Alhambra on the Hawkesbury

The last few times I passed by Bujwa Bay, on my way downriver from Berowra Waters, it was shrouded in mist.

But last Sunday, in the golden light of late afternoon, there was a revelation.

I’m familiar with the Hawkesbury’s sculpture parks and sandstone art galleries.  But the fact that Berowra Creek had well preserved fragments of an ancient Moorish fortress – well, that was news to me.

When I went home and told RB I’d seen something very like the famous stucco inscriptions of the Alhambra on a estuarine cliffside at the end of Berowra Waters Road, his comment was “You’re barking!”.  And he’s probably right.

After all, the Alhambra is an artistic jewel, a masterwork of European Islam, preserved over the centuries after the Moors themselves were driven first into the mountains and then out of Spain altogether.  Its delicate carved plasterwork miraculously survived Christian conquerors, dodgy architectural restorers, squatters and tourists.  And the sandstone of Bujwa Bay is just, you know, rock.

But I’ve been reading about “thing power” and it’s given me a whole new angle on inanimate objects.  “Thing Power!” – sounds like a killer bathroom cleaner that will sort out all the disturbing life-forms, named and unnameable, in your shower cubicle.

But according to Jane Bennett, its “a creative not-quite-human force capable of producing the new [that] buzzes within the history of the term ‘nature’ ” (2010, 118).  Electrons, microbes, minerals, waste, all busily making and shaping things, inside, around, through, against and despite humans and their fancy-pants plans.  She reckons things and people rub along or against each other in a pattern that’s “not random or unstructured, but conforms to the strange logic of vortices, spirals and eddies” (2010, 118).

Kooky as it sounds, this is not a bad description of how the Bujwa Bay Alhambra came into the world, according to a paper coauthored, in a way that pleases my penchant for magical thinking, by a geologist from Granada, home of the famous palace.

Honeycomb weathering like this happens in all sorts of porous rocks, around the world – from Antarctica to Jordan – and maybe even on the surface of Mars. It might seem like  hollows would form in weaknesses in the rock, but it’s not necessarily so. Blistering heat, frost, chemical weathering and rain are all in the frame – with maybe a little help from the odd patch of algae or lichen. But mostly it’s about salt and wind.

Salty water – in this case from seaspray – seeps into the rock and crystallises, making tiny fractures. If there’s plenty of water, salt crystals forms on the outside surface to form efflorescence, a mineral flowers blooming on a cliffside or a cellar wall or a garden fence.  But the real damage is done deep in the rock.

According to Rodriguez and friends, once a depression is formed in the rockface, wind eddies and swirls inside the concave parts of the stone.  Faster breezes mean more evaporation and a super-saturated salt solution, meaning more salt crystals and more fretted stone. Eventually the rockface becomes lacework, without any intervention by a rock lacemaker.

Alhambra rocks 1 crop long

The other name for honeycombed rock is alveoli.  It’s stone with lungs.  Made of mineral flowers.  Not alive (or mostly not alive – sorry algae) but doing complicated and beautiful things.

Not immortal, invisible, unfathomable.  In fact, as fathomable as the waters of Bujwa Bay at low tide, that is, knee deep to a heron.  Just exceedingly hard to grasp.

And that’s not just me banging my head against a corroding brick wall of “Salt weathering: a selective review” – the geologists are still bickering over exactly how it works. In Bennett’s (possibly slightly loopy) words, it’s vital matter, “hard to discern… and, once discerned, hard to keep focused on.  It is too close and too fugitive, as much wind as thing” (119).  Or perhaps, in this instance, both wind and thing.

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A crab wondering what I’m on about, on a beach near Bujwa Bay

References

Jane Bennett 2010 Vibrant Matter, Duke University Press

Eric Doehne (2002) “Salt Weathering: a selective review” from Natural Stone, Weathering Phenomena, Conservation Strategies and Case Studies. Vol 205, 51-64, Geological Society Special Publication

Carlos Rodriguez-Navarro, Eric Doehne,Eduardo Sebastian (1999) Origins of honeycomb weathering: The role of salts and wind, GSA Bulletin; August 1999; v. 111, no. 8; p. 1250–1255

Huinink, H. Pel, L, Kopinga, K. 2004 “Simulating the growth of tafoni” Earth Surface Processes and Landforms 29 1225-33

Snakes vs whining teenagers

 

Tiger snake curled face crop longThis is what people who hate camping think it’s all about, right?  I suspect spiders, high winds and rowdy neighbours also make that list.  Yep, a big tick next to them too – it’s all to play for when you camp in the summertime in Wollemi National Park.

But Ganguddy, or Dunn’s Swamp, to give its inaccurate and charmless non-indigenous name, was just as marvellous this January as it was when we first visited this time last year.

Sunrise corner sky

Ganguddy in early dawn light

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View from the pagoda lookout

Yes, there were more reptiles – lethal and benign – but to balance it out, there was also less torrential rain.  At no point this year did it seem likely that the full set of adult campers, each clinging to a leg of the kitchen-gazebo, would take off and fly over the pagoda rock formations like a quartet of grubby Mary Poppinses.  It rained, but not inside any of the tents.  And the whining teenagers weren’t my delightful children but the feathered offspring of the camp ground locals.

Noisy friarbird getting food crop

Juvenile noisy friarbird wants a snack

It seems a bit unfair for such giant children to be demanding food, although Gisela Kaplan in her fascinating book “Bird Minds” suggests some evolutionary advantages to having hungry teenagers hanging around.  Apparently adults noisy friarbirds only feed the young’uns for three weeks after fledging -hard to believe this galumphing one was so close to being a fluffster.

But you can see where all that food goes.  You reckon your adolescent’s feet are big?  What about junior purple swamphen‘s clodhoppers?

Unhygenic as it sounds, the drop dunny seemed to be a particularly popular spot for a snack.  The baby grey fantails spent a lot of time looking deliberately cute there in order to get a feed.  If you were still uncertain about the superiority of the earth toilet, this little guy is a clincher I reckon.

The white-browed scrubwren also enjoyed loitering out around the toilets.  I didn’t see any juveniles, but then this one looked so stern, perhaps they were there but just too nervous to beg for tucker.

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Grumpy looking white browed scrubwren

The suspiciously touselled looking eastern yellow robin – a juvenile perhaps – had worked out that the best place for tucker is definitely the barbecue.

I’m not sure if the adult reed warbler had gone into head down, bum up, to feed some chicks, or if it was just going to extreme lengths to avoid facing the long-lensed papperazzi.  I was rather pleased when after two years of trying I finally got a picture of one, without even having to visit the Rylstone Guns and Ammo for a flame thrower to thin out that pesky, snap obscuring habitat.

And, miracle of miracles, I found an azure kingfisher without ADD.  I reckon I can put away my paddle now – 18 months of kayaking have not been in vain.

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At last – a sluggish azure kingfisher

The invasive gambezi minnows that fill this reservoir – built in the 30s as a water supply for a concrete works – seem to be an optimal snack size for the kingfishers – I saw plenty of them, along with a randy musk duck, the ubiquitous Eurasian coots and a pair of Nankeen night herons that alighted, mockingly, in the trees opposite the campsite, just after it got a tiny bit too dark for a decent photograph.  But there was nothing larger – no whistling kites, for one.  Judging from the frustration level of the fisherman in our party and the track record of these mosquitofish of outcompeting native rivals, I suspect there weren’t many more substantial meals to be had (on the bright side, possibly thanks to the fish, there weren’t too many mosquitos making meals of us either).

With all these LBBs – and all the fast moving ones I didn’t get a decent shot of – busy flocks of brown thornbills high in the canopy, white-throated tree-creepers spiralling their way up the tea trees, the baffling grey strike-thrush, the white-eared honeyeaters darting around in the dew drenched dawn – I guess I shouldn’t be surprised at the snake that sidled through the camp site or or the one slithered along the ironstone tops.  Let’s hope the top predators were more successful at catching the flighty little buggers* than I was.

Western country rocks

Rock formations near the dam

Sunrise over swallow rocks

Dawn over “Swallow rocks”

 

*Okay I know red-bellied blacks mostly eat frogs, which is why they were down by the reedbeds near the camp. But I bet they don’t object to the odd gormless yellow robin if it’s available.

* * *

There’s more info about the history and geology of Ganguddy in my previous post from here: In other sandstone country

A bridge fetishist paddles to Brooklyn

I have a weakness for bridges.  Romantic trysts just happen to be arranged with the backdrop of the world’s first iron bridge.  Multiple crossings of the gorgeous Severn Suspension Bridge are absolutely essential for that work trip.  And in pride of place of the mantlepiece, of course, is a railway poster of the famous cantilever bridge over the Firth of Forth.

So perhaps it’s not surprising that my paddles lately all seem to end up under what it pleases me to call Brooklyn Bridge.  That’s not its real name, mind, but since it starts  on Long Island and takes you through the thriving metropolis of Brooklyn (population 744) I think I can get away with it.

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There was that morning jaunt from Parsley Bay, past the oyster leases and beneath the swooping welcome swallows, to the top of Mullet Creek, where the Newcastle trains disappear into the Woy Woy tunnel, once the longest tunnel in the southern hemisphere.

I’ve been lucky enough to go on on some beautiful railway journeys in my life – from Montreal to New York in winter, past above-ground swimming pools frozen like giants’ ice-cubes; from southern Thailand to Bangkok, looking out at the richest of tropical orchards woven into the jungle; between snowcapped mountains and sea on the West Highland line to Hogwarts Mallaig.  But I reckon this journey along Mullet Creek, not a place that will ever be immortalised in the baby names of the rich and famous, is my favourite.  There’s something about a railway line that leaves roads far behind, forging its own way along the empty shore.

Sunrise at Brooklyn

If you ask the driver, you can get off near the top of the creek at Wondabyne, the only station sans road access in Australia.  Every now and then, you see people jumping off the train and straight into a tinnie, zooming off to the shacks on the other side of the river before their fish supper gets cold.

For a few years in the late nineteenth century, while the first Hawkesbury River bridge was being built, if you were travelling north by train from Sydney, you would disembark at Long Island, board the double-decker paddleboat the General Gordon, and steam off to Mullet Creek Station, then just north of Wondabyne.  Now people hop off here to do part of the Great North Walk – a 250 kilometre walk from central Sydney to the beautiful beaches of Newcastle – or to wander up to Pindar Cave.  Judging from the smorgasborg of rusted out craft I saw in the shallow water at the top of the creek, it’s also a place where people take their boats to die.

Then there was this weekend’s jaunt, downriver from Deerubbin Reserve – a popular spot, right by the freeway, to fish or have a picnic for those who find the perpetual roar of traffic reassuring.  With the ever present possibility of a quick exit, I guess it’s ideal for the heavily pregnant or those who find their relatives a bit hard to take.  But I can’t really bag people for their passion for the internal combustion engine since I get all hot and bothered at the prospect of a paddle underneath (count ’em) three great big bridges.

This weekend’s jaunt took me past Spectacle Island Nature Reserve, under the Hawkesbury River Railway Bridge, natch, and around Dangar Island, swished along smartly by the current and the falling tide.

Have you ever been bored enough in an airport to try walking  the wrong way up a moving footpath?  Trying to paddle across the current to get to one of the beaches on the eastern side of the island was a bit like that.  It all seemed a bit too hard in the end, so I went where the river wanted to take me, downstream, floating just above perilous rocky reefs by off Bradley’s Beach and veering round the seagrass beds.

And then through the sailing boats, swaying and tinkling like expensive marine windchimes, to Sandy Bay, the best place in the world to be homeless.  The folks whose setup I saw there – a tarp flanked by a beached ramshackle boat and a solar panel – had no-one for neighbours but a horde of blue soldier crabs.  There was no sign of the human residents, but I now know what it’s like to be a celebrity, thousands of beady eyes watching and waiting on your every move.

Quite a few people live rough around Brooklyn.  “Good caves, a shower at Brooklyn Baths and walking distance to the bottle shop”, as RB commented with unseemly enthusiasm.  In the Depression, apparently, lots of people came to live in these parts for just this reason – shelter and a bit of space for chooks or a veggie garden.  I didn’t see a chicken run in Sandy Bay but Brooklyn does seem to have some kind of common flock, judging from these good looking fellas that we met down by the marina a while back.

I reckon the Hawkesbury estuary is Sydney Harbour through the looking glass – a parallel flooded river valley, bordered by bush instead of multimillion dollar apartments.  If the Harbour has its iconic Bridge, the Hawkesbury has its own engineering marvel – nearly three times as long, resting 50 metres and more deep in soft black mud.

The modern bridge is the second one to cross the river here.  The old bridge, finished in 1887, was the last link in the railway that spanned four colonies, connecting Queensland to South Australia.

Sir Henry Parkes, on the day of the bridge’s official opening, pronounced: “In this great system of material arteries which we completed today, we see the crimson fluid of kinship coursing through all the iron veins” (Sharp, 2001, 4).  Apparently the other grandees were a bit more underwhelmed by the prospect of a federated Australia, bound together with railways.  Nonetheless, the day after, the headline in the Sydney Morning Herald was headline was “United Australia”

Bridge silhouette 1

At the time it was built, the old bridge was the longest in Australia and had the deepest footings in the world – 180 feet below the high water line – though they still didn’t reach solid ground.

The Union Bridge Company from New Jersey won the contract to build it (on a pin-jointed truss system, as I’m sure you want to know), giving Brooklyn, the railway town that was set up to house the workers, its American name.  The tender being won by an American company was one in the eye for the old country, though it pleases me in some strange way that the riveted steel for the spans was made by Arrol Brothers in Glasgow, who also worked on the bridge across the Firth of Forth.

But the original Hawkesbury River Railway Bridge didn’t last.  Its piers, filled with rubble instead of solid concrete, fractured under the weight of the trains that crossed here, the only  bit of duplicate track on the line.  The piles were starting to crack in the 30s, but the problem only came to light when a US railway geek doing a bit of light recreational reading of an engineering textbook spotted that the piles weren’t built to the original specifications.  The death knell of the old bridge, though, was the extra rail traffic of the war.

The piers of the old bridge remain, like golden castles guarding the river.

Castles 2

The footings of the 1887 Hawkesbury River Railway Bridge.  Or castles as I like to call them.

I’ve had a great time reading the fantastically detailed history of the building of the new bridge by Major-General Albert Cecil Fewtrell, the Chief Civil Engineer of the NSW railways, who supervised its completion.

There’s some entertaining reading between the lines.  When it came to putting the metal spans onto the concrete footing, it seems some fool had a plan to float the 1,600 tonne metal spans over to the pilings at water level and then haul them out with giant cranes perched on the piers.  But Major-General Fewtrell soon sorted them out:

“Consideration had been given early to the proposal to float out the spans at low level … The decision [was made] to revert to the high level method of floatation following the return of the Author from active service in 1943” (Fewtrell, 1946, 27)

The prep they did for the task of floating the massive spans from the construction docks – the cuttings still visible on the north shore of Long Island – onto the concrete pilings at high tide also gives you a sense of the guy.

A large board, representing the land and water at the site of the new bridge, was laid down in the southern tunnel. Model piers were accurately fixed in position in the “stream,” and miniature spans, pontoons, and equipment were used so that the men could practice in detail movements and prepare for emergencies.

Don’t you want to play with those 1/32 scale tiny cranes and miniature pilings?  I really really do.

Fewtrell thought that everything had gone swimmingly.  But the new bridge, the bridge that was supposed to last 200 years, is crumbling.  After years of delays, just this last week, work started on repairing the concrete footings and its rusting reinforcing steel. When I paddled past, there were huddled men in high vis jackets and mysterious icons dangling from the bridge deck – all the signs that a new engineering miracle is about to begin.  And I’m sure it’ll happen.

But at this stage, once again, I reckon it’s Hawkesbury River 1: human engineering 0.