Llangollen Canal, mooring points at lift bridges.

[by'eck]

I don't really understand why any electrically operated bridges, swing or lift, don't have the control panel on the towpath side. The lift bridge at Shirley has the controls on the towpath so why don't they all do that?

 

Well the historic reason has already been explained, post #6. Once you accept that the bridge workings are mainly on the non-towpath side, it generally becomes neccessary for the electrical and hydraulic links and controls to be on that side also.

 

The radio link repeated controls seem the ideal solution therefore.

[john6767]

Well the historic reason has already been explained, post #6. Once you accept that the bridge workings are mainly on the non-towpath side, it generally becomes neccessary for the electrical and hydraulic links and controls to be on that side also.

 

The radio link repeated controls seem the ideal solution therefore.

 

The historical reason with mechanical operation is clear, but as soon as you electrify, I see no reason why the controls need to be colocated with the hydraulics. At that point you may as well locate the controls in the most convenient location for operation, but only some do that, so my question was why don't they all. I don't see radio operation is key, you are probably no more than 20ft away anyway, so a cable should, and clearly is, no issue.

[KJT]

The historical reason with mechanical operation is clear, but as soon as you electrify, I see no reason why the controls need to be colocated with the hydraulics. At that point you may as well locate the controls in the most convenient location for operation, but only some do that, so my question was why don't they all. I don't see radio operation is key, you are probably no more than 20ft away anyway, so a cable should, and clearly is, no issue.

Indeed. I guess its just that those responsible for installing the electric controls just haven't thought it through. If they can do it at Thrupp on the South Oxford, why couldn't they do it, for example, at Wrenbury on the Llangollen. They had to lay a cable to work the traffic lights (and I assume to operate the catch on the barrier) on the towing path side so why not install the controls on that side as well?

 

Ken

[Southern Star]

I can understand wanting to retain the characteristics of traditional canals, and thus keeping the operating mechanism on the non-towpath side, but it surely wouldn't be beyond the wit of man to place a bollard on the non-towpath side to which the boat could be secured on the centre line? I managed to chip a bit of paint off of my roof yesterday when heading eastbound and tieing up with the bow line when the current pushed the boat into the bridge. Not the end of the world I know, but if I was a member of the Shiny Boat Brigade I don't suppose I'd be too impressed.

[LoneWolf]

I can understand wanting to retain the characteristics of traditional canals, and thus keeping the operating mechanism on the non-towpath side, but it surely wouldn't be beyond the wit of man to place a bollard on the non-towpath side to which the boat could be secured on the centre line? I managed to chip a bit of paint off of my roof yesterday when heading eastbound and tieing up with the bow line when the current pushed the boat into the bridge. Not the end of the world I know, but if I was a member of the Shiny Boat Brigade I don't suppose I'd be too impressed.

 

But they all do have bollards on the offside to which I can tie my centreline - maybe you need a longer centreline for singlehanding

 

The manual bridges on the Llangollen are the easiest movable bridges to singlehand. If you struggle with them don't go on the L&L

[by'eck]

The historical reason with mechanical operation is clear, but as soon as you electrify, I see no reason why the controls need to be colocated with the hydraulics. At that point you may as well locate the controls in the most convenient location for operation, but only some do that, so my question was why don't they all. I don't see radio operation is key, you are probably no more than 20ft away anyway, so a cable should, and clearly is, no issue.

 

 

Indeed. I guess its just that those responsible for installing the electric controls just haven't thought it through. If they can do it at Thrupp on the South Oxford, why couldn't they do it, for example, at Wrenbury on the Llangollen. They had to lay a cable to work the traffic lights (and I assume to operate the catch on the barrier) on the towing path side so why not install the controls on that side as well?

 

Ken

 

Well the main reason that springs to mind is avoiding having to lay control cables under the canal. I take the point about need for traffic lights both sides, but that is one relatively small addition to the main bridge controls. I suspect BW would have sought and exercised economies when electro-hydraulic bridge operation was introduced, despite the short sightedness.

 

Intrigued why John dismisses radio repeaters as a solution, in favour of what would be a very expensive exercise installing control cables under the canal

Edited July 28, 2015 by by'eck

[john6767]

Well the main reason that springs to mind is avoiding having to lay control cables under the canal. I take the point about need for traffic lights both sides, but that is one relatively small addition to the main bridge controls. I suspect BW would have sought and exercised economies when electro-hydraulic bridge operation was introduced, despite the short sightedness.

 

Intrigued why John dismisses radio repeaters as a solution, in favour of what would be a very expensive exercise installing control cables under the canal

 

Not dismissing but just not seeing it as a major enabler, the reason being that you probably already need to run a cable for the barrier and light control anyway so you might as well use the cable for the control panel. If no cables you would also need an independent power source both sides of the canal. So the locations where wireless would be the best option seems limited, and lets face it running a cable a accross a narrow channel is no big deal.