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magpie patrick

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Posts posted by magpie patrick

  1. 1 hour ago, MtB said:

     

    Well it certainly fits through some of the locks as it is in a pound with no crane pad or any other opportunity to lift it in. 

     

    Either that or it isn't 74ft at all!

     

    My money is on the latter...

     

     

     

    Whereabouts on the K&A?

     

    The bit built by the K&A company had locks built for boats 69 feet long by 13 feet 8 inches wide. The locks are, for obvious reasons, slightly bigger than this, but that's why Baldock needed to open the gate on the opposite side when going down. It's also why Juno pinches in some locks if using only one gate. Lutine Bell was only about 6 foot 8 and the difference when using one gate was very noticeable.

     

    The original Kennet locks were 'uge and some still are. 

  2. 38 minutes ago, AJLElectronics said:

      I would guess that during a Bore, 40BHP would not be adequate!  One day if I can be experienced enough, I would like to get adventurous.

     

     40hp will be adequate for the trip down the estuary from Sharpness to Portishead and thence Bristol. From there up the Avon to Bath.... whilst narrow boats do this trip, a Viking wide beam is much better suited for it. 

  3. 23 minutes ago, billh said:

    Was Uncle Irvine on that trip also? I think he would have been Deputy Head at that time. If appropriate, move to history and heritage😃

     

    I'm pretty sure he was... we had to remember to call him "Mr Holmes" for the week! 😳😂

  4. I have a Viking 23 narrow beam, but I guess the steering will be the same. Wheel connected to the outboard by a cable that works on the "morse control" principle - the sheath is anchored and the cable can push and pull. 

     

    Almost certainly the cable causing your problem, and if it is the only solution is to replace the whole cable, measure the length of the one you've got,  make sure its correct, and order a replacement of the same length.

     

    Before that , disconnect the cable and check that both the wheel and the outboard move freely. Also check for anything restricting the movement of the cable. The sheath may be anchored but it still moves sideways - when I changed my outboard the different mounting position meant the cable hit the battery compartment and restricted the movement when turning right. 

    • Love 1
  5. 5 hours ago, Jerra said:

    I am puzzled.  You had to be educated in metric (the regulations and OFSTED) said so yet you think in imperial.  How and why?

     

    In my case, canals are a big part of it - they were built to imperial measures and for accuracy I stick with that rather than cinvert it.

     

    For roads I use metric for carriageway width as that's how they're built now..

     

    For Tim @mrsmelly I convert to roods, poles, chains... 😉

     

    Take care Tim - don't overdo it but don't underdo it either

    • Haha 1
  6. 1 hour ago, alan_fincher said:

     

    Had you been going through (say) 50 years ago there wouldn't have been anybody other than boat crews controlling how things were done.

     

    It sounds surprising now, but I don't recall things working any less well than is now the case with volunteer lockies.

     

    It's the volume of boats rather than the competence of crews (or rather, in combination with...) that is the issue - the first time mum and dad went through Foxton they met nobody between Crick and Market Harborough, and had lunch in the locks, yet by the late 1970s there were problems with boats just following through and no-one being able to come the other way. Dad took a school party with four Willow Wren boats through Watford in the 1970s, and blocked the top lock and let boats come up after plaintive cries for help from crews who had been waiting hours. 

  7. 4 hours ago, 1st ade said:

     

    I believe in other situations (around Bow) there were concerns that a very large barge could break an equally large road...

     

     

    When freight was considered onto the Olympics modelling suggested that, should an unladen barge with a capacity of around 600 tonnes get stuck under Stratford High Street on a rising tide, it would lift the bridge off its bearings before the barge sank (which it would with an unhinged bridge on top of it) Sorting that out would be messy. 

    4 hours ago, 1st ade said:

    Looking at the examples given by others - I think the difference is it would break the bridge (wood) rather than sink the boat (and/or kill people)

     

     

    Yes, and the boat would stick out each side making egress possible. 

     

    A risk assessment would suggest that (a) the procedure should minimise the risk of a boat getting trapped and ( b) have a process for getting crew off it a boat is trapped. In the absence of an interlock then the procedure is a sign telling you to open the bridge. Where an interlock can be provided then usually it will be. 

     

    The various acts use the words "practical steps" or similar

  8. 8 hours ago, dogless said:

    Good luck with this.

    Is it what you want to do ?

    If it is, crack on ... if its too much effort,  don't bother ... they're not decisions others can make for you.

     

     ^^^^This

     

    As a community radio presenter (Magpie's Folk Cafe, Frome FM) we do it for love - I get approbation from others who either enjoy the show or feature on it, but it's not why I do it. 

     

    So if this is your thing, go for it. 

     

    Given my health these days, listening to podcasts is starting to feature large so I will log in on the old ear trumpet

    • Greenie 2
  9. 6 hours ago, booke23 said:

    . It must have cost an absolute fortune (I've done a bit of digging and a figure of $110 million seems to come up)....

     

    I imagine the electricity bill is quite impressive too...

     

    IIRC a similar scheme was considered on the Fox River to allow restoration, but the funding was problematic 

  10. 10 hours ago, David Mack said:

    If you are going to double up on the gates either end, why not just build two conventional locks with a low pound between them? When not in use the low pound is kept one lockful below navigable level, so that when a boat passing through the first lock empties it, the pound level comes up to navigation level (a bit like staircase locks). Once the boat has passed through the low pound can be pumped out again back into the main canal.

    The sudden flooding case can surely be addressed by providing a large overflow weir (running to waste) just above normal navigation level (again like staircase locks).

     

    Your mind clearly works the same way as mine David - when drop locks were first considered as an "in principle" solution it was assumed they'd be back to back locks, and we started building in safety features like big overflows. Most of the places there were considered that locks would be immediately either side of bridge - in some instances they would be further apart which is much easier - I've a plan for one with the locks 400m apart which is very easy to make safe - the arrangement at Staveley on the Chesterfield is close to this, although in the end the bridge we needed to get under has never been built!

     

    The first thing that was obvious for two locks back to back was we'd have to manage traffic, as waiting between the locks was risky - we could have boats pass (like a wide two rise) but not wait in the gap. Then we had to try and fit in a drain and an overflow, the overflow had to cope with the full force of a lock emptying suddenly - the scale of this arrangement is more than most locations can easily accommodate.

     

    The big hazard is gate failure - at the time I was looking at it, it seemed that once every couple of years a bottom pair of mitre gates would fold and empty the lock pronto, not just a hazard to any boat waiting below the lock but to one in it, especially if the top gates were open. This seems to happen less often now. Gates can create this hazard in two ways - mitre gates can blow, guillotine gates can be opened against a head of water - but the reverses are not true, so the designers of the lock put a mitre AND a guillotine at each end and did away with the middle gates. I didn't come up with this - I think it was SWK who did, but having been so critical of the risks of drop locks I reviewed the design with colleagues, and much as we tried to find a safety failing we couldn't other than operator failure, e.g. using the lock without closing all the gates. 

     

    Some restoration schemes would benefit from a drop lock that can be safely user operated - the only way I can see to do that is to put two locks about 400 yards apart.     

    • Greenie 1
  11. 12 minutes ago, 1st ade said:

    Catastrophic "leak" at one end or the other? Water rises too quickly to get craft to safety?

     

    In principle I'd agree, but that's why the thing has more than the usual number of gates at both ends - a mitre pair and single leaf gate that (I think) folds to the floor. They're both closed when the lock operates.

     

    We did look at this at the time, because occasionally gates "blow", something that would fill the lock in seconds, hence doubling up on the gates - something also done on the Panama Canal BTW. 

    • Greenie 1
  12. 49 minutes ago, Iain_S said:

    Dalmuir Drop Lock on the Forth and Clyde. It's a bit of a monster, really. The water has to be pumped out of the lock once the boats are in it. Takes about 40 minutes, assuming the inflows to the pumps are reasonably clear and not blocked by weed. Used to be a bit quicker, when the operator was able to drop the lock just enough to get the boats under the bridge, but it now has to go all the way down for H&S reasons.

    If building another one, a big improvement would be the provision of a reservoir below lock level, so that the lock could be emptied using paddles rather than a pump. You'd still need pumps to empty the reservoir back into the canal, but you'd get away with lower pumping capacity and the lock operation would be a lot quicker.

    The original plan was simply to drain the water away, but presumably this used too much water. 

     

    Having done a certain amount of work on the safety of these monstrosities I'm curious as to why a partial drain too reveal "enough" headroom is unsafe. 

  13. Moral codes of the time would not have encouraged a woman to be anywhere near the Bridgewater Canal - it wasn't so much being with their husbands, it was all the other men, some of who would have felt distinctly uncomfortable in the presence of a woman who was not their wife. Just not the done thing. Women and men didn't mix in pubs either (if the women went in a pub at all)

     

    There would be many other social and moral conventions too, this was an era when women and men only mixed in a family setting. 

     

    I'm not sure when families started living on narrow boats but that was a change of context, the woman was now with her family 

     

    It's hard to think of a modern parallel for "not the done thing" 

     

    15 hours ago, booke23 said:

     

    One things for sure, James Loch would be turning in his grave if he could see the change in morals today compared to 1837!  

     

    Indeed - although I'm rather glad I can go to the boat with Ness (or any other woman for that matter) without Mr Loch feeling moved to write a letter about it!  Can you imagine the pages of this forum... 😳

  14. 31 minutes ago, ditchcrawler said:

    I did point that out

    I did point that out

     

    So you did

     

    So you did

     

    🤭

     

    I have to be honest and say I'd missed the reference you were making 

     

     

    1 hour ago, Pluto said:

     I would recommend trying to keel any design as simple as possible.

     

    Wise words! The ability of folks to embellish designs with needless add ons that then go wrong is astounding. 

  15. 18 minutes ago, David Mack said:

    Is this for a farm track or a public road? 

     

    Right of access to third party land (and even that's disputed but we need a bridge for other reasons e.g. maintenance and towpath access) - public road loading first choice is  for a swing bridge with jacks (edited to add - powered swing bridge) - it's not the absolute axle load but the frequency that does the damage. 

     

    Last scheme I looked at on a public road though the gradient wouldn't work with a swing bridge! I am also looking at one in south Wales where it will have to swing as its half under a railway bridge - no room to lift

     

    I can see it might be worth locking a lift bridge down though 

  16. 15 minutes ago, David Mack said:

     

    Why a lifting bridge anyway? Surely a swing bridge is less intrusive, more reliable, well established technology and probably no more expensive.

     

    At larger sizes I'd agree, indeed at very large sizes swing is undoubtedly better. But at narrow canal size, where a bridge can easily be hand operated, it's no contest. The main issue is that without jacks a swing bridge takes all the weight through the bearings and will tend to hog, a lift bridge doesn't do this. A manual swing bridge can have jacks, but it complicates operation, a lift bridge doesn't need them. 

     

    Reading through stoppages and complaints about difficult bridges on the canal system, I'd say swing bridges give far more trouble. 

  17. I've become involved in a discussion about whether to build a moveable bridge on a canal restoration project rather than a fixed bridge - in this case the advantage of a moveable bridge is less ground load and less land take (utility services being a major influence in this) - in reviewing options we looked at others elsewhere for inspiration and among them is the vertical lift bridge, as opposed to the bascule bridge - an example below

     

    hbc013.jpg.b0a702a62bd26abda3941b24732d18a4.jpg

     

    This is Locomotive Bridge, Huddersfield, with acknowledgements to Martin Clark and Pennine Waterways. Cables pull the bridge vertically. When asked to consider the pros and cons of such a bridge I'm stumped - there is, as far as I know, no documented design considerations, and there are so few that I can't really work out the reasoning, a sample of one (that I used once, many years ago) doesn't really tell me what the advantages of this design are.

     

    So does anyone have any thoughts on the pros and cons of vertical lifting ? And are there any others on the canal system? I'm aware of them on much bigger waterways where presumably the size of the span is a factor, but not really on waterways the size of our typical canals, where lift bridges are nearly all the bascule type. 

  18. 3 hours ago, magnetman said:

    Water pistols are good for swans. 

     

     

    I think the swan would argue with that assessment, unless you're suggesting it's the swan who's using it

    • Greenie 2
  19. 1 hour ago, David Mack said:

    There are several on the National Rail network too. A forum discussion on the subject:

    https://www.rmweb.co.uk/forums/topic/119160-stations-with-the-same-name/

     

    I spend quite enough time on this forum with people pointing out others I could get absorbed in!

     

     I could add that it was the railways that added the "Welsh" to Welshpool....

     

    Going back to the tunnels. Bradshaw refers to the one on the Worcester and Birmingham as "West Hill, commonly called King's Norton" and the one on the Stratford as "King's Norton" :blink: I'm not sure when West Hill became Wast Hill. 

     

    I note in the railway forum reference to BR changing station names when they ended up with two in the same town that had previously been in separate ownership. Maybe BW did the same with these tunnels, and then briefly thought better of it

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