyond this Point" refers to Dukes Cut or the Canal towards Oxford. This could be reworded "No turning in Oxford for boats over 52ft in length beyond this point" (note intentional lack of capital letters).
    7. On the alternative sign, the second half's wording is "Craft Over 52ft proceeding beyond this point will be required to enter the River Thames to wind. Please follow the advice provided at Isis Lock." Because hirers may not be familiar with the term "winding", we suggest this alternative wording: "Craft over 52ft proceeding beyond this point will need to enter the River Thames to turn. Please follow the advice provided at Isis Lock." (No capital O)
    8. It is important that wording on signs is carefully considered and double-checked. Consultation with users is recommended.
  6. Oxford Winding Hole

    1. It appears that a lot of the problems that BW needed to remedy relating to winding at the end of the Oxford Canal could have been secured by the provision of a full-length winding hole. There are at least 3 options. We hope you can provide adequate justification for what you have done as opposed to a simpler solution. We realise you would have had to purchase land to enable one of the following, but any one could have been a better solution:

      1. Widen the winding hole at the end of the Hythe Arm
      2. Widen the winding hole above Isis Lock (see Picture 16). Incidentally, there is still a sign 50' max as well as 52' max here.
      3. Create a new winding hole at or near the entrance to the Jericho Boatyard (see Picture 17).

We hope these comments are helpful and look forward to a response in due course. Please do not hesitate to be in touch with me if you have any questions.

John Slee

for NABO COuncil

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