Clearance Bursledon Bridge
I can get my Fairline Turbo 36 under at High water springs with 4m under the bridge. I drive from the fly so my head is the high point, and I don't uite have to duck.
Beware of boats approaching though as once committed you have little space to change your bearing under the bridge
I have to fold the arch down before I get there, and mostly remember to drop it before I set off !
I can also get back to my berth at Foulkes at the bottom of a similar tide. The T 36 has an air draft with the arch down of about 3.7m. I would say with 3.5m with the arch down you will be OK. Avoid the astro extreme springs.
There are also tide gauges either side.
Thanks for that.I will treat the bridge with respect.As I've said before I am retired so waiting
Originally Posted by superheat6k
an hour or so is not a problem.There has to be some advantages of being old and decrepid.
I have always fancied a trip up river under the bridge but the whole air draft issue has put me off esp. if you cock it up on the outward trip back.
I was also told of a horror story where a guy got caught in the tide stream and hit the bridge midships side on with loads of damage......Eeek!
I am afraid that this is one area of conning your boat that cockups could cost dearly - I am afraid you have to have the courage of your conviction and simply get it right first time.
This does mean that in order to maintain steerage on a hard running ebb, your ground (and under static bridge !) speed could approach 8 knots. An 8 knot impact with a hard concrete bridge will cost dear, hence the advice to check your clear passage whilst still well clear and before finally committed.
However the hard ebb doesn't kick in until the clearance has increased by at least 1 metre, and fast Spring ebbs on the Hamble are always mid to late PM, so go out in the morning, and return against the tide and with plenty of steerage later.
Note because the channel narrows so much the fast ebb remains almost to the bottom of the tide under the briodge, and last time up my ground speed was 2 - 3 knots with a water speed of 6 knots, and my Turbo 36 makes quite a stern wave splash at 6 knots against a running tide, certainly enough to annoy the yachties who choose to use fixed moorings adjacent to a tight navigable passage. I followed this up with a call to Hamble HM who advised they are concerned of wash, but appreciate that certain circumstances do arise when it cannot be avoided, so I shouted back at said yachtie.
I always understood that the correct procedure is to go about and go through astern, you then have total control, if you have misjudged it simply increase power and drive away [ahead].
a good suggestion so long as no one else around.
Originally Posted by capsco
Not quite sure what you mean by that, naturally you would take that into consideration, and make the correct sound signals, no different to any other situation really.
Astern through the bridge
Not for me that one !
Nor have I ever seen anyone try it at Bursledon, but if some one is going to try can I have a ticket to watch !
Most if not all boats will weathercock when going astern to pivot on the rudder post, and will want to turn the back end into the wind, so fine if the wind is straight down the river, but northerly winds are rare, and more likely any wind would be on one side of the bow or the other.
Thus the boat would end up crabbing back at some undesirable angle, and even with a bowthruster an un-acceptable side drift may result.
At Bursledon there definitely is not space at any state of the tide either side of the bridge to turn even a 25' sideways on, and very little free space when things go awry anyway.
Better to maintain the water flow over the props and rudders and maintain proper steerage way. There is time and space to get a good line up, but in thinking about all this I don't think I would try to pass under with the tide on a fast Spring ebb. Fortunately for most of my pattern of boating departures I do not have to consider this possibility.