Wednesday, 31 August 2011

Severnth Heaven - Tideway Adventures

The Severn Estuary -
Portishead to Sharpness in a floating library - sshh! quiet please.
30th August 2011

Its not every day you wake up to a text message offering a trip up the tideway from Portishead to Sharpness.

Portishead harbour at dawn

Sarah of the Book Barge fame finally sought refuge from the officialdom of Bristol, where the powers that be  were so fearful of her mind expanding library that she received a visit from the boys in blue to ensure she was not  pedaling her illicit literary wares.

Portishead lock at high tide

The Book Barge at Portishead

On Monday she made her way down the Avon to Portishead in the company of Stu and her pilot and the question was: do you fancy a trip up the Severn to Sharpness? - we leave on the flood tide at 6.00am on Tuesday, be here at 5.00am. Well, this is a trip I have drooled over for ages. Of course I want to do it, its one the inland waterway's great tidal challenges, and not being the skipper or steerer I would be free to savour the experience and hopefully take lots of photos. The issue was the day and the time. 

Portishead Lock at first light 5.20am

Sadly work keeps getting in the way of my boating interests and my employers were kind of expecting me to put in an appearance. A few frantic texts and voice mails and I got what I took to be consent so I signed up, but to be in Portishead for 5.00am from Birmingham would mean pretty much getting up before I went to bed (cue: they don't know they are born...). As alternative Jeff and I cadged a few square metres of floor on the Book Barge and kipped down for the night having dined on kebab shop fish and chips washed down with Belle's surprisingly agreeable rhubarb schnapps.

Portishead Lock

The night passed relatively uncomfortably, I think I am getting too old for hard floors and camping mats and I was well awake when Stu's alarm started to buzz at 5.00am. Every 10 mins we peered out of the windows concluding "not dawn yet". Finally, at 5.20am the sun made a bleary appearance and we staggered off to avail ourselves of the Portishead Marina facilities - and very good they are. Mind you, so they should be at £30 a night.

Pressing out into the main navigation channel 6.15am

We we one of two narrowboats making the northward crossing to Sharpness, the other being Francesca Leah which was fortunate as her presence added interest to the photo opportunities. For all the articles written about it, this crossing is still relatively rare with only about 60 narrowboats making the trip each season, and some being held up for weeks waiting for favourable conditions. The rule is that anything more than a force three is considered too dangerous. The forecast for today was benign in the extreme, but worsening as the week progresses to Sarah's passage was advanced. The wind was a gentle three or four knots  from the north west which meant no discernible swell.

Francesca Leah approaches the New Severn Crossing

We made our was out of the huge Portishead sea lock at 6.00am precisely, initially making placid progress out of the inlet but then suddenly we watched as Francesca Lea swerved bodily to the north, she had found the main current. The tide was particularly high which meant we made a lot of leeway as we crabbed our way out into the middle of the main navigation channel, clear of the adjacent docks and out under the massive towers of the New Severn Crossing.

Severn Bridge

Its very hard to get any idea of our progress when you are so far out in the estuary, apart from the pilot's GPS which indicated about 8 knots. The speed of travel was rammed home as we were swept under the twin towers of the new suspension bridge and watched the huge pile of water mounded up in front of the piers. At this point the flood tide reaches its peak speed and the GPS told us that we were travelling at 12.2 knots (that's over 14 mph in real money), with the engine chugging along sedately as if we were out for an afternoon cruise down the Grand Union.

Strong tidal flows under the bridge

Between the two Severn Crossings the fast flow runs over some huge holes in the river bed and this throws up some awesome turbulence near the west bank. Water swirls and roils lumping up and spinning round. These back currents are so severe that even big sea going boats are sometimes spun through 360 degrees.

Navigation Buoy near the New Severn Crossing

Given the number of photos I will take a break here and pick up the tale in my next post. Click here.



4 comments:

Koos@manchester.com said...

That's fascinating! Thanks for sharing.
Copy to Google Earth 51°34'28.64"N 2°41'59.32"W
On Google Maps

Captain Ahab said...

Koos - looks like we went to Wales for a bit!

Anonymous said...

Wonderful stuff - and so much better without the fog - it's one of Richard's lasting regrets that he didn't get photos of ID's trip.

Sue, nb Indigo Dream

Captain Ahab said...

I thought about ID during the passage. You would have loved it. Mind you, navigating the channel blind is quite an achievement.