Wow. Chi marina extreme freeflow

[benjenbav]

Apart from managing the salinity - don't know if this is tested, ever? - the whole issue of water levels must be quite difficult to manage.

Quite often at the top of big springs the level in the harbour is too high to allow freeflow. I imagine the articulation of the pontoons is not able to cope. Needless to say, if too much water were to be let out there would be considerable potential for damage to underwater gear.

All fine in theory, but on a sunny Sunday when there is a demand to get freeflow started as soon as possible and keep it in operation as long as possible there must be some fine calculations being done in the lock office.

 

[ricky_s]

Very interesting. I thought the fresh water would be of benefit to the anodes, often thought the boat would be better off in the marina than out in the wilds of the harbour

 

[benjenbav]

I'm definitely not qualified to comment on this but I think you need different metals as anodes in fresh and salt water. Zinc in salt and ? in fresh>

 

[ricky_s]

I think the worms like the brackish water too. They were always a lot worse when I was up that end of the marina.

As for the water flow - probably just flushing out the approach channel a bit.

Am I in a good bit for worms? I am on P.

 

[KevB]

I think the worms like the brackish water too. They were always a lot worse when I was up that end of the marina.

As for the water flow - probably just flushing out the approach channel a bit.

 

[ricky_s]

Something very odd just happened!

 

[l'escargot]

Can anyone explain why thats happening? Or even give a link to a Google Map so I can take a look?

I've never been near the area and don't know it at all - i'm in West Ireland

http://maps.google.co.uk/maps?ll=50.804978,-0.82443888&z=17&t=h&hl=en

 

[AndieMac]

Ricky

What's going on with all those lines attached to bollards on the opposite side to where you were shooting the footage, just dangling in the channel?

 

[ricky_s]

Ricky

What's going on with all those lines attached to bollards on the opposite side to where you were shooting the footage, just dangling in the channel?

They are for grabbing hold of, popping yourself a bit further on etc. When I had a smaller boat I used to just grab hold of one instead of using the ropes from the lock keeper. Think the are attached to the bottom.

 

[johnwest]

At the eastern end of the marina basin is an area of marshland fed by a small stream and the marina is obliged to maintain its level to prevent flooding of the main Chichester road.
This means a build up of fresh water on top of the salt and if temperatures drop to freezing of course the marina ices over so freeflow is run certainly at weekends to try to overcome this. Having said that from the video it would seem that the inner gates had been closed during freeflow probably to allow walkers to cross and may have not been opened quickly enough hence the large differential in water levels between the marina basin and chichester harbour. The speed of flow does seem fairly high. Having spent some hours if not days watching freeflows at Chi it can be troublesome to transit the lock at certain stages of flow.

j

 

[robp]

Thats a regular occurence at Chi Marina on both the ebb and flood tides as I'm sure some local will come along and tell us soon. You can radio the lock staff and ask them to shut the far gate to stop the flow whilst you motor into the lock and then shut the near gate to let you out. I once saw a large motorboat get sluiced through the lock on a big flood tide and spear a Trader parked the other side. Made quite a mess so you have to be careful

Almost every season Owen's Trader gets swiped by somebody, hence the row of assorted fenders he now hangs out. Poor guy is a bit embarrassed by the look of them but he's been clouted so many times now! During freeflow on a rising tide you need power to maintain steerage of course. Slowing up when inside catches many visitors out. A bit like putting the car brakes on with ice under you!

I've seen big cruisers bouncing from wall to wall - nasty.

 

[Deleted User YDKXO]

Almost every season Owen's Trader gets swiped by somebody, hence the row of assorted fenders he now hangs out. Poor guy is a bit embarrassed by the look of them but he's been clouted so many times now! During freeflow on a rising tide you need power to maintain steerage of course. Slowing up when inside catches many visitors out. A bit like putting the car brakes on with ice under you!

I've seen big cruisers bouncing from wall to wall - nasty.

Blimey, I would have thought he'd have moved it by now!

 

[AndieMac]

I've seen big cruisers bouncing from wall to wall - nasty.

That's what I thought would be the case, going in the same direction as the fast water in a narrow channel.

Reminds me of the old blue tourist boat that used to take folks around the Falkirk Wheel canals in Scotland. On the upper canal section, they would go roaring through bouncing from one side to the other at get speed. Mind you there was only a metre of space either side.