Poole bridge

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scej

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I have had the misfortune to have to transit the bridges a number of times in the last few days.

Be aware that the Schedules seem to change on a hourly basis at the moment.
Monday for instance twin sails opens 09.30 Poole bridge according to printed info from harbour commissioners 0945 which passes happily, on calling the bridge operater oh no sir we are running a revised schudule we will lift 1000.

Today from a mooring between the bridges twin sails lifts 10.30 revised schudule we think so slip moorings at 1055 to discover oh no sir 10.45 next lift is 11.40 hmm ok. So to go back in the 'indicative' lift is at 1500 for Poole bridge. So I ring the bridge operator and ask when I can go thru 1500 he says ok that is a indicative time says I, oh yes sir we'll probably lift at 1440 depending on how many boats are waiting. This is helpful when you are tied up thinking slip lines at 1450 potter to the bridge from Poole quay marina to discover its opened 10 min earlier......

The bridge operators numbers are on the web site in future I shall be calling them to discover what time they will open the bridges as currently they seem to open when someone feels like it.

There will be a lot of p###ed of boat owners soon
 
Bridge times

Sir I think you may be mixing up your week day with your w/e timings.having noted your comments re timings I am afraid they don't seem to tie up with the printed schedule & it is becoming increasingly obvious that we need to be on station considerably earlier than the indicative printed time for the second lift!,especially if it is quiet.do you know if the third lift in the sequence happened as promised. Regards mm1.
 
There is a revised schedule between 2 &13 April which a notice to mariners was published at the beginning of the week!

The lift when I returned to hole bay yesterday was 1500 indicative confirmed by bridge operator by telephone bridge actually lifted at 14,35 the twin sails bridge was scheduled to lift at 15.30 but infact lifted at 1500

So I suggest you are on station at least 30 min before any published times just in case
 
Went through the two bridge system for the first time ourselves over the weekend.
Must say it is quite a dramatic sight when it starts to lift!
Can see the confusuion with timings though as whilst the first lift in the sequence goes at the allocated time, the rest seems to depend a bit on demand and how long the first lift takes and it is a pain milling around waiting for the second bridge to lift.
One thing we discovered though is that according to the gauges, the new bridge is 0.5m higher than the old bridge and so we should be able to pass under the new bridge without a lift at all but spring highs, in fact on the way in we managed to just get under both bridges during the trough between the double high tides, that's with our headroom of about 2.85m.
So the good thing for us is that as we can get under the new bridge most of the time, we now have hourly lifts of the old bridge during the weekends instead on the old two hourly rota, ......if only we could work out for sure what time those lifts would be!!!!!
 
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"One thing we discovered though is that according to the gauges, the new bridge is 0.5m higher than the old bridge"

Now be very careful with that statement, I will attempt to explain.

Last week I contacted Poole HM requesting the Twin Sails bridge clearance at MHWS and have to admit I was extremely surprised to the reply I received, he didn't know it because the bridge belongs to Poole council, however according to the plans 5 years ago it should be 300mm. He recommended I contact the council, at this moment of time no-one has been able to confirm the clearance.

Now, back track to the latter part of last year and I started to note that the indicated air clearances on the old bridge did not match the given clearances on our Poole Bridge Clearance chart, it was normally out by 200mm, it has continued this way all of this year as well.

I have noted however that if you add 300mm to the bridge clearance on the old bridge chart it nearly always gives the indicated air clearance height on the Twin Sail bridge.

I hope this sort of makes sense but I expect someone of far greater knowledge will be along in a minute to correct me!
 
Peanuts said:
"One thing we discovered though is that according to the gauges, the new bridge is 0.5m higher than the old bridge"

Now be very careful with that statement, I will attempt to explain.

Last week I contacted Poole HM requesting the Twin Sails bridge clearance at MHWS and have to admit I was extremely surprised to the reply I received, he didn't know it because the bridge belongs to Poole council, however according to the plans 5 years ago it should be 300mm. He recommended I contact the council, at this moment of time no-one has been able to confirm the clearance.

Now, back track to the latter part of last year and I started to note that the indicated air clearances on the old bridge did not match the given clearances on our Poole Bridge Clearance chart, it was normally out by 200mm, it has continued this way all of this year as well.

I have noted however that if you add 300mm to the bridge clearance on the old bridge chart it nearly always gives the indicated air clearance height on the Twin Sail bridge.

I hope this sort of makes sense but I expect someone of far greater knowledge will be along in a minute to correct me!
Click to expand...

300 mm? That's only about a foot in old money

Charted clearance for the old bridge is 1.79 m !
 
VicS said:
300 mm? That's only about a foot in old money

Charted clearance for the old bridge is 1.79 m !
Click to expand...

Absolutely correct, however what you must remember is that the old bridge has transverse beams, so although the air clearance might for example be 2.0m, that is to the bottom of the beams, you then have another 0.7m to the actual underside of the bridge. That is how many of us go under the bridge using that gap to guide our light/radars and other items on our radar arches but at times we cannot then get under the Twin Sails bridge because we do not have the clearance - does that make sense to you?

The actual bridge clearance at MHWS is 2.2m (tide 2.2m) and at MLWS (tide 0.6m) is 3.8m.
 
All I can add is that the Harbour Master has responded to an email of mine and has stated;-

"The height of the bridge (main central span) above MHWS is 2.5 metres which is slightly more than Poole Bridge. However there is an electronic digital display showing the airdraft at any given time which can be viewed as you approach the bridge."

My own calculations led me to believe that with an air draft of about 2.85m we could pass the old bridge during tide levels of 1.7m or less.
This was bourne out by our experience on Sunday as the predicted tide at the time was indeed 1.7m and we just got through.
The gauge at the old bridge displayed 2.7 however so I either measured my headroom wrong or the gauge is 'pessimistic'

The gauge at the new bridge indicated 3.2 and whilst I did not measure it the apparent extra headroom was certainly of the order of 300 -500mm>

I suppose a factor regarding the gauges would be how they round up or down, ie does 1.88 show as 1.8 or 1.9?? and how accurate are they anyway!!
 
I did my advanced powerboat course last week from Cobbs and as a result was in and out of holes bay quite a few times over a couple of days.

One thing I noticed was the difference in air clearence between the two bridges (based on the elelectronic display) varied between 10cm and 50cm????

Andrew
 
"The height of the bridge (main central span) above MHWS is 2.5 metres which is slightly more than Poole Bridge".

So that falls in line with the 300mm he (Harbour Master) mentioned in my email. As I have already stated the Old Bridge is 2.2m at MHWS and he now states the Twin Sail is 2.5m. I rest my case.
 
Peanuts said:
"The height of the bridge (main central span) above MHWS is 2.5 metres which is slightly more than Poole Bridge".

So that falls in line with the 300mm he (Harbour Master) mentioned in my email. As I have already stated the Old Bridge is 2.2m at MHWS and he now states the Twin Sail is 2.5m. I rest my case.
Click to expand...

Ah I see, I think.

This sentence was confusing me.

"Last week I contacted Poole HM requesting the Twin Sails bridge clearance at MHWS and have to admit I was extremely surprised to the reply I received, he didn't know it because the bridge belongs to Poole council, however according to the plans 5 years ago it should be 300mm."
 
dpb said:
All I can add is that the Harbour Master has responded to an email of mine and has stated;-

"The height of the bridge (main central span) above MHWS is 2.5 metres which is slightly more than Poole Bridge. However there is an electronic digital display showing the airdraft at any given time which can be viewed as you approach the bridge."

My own calculations led me to believe that with an air draft of about 2.85m we could pass the old bridge during tide levels of 1.7m or less.
This was bourne out by our experience on Sunday as the predicted tide at the time was indeed 1.7m and we just got through.
The gauge at the old bridge displayed 2.7 however so I either measured my headroom wrong or the gauge is 'pessimistic'

The gauge at the new bridge indicated 3.2 and whilst I did not measure it the apparent extra headroom was certainly of the order of 300 -500mm>

I suppose a factor regarding the gauges would be how they round up or down, ie does 1.88 show as 1.8 or 1.9?? and how accurate are they anyway!!
Click to expand...

Why are they quoting at MHWS?? Charts show clearance at HAT.
 
"Why are they quoting at MHWS?? Charts show clearance at HAT."

Both are right. Historically clearances were referenced to MHWS however as charts are being redrawn/reissued clearances are being re-referenced to HAT.

Don't have the latest Poole Chart to hand to check whether Y23 refers to MHWS or HAT but have a feeling it is HAT. That said if you have an older chart it will be to MHWS.

Remember years ago when we first started teaching from Cobbs calling PHC and the Bridge to get the official clearance (as it wasn't on the charts or in the almanac) - and no-one had a clue. It is only over the last few years that the almanac and chart have carried it

Regards, Paul
 
scej said:
So I suggest you are on station at least 30 min before any published times just in case
Click to expand...

Thats a big ask. Half an hour milling around there with a dozen or so others can be hard work in any kind of wind/tide. With proper timing on behalf of owners and especially bridge operators, nobody should have to be put through that every time they want to leave or enter. Glad Im niot there any more.
 
Elessar said:
Land features are above MHWS, eg lighthouses and hills. Clearances are now HAT it changed on new charts about 6 years ago I think.
Click to expand...
Thanks for the explanation.
I must admit it is more logical that clearances should be above HAT. That way you never normally have less than the figure on the chart.
 
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